Design and Construction of the IRT: Civil Engineering (Scott)
View of the north end of the deep tunnel station at 181st Street, showing wall treatment and platform extension. Photo by David Sagarin, Library of Congress, Prints and Photographs Division, Historic American Engineering Record, August 1978.
Historic American Engineering Record · Survey Number HAER NY-122, pp. 207-282.
By Charles Scott
Historic American Engineering Record
National Park Service
Department of the Interior
Washington, DC. 20240
The records in HAER were created for the U.S. Government and are considered to be in the public domain. It is understood that access to this material rests on the condition that should any of it be used in any form or by any means, the author of such material and the Historic American Engineering Record of the Heritage Conservation and Recreation Service at all times be given proper credit. For information on HAER, visit Built In America: Historic American Buildings Survey and the Historic American Engineering Record, 1933-Present, Library of Congress American Memory Project.
The October 24, 1885, Engineering News and Contract Journal announced:
Mr. W. B. Parsons, Jr., has resigned his position as Roadmaster of the Susquehanna Division, Erie Railway, and has opened an office as Civil Engineer at 35 Broadway, N.Y; Room 73.1
William Barclay Parsons, future Chief Engineer of the Rapid Transit Commission and one of the men most responsible for New York's first subway, the IRT, had returned to the city in which he had acquired his engineering education.
William Barclay Parsons graduated from Columbia College in 1879. The following fall he entered the Columbia School of Mines, from which he received a degree in civil engineering in 1882. Shortly thereafter, he joined the Erie Railroad, where he was assigned to the division engineer's office at Port Jervis, New York. From Port Jervis, Parsons moved to Rochester, where he supervised the reconstruction of the Erie's "Rochester Division." His experiences on the Erie provided him with the material for his two textbooks on railway maintenance of way, Turnouts (1883), and Track (1884). At the urging of his brother-in-law, civil engineer S. A. Reed, he returned to New York City to establish himself as a consulting engineer. Once in New York, Parsons devoted a portion of his time to a new field of civil engineering, subway construction. He served on the engineering staff of two companies, the New York District Company and the City Railway Company, which sought, unsuccessfully, to construct underground rapid transit railways. While neither the District nor the City Company succeeded in constructing its underground road, Parsons gained valuable experience and a thorough knowledge of Manhattan's geography and transit needs.2
In October of 1886 Parsons left New York to serve as Chief Engineer for the Fort Worth and Rio Grande Railroad. He did, however, retain his affiliation with the District Railway Company.3 In 1887 he became the Chief Engineer and General Manager of the Denver Railroad and Land and Coal Company.4 Upon the completion of these railway projects and a number of water-works ventures in Mississippi, Parsons returned to New York in 189l.5
His reputation as a railroad engineer, his experience with the City and District Companies, and his past association with iron-maker and New York Mayor Abram Hewitt,6 made Parsons a logical choice for appointment in 1891 when the New York City Board of Rapid Transit Railroad Commissioners chose an engineering staff to design the specifications for an underground railway. He was made assistant to the Chief Engineer, William Worlen, a past president of the A.S.C.E. When, however, private capital neglected to bid seriously on the proposed franchise the plan was abandoned and both Parsons and his chief, the sole professional experts on the Commission, were dismissed.
In 1894, a second attempt to finance an underground rapid transit railway was made by a reconstituted Board of Rapid Transit Commissioners. This time, Parsons was appointed Chief Engineer. He modified the 1891 plans, proposed a four track, electrically powered underground railroad located close to the street surface, and spent the latter half of 1894 defending the feasibility of the proposal.7 He made frequent appearances before a special commission empowered by the Supreme Court to investigate the practicability and desirability of the underground railway. Confident and articulate in defending the proposed subway, he rapidly answered the technical questions addressed to him during the commission's public hearing, and impressed even those opposed to the line's construction.8
Negative legal decisions, economic uncertainty, and the outbreak of the Spanish American War, however, impeded the line's construction. Parsons spent 1898 and 1899 surveying rail lines in China.9 In 1899, when approval was received for the subway to be built, he returned to New York to supervise its construction.10 At the end of 1904, with the majority of Contract One construction completed and a large portion of the subway in operation, William Parsons resigned as Chief Engineer of the Board of Rapid Transit Railroad Commissioners.11 Appointed to the Isthmian Canal Commission, he traveled to Panama as a member of the Committee of Engineers and urged the construction of a sea level canal rather the lock type subsequently constructed. Upon his return to the United States in 1905, he established a consulting engineering firm with Eugene Klapp, a former division engineer of the Board of Rapid Transit. The Steinway Tunnel, a railroad tunnel beneath the East River, connecting mid-Manhattan, (34th Street) to Queens, financed by August Belmont, was the firm's first project. Saint-John Clarke, another former Board of Rapid Transit division engineer, assisted Parsons in supervising the tunnels' construction. In 1905, Parsons accepted the position of Chief Engineer of the Cape Cod Canal, whose design and construction he supervised over the next nine years. Other projects undertaken by Parsons after constructing the New York subway included hydroelectric plants throughout the eastern United States; urban and interurban transit studies for San Francisco, Detroit, Baltimore, Chicago, Philadelphia and other American cities; and a bridge, dock, and land reclamation study in Cuba. Parsons also found the time to write American Engineers in France, a chronicle of his experiences as a military engineer during World War I, Robert Fulton and the Submarine, and a multi-volume Engineers and Engineering of the Renaissance. Parsons died on May 9, 1932.12
As a civil engineer, William Parsons numbered among the elite of the profession. Early in the 19th century, the precise functions of the civil engineering profession were undefined, and civil engineers were often craftsmen/entrepreneurs rather than highly specialized and professionally-trained experts. The engineers of the early canal and railroad construction projects were practically trained men whose responsibilities "involved propriety and managerial functions in addition to the strictly technical."13 The rapid growth in the number of engineers during the second half of the 1800s forced a redefinition of the traditional relationship between the engineer and society. Founded in 1852, the American Society of Civil Engineers had become by the 1870s the recognized professional engineering organization. By the turn of the century, with the aid of the A. S. C. E., the modern engineer had emerged.
The civil engineer of 1900 was ideally well educated, cultured, and imbued with a sense of social responsibility. Whether he supervised the building of railroads, the tunneling of sewers, or the construction of aqueducts, his jobs were large, socially significant, and often publicly financed projects.14
New York's underground rapid transit railroad was just such a project. Other means of transportation existed in the city surface and elevated lines, but they had originated as short stretches of track, expanding and consolidating to form the systems evident in 1900.15 The subway system was conceived on a large scale from the start. It was to serve the entire length of Manhattan and parts of the Bronx, connecting not one avenue to the next, but linking distant communities. The social repercussions of such an undertaking were likely to be proportional to the enormity of the project itself.16
Parsons, associated with this municipally sponsored project from 1891 until his resignation in 1904, keenly felt the social implications of his role as Chief Engineer. In March of 1905, one half year after completion of the first part of the IRT, he delivered an address at Purdue University entitled "Rapid Transit in Great Cities," which reviewed several of the most recent and significant transit projects, including New York's first subway. He argued that America's myth of the practical man, the enthusiastic individual battling the odds, was outdated. The socially significant engineering works of the day, he said, required "something more in the way of a foundation than an enthusiastic dream; there is needed from the beginning the cold analytical methods of a trained and educated mind."17
Parsons envisaged an educated professional engineer: "The engineer of today, and more especially of the future, will be concerned not only with calculations, but will also have to study men and their needs, questions of industrial demand, the law of finance, and much in regard to legislation. His it will be to conceive, to plan, to design, to execute, and then to manage."18 The education of the engineer was to equip him, in short, to do it all. The engineer was, unlike other workers, to manage the fruits of his labor.
Parsons conception of the engineer, demanding a mastery of numerous social sciences, underscores the emerging sense of the delicate yet vital relationship between engineering and broad social problems. The stress was on the project and on its designer/manager. The engineer, rather than the financier or workman, was society's ultimate benefactor.
The engineer was the advocate of efficiency, and for this reason Parsons deplored the wasteful competition of the numerous private companies undermining the success of rapid transit in London. In Paris, on the other hand, he saw "monopoly working smoothly for its own advantage and the public benefit..."19
This social awareness, a vague commitment to the public good combined with a sense of leadership and responsibility, was shared by many of Parsons professional contemporaries.20 Benjamin M. Harrod, in his presidential address to the American Society of Civil Engineers, predicted that civil engineers would be the leaders in the state of the future. H. G. Prout, editor of Railroad Gazette, told the 1899 graduating class of Stevens Institute that engineers might serve by virtue of their professional training, as correctors of human depravity as well as designers of structures. George S. Morrison, in 1903, disparaged "Yankee ingenuity" as a progressive force. His view of the scientific training and analytical ability demanded of engineers tailed nicely with Parsons'; Charles F. Scott, a prominent electrical engineer, wrote in 1904 that the young engineer was entering the profession "at a time when social and industrial affairs are in the middle of great changes, and at a time when the work of the engineer is most fundamentally and intimately related to these great movement."21
These prominent engineers did not, in their public addresses, tie their sense of social obligation concretely to specific engineering works. They pictured themselves as the planners, managers, leaders of society, with visions and duties extending beyond individual projects.22 Parsons' work on the New York rapid transit subway allowed him to translate his more general belief into practice.
Three principle factors guided and shaped the work of the Board of Rapid Transit Railroad Commissioners: a particular vision of rapid transit; the acquisition of a large, well-trained engineering staff; and the organization of the engineers into two distinct groups, the staff of the Commission and the staff of the Rapid Transit Subway Construction Company. High speeds along an independent right of way covering great distances were essential to the Board's view of rapid transit. All planning and implementation of the system would have to be done with these objective in mind.23
Parsons wrote in 1905 that an engineer "...is more valuable... in proportion as he can successfully master all the elements of his problems."24 The work was to be approached broadly, because a narrow frame of reference would result in a product ill-suited to its intended use. Parsons' 1894 report for the Board, Rapid Transit in Foreign Cities, exemplified this broad outlook. It analyzed the different transit systems within their own physical and social contexts, evaluating their applicability to other cities with a consideration of the different needs and aims in each individual situation.25 Parsons did not examine street railway systems, only tunnel and elevated roads providing rapid transit on exclusive rights of way. Nor did he confine himself to the examination of a particular type of motive power. The purpose of the Board, as Parsons saw it, was not to tunnel a road and run electric cars through it. Its purpose was to establish a system of rapid transit for a significant urban area, with the particular needs of New York City in mind.
The credentials of the engineering staffs of the Board and the IRT met Parsons' high standards. Parsons' Deputy Chief Engineer, George S. Rice, served as Chief Engineer for the Boston Rapid Transit Commission between 1891 and 1892, and made extensive investigation and reports. Parsons and Rice, after years of study of rapid transit systems in intimate relation to the specific urban environment, were well suited to direct New York City's rapid transit project in accordance with the Board of Rapid Transit's broadly conceived plan.
Building the subway rapidly and economically required that construction be started at as many places as possible. To ensure that the materials used complied with the contract specifications, and supervising the diverse and often geographically scattered work sites required a large and effectively placed staff of engineers and inspectors. "For the convenience of superintending the construction,"26 five engineering divisions were established. Each engineering division was supervised by a Division Engineer. One division, the sewer division, was responsible for supervising the contractors employed to excavate, relocate, and reconstruct all sewers and drains to be disrupted by the subway. The other four divisions corresponded to the four geographical sections listed in the construction contract. A Deputy Chief Engineer was appointed to assist in directing the work of the large staff of draftsmen and inspectors. A Bureau of Inspection was established responsible for to test and inspect materials at the point of production. Dozens of inspectors and assistant engineers monitored the actual construction.27
Final authority for the design and construction of the subway rested with the engineers of the Board of Rapid Transit.28 The contractor and sub-contractors also employed an engineering staff. The contractor appointed a Chief Engineer and General Manager, the latter to "lay out a scheme for the operation of the road and the acquisition of the necessary equipment."29 The contractor also employed an electrical engineer, a mechanical engineer, and a car designer, "all particularly eminent in their several specialties."30 Because of the size of the project, the contractor divided the route into fifteen sections and enlisted subcontractors to perform the actual construction. Each of the subcontractors employed a civil engineer responsible for directing the work on his particular section and implementing the directives of the engineers of the Board of Rapid Transit.
The composition of the Commission's engineering staff was rich in technical school graduates. Parsons' belief in the necessity of a broad engineering education was of course not the only factor bearing on staff selection; the large percentage of graduates may simply have reflected the greater number of men preparing for engineering careers in such schools.31 But, Parsons' supervision of personnel selection doubtless contributed to the highly professional character of his staff. Like him, 27 of his 117 original engineers, were Columbia graduates. George S. Rice, the Deputy Chief Engineer, was a Harvard graduate. Among the division engineers, Beverly R. Value represented Columbia; William A. Aiken held a B.A. from Loyola and a degree in civil engineering from Rensselaer; and Albert Carr was a Yale graduate. Of all division engineers and assistant engineers, 100 of 118 were college graduates. Among the rodmen and axmen of the surveying staff, 73 and 37 respectively were graduates of a college.32 Positions below the level of Division Engineer were filled by competitive Civil Service examination, but many of those holding these positions were also technically trained men. Both the popular and the engineering press found this information worth comment.33
The credentials and backgrounds of engineers attracted to the consulting positions and to the service of the Rapid Transit Subway Construction Company, were no less impressive. Louis B. Duncan, of Duncan and Hutchinson, the electrical consultants to the Commission, held a doctorate from John Hopkins University. During his tenure as consultant to the subway project he was appointed chairman of the Electrical Engineering Department at Massachusetts Institute of Technology.34 In supervisory positions on the Rapid Transit Construction Company staff, S. L. F. Deyo, the Chief Engineer, and John Van Vleck, designer of the boiler and operating plant of the subway power house, were both Union College graduates. Lewis B. Stillwell, the electrical engineer, held an engineering degree from Lehigh, and George Gibbs was a Stevens Institute graduate.35
While the construction of the New York rapid transit subway was a major engineering project, it was also a business venture. The end product was to be a commercially profitable rapid transit railroad. August Belmont, financing the venture, took an active interest in the recruitment of the engineering staff of his construction and operating companies.36 One of the earliest recruits was E. P. Bryan, superintendent of equipment and later general manager of the Interborough Rapid Transit Company. Through without an engineering degree, he had vast railroad experience, beginning as a telegraph operator and advancing to General Manager of the Terminal Railroad Association of St. Louis. His most noteworthy achievement was the supervision of the Union Station in that city. He brought managerial and business expertise to the Interborough Company, qualities useful to financier Belmont.37 Bryan's early arrival may also have enabled him to advise Belmont in the selection of other railroad engineers.
Solomon L. F. Deyo, Chief Engineer of the Rapid Transit Subway Construction Company, also came to the Interborough Rapid Transit Company from steam railroading. After graduating from Union College, his railroad work was interrupted only briefly when he served as superintendent of the American Metaline Company, a manufacturer of dry lubricants. He then joined the staff of the Buffalo and Geneva Railroad, and later worked for the New York, New Haven, and Hartford Railroad.38
Among the electrical and signaling engineers, Lewis B. Stillwell and George Gibbs stand out as significant designers and innovators. Stillwell's background and experience was remarkably suited to his work on the subway. He joined the Westinghouse Electric and Manufacturing Company staff in the 1880s and by 1895 was an assistant manager. He joined with engineer and scientist O. B. Shallenburger and William Stanley in research on alternating current technology. The extensive hydroelectric project at Niagara Falls in the 1890s was one of the first great ventures in alternating current transmission,39 and when Westinghouse took the contract for the electrical equipment, Stillwell took charge of production and installation. In 1895, he left Westinghouse to become electrical director of the Niagara Falls Power Company and the Contract Construction Company.
The Niagara project publicized the possibilities of alternating current transmission. While at Niagara, Stillwell took on consulting assignments at other power and railway installations. Most important of these, with reference to his later work on the subway, was his job as electrical consultant to the Manhattan Railway Company during the electrification of its elevated lines between 1899 and 1902.40 His experience on this project proved of great significance in the selection and design of an electrical system for the subway as the subsequent electrical engineering report will show.
George Gibbs' first job after his graduation from Stevens Institute in 1882 was at Thomas Edison's Menlo Park laboratory. He was involved in the early operation of Edison's first central electrical generating station at Pearl Street in New York. In 1895, he worked for the Chicago, Milwaukee, and Saint Paul Railway as head of the testing department, performing chemical and physical analyses of materials for railroad car construction. His work with this road, which included designing and occasionally patenting steam heating and electric lighting systems for railroad cars and improved signaling systems, brought him to the attention of George Westinghouse. Westinghouse was just entering the direct current railway field and Gibbs became his representative in Europe. In this capacity, Gibbs took charge of the electrification of the Mersey Tunnel in Liverpool, England, and was a consultant to the Paris underground railroad. His consulting work for the New York subway, involving supervision of rolling stock, tracks, switching, signaling and repair shops, drew on this rich experience. In New York, Gibbs continued his career as inventor and innovator, designing a trip for the automatic safety brake for the subway, and latch mechanisms for the sliding doors adopted for the rolling stock. With the cooperation of both the Interborough Company and the Pennsylvania Railroad, Gibbs designed the first all steel passenger cars used in heavy railroading. He introduced them into subway service, and the design was soon adopted by the Pennsylvania and the Long Island Railroad Companies, and their use quickly became standard railway practice.41
The most prominent engineers on the staffs of the Board of Rapid Transit Commissioners and the Rapid Transit Construction Company had experience primarily with steam railroads on electrically operated elevated, tunnel, or trunk lines. None of those considered above had experience in electric street railway work. The experience of men in the heavy, high speed lines offered more to the projects than could those experienced with smaller, slower surface lines. The common thread which wove their efforts together was the desire of the Board, and especially its Chief Engineer, to provide New York City with a transit system characterized by a rapidity and convenience unknown in other major cities. The "Contract One" New York subway was to be the model for, and basis of, a system of underground rapid transit whose periodic expansion could serve the City's constantly growing population.
The idea of underground railway transit had fascinated civil engineers as early as the 1850's. The first passenger carrying underground railway, the Metropolitan Railway, was built in London, 1860.1 The first section of the Metropolitan was completed in January, 1863.2
The Metropolitan and the later Metropolitan District Railway operated beneath public streets and private property. The two roads traveled through shallow open cuts and in brick arch tunnels. A special construction, "masonry side walls and iron cross girders with brick jack arches turned between them," was used wherever it was necessary to reduce the height of the tunnel.3 Only a small portion of the railway, was built by tunneling "cut and cover" construction, in which the railway structure is built in an open excavation, with the surface later restored to its original condition, was used almost exclusively in constructing the Metropolitan and Metropolitan District Railway.4 Steam locomotives propelled the trains on both lines, and no mechanical system of ventilation was used in the tunnel portions of the railway. To compensate for the lack of adequate ventilation, "condensing" type steam locomotives, burning only sulfur free coke, were used.5
The early technical and financial success of London's underground railway spawned a multitude of proposals for railroad transit beneath the streets of Manhattan. The American proposals were little more than imitations of the London Metropolitan Railway, a masonry arch tunnel built at a depth of between twenty-five and thirty-five feet below street.6 As these first schemes were never realized, engineers suggested other types of underground transit design. The two most common of these alternative designs were the deep tube tunnel and the close to the surface or "Arcade" rail road. During the years between 1864 and 1896 the feasibility of each of these types of underground railroads was continually debated as each new underground rail road plan was proposed and then abandoned.
