East Boston Tunnel News (1923-1928)
New Cars for East Boston Tunnel
Electric Railway Journal · Vol. 61, No. 2 · January 13, 1923 · pp. 85-86.
Cars Being Built for the East Boston Tunnel Service of the Boston Elevated Railway.
Boston Elevated Railway Develops Car for Rapid Transit Service, Weighing with Motor Equipment Only About 1,000 Lb. per Passenger Seat or 250 Lb. per Passenger on the Basis of Total Rated Carrying Capacity.
The Boston Elevated Railway supplies transportation between Boston and East Boston through a tunnel under a branch of the harbor at the point where the Charles River empties into it. The entire length of the tunnel from Bowdoin Square, the western or Boston terminal, to Maverick Square, the eastern or East Boston terminal, is 1.49 miles. Between these terminals there are three additional stations on the Boston side of the harbor. When this tunnel was first put into use it extended from Court underground station, on the Boston side, to Maverick Square on the East Boston side, where the cars came to the surface and continued on, over the several routes, to their destination. In later years the tunnel was extended, on the Boston end, to its present underground terminal at Bowdoin Square.
For a number of years single-car operation was maintained over this line, but as traffic increased two-car trains and ultimately three-car trains, consisting of center-entrance multiple-unit surface cars, were resorted to during the rush hours. This service is still in operation, but the capacity of the tunnel has been reached. Therefore, to take care of the constantly increasing population, the company has decided to substitute cars of the rapid transit type to be operated in trains, thus obtaining greater tunnel capacity, as well as greater capacity per car and per train, more rapid service and lower cost for platform labor per passenger. It was found to be impossible to use, for the tunnel service, the type of car used in the Cambridge Subway or on the company's elevated system, because of limitations in tunnel clearances, platform heights, etc. Consequently a new car was designed to be of all-steel construction with brass sashes.
At the present time an underground station is in process of construction at Maverick Square, into which, when completed, the surface cars serving the East Boston district will enter and discharge passengers onto a platform, from the opposite side of which the passengers will board the rapid transit trains and continue through the tunnel to the several stations on the Boston side of the harbor. After discharging passengers the surface cars will be operated, empty, around a loop to a loading platform, where they will receive passengers from the rapid transit trains and then continue out to the surface and over their several routes to their destination.
As the new tunnel cars will never inter-couple with any other type of car on the system, the railway had great latitude in the design of the car and its equipment, although it was limited as to length, height and width of car. Under these conditions a car has been designed which will provide for forty-four seated passengers and 136 standing passengers in all but the forward car in Ihe train. This car, on account of the cab being occupied by the motorman, will have two less seated passengers and standing area for two less passengers than given above. The total passenger capacity in the first case will be 180 per car and in the second 176, and has been obtained with an estimated weight on the rail of 44,000 lb. per car.
It has been found by the engineers of the railway that a reduction in car-body weight means an equal or greater possible weight reduction in truck, motor and other equipment, as their experience indicates that with every 1,000 lb. added to the car body, about 1,200 lb. must be added to the truck and equipment. This ratio is not always correct for the reason that there is considerable difference in the steps of standard motor capacities.
In the study of the design of this car it was evident that if sufficient weight could be eliminated in the body and its equipment, a smaller capacity, and consequently a lighter motor, with a proportionate saving in trucks, air brake and control equipment weights, could be used. With this in view the idea of operating two cars, semi-permanently connected together, as a single unit, was evolved. This arrangement, it will be seen, requires an operating cab on the ends only of the two-car unit, eliminating the necessity of a cab in each end of each car, saving the weight of the material entering into the construction of the cab, also the weight of one set of air brake, control, and miscellaneous cab apparatus with its piping, wiring, etc. The estimated saving in the above arrangement is approximately 1,200 lb. per car.</P>
Cross-Section of East Boston Car at Motorman's Cab End.
With the two-car unit arrangement a train will consist of two, four or six cars. Each unit will be controlled by a single guard as on the present rapid transit cars.
A considerable reduction in weight has been obtained by the use of what is known as "truss-plate" flooring. This consists of two steel plates, each having depressions regularly spaced. The plates are placed together so that the convex surfaces of the depressions come in contact and are then spot-welded, resulting in a single "truss-plate" of 7/8-in. thickness and an insulating air space between the plates of approximately 13/18 in. The "truss-plate" will be covered with a mastic floor compound to a thickness of 5/16 in. The total weight of this floor will be approximately 4 lb. per sq.ft., whereas the flooring in the present rapid transit cars in Boston weighs from 9 to 14 lb. per sq.ft.
A further reduction in weight was obtained by the use of copper-covered, soft pine or balsam wood doors, arranged to slide on the exterior of the car, thus eliminating the double wall at door pockets, and reducing the thickness of the side posts and walls of the car. The weight of the doors is 50 per cent less than that of the doors on the latest Boston rapid transit cars.
One of the interesting features of this car is that each side door will have its own motor-driven actuating mechanism, which will be placed under the seat inside of car and will have a shaft extending through the side of the car to which the door-actuating lever is attached. These mechanisms will be controlled from the guard's position, between the two cars, by means of a controlling switch for each door mechanism. Whereas no saving in weight is expected from this feature, it is believed it will be less necessary to keep heat on cars, when stored in the open in cold weather, which the Boston men consider necessary with pneumatic door-operating mechanism, to prevent sluggish action.
Some question has been raised as to the possibility of keeping the outside doors weathertight, but from the experience the railway has had for several years on its surface cars, the engineers have no fear from this feature, in the event that, at a later date, the service will be extended and the cars operated on the surface.
On account of limited height of the tunnel, it was found necessary to make the distance from the rail to the top of car floor somewhat less than on the present rapid transit cars. This in turn necessitated the use of a 26-in. diameter wheel in place of 31-in. and 34-in. wheels at present used on rapid transit cars. Some saving in weight is thus made.
Another reduction in weight is brought about in the drawbar equipment in that the link or drawbar, connect- ing the two cars of each unit, is somewhat lighter than the regular drawbar with its electric couplers which will be used at the ends of each unit.
Each car will be equipped with swinging end doors, thus eliminating the weight of the door pocket partition, located as usual in the rapid transit type of car, but these will not be used by passengers, except in case of emergency.
These cars will be equipped with the Westinghouse variable load brake, which has recently been described in these pages. In tunnel service the distance apart at which the blocks can be set depends upon the distance in which cars can be stopped, so that there is special reason in the East Boston cars for an automatic brake which will increase or decrease the braking pressure according to the increase or decrease of the load, thus always providing minimum stopping distance.
The cars are lighted with a single row of five units in the center of the ceiling and each electrolier has a shade. There is also provision for emergency lighting.
Statistics for East Boston Tunnel Cars
- Length over all: 47 ft. 3 in.
- Width over all: 8 ft. 3-1/2 in.
- Height from top of rail to top of roof: 11 ft. 3-1/2 in.
- Width outside sills: 8 ft. 3-1/2 in.
- Width over all: 8 ft. 7 in.
- Width of side doors: 3 ft. 9 in.
- Diameter of wheels: 26 in.
- Seated passengers (with cab open): 42
- Seated passengers (with cab closed): 44
- Standing passengers (with cab open): 134
- Standing passengers (with cab closed): 135
- Sashes: Brass
- Roof: Monitor arch
- Ventilators: Perry
- Flooring: "Truss-Plate" with mastic coating
- Electric door engines: Consolidated Car Heating Co.
- Speed control brake: Westinghouse Traction Brake Co