In 1864, H. B. Willson proposed the construction of a five-mile long railroad, partly in tunnel and partly over ground, running between the Battery, on the southern tip of Manhattan, and an unspecified location near Central Park. A major portion of the double track, steam powered railroad. was to be constructed in a tunnel beneath Broadway. Willson proposed constructing the tunnel under Broadway, "there being found, on careful examination, no engineering difficulties of any moment in the way."7 The "Metropolitan" or "Underground Railroad" as Mr. Willson labeled his proposed railroad, was to provide local and express service. Trains, operated at a speed of twenty to twenty five miles per hour, were expected to cover the five miles between the southern terminus at Bowling Green and the northern station at Central Park in twelve minutes. Willson believed that railroad "when fully completed will be regarded as a work in point of utility and importance not inferior to the Croton Aqueduct,"8 but it was never constructed.
Refined versions of the Willson plan were periodically offered. The 1856 version of the Underground proposed to run beneath Fifth Avenue and 59th Street. Fifth Avenue was chosen because, unlike the other north-south avenues, it did not have a large number of water and sewer pipes buried beneath it.9 Civil engineers were enlisted to design the structure and the specific steps to be taken to construct the line.
A. P. Robinson served as chief engineer for New York's "Metropolitan Railroad."10 The design advanced by Robinson called for a brick arch tunnel whose crown was to be approximately eight feet below the street and thus well beneath the water pipes and sewers. The tunnel was to be twenty-five and one-half feet wide and sixteen feet high at the center of the arch. The tracks were to be twenty-four feet from the street. Ventilation was through pipes running between the tunnel and the street. Drainage presented "no particular difficulties".11 Passengers were to ride in cars nine feet wide and forty feet long at a speed of twenty miles per hour between stations located at intervals of one half mile. Each car was to be capable of transporting eighty passengers. The sponsors of New York's Metropolitan Railroad estimated that three years would be needed to complete the project. Work was to commence at several points simultaneously to expedite the construction of the road.12
The Chief Engineer of the Croton Aqueduct, W.S. Craven, vigorously objected to any excavation necessitating the relocation and reconstruction of Croton water mains. He was certain the excavations would sever sewers and interrupt water service.13
Countering Craven, the sponsors of the Underground argued that the open methods to be used in constructing their line had been proven safe in constructing the London Underground railway, which ran through streets more heavily laden with fragile pipes than any street in New York. In constructing the railroad, "not a single experiment is proposed or to be attempted," concluded the Underground's directors.14 Engineer Robinson, however did admit that some problems would be encountered in building the railroad. Canal Street was "the real engineering difficulty."15 In crossing Canal Street, the railroad would bisect the sewer outlet to the North (Hudson) River. Robinson proposed building new sewers that would recognize the Underground Railroad as the dividing line between the east and west side drainage systems. The construction of the Underground Railroad would require that the sewers be rebuilt so that henceforth all sewers east of the railroad would drain into the East River and those sewers on the west side of the line would flow into the North (Hudson) River.16
The fear of a massive disruption of street traffic during the construction of an underground railroad was a powerful objection frequently used against the proposed line. To minimize the inevitable disruption of street traffic, Robinson suggested that the tunnel be constructed in four separate stages. First, a trench would be dug and sheet piling erected to hold back the earthen walls. In this narrow trench the foundation and one sidewall would be constructed. Upon completion of one sidewall, the second wall would be constructed in an identical manner on the opposite side of the street. Once both sidewalls were in place and covered with earth so that traffic could again travel above them, the middle of the street could be excavated and the arch between the sidewalls built while traffic was detoured to the sides of the street. With the arch completed, the street could be backfilled and repaved while the construction of the invert or bottom of the tunnel proceeded without interruption. Where this method of construction proved impractical, wooden bridges were to be built covering the entire excavation and allowing traffic to travel as usual while the excavation of the entire street took place beneath.17
The Central Underground Railway made the second attempt to construct an underground railroad in 1868. The Central proposed constructing a steam powered railroad running beneath Broadway from City Hall north to Astor Place and then up Fourth Avenue to Union Square. From Union Square the line was to travel beneath Madison Avenue as far as 120th Street.18 To "inspire the public with confidence in the success of the undertaking,"19 the directors of the Central Underground Railway relied heavily upon the expertise of British underground railroad engineers. Two of the directors, George Griswold and William Duncan, toured London's Metropolitan Railway, consulted with the engineers of the line, and contracted with the Metropolitan to import an engineering staff to direct the construction in New York.20
In 1869, the Central Underground reported that the examinations conducted by their engineers had removed "every obstacle that had been supposed to be in the way." With the questions of grades, lighting, tunneling and ventilation solved, construction could begin as early as February, 1870. Ventilation was no longer to be a problem as the Central intended to use a rather mysterious, "new motive power, which the engineers recommend for use in propelling the trains, dispensing with steam and smoke and much of the noise caused by running locomotives."21 To expedite construction, the railroad was to be built by a number of contractors, each undertaking a half-mile section simultaneously. Five thousand men were to be employed so that the work could be pushed forward by day and at night. Disruption of street traffic was to be kept at a minimum, "the earth being drawn out on over a thousand carts during the night while the streets are unobstructed."22
While the proposals of the Metropolitan Underground Railroad and the Central Underground Railway were looked upon favorably for their promise to substitute "steam power for horse power,"23 in their conveyance of passengers, their reliance upon British designs and construction methods prompted a measure of criticism. The New York Times cautioned that:
... it is a very great mistake to regard the experience of London as conclusive for us in this matter or to assume that the success of an underground in that city demonstrates the feasibility and success of an underground rail road here. The conditions in the two cases are widely different, as are the object which the two roads are intended to service. The Metropolitan road is underground for only a portion of its length; for the larger part it is simply an open cutting.24
A third and significantly different underground railroad proposal was advanced by the New York Arcade Railroad. The Arcade Railroad differed from the New York Metropolitan and Central Underground Railroad primarily in the type of structure to be built and in the depth of its location. The Arcade Railroad Company proposed a shallow excavation of Broadway to a depth of fifteen feet. At this depth a subterranean street would be built within the curb lines of the street above. Upon this subterranean street a four-track steam powered railway was to be constructed. The railroad was to be bordered by sidewalks and stores occupying the basements and vaults of adjacent buildings.25
By 1870, the Arcade Railroad boasted that its revised plans had "the unqualified and unanimous support of Broadway property holders who have taken the time to study it."26 To reduce the noise and vibrations, the revised plans of the Arcade Company called for the tracks to rest on a "longitudinal section of rubber or other elastic substance." To allow street traffic to move smoothly, the Arcade Company planned to use movable wooden bridges to fully cover the excavation.27
The first actual construction of an underground railroad in New York began in 1869. Alfred E. Beach, the editor of Scientific American, proposed a pneumatically propelled railroad running beneath Broadway. In 1867, Beach demonstrated the feasibility of his concept of pneumatic transit, building a short wooden tube in which a railroad car carrying twelve passengers was propelled by a large fan located at one end of the tube. In 1869, Beach began excavating his tunnel from the basement of a building on Warren Street near Broadway. The Beach tunnel ran east from Warren Street to Broadway, where it turned at a 90" angle and ran for one block beneath Broadway. Since Beach did not have a franchise to excavate beneath Broadway, the construction of his tunnel was carried out clandestinely for 58 nights. At the Warren Street end of the 312 foot long, 8 foot diameter tunnel, a large chamber housed a small station and a large blower for propelling the single passenger car. The car was circularly shaped and only slightly smaller than the diameter of the tunnel. The fan generated an air current that forced the car forward. A vacuum, created by reversing the fan so that suction discharged the air through an exhaust vent, permitted the car to be returned after it had been blown forward.28
Beach opened his underground railroad to the public in February of 1870 and continued to operate it for almost a year, until pressure from some Tammany politicians forced its abandonment. The method used by Beach to construct his tunnel was almost as unique as his pneumatic railroad. Beach was the first American to use a hydraulically powered "shield" in driving his tunnel. The shield used by Beach permitted the tunnel to be driven without disturbing the surface above the tunnel. Eight iron shelves with sharpened edges formed a full circle the width of the tunnel. The material inside the shield was removed and a permanent cast iron or brick lining installed. While Beach used a relatively advanced method to drive his tunnel, his methods of aligning its course was considerably less advanced. Each night, Beach aligned his tunnel by driving a jointed rod up through the roof of the tunnel and through the street where he could view it.29
In 1873, at the urging of prominent civil engineer Octave Chanute, the American Society of Civil Engineers, established the "Committee on Rapid Transit and Terminal Freight Facilities." The committee investigated hundreds of designs for surface, elevated, and sub-surface passenger and freight railways.30 Their report, issued in 1875, recommended elevated rather than underground passenger railways for Manhattan. Among their objections to underground railways were:
- The roads could not be built and equipped much short of two or three million dollars per mile.
- It would, during its construction, seriously interfere with the present surface traffic on the streets.
- It would require expensive and inconvenient alterations of the sewer and of the water and gas pipes of the city.
- At many points it would be below the high water mark and the cost of artificial drainage would add materially to the maintenance charges.
- Ventilation would be difficult and expensive. (Serious trouble already exists in similar tunnels although much shorter both in the vicinity and in London). The use of locomotive engines would make expensive mechanical ventilation necessary.
- The patronage might be limited by the unwillingness of many persons to travel in tunnels and the operating expenses and maintenance be greater than above ground.31
One engineer, Charles H. Fisher, argued that the topography of Manhattan itself prohibited the construction of an underground railway. Concluded Mr. Fisher, "It is well known to those familiar with the topography of New York, that it is not at all suited to underground projects owing mainly to the low depression which crosses the City from North to East Rivers, in which there was formerly a canal."32 (A reference to Canal Street).
Despite the ASCE's endorsement of elevated rather than underground railways, civil engineers continued to offer designs for underground transit systems. The Harlem River Tunnel Company, which had proposed building railroad freight tunnels beneath Manhattan, and the remnant of the original Underground Railroad of 1864, joined, in 1880, to form the.New York Underground Railway. The New York Underground Railroad proposed building two double track tunnels between Battery Park and Central Park similar in design to those suggested by the Underground Railroad between 1864 and l866.33
The Broadway Underground Railroad, the successor to the Arcade Railroad Company, also sought to build their railroad using a modified version of an older design. In 1884 the Broadway Company obtained a charter to excavate Broadway to a depth of fifteen feet and construct a passenger transit railroad in the manner of the original Arcade Railroad scheme. The charter, however, limited the width of the excavation to thirty-five feet, insufficient for a four-track standard gauge railroad. To operate within the limits of their franchise, the Broadway Company proposed constructing not a two-track railroad, but rather, four narrow gauge tracks. Unlike the original Arcade Railroad, the Broadway proposed using either electricity or compressed air to operate their locomotives.34 A year later the Broadway Company had committed themselves to using electric engines, but had moved no closer to constructing their line than any their predecessors.35
In 1886, the New York District Railway obtained the right to construct a passenger railway beneath Broadway. The District Company proposed a build a line from Bowling Green at the southern tip of Manhattan north, beneath Broadway, to Madison Square. At Madison Square a west-side line was to branch off, run beneath Broadway and terminate at Eighth Avenue and 59th Street, while the main line continued up the east side beneath Madison Avenue, under the Harlem River and into the Bronx. The line was to be built with four tracks, so that both express and local service could be provided. The engineers of the District Company, with Parsons at their head, proposed to construct the line entirely beneath public streets and to use the existing curb lines. Water, gas and steam pipes, pneumatic tubes, electric cables, and sewers were all to be relocated in galleries constructed parallel to and adjacent with the route of the subway. The line was to be constructed by open excavation in small sections so as not to disrupt a large volume of surface traffic.36
Plans called for the excavation of the line to be 16 feet deep and 35 feet wide, with an additional four and one-half feet on each side of the railway to be occupied by the pipe galleries. A foundation of concrete two feet thick, coated with a thick layer of "Trinidad" asphalt, was to be laid along the entire length and width of the line. The external walls, the partitions separating, the railway from the pipe galleries, the track, and the columns supporting the roof girders were to be built upon this foundation. The exterior walls were to be of brick masonry and the center columns were to be wrought iron, spaced four feet apart resting upon cut granite footing stones. Iron girders were to be placed transversely across the columns and a roof constructed from steel plates would rest across the girders. Upon these plates was to be placed a full two inches of asphalt waterproofing and a six-inch layer of concrete. The street pavement was to be relaid directly above this steel, asphalt, and concrete roof. A unique feature of the District Company design was the proposal to place between the iron columns a longitudinal partition of "steel wires interlaced with flax or vegetable fiber and oil compound, the whole pressed into a solid panel by hydraulic pressure." The "Ferflax" was expected to significantly deaden the noise produced by the electrically powered trains that were to utilize the tunnel. It was estimated that with the methods of construction to be used the cost per mile would not exceed three million dollars per mile.37 The District Company, however, never obtained the funds necessary to begin construction.
The high cost of construction was not the only criteria used to question the viability of underground rapid transit. The Sanitary Engineer argued that a system of rapid transit would provide riders with a comfortable, rapid and inexpensive ride that did not annoy residents adjacent to the route to travel. In looking at existing modes of urban transit, the Sanitary Engineer concluded:
It is certain that the requirements of rapid transit are not fulfilled by railroads on the surface of the ground. They are not fulfilled by iron-constructed trestles built over public streets and too flimsily constructed to carry motors of sufficient power to draw the necessary loads, yet carrying machines which are so noisy in their operation as to be a frightful nuisance.38
However, underground railway transit was seen as even less of a viable alternative than the surface or elevated lines. Even with the prospect of an electrically propelled underground railroad, the Sanitary Engineer concluded:
Still less can the necessary condition of comfort and health be fulfilled by any subterranean structure, such as is suggested for Broadway. In London, where underground roads have been built and operated for several years, with all the efforts of the ablest men, theoretical and practical, to attain perfection, the testimony of the builders and managers of the roads so very strong to the effect that all their efforts to secure good ventilation have proved unsuccessful. In New York the discomfort of underground travel is abundantly proven to the thousands who pass daily through the tunnels and covered ways of the Fourth Avenue road (the street car line) from Thirty-fourth to Forty-First Streets. The health and safety of the public which are the 'supreme law,' demand... the keeping of the passengers above ground at any cost."39
The City Railway Company offered New York another variant of underground rapid transit, one that promised to improve at the very least, the health and safety of those living above the route of the proposed railroad. The City Company proposed constructing an underground railroad through the middle of blocks, beneath private property. Once the four track line was constructed, new fireproof residential and office buildings would be constructed over the railway. Drawing upon the idea of the Arcade Company, the City Railway intended to construct their line as a shallow tunnel railroad with the track twelve feet below the surface of the street. Electricity was to provide the motive power for the line. The City Railway Company anticipated that building its four tracks line and restoring the surface with five story fireproof buildings would cost approximately $3,500,000 per mile.40
Less than one month after the City Railway proposed its novel form of underground transit, an underground railroad unlike any previously considered, a deep tunnel line, was proposed by a New York City construction contractor. The route of this deep tunnel railroad was also unlike any previously proposed. The line was to begin in the Bronx, cross into Manhattan and, buried deep beneath Central Park and Fifth Avenue, continue south to Washington Square. A Washington Square line was to proceed to City Hall Park where it would divide, one line turning west and crossing into Jersey City, New Jersey, where it could connect with the large terminals of large trunk railways, while the other branch continued south to the Battery. From the Battery the railroad line was to cross into Brooklyn and emerge as a surface road at Prospect Park, continuing above ground to a terminal at Coney Island.41
The tunnels were to be driven at a depth of 150 feet below the surface. Elevators were to transport passengers between the street and the tunnel stations. Asked why he had chosen to propose a deep tunnel rapid transit railway, contractor Clarke responded: "In order to avoid steep grades and to get a perfectly unbroken solid sub-stratum of rock in which to work. Furthermore, at that depth the concussions and jars from explosions in mining will be hardly perceptible at the surface and therefore unobjectionable."42
Clarke did not specify whether steam or electric locomotives would power his underground railroad. He did indicate that mechanical devices would be employed to assure that the tunnels were adequately ventilated.43 The deep tunnel proposed by Clarke was never constructed. His idea for a deep tunnel railway connecting Brooklyn and Manhattan with the major railroad terminals on the west side of the Hudson was, however, revised and subsequently championed by the Metropolitan Railway Company of New York in 1890.
While American engineers were designing and proposing underground railways that were never built, European engineers were supervising the construction of subways that would provide the model for the IRT. Between 1884 and 1900, steam powered underground railways, electric underground rapid transit railways, and electrically powered elevated railways were constructed in London, Liverpool, Glasgow, Paris, and Budapest.44
The City and South London Railway, begun in 1886, was a radical departure from previous London underground railway construction. Unlike the Metropolitan Railways, the City and South London was built as a deep tunnel. The three-and-a-half mile railway traveled in two cast-iron lined tubular tunnels located between forty and eighty feet beneath the streets of London. The deep tunnel construction necessitated the use of both stairways and elevators in the stations. The City and South London was unique for two reasons. First, the railway tunnels were driven using a circular shield in a manner similar to that used by Alfred Beach in driving his short tunnel beneath Broadway. Second, the City and South London, though designed as a cable railway, adopted electricity to propel its trains. Electric locomotives weighing between ten and a half and thirteen and a half tons pulled three-car trains up grades as steep as three percent at speeds of ten to twenty-five miles per hour.45
The completion of the City and South London Railway encouraged the construction of a number of similarly designed, electrically powered deep tunnel railways. The construction of the Waterloo and City Railway; Central London [now the Central Line]; Waterloo and Baker Street [Bakerloo Line]; and Charing Cross, Euston, And Hampstead [Northern Line Charing Cross Branch] added twenty-three and a half miles of deep tunnel railway to the London system.46
In 1886, after three years of construction, the Glasgow City and District Railway began operation. The three-mile line was built by an equal mixture of cut and cover, deep tunnel, and open construction. A steam powered road with a conventional brick arch tunnel, the Glasgow line was unique primarily because construction began at twenty-two different locations.47
The Glasgow Central, begun in 1888, used both brick arch and flat roof, iron girder construction. Because of the presence of large deposits of mud, clay and sand, the latter generally saturated with water,48 Glasgow's second underground railway was built close to the surface and almost exclusively by cut and cover. The presence of a large number of sewer pipes in the path of the railway, and the desire of the municipal officials that construction not disrupt traffic, necessitated some imaginative construction techniques. Sewers that intersected the subway were rebuilt to travel parallel streets, and water and gas pipes that crossed the route were replaced by a larger number of smaller diameter pipes, easily relocated above or long the side of the railway structure. Municipal officials limited the interruption of street traffic by permitting open excavation only between 12PM on Saturday and 5AM on Monday. Compliance with this regulation necessitated excavating, erecting, and restoring as large a section of railway structure as could be completed in the forty-one hours alloted by the municipal government. Glasgow's construction of a shallow tunnel by means of open excavation through difficult terrain, with a minimum of interruption to street traffic, demonstrated that the subway construction need not be prohibited for fear of disrupting the daily life of the city.49
The Liverpool Elevated Railway, provided further and more dramatic testimony to the economy of electrical propulsion. Using the most advanced electrical generating equipment and burning an inexpensive grade of coal provided "financial results... even more satisfactory than in London...."50
In Paris, two steam railways provided local passenger service. The Chemin de Fer Ceinture, a twenty-mile long, two track belt railway, was built "according to the topography -- surface, open cut, tunnel and viaduct" construction being adopted. The Chemin de Fer de Sceaux, begun in 1891, while short in length (6,240 feet), provided a number of lessons in economical construction of sub-surface railway structures. Masonry arch tunnel, flat, iron girder tunnel, and open cut, comprised respectively 79, 15, and 5% of the line. Cut and cover construction was used extensively.51
In Paris, as in Glasgow, a unique method of construction was devised in order to reduce disruption of street traffic. Unlike Glasgow, where short sections of the whole structure were erected, the Chemin de Fer de Sceaux constructed longer sections of one half of the tunnel structure, leaving the other half of the street unexcavated. Where brick arch tunnel was used, one half of the street was excavated, the side wall and half of the arch constructed, and the street surface immediately restored. Shifting traffic to the completed side of the street, the other side was excavated, the remaining side wall built, and the arch completed. Once the arch was completed the core of earth left untouched beneath it was excavated using a railway constructed within the tunnel to haul it to a central hoisting structure. Where iron girders were used to build the structure, a similar procedure of erecting only one half the structure at time was also followed.52
The engineers responsible for supervising the construction of the Chemin de Fer de Sceaux reported that it was both "better and cheaper to: remove and introduce all material by train and not through the streets by wagon; use simple material, especially concrete; keep the rail level as close to the surface as possible, as the difficulties and expense increased with the depth."53
The Budapest underground railway, completed in 1896, was the first underground railway to substitute steel for iron and concrete for brick. The Budapest line, like the American "Arcade" and "District" Railway plans, ran through a shallow tunnel with masonry walls and a flat roof. Unlike its projected flat roof predecessors, the Budapest line used steel beams in the roof between which concrete arches were formed.54
While no American city had an underground railway comparable to those found in Europe, two American railroads, the Baltimore Belt and the Intramural of Chicago, contributed to the technical progress of rapid transit. The Baltimore Belt was constructed by the Baltimore and Ohio Railroad to travel through Baltimore and cross the Patapsco River without using a car ferry. The critical portion of the seven mile, electrically powered railroad was the 8,350-foot section beneath Howard Street, one of Baltimore's most heavily trafficed streets. Cut and cover construction was used for 1,200 feet while almost 7,000 feet was tunneled. The tunnel was a brick arch structure whose crown ranged from ten to fifty feet below the street.55
The construction of the Baltimore Belt Railroad made a contribution to the future New York Rapid Transit Subway. It demonstrated that electric locomotives were capable of hauling heavy trains. The difficulty of constructing a tunnel railroad through water-laden sand, beneath a heavily traveled and built up street, necessitated that the contractor devise cautious methods of construction. The contractor who constructed the Baltimore Belt Railroad and gained this valuable experience was John B. McDonald.
The Intramural Railway of Chicago, a short (2,800 feet) elevated railway, was the first United States railway to use electricity to propel "full trains run in a regular service." The success of the Intramural in 1894 prompted the Metropolitan West Side Railway of Chicago to choose electricity to propel their trains.56
The construction of the European undergrounds demonstrated that "... it had become possible to use, with comfort and cleanliness, the great sub-surface for transit purposes, a space hitherto considered of value only as a place to bury sewers, water and gas mains in haphazard and disordered confusion."57 European precedents encouraged American engineers to see that a practical and desirable alternative to the elevated railroad did exist. The introduction of electricity to propel the trains permitted the underground railway to be transformed into an underground rapid transit railway. Not only did electricity render ventilation less of a problem, but is also reduced the costs of operation. The introduction of steel and concrete provided engineers with an economical means of constructing large sub-surface railroad structures.
With all the evidence available from foreign and domestic examples, two factors emerged to determine which of the many types of underground railways was most appropriate for New York: the cost of operation and the cost of construction.
The operation of London's electrical underground railways, the Liverpool elevated, the Baltimore Belt Railroad, and the Intramural Railway of Chicago demonstrated that electricity offered the most economical means of propelling urban passenger trains. Electricity also permitted the trains to be operated in any type of tunnel, deep, intermediate, or shallow depth, where steam locomotives, because of the ventilation systems required, were restricted to the shallow or intermediate-depth tunnels, And since "the substitution of a motor other than an ordinary steam locomotive would at once remove "99.997% of the foul atmosphere from an ordinary railway tunnel,"58 the cost of ventilation systems could be avoided.
Glasgow demonstrated deep tunnels were eight times more expensive than open excavation. Paris confirmed that cut and cover construction of the shallow depth tunnel was the most economical. The general hypothesis that emerged from the European experiences was that the deeper the tunnel the more expensive it would be to construct.59 Additionally, the need for mechanical ventilation and elevators in the deep tunnel railway added to the cost of both construction and operation. The conclusion was that an electrically propelled railway built in a shallow or intermediate depth tunnel was both more economical to construct and operate.
Private capital's inability to construct an underground railway in New York prompted more active municipal involvement in the rapid transit decision; in 1891 Mayor Hugh Grant appointed a new Rapid Transit Commission, the first in the city's history to have an engineering staff confined, as previously mentioned, by William Worthen and William Barclay Parsons.
Charting the topography that the subway structure would encounter was the first step. Test borings were made along Broadway from South Ferry to 34th Street. The results of these tests were both unexpected and encouraging. The engineers learned that in general the presence of solid rock was was at a depth greater than generally believed; they encountered rock until 163 feet beneath Duane Street in lower Manhattan. The rock beneath Canal Street, however, was closer to the surface than had previously been believed. And the material encountered at Canal Street was not "muck and fine sand, but on the contrary," consisted "largely of good, coarse gravel and presents an excellent material for foundations."60
With the added knowledge devised from the borings, Worthen and Parsons proceeded to produce two differing proposals for a Broadway underground railway.61 Worthen offered a structure where all four tracks were located on a single level, while Parsons placed four tracks on a two-tiered, double track structure. Both Worthen and Parsons chose electricity as the motive power.62 Worthen envisioned a four track road built upon a concrete foundation. Iron columns would support a roof of wrought iron girders covered by iron plates. Upon this iron plate ceiling a layer of coal tar was to be placed to insure against water seepage and corrosion. The tunnel was to be built without interfering with the sub-surface sewers and pipes, because the roof of the structure was to be kept at least eight feet below the street.63
Parsons prefaced his proposal with a general description of the problems to be anticipated in constructing a subway beneath the streets of lower Manhattan and a discussion of the alternatives that existed to overcome the impediments. He found the major obstacle to the rapid and economical completion of an underground to be the maze of pipes, conduits, cables, and sewers beneath the streets. He concluded, "There are two general systems by which it seems possible to construct a railway under Broadway without interfering with the pipes and wires: a tunnel in solid rock reached by elevators, or a tunnel midway between the rock and surface, driven through the sand by a shield.64
The result of the test borings had strengthened the argument against the construction of a deep tunnel railway, indicating that certain points in the downtown area rock was as deep as 160 feet below the surface of the street. To build a structurally sound tunnel, boring through solid rock would be required. With the surface of the rock at such varying depths, the construction of a deep tunnel railway would have to be at so great a depth, in some places 200 feet below the street, as to be excessively costly both to construct and to operate. Since a tunnel this deep would be inappropriate for a system designed for local as well as long distance travel, the alternative was to construct a tunnel through the deep layers of sand at a depth below the deepest pipe, or a tunnel that was located directly below the street, requiring relocation all pipes encountered during its construction. Parsons choose the latter alternative and explained the rationale for his choice:
As to tunneling through sand, while I believe it would be possible to drive such a tunnel, I also believe that the cost of doing so would be very excessive, and the risks run very great. The borings show that along a large portion of Broadway, especially where the buildings are the largest, and the traffic greatest, the sand is exceedingly fine, approaching, if it is not actually, a quicksand. In the space above the the top of the tunnel are all the water mains and sewers; and if the slightest settlement takes place in the roof of the tunnel (which it would be almost impossible to prevent), a leak in the pipes would be almost inevitable; and as soon as sand should be charged with water the tendency to flow would be greatly increased, and a further settlement would follow. Not only is the weight of the sand above to be considered, but the weight of the enormous buildings along Broadway, which practically amounts to surcharging the soil, and also the street traffic, constantly settling up a jar or trembling of the sand and also increasing the tendency to run. If an accident should occur the loss might be so great to beyond the power of any company of contractor to make good. From Twelfth Street north the shield had to be driven partly through rock and partly through sand, increasing the cost and danger.65
Parsons concluded a tunnel that avoided interfering with sub-surface pipes would be uneconomical to construct. He recommended the railroad be constructed as close to the surface as possible and all pipes encountered during construction be relocated in such a manner as to avoid the subway and still allow access for repairs. Specifically, Parsons called for the construction of a two-tier roadway, each with two tracks and a center gallery for all pipes. Parsons' structure, like Worthen's, was to be built on a concrete foundation, have iron columns and cross girder, and be topped by an iron plate roof covered with a protective covering of asphalt.66
Both plans received considerable discussion in the popular press and among the engineering journals.67 Four consulting engineers were chosen to evaluate the two plans and decided Worthen's plan the least disruptive of street traffic. However, despite the popular discussion and the endorsement of the consulting engineers the plan went no further than the paper upon which it was drawn.
Passage of the Rapid Transit Act of 1894 inaugurated another attempt to construct a rapid transit subway. The 1894 Board of Rapid Transit Railroad Commissioners appointed William Barclay Parsons Chief Engineer, provisionally adopted the 1891 plan for a single level, four track subway beneath Broadway, and instructed Chief Engineer Parsons to investigate European rapid transit railways.68
Upon his return from Europe, Parsons expressed disagreement with the route chosen by the 1891 Rapid Transit Commission. He argued that since any construction beneath Broadway would provoke vigorous objections from adjacent property-owners, New Elm Street, an avenue parallel to and 100 feet east of Broadway, should be the route of the subway between City Hall and Astor Place.69
The Board of Rapid Transit Railroad Commissioners appointed a Board of Experts to evaluate Parsons' proposal. The Board of Experts consisted of four civil engineers; Octave Chanute, Thomas C. Clarke, William N. Burr, and Charles Sooysmith; and former Mayor Abram Hewitt. The five advisers endorsed Parsons' objections to the 1891 route, approved his altered design and verified the accuracy of his estimates of the cost of construction.70 The Board of Rapid Transit Railroad Commissioners, however, rejected the substitution of Elm for Broadway and accepted with minor modifications the 1891 plan of construction.71
On May 22, 1896, the New York Supreme Court denied the Board of Rapid Transit the authority to construct the subway along the Broadway route proposed in 1891. Having been denied the right to construct a rapid transit subway beneath Broadway, the Commission came round to the views set for by Parsons and the Board of Engineering Experts. A resolution passed by the Commission shortly after the Supreme Court decision directed the Chief Engineer to:
... submit to this board at as early a date as possible routes and a general plan of rapid transit which shall conform to the following conditions:
1. Total cost after abundant allowance for contingency not to exceed $30,000,000.
2. Route to proceed from the southern terminus at or near the Post Office and under the City Hall Park and Park Row to Elm Street and Fourth Avenue to or near the Grand Central Station, and there to divide into the east and west side routes. The west side route to proceed under 42nd Street to Broadway and the Boulevard to a point above 125th Street. The east side route to proceed under Park Avenue and over private property to the Harlem River and across and beyond the Harlem River to as distant a point as the proposed limit of cost will permit.
3. The railroad to have four tracks to the junction of the east and west side routes and above that point two tracks on each route, except for a third track for express service shall be added on both routes when conveniently and economically possible.
4. The road to be in a tunnel, except on the east side north of 98th St. and on the west side at Manhattan Valley, 125th Street.
5. Plans to be drawn so as to permit further extensions in the future from the south and north termini and permitting the two and three track portions to be widened into a four track system without unnecessary expense or interruption of service.72
Within four months Parsons returned with a plan containing the modifications in compliance with the Court's objections to the 1891 plan. Parsons estimated that sufficient savings could be made if the portion between the Battery and City Hall Park were eliminated. The southern section of the line was placed beneath Elm Street, and the junction between the east and west side lines was moved from 14th Street to 42nd Street.73
As part of his relocation report, Parsons conducted test borings along Elm Street. The borings indicated that to the depth for which the excavation for the railway will be made, there was "no material found which would slide or give difficulty in handling."74 Rock at a level interfering with the subway structure was first encountered at 12th Street and continued north. It was during the Elm Street borings that tests for standing or ground water were first made. The tests revealed the ground water was found "about one foot above the level of the mean high tide."75 Parsons found this information encouraging since it indicated that with the exception of the line between Leonard and Grand Streets, a distance of 1,600 feet, the Manhattan portion of the subway would be above the high tide, a level which made mechanical drainage equipment unnecessary. Since Elm Street lay near the City's drainage dividing line, the problem of relocating the sewers intersected by the subway would be considerably reduced, an additional economic realized.76
... slow or difficult to build and the proposed route therefore escapes entirely the difficulties of construction which were present along Broadway incident to the heavy traffic, cable railways, complications of subsurface structures, and the care of abutting buildings. The work can be attacked at once at as many places as can be conveniently operated at once.77
Beyond the modifications presented, Parsons envisioned that the remainder of the route could be built in accordance with the earlier plan.
The Court approved this new proposal, subject to a number of financial conditions which were not met until November, 1899. This done, the Board of Rapid Transit Commissioners authorized the drafting of formal specifications that could be inspected by contractors interested in constructing the railroad. The route finally adopted called for the subway to begin, "at a point at or near the intersection of Broadway and Park Row and proceed North beneath Park Row and Centre Street to New Elm Street. After traveling beneath Elm Street as far as Eighth Street, (Astor Place) the line was to proceed north beneath Fourth Avenue until Union Square (14th Street) was reached. From 14th Street to 42nd Street the road was to travel under Park Avenue. Upon reaching 42nd street the line was to travel west beneath 42nd Street as far as Broadway. Between 42nd Street and 190th Street the route followed first Broadway and, after crossing 167th street, Eleventh Avenue. North of 190th Street, Elmwood Street and Broadway were to carry the line across the Harlem Ship Canal and into the Bronx. An east side route was to diverge from the Broadway line at 103rd Street and proceed east under Central Park to the intersection of Lenox Avenue and 110th Street. The subway was to continue north beneath Lenox Avenue as far as 141st Street where it was to cross under the Harlem River and emerge as an elevated road, traveling via Westchester Avenue, Southern Boulevard, and Boston Road to the northeastern terminus at Bronx Park.78
The contract divided the construction into four sections, so that if funds for the entire line were unavailable, construction of a portion or portions of the line could begin. The four sections were:
- Section 1 commencing at the southern terminus of the line at City Hall and continuing north to 59th Street.
- Section 2 beginning at 59th Street and proceeding north to the station at 137th Street.
- Section 3 beginning at the north end of the 137th Street station and running along the west side as far as the station at Fort George and on the east side from 135th Street to Melrose Avenue, the Bronx.
- Section 4 the remainder of the west side route, from Fort George to Kingsbridge and on the east side from Melrose Avenue to the northern terminus of the east side line.79
In November of 1899, the Board of Rapid Transit published an "Invitation to Contractors" formally soliciting bids for the construction of the proposed rapid transit subway.80 Engineering journals criticized the format of the invitation. The Engineering News was convinced that no contractor was in a position to equip and operate the road as the contract specified. The Engineering Record argued that constructing the subway, "at a time when materials are unprecedentedly high" and in a city where the compliance with "state and city labor laws... considerably increases the cost of work" would diminish the enthusiasm of any contractor to bid on the project.81
Two contractors, Andrew Onderdonk and John B. McDonald, did submit bids to construct and operate the New York rapid transit subway. Mr. Onderdonk and his son, a civil engineer, operated the New York Tunnel Construction Company.82 McDonald was a railroad and public works contractor who had performed construction work for the Baltimore and Ohio, Pennsylvania, West Shore and Potomac Valley Railroads between 1881 and 1889. In 1890, when the Board of Rapid Transit was first at planning the subway, McDonald began the construction of the Baltimore Belt Railroad, successfully completing it in 1895. At the time McDonald bid on the subway, he was working on the Jerome Park reservoir. In February, 1900 the Board of Rapid Transit announced that he had been selected to construct all four sections of the subway.83
The size of the project, the variety of the structures to be constructed and the terrain to be worked, and the general desire to complete the project in as short a time as possible,84 prompted the contractor to divide the project into fifteen sections, "the beginning and ending of these several sections being fixed by local conditions necessitating variations in the construction."85 Individual sections were then placed under the jurisdiction of sub-contractors. Steel erection all along the route was contracted to one firm, Terry and Tench Company. The work of relocating and reconstructing the sewers, the first step, was distributed among a number of small sub-contractors.86
Two of the biggest contracts were for furnishing structural steel and cement. The Carnegie Steel Company undertook the manufacture of the 74,326 tons of structural steel and 4,000 tons of rail required to construct the subway. The contract required 22,439 tons of steel beam, 20,466 tons of rivet steel, 7,921 tons of steel column, 23,500 tons of steel viaduct, and 4,064 tons of rail. United Building Materials Company was awarded the contract to supply McDonald and his sub-contractors with 1,500,000 barrels (300,000 tons) of cement. In 1895, the total amount of cement consumed in the United States was less than 100,000 barrels. The largest portion of the cement was used in making concrete. Mixed with twice as much sand and four times as much crushed stone, the engineers estimated that 400,000 cubic yards of concrete would be produced for use in constructing the subway. These two contracts were "the largest ever undertaken by an individual firm for supplying cement and steel for a single engineering work."87
The contract between McDonald and the Board of Rapid Transit consisted of ninety-four pages of basic construction specifications accompanied by three volumes of maps and drawings. The contract described not only the route and the type of construction to be followed, but also the specific materials to be used in constructing the subway, and methods of construction permitted.88 The contract permitted open excavation (cut and cover) construction and tunneling. Open excavations were not to exceed 400 feet in length unless covered to permit the passage of pedestrians and vehicles. Open excavation was permitted between the southern terminus at City Hall station and 34th Street. Tunneling was required between 34th and 40th Streets and on the east side route from 104th Street, beneath Central Park, to Lenox Avenue and 110th Street. Open excavation was permitted along 42nd Street, and on the west side as far north as 60th Street. North of 60th Street the contractor could choose "the most expeditious manner possible, having due regard to safety of persons and property and reasonable consideration for the accommodation of street traffic."89
Having studied the deep tube, intermediate depth, arches of masonry, and shallow flat roof or "Arcade" style tunnels, the Board chose the latter. Chief Engineer Parsons explained, "weighing all the advantages and disadvantages, your Engineer recommended the adoption, so far as possible, of the shallow excavation type on account of the greater convenience when completed and probable less expense to construct.90
The Board's preference for a shallow tunnel railway received tangible encouragement from the example of the Boston subway. In 1895, Boston began constructing an underground right of way for a portion of its electric street car line. Boston desired to decrease the congestion of its downtown streets and increase the rapidity of streetcar travel. To accomplish both objectives, the city decided that in the most congested area the streetcar tracks should be relocated beneath the street. To assure maximum accessibility, the "Arcade" or shallow depth tunnel was chosen. Like the recently completed Budapest railway, the Boston engineers used steel beams with concrete arches between them in constructing their flat roof tunnel. The Boston tunnel introduced steel columns with concrete arches between them into the side walls as well.91
In New York, however, "abrupt changes in topography and geological formation" prevented shallow construction everywhere. Between City Hall and 31st Street, 41st Street and 122nd Street, 135th and 150th Street, and beneath Lenox Avenue, the structure was built close to the surface. Between 33rd and 40th Streets, the presence of the Metropolitan Street Railway's Park Avenue tunnel necessitated dividing the subway and passing the tracks under Murray Hill in two separate concrete-lined tunnels. The need to maintain reasonable gradients also necessitated tunneling beneath Central Park between Broadway and Bronx Avenue, and on the west side, between 150th and 155th Streets, and from 158th Street to Fort George. Depressions of the topography required the construction of a viaduct between 122nd and 135th Streets. Topography and economics encouraged the use of an elevated structure on the west side, north of Fort George, and on the east side north of Melrose Avenue in the Bronx.92
Different types of construction were used in building the subway. The majority of the tunnel, 10.6 miles or 52.2% of the Contract One road, was constructed with a flat roof of steel I-beams and transverse concrete arches. Steel I-beams, spaced five feet apart longitudinally, served as side wall columns and horizontal ceiling beams. Between the I-beams, concrete arches were formed. Four bulb-ended steel angles, six inches in width, were riveted together to form a single bulb-angle column. The bulb angle columns were placed between the tracks to carry the steel roof beams. Knee braces were used in connecting the bulb angle columns and the roof beams. The steel frame rested on a concrete foundation, the full width of the subway, with a minimum thickness of eight inches. Granite footing stones within the concrete foundation supported the bulb angle columns located between the tracks. The steel beam and concrete structure allowed either the full or a partial width to be built, "with an absolute certainty that the several sections will fit together, connections between the rigid members being made of plastic and easily molded concrete."93 The entire structure, top, bottom, and both sides, was coated with a thick layer of waterproofing, eight layers of felt and asphalt paper, applied prior to backfilling and resurfacing the street.
A modification of the standard steel beam and concrete structure was used in constructing the subway beneath Lenox Avenue. The steel I-beams normally used in the side walls and roof were replaced by one-and-an-eighth to one-and-a-quarter inch thick steel rods embedded in the concrete. The rods were spaced from four to ten inches apart and surrounded by eighteen to thirty inches of concrete, depending upon the load the roof was expected to carry.94 Standard bulb angle columns located between the tracks added support to the roof.
Four and a half miles, 23% of the subway, was built as a concrete lined, arch tunnel. Five miles, 24.6%, operated above ground, running upon a steel viaduct. Cast iron lined tubular tunnels carried the subway beneath the Harlem and East Rivers.95
With the route and type of structure decided upon,
... an investigation was begun as to the topographical and geological features, the nature of the abutting buildings and their foundations, the sewerage system affected, and the presence of other surface and subsurface structures, such as elevated and surface railways, water mains, gas pipes, compressed subways for telegraph, telephone, light power and other electric wires, etc.96
To assure adequate supervision of the sub-contractors, the sub-contract sections were organized into four engineering divisions:
- Division 1, sections 1, 2, 3, and 4;
- Division 2, sections 5a and b, and 6a and b;
- Division 3, sections 7, 8, 9a and b, 11, 13, and 14;
- Division 4, sections 10, 12, and 15.
A Sewer Division was also created to supervise the work of relocating and reconstructing the sewer and drain system.97
The first shovel of earth was turned at City Hall Park in ceremonies held on March 24, 1900. The next day work on the 20.5 mile subway began in earnest.
The first step in constructing the subway was relocating all the sewers and storm drains intersecting the right of way of the subway. The Chief Engineer estimated that 7.2 miles of sewer along the right of way and 5.13 miles of sewer beneath other streets would be reconstructed.98 Manhattan's sewer system was the combined type where both sanitary sewers and street storm drains connect and discharged together. The sewers ran beneath the streets and avenues where they discharged into larger, lower level mains whose final outlet is in either the North (Hudson) or East Rivers, depending upon the specific gradients and topological conditions of each local area. Since constant expansion and frequent alterations made the records of the Sewer Department cumbersome and confusing to work with, the contractor undertook a comprehensive sewer survey. The sewer division engineers sought to locate all sewer mains and outlets, measure every manhole for depth, determine the flow, drainage, area covered, and run-off of each locality, and wherever possible, examine the internal condition of the sewer mains along their entire length. The engineers concluded that since the path of the subway bisected Manhattan along a north-south axis the the best solution was to accept this division and direct the flow of the sewers on the east side of the line to the East River and all sewers on the west side of the line to the North (Hudson) River, unless gradients prohibited this practice. This system resulted in the construction of sewers running parallel to the subway which then emptied into the existing low lying mains.99
The need to construct the sewers in accordance with a multitude of specific local conditions produced a sewer system that lacked a uniform method or type of construction, varying instead as local conditions dictated. The finished sewer system used all of the standard types of sewer construction as well as few novel designs created to overcome the problems encountered at Canal Street and Chatham Square, and 110th Street and Lenox Avenue, and Railroad Avenue and 149th Street. The construction contract specified that sewers be constructed of either arched brick masonry or vitrified concrete or iron pipe, whichever way was most appropriate for each section.100 Wooden stave (circular) and wooden box construction were permissible where conditions necessitated, primarily at the East River disposal outlet.
Concrete sewers, costing as much as one third less than the conventional brick arch sewers were also constructed. The Engineering News described the construction of concrete sewers:
Previous to setting the invert form in place for constructing a length of invert, concrete was placed on the bottom of the trench in a layer thick enough to bring its top surface up to within from 1/2in. to 1/4in. of low-line grade. To ensure the accuracy of this work and also to ensure the accurate alignment of the form, a template was suspended from the trench timbering and adjusted to line and grade. After placing the bottom layer of concrete, the form was accurately set in position by resting its rear end on that end of the last completed invert and supporting its forward end on a foundation accurately set to grade. The flow line was then accurately formed by filling the space between the bottom of the form and the concrete foundation layer with a mortar of one part Portland cement to one part sand. The form was then firmly braced in position by struts nailed to the trench sheeting and vertical planking was set up to form the outside of the spandrel. The concrete was then placed and carefully rammed against the form so as to ensure a smooth surface. The invert concrete was composed of one part Portland cement, two parts sand and four parts of stone broken to pass a one-inch ring. This mixture was placed (not dropped) into position and carefully rammed. The ends of each successive section of invert were mortised to ensure a firm and intimate connection with the next section, and 2 x 4-in. strips, laid longitudinally along the center of the tops of the sidewalls of the invert section formed mortises for bonding the arch ring to the invert. The forms were left in place at least 24 hours to allow the concrete to set. After the invert was set and the form withdrawn a thin cement wash was brushed over its surface to smooth any slight roughness. This work gave a surface almost polished in comparison with the best brick-work.101
Combinations of concrete and brick construction, where concrete inverts (bottoms) carried a roof arch of brick, were also used.
There were points at which the sewers had to be carried across the path of the subway or where the large size of the sewer required special construction. Canal Street, 110th Street and Lenox Avenue, and Railroad Avenue and 149th Street were the most prominent examples of special work. The Canal Street sewer, draining an area of 180 acres, had previously emptied into the Hudson River. With the construction of the subway, the Canal Street sewer had to be diverted to the East River and a new outfall line constructed. The sewer started as a five and a half foot circular brick sewer beneath Canal Street, expanded to a six and a half foot sewer beneath Chatham Square, Leonard, and Madison Streets, became a box sewer between Madison and South Streets, and was finally funneled into two circular wooden stave pipes at its outlet at the East River. With the exception of the Chatham Square section, which was built in tunnel, the Canal Street sewer was constructed in an open cut. Because of the heavy street traffic and the large number of street railway tracks, the thirty foot section beneath Chatham Square was built in tunnel. The diameter of the tunnel was only six and a half feet, but the fine sand that was penetrated and the fact that the tunnel was only thirty feet beneath the surface complicated the task.102
At Lenox Avenue and 110th Street, a six foot six inch diameter circular brick sewer, draining 124 acres of the west side of Manhattan, was intersected by the subway. A new sewer of equal diameter, but to a depth sufficient to pass beneath the subway was constructed on either side of the subway structure. Where the sewer passed beneath the subway, the brick sewer was replaced by three 42 inch diameter cast iron pipes.
An objective of the sewer division-engineers was "to arrange for the permanent flow of sewerage without pumping."103 Only one sewer was reconstructed below the tide line, necessitating the use of a siphon to assure proper drainage. In crossing beneath the subway at Railroad Avenue and 149th Street in Manhattan, the sewer dropped below the tide level. Two siphons were built so that should the sewer prove not to be self-cleaning, one siphon could be shut off and cleaned while the other continued to function.
During the first few months of sewer reconstruction, the engineers and contractors organized the work force, procured the equipment, and arranged for the delivery of the materials needed for the actual construction of the subway. All but one sub-contractor agreed that the economical and efficient use of pneumatic tools hoists, drills, pumps, concrete mixers, and riveters required a central air compressor power plant for each section or groups of sections. To satisfy the need for compressed air, nine central compressed air stations were constructed.104
The heavy volume of street traffic, the presence of large buildings with footings resting on sand close to and above the bottom of the subway excavation, and the complicated design of the City Hall station and turning loop, made section 1 especially costly, difficult, and tedious to construct. The original plans for section one called for the four track line to continue south past the Brooklyn Bridge station and form a two track turning loop around the United States Post Office building. The decision in 1900 to extend the line down the east side and into Brooklyn brought about an alteration in this design. The revised plans called for the two interior or express tracks of the main line to continue to Brooklyn while the two exterior or local tracks dropped below the main line, veered west a short distance, and formed a single track turning loop beneath City Hall Park.105
The loop under City Hall Park was the first part of section 1 to be excavated. The loop, unlike the steel frame portions of the subway passing beneath Park Row, was a concrete arch structure with a width of 11 feet and a height of 14 feet, 10 inches. The excavation was open cut work except for that portion of the loop passing under the vaults of the Post Office Building and the ten story New York Times Building. Tunnels were driven beneath these two structures. The entire excavation for the loop, as was all of sections 1 and 2, was in soft, loamy sand, which was removed by hand shoveling.
In excavating sections 1 and 2, the methods varied depending upon the volume or surface traffic and the extent to which a particular street could be closed to traffic.106 The heavy volume of street railway traffic on Park Row prohibited its being closed. It was necessary to dig four narrow trenches parallel with the street, one on each side of the street railway line and one each outside the line where the exterior wall of the subway structure would be built. When the trenches were six or seven feet beneath the street railway track, horizontal tunnels, perpendicular to the line of the railway and the trenches, were dug and the street surface supported by short timbers. Through these transverse tunnels, spaced at ten-foot intervals and between the locations where the actual subway columns and girders would be erected, 14 by 14 inch timbers or "needle beams" were placed. These needles beams were wedged up against the roof of the tunnel and held firm by temporary timber supports. Beneath these transverse beams, a half-dozen six by six foot shafts were then dug to a depth below the projected foundation grade of the subway structure. Timber columns, twelve inches square, were set in these shafts and wedged tight against the transverse needle beams. After the columns were in place and carrying the weight of the beams and the street above them, the remaining earth could be carefully removed and the trench excavated to the full depth and width required by the subway structure. Construction could then proceed while traffic on the street above continued to flow uninterrupted by.
Along Elm Street light traffic and the lack of asphalt paving permitted the contractor to close the street and excavate the full width of the subway without concern for maintaining a roadway above the excavation.
Section 1 and 2 were excavated entirely in sand. In section 3, rock at a level interfering with the subway structure, necessitated different methods of construction. The rock, first encountered at 10th street, gradually rose closer the surface until it was within three feet of the street and "directly beneath the yokes of the electric railway... at 15th Street."107 The excavation of the remaining portion of section 3 was through rock of varying depths. To minimize the disruption of traffic, the initial cut and cover construction in section 3 was limited to one half of the street. However, "as the work progressed it was found that the inconvenience resulting from the excavation on one side of the street was felt with almost equal force upon the other, and that the building of the railway half at a time produced almost as much interference with street traffic as would the building of two railways."108 Excavation of the full width of the street was subsequently permitted. Temporary steel and wooden bridges allowed the orderly, if restricted, flow of streetcar and vehicular traffic above the excavation.
The streetcar tracks were carried on temporary trestles while excavation and construction progressed below. In building these temporary trestles, trenches were dug at intervals of forty feet transverse to and beneath the streetcar tracks. Upon reaching the depth of the subgrade of the subway, concrete footings were poured in the trench and a timber trestle or bent erected. Along the outside and between the middle of the streetcar tracks, 24 inch steel beams, forty feet in length were laid longitudinally in a trench dug just below the bottom of the tracks. The beams rested upon the tops of the previously constructed timber trestles. Transverse to the street tracks, trenches dug so that cross beams beams could be inserted beneath the tracks and fastened to the longitudinal I-beams by rods and bolts. Once a sufficient number of transverse cross beams had been placed to carry the weight of the tracks and securely tightened, the excavation of all the remaining earth and rock could begin. This system of carrying the streetcar tracks permitted the total excavation of the street. The construction of the subway could proceed with only one interruption every forty feet. After the subway structure was completed, brick piers built on the roof of the structure carried the weight of the streetcar tracks while the trestles were removed, the excavation backfilled, and the pavement restored.109
Overhead cableways were used extensively in sections 1, 2, and 3 to remove the excavated material or "spoil." Derricks were placed where large masses of rock and earth were to removed. The derricks hoisted the steel buckets full of spoil out of the trenches and to the surface. Once on the surface the buckets could be attached to the cableway, elevated from the ground, and moved along the length of the system to the end of the excavation where the spoil was dumped into horse drawn carts for removal to any of several disposal sites.110
In the area of Union Square, the entire area below the level of the streetcar tracks was solid rock. A pedestrian bridge over the excavation, a stiff leg derrick for removing rubble from the excavation, and a multitude of air compressor lines were used in construction.111
To avoid damaging the streetcar tracks when using dynamite to excavate for the subway the tracks of the streetcar line were removed to the east side of 4th Avenue. After the relocation of the streetcar tracks, sufficient space was available to excavate and construct the two southbound tracks of the subway. The completion of the southbound side of the subway permitted the relocation of the streetcar tracks to their original position, and the construction of the remaining two, northbound, tracks of the subway. Section 4 presented the engineers and contractors with the most vexing problems. This section passes beneath a rocky elevation known as Murray Hill. In 1900, this neighborhood contained some of the most prestigious residences in Manhattan. Geologically, Murray Hill is a surface formation of mica schist rock whose strata lie at an angle of 45 degrees. This formation is subject to slides when sufficiently disturbed, and two such slides occured during construction. The contract for section 4 called for the subway to be entirely in tunnel from 34th Street to 41st Street. Complicating the construction was the presence of a two track tunnel used by the Metropolitan Street Railways. This tunnel under Park Avenue necessitated separating the four tracks of the subway and arranging them into two double track tunnels. The two pair of tracks were located beneath and at the sides of the Metropolitan Railway tunnel.
The first step in constructing the tunnels was to sink four shafts, one at each end of the tunnels. The shafts were located on the side of the streetcar tracks at each end of the tunnel. A strong timber platform was built over the street, connecting the two shafts. This timber platform carried the equipment needed to operate the compressed air drills used in driving the tunnel.
The two shafts at the south end of the tunnel were the first to be sunk. Work began on the east tunnel shaft on September 17, 1900 and on the west shaft on October 15, 1900. These two shafts were thirty feet long, twenty feet wide, and directly over the route of the tunnel. The south shafts penetrated a solid strata or rock that required no timbering. Using air drills and dynamite to break the rock loose, and stiff leg derricks to excavate the spoil, work progressed without incident. The final depth of the two shafts, 24 feet, was reached within four months. The two north shafts required timbering as they hit both rock and layers of hard earth. Although smaller than the south shafts they were sunk to a deeper depth, 38 feet.
On December 11, 1901 the driving of the west tunnel began from the south shaft. This tunnel was driven using the "top heading" method. Figure 1 indicates the sequence used in driving the tunnel by method. In driving the east tunnel northward a "bottom drift" was employed. The rapidity with which the east tunnel was driven northward using the bottom drift, prompted the contractor to discontinue using the top heading in the west tunnel and proceed with a bottom drift there as well. Figure 2 indicates the sequence of the excavation using the bottom drift. After the initial excavation (portion 1) the tunnel was widened by removing rock on both sides (portion 2). The removal of portion 3 followed, and lastly, the upper portion, number 4 was removed. Because of the very soft and decomposed rock encountered in driving the east and west tunnels south from 41st Street, the top heading was initially used on both. Here permanent timbering was also necessary. Improvement in the rock in the west tunnel permitted the contractor to substitute the bottom heading (Figure 2), while maintaining the top heading in the east tunnel.
The method of driving the Murray Hill tunnels differed from the conventional practice of American rock tunneling, which, with few exceptions; were driven using the center top heading pattern. The Murray Hill tunnels used the bottom drift method, wherever possible because, according to Chief Engineer Parsons, it was more economical and permitted more rapid excavation.112
In driving the tunnels, compressed air drills bored holes about seven feet deep with a diameter starting at 2 and 3/4 inches and tapering down to 1 and 3/4 inches. These holes were filled with small charges of dynamite and blasted. Throughout the driving of the Murray Hill tunnels, dynamite blasting presented major problems. The windows of buildings adjacent to 34th Street suffered considerable damage, which prompted the contractor to cover the shafts of the tunnels with heavy timbers. Deflecting the air flow in this manner considerably reduced the problem. Deeper holes were also bored so that rock itself would bear the burden of the explosive shock and reduce the vibrations experienced at the mouth of the shaft.113
While the driving of the tunnel differed at each end, the method of removing the excavated materials was similar at both ends. Three parallel narrow gauge tracks were laid on the floor of the tunnel and advanced to the face of the tunnel excavation. Small flat cars upon which steel boxes (skips) were placed, carried the excavated material between the face of the tunnel excavation and the shaft, where the surface derricks lifted the skips to the street. The material from the bottom portions of the tunnel was loaded into the excavation by hand. In removing the material from the upper portions of the tunnel, a "traveler" or rolling platform was used. Mounted upon this wooden platform were air drills and temporary roof support columns. The platform was moved back when blasting thus allowing the rock to fall upon the tunnel floor where it could be loaded into the excavation cars.
Lining the two tunnels with concrete presented an entirely new set of problems. The first problem was to establish an adequate concrete mixing facility. Stone crushing machinery was elevated above the street on heavy wooden platforms, and the concrete mixing machinery was placed within the vertical tunnel shaft. The stone removed from the tunnel was hoisted to the surface, transferred to cars, and pushed to the crushing machine on tracks laid upon the elevated platform. Once crushed, the stone was sent to the mixing machinery located within the shaft. The stone, sand, and cement were dumped down the shaft and funneled into a rotating mixer held aloft by a wooden framework. The mixed concrete could be discharged directly into the steel skips and pushed along the tunnel to wherever it was needed.
The footings for the tunnel sidewalls were poured first. These footings extended approximately 18 inches into the tunnel from the sidewalls. Rails were laid upon this concrete base to carry a rolling platform or traveler. Three travelers were used: one to build the sidewalls, one to carry a derrick, and a third for forming the roof arch. The first wooden platform carried the wooden lagging or forms which shaped the sidewalls. This platform was rolled to where the sidewalls were to be constructed. The forms were placed, and the traveler secured against movement. Concrete was then shoveled between the rock and the form and the sidewalls were constructed. After the concrete hardened the form was moved forward, and the next section of sidewall was poured. After the sidewalls were constructed the derrick and the roof arch traveler advanced. The derrick moved between the sidewall and roof arch platforms, lifting the concrete into a position where workers could shovel it into the forms.
The roof arch traveler provided the forms for lining all of the tunnel above the previously constructed sidewalls. The roof arch forms were placed, then concrete was shoveled through the top of the form until the concrete on both sides reached the crown of the arch. Starting at the rear and working forward, the concrete was shoveled and rammed into the crown of the arch until the entire area behind the form was filled.
Accidents plagued section 4. On January 27, 1902, the first of a number of fatal accidents occurred. A large but undetermined quantity of dynamite, stored at the north end of the section (41st Street) exploded. Five persons were killed and a number of buildings extensively damaged by this explosion.114 Less than two months after the explosion on 41st Street, a severe rock slide occurred between 37th Street and 38th Street beneath Park Avenue in the east tunnel. The Engineering News reported the event:
During the night of March 19, about 65 feet in length of the east wall and the east part of the roof slid down into the drift partly filling it. An examination of the slide showed that a wedge shaped stratum broadest at the bottom had slipped down between the adjoining strata. The slip did not reach to the street surface, that is, the fallen rock had broken away from the rock above, leaving a cavity.
Immediately after this first disturbance of the rock the subcontractor concentrated his workforce and began shoring the undisturbed roof of the drift. This work was continued during the following day, March 20.
Despite this shoring, a wedge shaped crack parallel to the drift and near the west edge of its roof began to open. This crack extended up into the rock at an inclination of 45 degrees, and constantly increased until the morning of March 21, when the east half of the roof of the drift fell in crushing the supporting timbers. The slide extended to walls of the adjoining houses, causing them to fall in part. Steps were taken at once to shore up the house walls and prevent further falls of rock by discontinuing work and by all other means which suggested themselves. The total length of the tunnel affected by the rock slide was about 65 feet.115
The accident alarmed adjoining property owners and focused public attention of the hazards of subway construction. A vigorous campaign waged by property owners followed resulting in the Board's appointing a committee of engineers to investigate the cause of the accident and recommend action to insure against recurrence. The investigating committee consisted of five civil engineers, two appointed by property owners, one by the Board of Rapid Transit Commissioners, one by the Chief Engineer of the Commission, and William Parsons as Chief Engineer. The report of the engineers concluded that work could continue in the east and west tunnels provided their precautions were followed.116
Work was resumed in accordance with the recommendations of the engineering committee and safely pursued until June 17, 1902, when the final fatal accident on section 4 occurred. During an inspection tour accompanied by Chief Engineer Parsons, Ira A. Shaler, the sub-contractor of the section, was severely injured. Parsons' diary describes the accident.
With Rice, started with Shaler at 34th Street and went through the east tunnel. Examined the work and then examined the rock at the north end of the roof at 40th Street. Told Shaler I did not like the looks of it and he replied that it was perfectly safe, when all at once some rock fell, injuring him.117
Two weeks later, Ira Shaler died.
The second engineering. division included 4 sub-contract sections, numbers 5a and b, and 6a and b. Section 5 began at the center line of 41st Street and Park Avenue, extended north to 42nd Street, and curved west beneath 42nd Street. This section continued west under 42nd Street until it intersected with Broadway. At Broadway, the line turned north and continued up along Broadway to 47th Street. The center line of 47th Street marked the end of section 5a. Work on section 5a began on February 25, 1901. The start of work on this section was delayed by negotiations between the New York Central and Hudson River Railroad Company and the Board concerning a possible joint station at 42nd Street. When months of negotiation with the New York Central produced no agreement, work proceeded according to the original plans.
The terrain in section 5a consisted of a five to fifteen foot layer of densely packed earth over solid rock. The major problem in section 6a was the multitude of large sub-surface obstacles: 48 inch water pipes, sewer mains, and electrical conduits and the electric railway tracks running along, and intersecting with, 42nd Street. Two tracks ran along 42nd Street, while lines crossed it at Park, Sixth, and Broadway. Large buildings on both sides of the subway right of way also posed problems. A number of buildings along 42nd Street maintained underground vaults extending as far as eighteen feet into the projected path of the subway, as did the foundations of the elevated railway station at 42nd Street and Sixth Avenue. While the presence of so many varied surface structures made construction in section 5a difficult, the subway structure itself was not unusual. With the exception of a small portion at the eastern end of the section, where it emerged from the Park Avenue tunnel and curved west beneath 42nd Street, section 5a was the standard four-track, steel bent structure. Differing excavation techniques were used, depending upon the specific surface and sub-surface impediments encountered. The property under which the subway zig-zagged from Park Avenue and curved west below 42nd street was privately owned. This property was condemned, and the subway was built in an open cut. The section of subway between Park Avenue and Fifth Avenue included a station and a fifth track built for switching operations. Consequently, this section of the line was wider than most other portions of the standard four track line.
The depth of the excavation between Fifth and Sixth Avenues varied from 25 to 35 feet below the surface of the street. Generally between ten and twenty-seven feet of the excavation penetrated solid rock. In excavating this portion of section 5a, a 15-foot wide trench was dug longitudinally along the south side of 42nd Street. This trench was sheeted and braced in the usual manner, and then steelwork for a single track was erected. At frequent intervals, however, roof arches were left unturned so that the rubble from subsequent lateral excavations might be removed. Once this single track was completed, transverse drifts north below 42nd Street were begun. These lateral excavations were at the level of the subway roof and driven north approximately 20 feet, to a point where the third row of steel columns would be erected. After this drift was sheeted, 24 inch steel beams were inserted into the drift, one end lying on the roof of the subway and the other resting on the rock within the drift. With the underpinning securely in place, the space to be occupied by the subway structure was excavated, the structural steel erected, and the roof arches formed.
Naughton and Company constructed section 5b, from the center of 47th Street north beneath Broadway as far as 60th Street. Work began on September 20, 1900, mostly through rock with a shallow cover of earth, and with the additional problems of a double track electric street railway line running along the middle of Broadway, and a multitude of sub-surface pipes and sewers. The contractors first excavated the space between the curb and the streetcar line. Lateral excavations beneath the tracks, supported by wooden posts, permitted the construction of one half of the subway structure. After the pavement was restored over the completed half of the subway, the same method was used to construct the other half.
What made the work of section 5b unusual was the necessity of constructing the line beneath the 724 ton, 75 foot high monument to Christopher Columbus located at Broadway and 59th Street.119 The Columbus monument is a large granite statue carried upon a 50 foot high shaft. The shaft is mounted on a three-tiered pedestal. The foundation is a 45 foot square, 14 inch deep pad of concrete and brick masonry. The first step in building the subway under the monument was to sink two shafts, one each on the north and south sides of the monument's foundation. These two shafts were carried to a depth three feet below the foundation-line of the subway construction. A tunnel 6 feet wide and 7 feet high was driven from these two shafts out beneath the foundation of the monument. Upon the tunnel floor concrete was laid and 12 by 12 wooden columns were placed between the concrete floor and the foundation of the monument. With this temporary wooden underpinning in place, workmen built a solid masonry foundation. A large steel girder, resting on two wooden trestles, was then placed beneath the eastern edge and wedged tight against the monument's foundation. The relation of the completed subway structure and Columbus monument is most clearly defined in drawing 191.
Section 6a and b were awarded to sub-contractor William Bradley. The material excavated along this portion of the line consisted of a layer of earth and rubble covering rock. Section 6a and b differed considerably from the four track line constructed in sections one through five. The standard steel-frame, four-track structure was carried north in section 6 as far as 96th Street. Ninety feet north of 96th Street, the interior, or express, tracks descended and the exterior, or local, tracks ascended. Between 103rd and 104th Streets the express tracks swung east, passing beneath the uptown local track. The two tracks veering east at 103rd Street formed the east side line into the Bronx. The two exterior tracks, separated at 96th Street, continued north beneath Broadway. At 100th Street a third track was added to the two already coming up Broadway. This third track carried blocking which supported the street surface. Once these were in place and the street was sufficiently supported, the contractor excavated the rock and erected the columns and roof beams for another track. He repeated this procedure until the steel frame and roof for all four tracks was completed. This continued as far as 135th Street where a large storage yard was located.
In both 6a and 6b, open excavation was the predominant method of construction. The street railway tracks were supported on wooden truss bridges, as in section three.120
The east side line and engineering division 3 began with section 7, which curved east from Broadway under private property from 103rd Street and Central Park to Lenox Avenue and 110th Street. Section 7 was a double track tunnel through rock, except for a short portion of open cut. The contractor easily tunneled section 7, as the rock was solid mica schist, bearing little water. The contractor drove the tunnel using two shafts and one portal. The use of a portal was made possible by the abrupt sloping of a rock ridge into a deep ravine in Central Park. Mules pulled small railroad cars loaded with rubble to the shafts, where a heavy elevator hoisted the rock-laden cars to the surface. Work progressed rapidly because of two 8-hour shifts on the headings served by the shafts and one 8-hour shift on the portal heading. Approximately 100 feet of section 7 was built using open cut methods. Once the cut was excavated, a two track concrete arch was formed.121 Fallen rock and rubble was loaded by hand into the mule drawn cars, pulled beneath the traveler to the shaft-head, and removed to the surface.
Section 8 extended from 110th Street to 135th Street under Lenox Avenue. Two contractors, Farrell, Hopper and Company and John C. Rodgers built this section. Farrell, Hopper constructed the portion between 110th Street and 116th Street, sub-letting the portion between 116th Street and 135th Street to Rodgers. In section 8, the subway traveled in a two track, flat roof, reinforced concrete structure. The structure was located on the west side of Lenox Avenue, between the west curb and the street railway tracks that occupied the center of the avenue. Four stations were located within this section.
Section 8, built through sand and sand mixed with gravel, offered few serious difficulties. Much of the sand was of a high enough quality to be screened, washed, and used for mixing with concrete and mortar. Because of the width of Lenox Avenue, the relatively low level of development along this portion of the line, and the nature of the excavated material, no unique methods of construction were employed. The standard procedure was to sink a single trench to the foundation grade of the structure, brace and sheet the sidewalls, lay the concrete foundation, erect the steel, and concrete the roof all within this single trench.122
The only thing worthy of note in section 8 was the reliance upon mechanical devices different from those used for other sections. The location of the subway on one side of the avenue, and the absence of street railway tracks above the excavation, made for an easy job. Bridges were required at the intersection of cross streets, but these were of routine construction. The contractor could use a locomotive crane to handle the excavated material. This steam powered crane traveled on tracks laid on the street parallel to the excavation. The crane was used for removing the loaded skips and dumping them directly into horse drawn wagons. Along Rodgers' portion of section 8, overhead cableways of varied description were used to remove the material from the trench.123
As his job was the simplest, Rodgers completed it quickly, finishing a two and a half block long section of two track subway and resurfacing the avenue in 90 days. And even with delays in steel delivery, he completed a one-block section of subway in 36 days.124
Steep grades and cast iron tubes distinguished section 9 from the remainder of the Contract One rapid transit subway. The 8,000 feet of section 9 began at 135th Street and Lenox Avenue in Manhattan, ran under the Harlem River, and surfaced in the Bronx at Melrose Avenue. In the portions of this double track section not beneath the river, three types of construction, standard steel frame, reinforced concrete, and concrete arch, were used. Open excavation was permitted for the entire length of section 9 except, of course, for the Harlem River tunnel.
In tunneling the Harlem River, twin cast iron tubes were constructed. The two tubes were each 450 feet long with an interior diameter of fourteen feet, and were connected by a vertical cast iron diaphragm. The two tubes were surrounded by a layer of of concrete with a minimum thickness of one foot. The roof of the tubes was covered by a layer of concrete two and one-half feet thick. An order issued by the United States War Department required that the top of the subway tunnel be at least twenty feet below the tide level of the river.125 The grades approaching the Harlem River tunnel were a full three percent, the steepest anywhere along the Contract One right of way.146
An examination of the riverbed indicated the presence of a layer of clay of varying thickness lying above fine silt. The rock beneath the clay and silt dropped sharply at the west bank. The presence of clay, silt, and irregular rock assured the contractor of difficulty and danger should he proceed to drive the tunnel with a conventional shield. He suggested building a rectangular-shaped, submerged coffer dam extending from the shore to the middle of the river and within this caisson-like structure, excavating the rock and earth and constructing the tunnel one half at a time. The Chief Engineer of the Rapid Transit Commission agreed to permit this unique method of tunnel construction, and work on the Harlem River tunnel began from the west side of the river in June, 1901.
The first step was dredging a channel across the bottom of the river following the projected line of the tunnel. On both sides of this channel, working platforms, carried on piles, were constructed to house compressed air equipment and derricks. Contractor McBean described the remainder of the construction:
In this channel foundation piles and a row of specially prepared heavy timber sheeting, along each side and across the ends, were driven and cut-off to a true plane about 25 feet below the surface of the water. This sheeting forms the sides and ends of a pneumatic working chamber. For the roof of this chamber, a platform of timber, 40 inches in thickness and extending the full width and length of the tunnel section, was built and sunk and rested on the cut-off sheeting, which formed the sides and ends as above described. Simultaneously with pumping the water from under this roof compressed air was forced into the chamber under pressure corresponding to the pressure of the water above the roof. Inside this chamber the west half of the tunnel was built and then the timber roof was removed.127
While constructing the easterly portions of the tunnel, a number of modifications made the construction "simpler, safer, more expeditious and less costly."128 The sides of the east side compressed air caisson were prepared identically with those of the west side. However, the sheeting and pilings on the east chamber were cut twelve feet lower than those of the west side caisson. Contractor McBean explained the rationale for this change:
The top half of the tunnel will be built at the surface on pontoons, then launched and floated over the tunnel site and sunk into its final and true position, the outward flanges of it resting on the cut-off sheeting above described; then the top half of the tunnel will be used to form the roof of the pneumatic working chamber. In this chamber the foundation and bottom half of tunnel will be constructed, with the use of compressed air, thus dispensing with the timber roof as used in the first method and greatly decreasing the cost of the construction of the tunnel in many ways.129
Once the sections had been joined together beneath the water, a concrete lining was applied to the interior of the tunnel to protect the cast-iron rings. Heavy duty water pumps were installed to prevent any possibility of flooding.
Section 11 began at the center of 104th Street and continued north along Broadway to 125th Street. The original specifications for section 11 called for the line to be a standard steel, double track structure from the beginning of the section at 104th Street to 116th Street. Between 116th Street and 121st Street the structure was to be built as a concrete arch, double track tunnel. North of 121st Street the two tracks were to be partially built in an open cut, and as the terrain drops considerably, the northern portion between 122nd and 125th Streets was to be built between retaining walls on a masonry embankment. All work in section 11 was to be conducted in an open excavation.
With a terminal to be located between 135th and 145th Streets, the contractor suggested constructing a third track connecting the terminal area with the four tracks at 96th Street. The Board acknowledged the utility of having a third track for express trains geared for the direction of traffic, and authorized the construction of a third track between 135th Street and the junction of the east and west side lines, just south of 104th Street.130 The alteration of section 11 from a two track to a three track tunnel necessitated the demolition of a short piece of two track concrete arch already in place. While only 215 feet in length, the two track arch was "so strong... blasting had to be resorted to." The two track arch was replaced by a three track concrete, "polycentric roof arch" with an interior width of 37.5 feet.131
Section 13 began at 133rd Street and terminated at 181st Street, while section 14 began at this latter location and terminated at Hillside Avenue. The original sub-contractor abandoned the work prior to its completion and both sections were completed by McDonald. The unique feature of section 13 and 14 was that almost two and a half miles of the three and a quarter miles was built as a deep rock tunnel. In 1900, only the Hoosac tunnel in western Massachusetts possessed a longer unbroken rock roof than the deep tunnel driven through section 13 and 14.132
The short distance between 133rd and 134th Streets was part of the north side approach of the Manhattan Valley viaduct. This structure was an earthen fill between brick and granite retaining walls. The distance between the track and the street was greatest at 133rd Street and diminished in height as the street surface rose toward 134th Street. At 134th Street, the surface of the rails and the street was almost level. The street surface continued to rise and the subway gradually descended from this point so that at 135th Street the tracks were again beneath the street.
Near 135th Street the subway is close to the surface and traveled through the standard steel frame structure. Here the structure was built by open excavation through loam and sand with a small layer of rock at the lower depths.
Between 135th and 145th Streets there are three operating tracks for the subway and five parallel storage tracks, giving the line a width of eight tracks at this point. This steel frame portion was also constructed by open excavation. Because the width of the eight track yard necessitated using the entire area beneath Broadway, this section was built one-half or four tracks at a time.133
With the roof arches in place, backfill, broken rock from other sections of the excavation, was placed upon the structure with the use of an overhead cableway. After the backfilling was completed and the street resurfaced, construction of the other half of-the structure began. North of 145th Street the line was double track traveling through a concrete arch structure built in an open excavation.
Beginning at 150th Street, the street surface rose abruptly until peaked at 153rd Street and then descended rapidly again as it heads toward 157th Street. North of 157th Street there was another abrupt rise and the street surface remained high above the level of the subway until it dropped sharply at 191st Street and Fort George, and the subway, emerging from its rock tunnel, proceeded north on a viaduct. A small section of track, 1,112 feet in length was constructed in tunnel between 151st and 155th Streets. Another small portion between 155th and 158th Streets was built in an open excavation. This short portion was steel frame construction and included the 157th Street station.134
The major tunneling project was the over two-mile-long section between 158th Street and Fort George. The tunnel was driven from portals at either end and from two shafts, one each at 168th and 181st Streets.
This distance between the street and the subway at 168th and 181st Streets necessitated the use of elevators. The two shafts sunk here for driving the tunnel were designed to house these elevators and to serve as a part of the station. Because they were to be used after the completion of the tunnel excavation, the location and dimension of the two shafts was determined in accordance with the needs of both construction and subsequent operation. The two shafts were located sixty feet east of the center line of the tunnel. Top heading, the traditional method employed in driving tunnels in the United States, was used exclusively.136 Compressed air powered the drills used to bore the holes in which dynamite charges were placed. Forty holes were bored for each short section of tunnel fully excavated. The rock for this section was generally solid mica schist. However, a few short stretches (less than 500 feet) of soft rock were encountered. At 155th, 168th and Fort George, soft rock required permanent timbering between the rock and the concrete lining.
Blasted rock was hand loaded into buckets, and carried on 36-inch gauge railroad cars. The cars were pulled by mules to the shaft and hoisted to the street. The tunnel was completely lined with concrete. Traveling sidewall and roof arch forms, similar to those used in section 4, were used in both sections 13 and 14. Although the concrete for sections 13 and 14 was all machine mixed, workers shoveled it by hand into the sidewall and roof arch forms.137
As with section 11, the addition of a third track necessitated reconstructing a portion of the completed two track structure. In section 13, however, the steel frame structure and concrete retaining walls between 134th and 135th Streets were not demolished, but widened to accommodate three tracks.138 Separated from the remainder of the steel frame structure, heavy screw type jacks pushed the wall, on rollers, to its new location. Once the wall had been moved, an additional row of longitudinal bulb angle columns and roof beam spanning the additional track were erected.
Engineering division four consisted of three widely separated sections, number 10, 12, and 15, whose common denominator was their steel viaduct construction.
Section 12 begins at 125th Street and Broadway and continues north as far as 133rd Street. Section 12 contains the IRT's most visually impressive steel structures, the 168-foot steel arch spanning the broad depression known as Manhattan Valley. Three structures comprised the Manhattan Valley viaduct, the masonry approaches, the steel frame viaduct, and the center steel arch span. The subway approached the Manhattan Valley viaduct from both the north and the south on embankments formed by brick and granite retaining walls. As the slope toward Manhattan Street increased, steel viaducts assumed support of the track. This portion of the viaduct consists of double bent steel towers spanned by plate girders. Over Manhattan Street (125th Street), the road was carried by "three ribbed parabolic braced arches of 168.5 feet span flanked at each and by a double bent viaduct."139 The truss bracing of the arch ribs created fourteen panels of equal length, and from each panel point a column rose to carry the floor system upon which the track and station were built. The foundations for the viaduct were concrete capped with granite. The foundations for the arch itself were three parallel piers of concrete. These arch foundations were carried to a depth of thirty feet below the street surface.140
Since steel delivery was delayed, the contractors had to resort to an unusual method of erection. Instead of erecting the plate girder spans at both ends and then proceeding toward the middle of the structure, the contractor began at the north end of the structure erecting one span of the viaduct from the ground. Upon this single span, an erecting traveler was built and the succeeding spans set up in the traditional manner. Once the northern portion of the viaduct was completed and the steel for the southern portion delivered, the traveler was disassembled, moved to 125th Street, and the construction procedure was repeated from the southern end of the viaduct moving north. After all the viaduct spans were standing, construction of the arch began. Each arch was shipped in four sections. Two sections, one half of the arch span, were connected on the ground. With the traveler at the southern end and derricks on the north side, the two halves of the arch were lifted into place and riveted together at the center.
On the west side, section 15 carried the subway on a steel viaduct north from Fort George, across the Harlem River ship canal, and into the Bronx. The standard viaduct had steel columns carrying steel plate cross girders (transverse to the street), and longitudinal plate girder spans. Parsons provided additional details:
"This structure is supported by two rows of columns spaced 29 feet apart, so as to clear by a good margin the cars of the surface electric railway. The span between the columns varies from 40 feet to 87 feet, but is usually about 50 feet. The structure has been designed to carry as a live load motor cars with a length of 46 feet, and weighing 100,000 lbs.141
To assure that the viaduct possessed "great stiffness and rigidity," the specifications required cross bracing, and knee bracing "between the columns and cross girders and between the columns and outside longitudinal girders."142
In crossing the Harlem River ship canal, the engineers recommended replacing an existing highway bridge with one that would accommodate the highway, the two-track subway, and a two-track street railway line.
Section 10 was the northernmost portion of the east side route. The entire length of section 10 was above ground, carried on a steel viaduct located over public streets. The same combination of contractors responsible for constructing the Manhattan Valley Viaduct and section 15, E. P. Roberts, and Terry and Tench Company, handled the foundation construction and steel erection of the section 10 viaduct.144
In the Report of the Board of Rapid Transit Railroad Commissioners for 1902, chief Engineer Parsons declared: "No changes in design have been found necessary, so that the structure will be completed substantially as planned... "145 One area where changes were made was the design for the track. The contract specified,
... in the underground portions of the railway the track shall consist of rails on a continuous bearing of wooden blocks... The blocks are to be held in place by guard rails secured to metal cross ties embedded in concrete.146
In April, 1902, when construction had proceeded to a point where track laying could begin, contractor McDonald petitioned the Board of Rapid Transit to change the track specifications. McDonald proposed installing conventionally constructed track steel rails spiked to wooden crossties on a rock ballast surface.147 Parsons defended his specifications:
I believe that a form of track on the line as shown by the contract drawings would, in subway work, be superior to a ballasted track. I believe it would furnish a track with a better line and surface, one making less noise and furnishing the opportunity for the whole of the roadbed to be at all times inspected and kept clean.148
However, Parsons admitted, "that such a form of track is somewhat experimental, while on the other hand the track suggested by the contractor is one whose good points have been proved by many years of experience," and recommended accepting McDonald's proposed track. The panel concluded:
... superior advantages can be obtained from the ordinary standard type of track, including less noise, greater cleanliness, better distribution of loads, superior facilities for electric connections and the maintenance of proper relation of the third rail to the track, more elasticity, less complication at curves and switches and decreased cost of future maintenance and renewals.150
The Board subsequently permitted the use of conventionally constructed track in the subway.
Within months after Contract One was awarded to John B. McDonald, the Board of Rapid Transit Railroad Commissioners decided to extend the subway into Brooklyn. The Brooklyn extension began at the end of the two track mainline beneath Park Row and continued south beneath Broadway to South Ferry. Between South Ferry and Joralemon Street in Brooklyn, the two tracks of the Brooklyn extension are carried beneath the East River in two cast iron tubular tunnels. Once in Brooklyn, the line proceeded beneath Joralemon, Fulton, and Willoughby Streets to a terminal at Atlantic Avenue.
Contract Two specified that traffic upon the streets of lower Manhattan not be disrupted. Compliance with this specification required methods of construction differing from those used in Contract One. The contractor proposed replacing the pavement with a planked roadway and excavating beneath this temporary surface. Objections to this method arose from the fear that leakage from gas mains beneath the roadway and within the excavation would produce a devastating explosion. Elevating the pipes above the street permitted the contractor to plank the roadway and proceed with the excavation for the subway.151
Construction of the subway in front of Trinity Church posed the most delicate engineering problem of Contract Two. The 286 feet high Trinity Church spire rested upon a shallow masonry foundation built upon a deep layer of fine sand. This foundation was located nine feet laterally behind the exterior wall of the subway. The bottom of the spire foundation was nine feet below the street, fifteen feet higher than the twenty-four feet deep subway foundation. The fifty-seven feet of subway bordering the Trinity Church foundation was constructed in three sections. Steel channels were used as sheet piling around the subway excavation. These steel channels were left in place after the construction was completed to prevent settlement from voids created by removing the sheet piling. No "measurable movement of the spire"152 occurred during or after construction.
Section 2 consisted of the short stretch of two track subway from Bowling Green to South Ferry and the Battery Park turning loop. Section 2A was the twin tunnels between South Ferry and Brooklyn. The Brooklyn extension crossed under the East River in a pair of single track, cast-iron lined, tubular tunnels. These tunnels were parallel and about twenty-five feet apart. The two tubes each had a total length of 6,550 feet and an inside diameter of fifteen and half feet.153 The 3.1% gradients of the Brooklyn extension tunnels are slightly in excess of those in the Harlem River tunnel of the Contract One subway.154
The Contract Two tunnels were driven from double shafts sunk in both Manhattan and Brooklyn. From a shaft at South Ferry, the tunnels were pushed east while, simultaneously, two headings were driven west from a shaft sunk at Joralemon Street in Brooklyn. In driving the Contract Two tunnels, the top heading sequence of excavation was used exclusively. Twelve by fourteen inch timber beams, set five feet apart, carried the heavy sheeting supporting the roof prior to the erection of the cast iron line.
The initial tunneling east from South Ferry was through rock, so no tunnel shield was required. Shields were required by the sand encountered in tunneling west from Brooklyn. All four headings were driven within a pressurized environment. After the headings had been driven approximately 100 feet, two thick brick walls were constructed, with an air locks between them. A thirty-six inch diameter upper lock provided workmen with access to the heading, while a lower lock allowed narrow gauge dump cars to be pulled by a steel cable between the heading and the shaft. Once at the shaft, the excavation bins carried by the cars were hoisted to the surface and emptied.155
Compressed air powered the rock drills, cast-iron lining erector, and grouting machines. Electric lights illuminated the tunnels. Assembling the cast iron lining required the use of a hydraulic lining erector. The erector, "a traveling platform provided with an extensible radial arm pivoting in the tunnel axis and revolving at right angles," was powered by a compressed air motor and traveled on rails affixed to the side of the previously erected lining. Once in position, at the end of the last complete circle of cast iron plates, the radial arm would life a 900 pound plate and pivot it into the proper position. A hydraulic ram contained within the arm would thrust the ring outward so workmen could bolt it to the already assembled lining. One man operated the device and three others assembled the lining. A grouting machine followed the lining erector. Compressed air forced the grout, a mixture of one part sand and one part Portland cement, through small holes in the lining plates and into the space between the cast iron and the irregularly excavated rock. Threaded plugs were screwed into these small diameter holes to complete the lining of the tunnel.156
Section 3 of the Brooklyn extension relied heavily upon reinforced concrete construction. The concrete floor in section 3 is like that of the Manhattan portion of the subway, a thick slab of unreinforced concrete. The walls and roof of the Brooklyn extension, however, are primarily constructed of reinforced concrete and lack steel columns, beams, and girders, except where excessively heavy surface loads were encountered, such as where the subway traveled beneath an elevated railway line. Beneath the columns of the elevated structure, the subway was constructed of "heavy riveted wall and center columns and deep roof beams, girders, and distributing grillages, all of which were completely enclosed in thick masses of concrete."157 Occasionally, standard bulb angle columns, spaced five feet apart, were used to help support lesser loads. The bulb angle columns found in the Brooklyn extension, like those used in the Lenox Avenue portion of the Manhattan subway, are embedded in the concrete floor and connected to the horizontal reinforcing rods in the concrete roof.158
The presence of both streetcar lines and an elevated railway structure made portions of the Brooklyn extension as difficult to construct as any section found in lower Manhattan. In Brooklyn, it was necessary to maintain the street surface, and to underpin a heavy elevated railway structure. The Brooklyn extension also differed from its Manhattan counterpart in its methods of excavation. Like the subway construction in Manhattan, the first parts of the excavation were made solely with "pick and shovel."159 In section 5 of the Contract Two subway, however, mechanical devices materially sped the removal of rubble. Earth and rubble were shoveled into a hopper which funneled the material onto a series of twenty-four foot long conveyor belts which carried the materials away from the excavation. The belts discharged the spoil into cubic yard buckets carried on narrow gauge railway cars running within the excavation. The cars were pulled along the trench to a point where a hoisting engine lifted the buckets of spoil to the surface and dumped them into gondola cars of the Brooklyn Rapid Transit Company. The street railway line, operating above the subway excavation, transported the cars to a marshy disposal site located off the Brooklyn Company's main line.160
Although strikes and accidents disrupted the construction of the Contract One and Two subway, neither materially affected the progress or completion of either project. The contract repeatedly specified that the work was to be done by "skilled workmen." Unlike the construction force, easily recruited from the local population of workmen, the men needed for tunneling, blasting, and hard rock excavating came largely from outside the New York City area. A New York Times article, "Miners Flock to New York," reported, "never until the last twelve months has New York been a mecca for miners."161
More than 500 men worked on the deep rock tunnel in sections 13 and 14, over 400 were members of the Miners Union and, "mostly foreign." Italians, Scandinavians, and Irishmen worked beside foremen fresh from supervising the construction of railroad tunnels in Colorado; Pennsylvanians, relics of many strikes, and full of yarns from the coal mines; and "Klondikers, boasting of gold they have found and lost again."162
The sub-contractors banded together and formed the Rapid Transit Railroad Contractors' Association to formulate a common policy for negotiating with labor. The Rapid Transit Railroad Contractors' Association required all workers seeking employment to sign an employment card, designed as a "guarantee to the sub-contractor against future demands by the men."163 The cards read:
The undersigned, a citizen of the United States, hereby applies for employment as _________ in the work of constructing the rapid transit railroad in the City of New York, for the compensation of $ ________ per day, which he represents to be the prevailing rate for a days work in said occupation in the City of New York. In consideration of which application and representation, _________________ hereby employs the undersigned in said capacity at the rate above specified until further notice.164
The introduction of the cards provoked a "storm of criticism." Workmen feared that by signing the cards they allowed the contractors to pay them less than the union rate.165
In March, 1901, the New York Supreme Court declared the "prevailing rate of wage" law unconstitutional. With this decision, the Rapid Transit Railroad Contractors' Association withdrew the cards. Harry Seaman, the engineer for sub-contractor Holbrook, Cabot, and Daly, asserted: "The decision of the Court ... no longer binds us to pay the prevailing rates of wages, which, by the way, was not necessarily the union wage..."166 Engineer Seaman had not only confirmed the workmens' fears that signing the cards permitted the employment of men at wages below union scale, but also raised the spector that without the cards wages would be even less. Seaman suggested that if the unions would avoid disruptive confrontations and refrain from striking, the contractor would most likely continue paying the existing wages and not implement reductions.167 He was less conciliatory when discussing the eight hour day.
I believe, and all other contractors I think are with me, that the decision ought to apply to the 8 hour law and that this law will also be declared unconstitutional. It works a hardship to industrious men who want to work overtime. We dare not employ them overtime, though sometimes it would be a great convenience without violating the law.168
During the height of construction, over 7,770 men were employed.169 A multitude of local unions represented the skilled workers. The majority of the unions were affiliated with the Central Confederation of Labor Unions. The Central Federation coordinated the political and negotiating activities of many New York City trade unions. In 1900, before construction began, the Central Federation urged the vigorous enforcement of the law prohibiting the employment of aliens on public works projects. The Federation argued that if aliens were permitted to obtain employment, they would, "work for the lowest wages possible, while our own American working men go about starving."170
The Central Federation sought to act as the voice of all the organized trades involved in subway construction and entered into negotiations with the Rapid Transit Railroad Contractors' Association to obtain an all-inclusive agreement on wages and hours.
A strike precipitated by rock drillers in section 5 led to the subsequent agreement between the Central Confederation of Labor Unions and the Rapid Transit Railroad Contractors' Association. On May 22, 1901, rock drillers employed by Naughton and Company walked off the job in sympathy with other drillers striking against Naughton and Company on an outside contract. The rock drillers demanded the contractor pay all his workers the same wages as the rapid transit construction workers. Strict compliance with the eight-hour day and raises to 25 cents per hour for hoist operators were added demands.171
The Central Federation demanded that all men working on the rapid transit subway be members of the trade unions that it represented.172 Confident that the work was far enough ahead of schedule that the contractors could remain inactive without failing to complete the project on time, the Contractors' Association offered only to arbitrate the demands of the Central Federation, ignoring those of the Naughton workers.173
Within a week, a tentative agreement between the Federation of Labor Unions and the Contractors' Association was reached. The Central Federation agreed to drop the rock drillers insistence on the unionization of outside contracts, and accept the arbitration of the hoist operators wages. The Central Federation announced that if the Contractors' Association would, "sign the agreement calling for union wages and an 8-hour day on all rapid transit operations, we will instruct our members to return to work."174 Negotiations over the refusal of two contractors to discharge non-union workmen hired to replace strikers temporarily delayed the formal acceptance of the two year agreement.175
The existence of an agreement between the Central Federation and the Contractors' Association did not assure tranquility. The Housesmiths and Bridgemans Union, neither a member of the Central Federation or a party to the agreement with the contractors, was the alleged source of a number of violent acts against sub-contractors.
The Holbrook, Cabot, and Daly Company employed union and non-union workmen on their section of the subway and "prevailing wages were paid to all." The engineer for Holbrook, Cabot, and Daly charged that between December, 1900, and September, 1901, the Housesmiths and Bridgemans Union "frequently attacked their non-union ironworkers and company."176 The Degnon-McLean Company, the sub-contractor for sections 1, 2, and 5a, also experienced "similar troubles" with the same union.177
The actions of the Housesmiths and Bridgemans Union, however were not exclusively directed against the contractors. In May, 1902, ironworkers represented by the Housesmiths and Bridgemans Union struck their employer, Terry and Tench Company, the specialty sub-contractor assigned most of the structural steel erection all along the route. The strike came amidst Terry and Tench's attempt to abandon their contract after allegedly suffering financial losses in sections 1 through 4. The Company argued,
The engineers were too exacting with the iron-workers. They made them do the work two and three times over sometimes. As we had to pay extra wages for this it was a continued loss and finally we had to give up the contract.178
Unlike Holbrook, Cabot, and Daly, Terry and Tench's relations with the Housesmith and Bridgemans Union were amicable. A spokesman for the Company reported: "We have been paying union wages all along and had no trouble with the Union." The spokesman concluded that the strike might have been motivated by the Union's desire to see Terry and Tench keep their contract under more rewarding terms.179
The employment of non-union men alongside of union men, and the introduction of new building materials also provoked strikes and the threat of strikes. In March, 1902, the threat of a strike by the Bricklayers and Masons International Union of America was resolved by an agreement between the union and the contractor limiting the use of concrete in the construction of the 59th Street power house. "Under this agreement, a new power house, which was to have been constructed altogether of concrete, will be built of brick, and enameled brick will be used at the stations instead of stucco tile."180
In January, 1904, tilesetters struck in section 3 against the use of non-union men at the 18th Street Station. The company employing the four men argued that its patented process for affixing the tiles necessitated the use of these non-union specialists. The Central Federation of Labor Unions used this issue to call attention to the fact that other, larger sub-contractors employed non-union labor. Since the original agreement between the Central Federation and the Contractors' Association did not cover the installation of equipment by specialty sub-contractors, the completion of the subway generated a confrontation between workmen and contractors over the use of non-union workmen by the sub-contractors installing electrical and mechanical equipment in the 59th Street power house. The use of non-union workmen by Allis-Chalmers, General Electric, and Westinghouse all brought about the threat of a general strike all along the subway.181
These three companies claimed that the installation of the switchboards and steam generators required the use of the non-union company specialists. The unions countered that at the very least the company men, "ought to belong to our union," and that there were in fact, "plenty of people in our union who could do the work."182 Immediate negotiations and the promise of compromise by the sub-contractors avoided a strike.183
With the subway between City Hall and 125th Street poised for opening, a dispute with the bricklayers union erupted. The dispute offered little actual threat of delaying the completion of the subway, but it did prevent the general contractor from announcing the commencement of trial runs. The bricklayers indicated that they intended to strike for an additional 10 cents an hour as soon as the opening of the subway was announced. The contractor delayed scheduling trial runs until work had advanced to a point where he was confident that a bricklayers' strike would not impede the inauguration of operation.184
Accidents during the construction of the Contract One and Two subway claimed the lives of at least 54 workmen and bystanders and injured at least 300 others.185 The largest single accident occurred in 1903 on section 14. While the deep rock tunnel beneath 195th Street was being driven, a large mass of rock fell upon a group of tunnel laborers, killing ten and injuring another dozen. Earlier, in 1901, a block of rock weighing over 150 tons dropped from the roof of the tunnel at 164th Street and killed 5 workmen.186 Commenting on the accidents at 195th Street, the Engineering Record editorialized:
"Although the accident resulted in the death or injury of oven a dozen men, it seems entirely wrong to ascribe it to any lack of care on the part of the contractor and the engineer. Tunneling in heavy rock is always a hazardous undertaking. These who take part in it do so at their peril, even when every means to avoid an accident is taken."187
On October 24, 1904, the Interborough Rapid Transit Company carried the first fare paying passengers between the stations at City Hall and 125th Street. After a decade of serious planning and another four and a half years of difficult construction, New York City finally possessed a subway. While the Interborough Rapid Transit Company was not the first electrically propelled urban underground railway, it was the prototype for a new dimension in urban transit. The IRT represented true rapid transit, electrically propelled cars running on an exclusive right of way, provided local and express service and avoided the impediments to speed that plagued surface transit.
The construction of the Interborough was also innovative. Steel frame and masonry construction had been used throughout Europe and in Boston prior to its use in the IRT. The use, however, of reinforced concrete, relatively sparse in Contract I, but extensive in Contract II, demonstrated the economy, practicality, and adaptability of this construction for underground rapid transit railway structures. Primarily because of the construction of the New York transit subway, the advisability and advantages of reinforced concrete were "so complete and so well understood," that by 1909, reinforced concrete had become "indispensable" for rapid transit railway construction.188 Likewise, on site construction of concrete sewers was first used in reconstructing sewers displaced by the IRT right of way. The experiments with concrete sewers, "gave such satisfactory results that the principle has been extended to other sewers in a similar manner during the year, except that instead of building the arch of brick, as was done at first, the whole sewer in many cases has been built of concrete."189 However, more than the evolution of concrete construction technology was hastened by the building of the IRT. Differences between the methods and rapidity of Contract I and Contract II construction spotlight the advances first made by the IRT which were later applied to general urban railway engineering. While the cut and cover method of construction used extensively in building the Interborough remains the basic method of urban subway construction, refinements in the procedure have reduced the disruption to the surface "while increasing the rapidity of construction."190 Chief Engineer Parsons, in his 1904 "Report" revealed:
... much more rapid progress has been made on Contract II than on Contract I due to the experience gained on the latter. This was accomplished in spite of the more rigid requirements of the specifications of Contract II, calling for the maintenance of the street surface from curb to curb during construction.191
Experience gained in excavating for the Contract I right of way provided the engineers with the basis for techniques that improved the rapidity of the Contract II excavation. Along Broadway, planking the full width of the avenue permitted the uninterrupted excavation and construction of the Contract II right of way with the absolute minimum of disruption to the surface traffic. Mechanization of the excavating, the use of electrically powered conveyors within the trench and, in Brooklyn, the use of streetcars to remove large quantities of excavated materials, gives credence to engineering historian James K. Finch's assertion:
To those who recall the building of the first New York subway in 1900-1904 this evolution in methods is particularly striking. "Parsons' ditch" was an open-cut job using hand labor, horse drawn carts, and steam hoists and drills. Street crossings were provided for by temporary wood bridges spanning the cut where, in long sections of open excavation, man and beast toiled with earth and rock. The later extension in lower New York of this first subway marked the change to a complete planking over the streets. Under similar decking with little disturbance to traffic, power shovels and motor trucks have excavated the more recent maze of subways which serve the city.192
The attention to every detail which characterized the planning and construction of the Contract I subway assured its successful completion and operation. The success of Contract I and the subsequent rapidity of the Contract II construction provided the foundation for the assertion made by the Chief Engineer in concluding his 1906 "Report":
The years 1905 and 1906 may be regarded as an epoch in the history of rapid transit, looking to construction of future subways on so extensive a scale as to have been hardly conceivable a few years ago, or never contemplated within the past decade.193
1. Engineering News and American Contract Journal, II, #14, October 24, 1885, p. 226.
2. "Memoir of William Barclay Parsons," Transactions of the American Society of Civil Engineers, vol 98, 1932, p. 1485. "William Barclay Parsons," The World's Work, VI, #1, May 1903, pp. 34, 67-68.
3. Engineering News and American Contract Journal, XVI, October 16, 1886, p. 251.
4. Engineering News, XVIII, May 21, 1887, p. 336.
5. "Memoir of William Barclay Parsons," p. 1485.
6. Letter of May 2, 1888 to William B. Parsons from Abram Hewitt, Letterpress Book, Mayoral Correspondence, three volumes, New York Historical Society.
7. "Memoir of William Barclay Parsons," p. 1486; "The New York Rapid Transit Railway: Six Years Labor for Municipal Rapid Transit," Engineering News, XLVII, #6, February 6, 1902, p. 106; "William Barclay Parsons," The World's Work, VI, #1, May, 1903, p. 3468.
8. New York Times, January 30, 1894; see also, New York Times, January 4, 8, 14, 15, 19, 24, 29 for other testimony.
9. "William Barclay Parsons," p. 3468-70.
10. "Memoir of William Barclay Parsons," p. 1486.
12. Ibid., p. 1486-91.
13. David Noble, American By Design: Science, Technology, and The Rise of Corporate Capitalism, (New York: Alfred A. Knopf, 1977), p. 35.
14. The early years of civil engineering are treated in Daniel H. Calhoun's The American Civil Engineer, Origins and Conflict, (Cambridge, Mass: 1960). Calhoun feels that civil engineering crystallized early in the 19th century, and only well before the Civil War can one detect organization and roles significantly different from those of the modern period. See his Preface, pp. v-xii. Raymond A. Merritt, Engineering in American Society: 1850-1875, (University of Kentucky Press, 1969), stresses the civil engineers' professed social awareness, civic-mindedness, and cosmopolitan attitudes with a strong sense of social service. Specific examples are found in Merritt, pages 8-9, 131-150, 157-176.
15. See section 1 of this report.
16. James K. Finch, Engineering and Western Civilization, (New York: McGraw Hill, 1951), p. 231-234.
17. William Barclay Parsons, "Rapid Transit in Great Cities, address delivered at Purdue University, March 13, 1905," (hereafter cited as "RTGC"), p. 2. Parsons wrote, "The mistakes of the practical man, pardonable in small things, are too costly."
19. Ibid., p. 22.
20. See Merritt, p. 7-8. He suggests that civil engineers generally tended to be anti-competition. See also Monte A. Calvert, The Mechanical Engineer in America: 1830-1910, (Baltimore, 1967). Calvert writes, "By the turn of the century, educators and publicists were suggesting that the engineer was especially fit to deal with the problems of society," p. 269. Calvert stresses that civil engineers felt this far more acutely than did mechanical engineers, who shied away from the "large role" in society.
21. Benjamin Harrod, "Address to the Annual Convention," June 30, 1897, A.S.C.E. Transactions, XXXVII (1897), p. 539-41, cited in Merritt, 206; H. G. Prout, address reprinted as "The Engineer and His Country," Wisconsin Engineer, III (January, 1899), p. 77-78, cited in Calvert, p. 269; George S. Morrison, "The New Epoch As Developed by the Manufacture of Power," (New York, 1903), p. 93, cited in Merritt, 61; Morrison's 1895 presidential address to the A.S.C.E., Transactions, XXXIII, (1895), p. 483, cited in Calvert, 199; Charles F. Scott, "The Young Engineer," The Electric Club Journal (May, 1904). p. 198-204.
22. Calvert writes that the interest of many civil engineers in urban planning and reform resulted in the late 19th century visions of a "sort of technocratic system," p. 206, staffed by engineer administrators.
23. See Board of Rapid Transit Railroad Commissioners, Report 1900-1901, 185-186; also New York Times, January 8, 1896, p. 4-5. This theme, the Board's special notion of rapid transit, will be explored in greater detail in the electrical introduction.
24. Parsons, "RTGC," p. 2.
25. Parsons, Rapid Transit in Foreign Cities, (hereafter cited as "RTFC"), 1894.
26. See "Report of the Chief Engineer," contained each year in the annual Board of Transit Railroad Commissioners Report. Details of the work of the Inspection Bureau appear in 1900-1901, p; 252-258; 1902, p. 284-292; 1903, 188-197, 1904, p. 303-315; 1905, p. 166-175; 1906, 232-243; see also, "The New York Rapid Transit Railway: Inspection of Cement," Engineering News, XLVIII, #13, September 25, 1903, 242-244.
27. "Contract between the Board of Rapid Transit Railroad Commissioners and John B. McDonald, Agreement for Construction," 1899.
28. "Report of the Chief Engineer, 1900-1901," p. 209.
30. Calvert notes, page 52, that by the 1890s the "education of engineers was becoming a profession on itself." He was discussing, of course, mechanical engineering primarily. However, while practical experience was undoubtedly valued in engineering instruction, the time was past when virtually the only "schools" for civil engineers were the great public works. See Calhoun, p. 25-53.
31. "Report of the Chief Engineer, 1900-01," p. 208, contains a "Table of Engineering Staff Education Statistics." Among schools with more than one graduates, the breakdown was as follows: Columbia, 27; Harvard, 10; Cornell, 9; Cooper-Union, 5: Rensselaer, 5; M.I.T., 4; Union, 4; Lehigh, 4; and Yale, 3. Of the 45 graduates among the rodmen and axmen of the surveying staff, 19 were from Cooper-Union.
32. (missing from original, but presumably refers to "Table of Engineering Staff Education Statistics.")
33. Technology Review, 4 (April, 1902); National Cyclopedia of American Biography (hereafter cited as "NCAB"), v. 14 (New York: 1910), 145-146.
34. New York Times, October 28, 1904, in August Belmont's scrapbook, Museum of the City of New York. Six of the 38, excluding the four mechanical engineers, had "Memoirs" in the Transactions of the A.S.C.E., five of them were graduates. Schools represented were Stevens, Rensselaer, Union. It does not seem justifiable, however, to generalize about the educational background of the Construction Company's engineering staff from this data.
35. "New York's Great Underground Railway", The Tramway and Railway World, v. 16 (November 10, 1904), p. 447-464. The article states that Belmont had a great deal to do with the selection of subordinates and engineers.
36. New York Times, October 28, 1904; August Belmont scrapbook, Museum of the City of New York; biographical information on Bryan in NCAB, v.11 (New York: 1901, 1904), p. 283.
37. NCAB, v. 24 (New York: 1940), p. 204-205.
38. See Harold C. Passer, The Electrical Manufacturers, (Cambridge, Mass.: 1953), pp. 276-295, for a discussion of the Westinghouse commitment to alternating current and the significance of the Niagara project.
39. NCAB, v. 14 (New York: 1910), 520-521.
40. NCAB, v. E, (New York, 1938), 120-121; see also Samuel S. Watkins, George Gibbs, [....] supplement 2, (New York: 1958), p. 231-232. Further information on both Stillwell's and Gibbs contribution will appear below in discussions of the power house and rolling stock.
1. T. C. Baker and Michael Robbins, A History of London Transport, (London: Allen and Unwin), pp 113-115.
2. Ibid., and New York Times, October, 14, 1866.
3. Parsons, Rapid Transit in Foreign Cities, p. 8.
4. Ibid., p. 11.
5. Ibid., p. 10. Parsons described the condensing type steam locomotive as one in which, "the steam instead of being blown through the stack, as in done in the ordinary locomotive, is conveyed back into a water tank and there condensed, so that although the smoke and the products of combustion are allowed to escape into the air, exhaust steam is not, and the air is thus kept drier and less disagreeable than it would be if the ordinary type of locomotive were used."
6. "Report of the Chief Engineer," p. 186, in Report of the Board of Rapid Transit Railroad Commissioners for the year ending December 31, 1900, (New York, 1901).
7. New York Times, April 7, 1864, p.8.
9. New York Times, December 27, 1865, p.8.
10. New York Times, January 29, 1866, p. 2.
11. New York Times, December 27, 1865, p.8.
13. New York Times, February 4, 1866, p. 5.
14. New York Times, March 26, 1866, p. 2.
15. New York Times, January 23, 1866, p. 2.
18. New York Times, October 6, 1868, p 4; see also Sanitary Engineer, July 16, 1886, Vol. 4, #7, p. 153.
19. New York Times, July 8, 1859, p. 5.
20. New York Times, October 6, 1868, p. 4.
21. New York Times, November 29, 1869, p. 2.
23. New York Times, February 18, 1869, p. 4.
24. New York Times, January 1, 1868, p. 2.
25. New York Times, April 2, 1868, p. 2.
26. New York Times, March 21, 1870, p. 2.
28. Robert M. Vogel, "Tunnel Engineering: A Museum Treatment," Paper 41, United States National Museum Bulletin, v. 240, (Washington, D.C.: Smithsonian Institution, 1964), pp. 227-231; "Early History of Rapid Transit Enterprises in New York City," Engineering News, Vol. XLVII, #5, January 30, 1902, p. 83-84.
30. Some of the proposals presented before the Committee appear in the New York Times, October 23, 1874, p. 3.
31. "Report of the Committee on Rapid Transit and Freight Terminal Facilities", Transactions of the American Society of Civil Engineers, Vol. IV, 1875, New York.
32. New York Times, September 24, 1875, p. 8.
33. New York Times, September 6, 1880, p. 5., New York Times, September 15, 1880, p. 8.
34. New York Times, August 7, 1884, p. 9.
35. Engineering News and American Contract Journal, September 5, 1885, Vol. 14, p. 158.
36. New York Times, December 29, 1885, p. 8. For a cross section and an illustration of the proposed road see "New York District Railway," Engineering News and American Contract Journal, January 2, 1886, p. 15.
38. Sanitary Engineer, January 28, 1886, Vol, 13, #9, p. 199.
40. New York Times, March 18, 1888, p. 1.
41. New York Times, April 8, 1888, p. 10.
44. William B. Parsons, "Rapid Transit in Foreign Cities," (hereafter cited as "RTFC"), provides the most concise descriptions of the transit lines constructed in Liverpool, London, Glasgow, and Paris. "Rapid Transit in Great Cities," (RTGC), pages 6-12, offers a brief comparative description of these systems plus the Budapest underground railway.
45. Parsons, "RTFC," p. 12-17.
46. Ibid., p. 18-20.
47. Ibid., 22-23.
48. Ibid., 25.
49. Ibid., 25-28.
50. Ibid., 36-37, 39.
51. Ibid., 44-46.
52. Ibid., 46.
53. Ibid., 49-50.
54. Parsons, "RTGC," p. 10-11.
55. Parsons, "RTFC," p. 51-53. Additional information on the construction and operation of the Baltimore Belt Railroad Tunnel is contained in Engineering News, December 12, and 19, 1891; January 9 and 16, and May 8, l893.
56. Ibid., 53-55.
57. Parsons, "RTGC," 6.
58. Parsons, "RTFC," 59.
59. Ibid., 50, 56-57.
60. William B. Parsons, "Borings in Broadway, New York," Transactions of the American Society of Civil Engineers, XXVII, January, 1893; see also, "Borings for Rock Along Broadway," Engineering News, July 18, 1891.
61. "The Report of the Rapid Transit Commission Engineers," Engineering News, October 10, 1891, 341-344.
63. Ibid., 341-342.
64. Ibid., 342.
67. "The Plans for the New York City Rapid Transit Railways", Engineering News, October 24, 1891, 389-393; see also, "New York's Rapid Transit Problem," Engineering Record, Vol 24, #19, October 10, 1891, 299-300; "Rapid Transit for New York," Engineering Record, vol. 24, #21, October 24, 1891, 334-335; "New York's Rapid Transit Plans," Engineering Record, vol 26, #21, October 22, 1892, 321-2; "New York Underground Rapid Transit Plans," Engineering Record, vol, 26, November 26, 1902, 411-414, "The Rene System of Tunneling for Rapid Transit," Engineering News, February 27, 1892, 204-205.
68. "The Report of the Rapid Transit Commission Engineers," Engineering News, October 10, 1891, 344-345.
69. "The New York Rapid Transit Railway: Six Years Labor for Municipal Rapid Transit," Engineering News; XLVII, #6, February 6, 1902, 106; see also, "The Latest Plan for A New York Rapid Transit Railway," Engineering News, XXXII, #26, December 27, 1894, 537-538.
70. "The New York Rapid Transit Railway: Six Years Labor for Municipal Rapid Transit," Engineering News, XLVII, #6, February 6, 1902, 106.
72. "Report on the Modified Routes for the New York Rapid Transit Railway," Engineering News, XXXVI, #20, November 12, 1896, 309; see also, "New York City Rapid Transit Report," Engineering Record, vol 34, #24, November 14, 1896, p. 440.
73. Ibid., p. 106-107.
74. "Report of the Chief Engineer, 1900-01," p. 29.
76. Ibid.; see also, "Report on the Modified Routes for the New York Rapid Transit Railway," Engineering News, XXXVI, #20, November 12, 1896, 309-311.
77. "Report of the Chief Engineer, 1900-01," p. 30; see also, "New York Rapid Transit Outlook," Engineering Record, XXXVI, #24, November 13, 1897; "The Supreme Court Commission Report on New York's Rapid Transit Railway," Engineering News, XXXV, #11, March 1.2, 1896, 173-1744 "The Outlook for Rapid Transit in New York City," Engineering News, XXXV, #22, May 28, 1896.
78. "Report of the Chief Engineer, 1900-01," p. 30.
79. Ibid., p. 195.
80. "The Contract for the New York Rapid Transit Railway," Engineering News, November 23, 1899. XLII, #21, November 21, 1899.
81. Ibid.; see also Engineering Record, Vol. 40, #22, November 23, 1899, p. 498.
82. "Memoir of Arthur Onderdonk," Transactions of the American Society of Civil Engineers [....]
83. "Report of the Chief Engineer, 1900-01," 196-197; information on John B. McDonald obtained from The World's Work, December, 1902; NCAB, vol 5, (New York: 1907), 481-482.
84. "Report of the Chief Engineer, 1900-01," p. 226.
85. Ibid., 209; "Report of the Chief Engineer, 1904," p. 231.
86. See "Report of the Chief Engineer, 1900-01," pp. 213-220, for a list of the contractors employed to reconstruct sewers.
87. "Contract and Quantities in the New York Rapid Transit Railway Work," Engineering News, XLIII, #21, May 24, 1900.
88. "Contract Between the New York City Board of Rapid Transit Railroad Commissioners and John B. McDonald," Agreement for Construction Specifications, pp. 67-161; see also, "New York Rapid Transit Railway: Contract and Specifications," Engineering News, XLVII, #7, February 13, 1902, p. 127-129; "New York Rapid Transit Railway: General Description of the Work," Engineering News, XLVII, #8, February 20, 1902, 161-163.
89. "Agreement for Construction: Specifications," p. 74.
90. "Report of the Chief Engineer, 1900-01," p. 188.
91. Parsons, "RTGC," 11; "Progress of the Boston Subway," Engineering News, XXXVII, #5, February 4, 1897, p. 76-78.
92. "Report of the Chief Engineer, 1900-01," p. 191-193.
93. Ibid., p. 193.
94. Interborough Rapid Transit, The New York Subway, 1904, p. 38.
95. Gilbert H. Gilbert, The Subways and Tunnels of New York, (New York: 1912), p. 18; General descriptions of the construction of the subway are provided by M. G. Gunniff, "The New York Subway," The World's Work, VIII, #6, October, 1904; "General Structural Details of the New York Rapid Transit Tunnel Railway," Engineering News, XLII, #24, December 14, 1899, 380-382; Frank W. Skinner, "Difficult Engineering in the Subway," Century, October, 1902, p. 908-911; Interborough Rapid Transit, The New York Subway, (New York: 1904), "Chapter II, Types and Methods of Construction," p. 39-66.
96. "Report of the Chief Engineer, 1900-01," p. 189.
97. Ibid., p. 199.
98. Ibid., p. 193.
99. "The New York Rapid Transit Railway: Sewer Division," Engineering News, XLVII, #12, March 6, 1902, 199-200.
100. "Agreement for Construction: Specifications, Section 17, Sewers," 110-127; "New York Rapid Transit Railway: Sewer Division," Engineering News, XLVII, #12, March 6, 1902, 99-200.
101. Ibid., p. 201.
102. "New York Rapid Transit Railway: Sewer Division", Engineering News, XLVII, March 20, 1902, p. 236-238; "Report of the Chief Engineer, 1900-01," p. 221.
103. Ibid., 222; see also, "Sewer Reconstruction in New York," Engineering Record, Vol. 44, #1, July 6, 1901, p. 12.
104. "Report of the Chief Engineer, 1900-01," 22-225; "The Contractor's Power Plants on the New York Rapid Transit Railroad," Engineering Record, Vol. 44, #5, August 3, 1901, p. 102-106.
105. "The Construction of Section I, New York Rapid Transit Railroad," Engineering Record, Vol. 51, #10, March 11, 1905, p. 291; "Report of the Chief Engineer, 1900-01," p. 226.
106. "New York Rapid Transit Railway: Contract Sections 1 and 2," Engineering News, XVII #15, April 17, 1902, p. 318-320; "Report of the Chief Engineer, 1900-01," p. 227.
107. Ibid., p. 227-228.
108. Ibid.,. p. 229-230.
109. Ibid., p. 230; "New York Rapid Transit Railway: Contract Section 3," Engineering News, XLVII, #19, May 8, 1902, p. 374-377; "Section Third of the New York Rapid Transit Subway," Engineering Record; vol 43, #2, 1901, pp. 32-33. The early use of "needle beams" permitting excavation without disruption of the street surface is detailed in "Tunneling Use of Steel Needles in Driving a Tunnel at Kings Cross, London," Transactions of the Society of Engineers, (London, 1893), p. 199-218.
110. "New York Rapid Transit Railway: Contractor Section III," XLVII, #19, May 8, 1902, p. 375-376; "Mining Methods in the New York Subway," The Engineering and Mining Journal, February 1902, p. 195. Photographs 3839 through 3842, of the Interborough Rapid Transit Subway Construction collection, New York Historical Society, reveal that large amounts of rubble were dumped along the Hudson River at 162nd Street.
111. New York Rapid Transit Tunnel Rand Drill Company, 1902, describes the use of Rand Company compressed air drills in the excavation the New York Rapid Transit Subway.
112. "New York Rapid Transit Railway: Contract Section 4," Engineering News, XLVIII, September 18, 1902; "Report of the Chief Engineer, 1900-01," 231-232; "Mining Methods in the New York Subway," The Engineering and Mining Journal, February 1, 1902, 175. David M. Stauffer, Modern Tunnel Practice, (New York: Engineering News Publishing, 1906), provides an extended description of hard rock tunneling.
113. "Report of the Chief Engineer, 1900-01," 232; "New York Rapid Transit Railway: Contract Section IV," Engineering News, XLVIII, #12, September 18, 1902, p. 204; See also, "Section Four of the New York Rapid Transit Railway," Engineering Record, vol 43, #26, June 29, 1901, p. 622-624; "Section 4, New York Rapid Transit Railroad, Part I Excavation and Timbering," Engineering Record, vol 43, #23, June 6, 1903, 596-599; "Section 4, New Rapid Transit Railroad, Part II, Timbering and Concreting," Engineering Record, vol 44, #1 July 3, 1903, p. 16-19.
114. "Report of the Chief Engineer, 1902," p. 223; "New York Rapid Transit Railway: Contract Section IV," Engineering News, XLVIII, #12, September 18, 1902, p. 206-207.
115. Ibid., p. 206.
116. Ibid., p. 206.
118. Diary of William Barclay Parsons, three volumes, Columbia University University, Special Collections, entry dated June 17, 1902.
119. "Report of the Chief Engineer, 1902," p. 234; "New York Rapid Transit Railway: Contract Section 5a," Engineering News, XLVIII, #14, October 2, 1902, p. 256.
120. "Report of the Chief Engineer, 1902," p 235-236; "New York Rapid Transit Railway: Contract Section 5b," Engineering News) XLVII, #17 October 23, 1902, 343-345; "Underpinning the Columbus Monument, New York," Engineering Record, vol 44, #4, July 27, 1901, 77-78; other articles describing construction of section V are: "The Second Division of the New York Rapid Transit Railroad, Part I," Engineering Record, vol 46, #3, July 19, 1902, p. 52-55; "The Second Division of the New York Rapid Transit Railroad, Part II," Engineering Record, vol 46, #4, July 26, 1902, p. 81-82; "The Second Division of the New York Rapid Transit Railroad, Part III," Engineering Record, vol. 46, #5, August 2, 1902, p. 102-103; "Section Five-A, Second Division New York Rapid Transit Railroad," Engineering Record, vol 49, #10, March 5, 1904, p. 290-292.
121. "New York Rapid Transit Railway: Contract Section 6a and 6b," Engineering News, XLVIII, #20, November 13, 1902, p. 390-393. "Section 5a and 5b, New York Rapid Transit Railway," Engineering Record, vol 43, #13, March 30, 1901, p. 294-296; "Report of the Chief Engineer, 1900-01," p. 236.
122. Ibid.; see also, "New York Rapid Transit Railway: Contract Section 7," Engineering News, XLVIII, #23, December 4, 1902, p. 478-482; "Section Seven Division Three of the New York Rapid Transit Railroad," Engineering Record, vol 48, #12, September 19, 1903, p. 335-339.
123. "New York Rapid Transit Railway: Contract Section 8," Engineering News, XLIX, #1, January 1, 1903, p. 19-20.
124. Ibid., p. 20; "Report of the Chief Engineer, 1900-01," p. 239.
125. "The New York Rapid Transit Railway: Contract Section 8," Engineering News, XLIX, #1, January 1, 1903, p. 20.
126. "Report of the Chief Engineer, 1900-01," p. 239; "Section Nine, Division Three of the New York Rapid Transit Railroad, Part II, The Harlem River Crossing," Engineering Record, vol 48, #10, September 5, 1903, p. 268-270.
127. "Section Nine, Division Three of the New York Rapid Transit Railroad, Part I, Open Trench Construction," Engineering Record, vol. 48, #8, August 22, 1903, pp. 210-213, for the details of the construction of the approaches to the Harlem River tunnel.
128. "An Economical Method for Subaqueous Tunneling, a letter to the Engineering Record from D. D. McBean, contractor, section nine of the Rapid Transit Subway," Engineering Record, vol 48, #25, December 19, 1903, p. 778.
130. Ibid.; see also, "Progress on the Harlem River Tunnel of The New York Rapid Transit Railroad," Engineering Record, vol 50, #8, August 20, p. 212-214; "An Improved Method of Subaqueous Construction at the Harlem River Construction of the New York Transit Railroad," Engineering Record, vol 48, #26, December 26, 1903, p. 814-816; "Report of the Chief Engineer, 1902," p. 252-253. 1904,
131. "New York Rapid Transit Railway: Contract Section 11," Engineering News, XLIX, #7, February 12, 1903, p. 147; "Report of the Chief Engineer, 1900-01", p. 240; see also, "Section 11, 13, 14, New York Rapid Transit Railway," Engineering Record, vol 43, #15, April 13, 346.
132. "Report of the Chief Engineer, 1900-01," p. 241; "New York Rapid Transit Railway: Contract Section 11," Engineering News, XLIX, #7, February 12, 1903, p. 147.
133. Gilbert, p. 21.
134. "New York Rapid Transit Railway, Contract Section 13 and 14," Engineering News, #24, June 11, 1903, p. 514-515.
135. Ibid., p. 514; "Report of the Chief Engineer, 1900-01," p. 242-243.
136. "New York Rapid Transit Railway: Contract Section 13 and 14," Engineering News, XLIX, #24, June 11, 1903, p. 517.
137. "Report of the Chief Engineer, 1900-01," p. 243; "Mining Methods in the New York Subway," The Engineering and Mining Journal, February 1, 1902, p. 176.
138. "New York Rapid Transit Railway: Contract Section 13 and 14," Engineering News, XLIV, #24, June 11, 1903, p. 518.
139. Details of this operation appear in "Widening A Section of the New York Rapid Transit Railway by Moving the Sidewalls," Engineering News, XLVII, #2, January, 1902, p. 26-27; "Moving A Long Tunnel Transversely," Engineering Record, vol 44, #25, December 21, 1901, p. 590-591; "Moving A Long Brick Wall," Engineering Record, vol 44, #17, October 26, 1901, p. 336.
140. "New York Rapid Transit Railway: Contract Section 12," Engineering News, XLIX, #8; February 19, 1903, p. 162.
141. Ibid.; "The Manhattan Valley Viaduct of the New York Rapid Transit Railroad, Engineering Record, vol 47, #13, March 28, 1903, p. 313-316.
142. "Erection of Manhattan Valley Viaduct," Engineering Record, vol 48, #6, August 8, 1903, p. 156-157; "The New York Rapid Transit Railway: Contract Section 12," Engineering News, XLIX, #8, February 19, 1903, p. 182.
143. "Report of the Chief Engineer, 1903," p. 147; also, "New York Rapid Transit Railway: General Description of the Work," Engineering News, XLVII, #8, February 20, 1902, p. 162.
144. Details of the replacement appear in "Replacement of the Harlem Ship Canal Bridge," Transactions of the American Society of Civil Engineers, LXVII, #1143, p. 3-31.
145. "Report of the Chief Engineer, 1902," 256; "Viaduct Erection on Section 10, New York Rapid Transit Railroad," Engineering Record, Vol 50, #15 October 4, 1904, 416-417; "Elevated Structure of the New York Rapid Transit Railroad," Engineering Record, Vol 47, #9, February 28, 1903, 220-221; "Erection of the Westchester Avenue Elevated Railway," Engineering Record, vol 49, March: 5, 1904, p. 287.
146. "Report of the Chief Engineer, 1902," [....]
147. "Agreement for Construction: Specifications, Section 16, Track," p. 104.
148. Minutes of the Board of Rapid Transit Railroad Commissioners, May 1, 1902, p. 1492-1493.
149. Minutes of the Board of Rapid Transit Railroad Commissioners, September 11, 1902, p. 1731.
151. Minutes of the Board of Rapid Transit Railroad Commissioners, September 25, 1902, p. 1771-1772.
152. "Report of the Chief Engineer, 1903," p. 167-168; "A New Method of Tunneling Under Broadway, New York," Engineering Record, Vol 48, #17, October 24, 1903, p. 492-494.
153. "Report of the Chief Engineer, 1904," p. 273-274.
154. A description of the construction of the Battery Park portion of the Contract Two subway appears in "Rapid Transit Railroad Construction at Battery Park, New York," Engineering Record, Vol 50, #26, December 24, 1904, p. 732-736. Information on the planning for the Brooklyn tunnels and a general description of the twin tubes is found in "Test Borings in the Bed of the East River, New York," Engineering Record, vol 45, #3, January 18, 1902, p. 53; "Tunneling Under the East River, New York," Engineering Record, vol 43, #6, February 9, 1901, pp. 128. A detailed description of the tunnels and the method used in their construction appears in "The New York and Brooklyn Tunnel for the Rapid Transit Railroad," Engineering Record, vol 49, #10, March 5, 1904, p. 305-306, vol 49, #11, March 12, 1904, p 329-331.
155. "The New York and Brooklyn Tunnel for the Rapid Transit Tunnel Railroad," Engineering Record, vol 49, #10, March 5, 1904, p. 304-305.
156. Ibid., p. 305.
157. Ibid., 305-306; "The New York and Brooklyn Tunnel for the Rapid Transit Railroad," Engineering Record, vol 49, #11 March 12, 1904., p. 330.
158. "Rapid Transit Railway Construction in Brooklyn," Engineering Record, vol 50, #17, October 22, 1904, p. 448.
160. Construction of the Fulton Ave. portion of the Brooklyn extension beneath the Brooklyn elevated railroad is described in "Rapid Transit Construction in Brooklyn," Engineering Record, vol 50, #18 October 29, 1904, 514-515; "Rapid Transit Subway Construction on Fulton Street, Brooklyn," Engineering Record vol. 52, #26, December 23, 1905, p. 705-707, vol 52, #27, December 30, 1905, p. 745-747.
161. "Electric Railways for Grading Work," Engineering Record, vol 52, #26, December 24, 1904, p. 736-737.
162. New York Times, April 28, 1901.
164. New York Times, March 10, 1901.
170. "Report of the Chief Engineer, 1904," p. 245.
171. New York Times, January 29, 1900.
172. New York Times, May 27, 1901; Parsons diary, May 22, 23, 24, 1901.
173. New York Times, May 29, 1901.
174. New York Times, May 28, 1901; Parsons diary for May 25, 1901, reveals that the Chief Engineer "urged both McDonald and McNulty to stand firm," in dealing with the strikers.
175. New York Times, June 3, 1901.
176. New York Times, June 4, 12, 16, 1901.
177. New York Times, September 6, 1901; Parsons diary, January 19, 1901, contains one reference to the beating of an iron worker foreman: "Carr (a division engineer), reported that the foreman of the iron working gang had been attacked by union men and very severly injured."
178. New York Times, January 24, 1901; Parsons also reported that contractor Fisher also had unspecified "trouble with the ironmen," Parsons diary, July 12, 1901.
179. New York Times, May 28, 1902.
180. Ibid.; Parsons' diary indicated that the cordial relationship between Terry and Tench and the Housesmiths and Bridgemans Union angered the other sub-contractors. His entry for June 26, 1901, reads; "Degnon (a sub-contractor) told of great difficulty in keeping his steel riveters at work on 42nd Street on account of Terry and Tench paying $3.76 a day."
181. New York Times, March 9, 1902; Parsons' diary reveals that as early as March 7, 1901, "a delegation of the Bricklayers' Union appeared before the meeting objecting to the use of concrete and asking that orders should be issued that the electric ducts be laid by bricklayers...."
182. New York Times, January 14, February 1, 1904.
183. New York Times, January 14, 1904.
184. New York Times, January 15, 16, 1904.
185. New York Times, June 22, 1904.
186. "Report of the Chief Engineer, 1900-01," 259; "Report of the Chief Engineer, 1902," 318, indicate that during these three years, 37 workmen and bystanders were killed and 278 injured. Casualty statistics do not appear in the 1903, 1904, and 1905 "Report of the Chief Engineer." A tabulation made from newspaper accounts of accidents related to the construction and operation of the subway during these three years reveals at least 17 were killed and 13 injured, although there is a strong likelihood that a larger number were in fact killed and injured between 1903 and 1905.
187. New York Times, October 25, 1903; New York Times, October 19, 1901.
188. Engineering Record, vol 48, #18, October 31, 1903, p. 515.
189. Charles M. Mills, "The Applicability and Comparative Cost of Concrete and Reinforced Concrete for Subway Construction," Proceedings of the 5th Annual Convention, National Association of Cement Users, vol. 5; January, 1909, 262.
190. "Report of the Chief Engineer, 1902," p. 271.
191. S. J. Pirrelli, "Description of Cut and Cover Construction as Used by the Transit Authority," (New York: New York City Transit Authority, May, 1970), p. 1.
192. "Report of the Chief Engineer, 1904," p. 272.
193. Finch, p. 233-234.
194. "Report of the Chief Engineer, l906," p. 301.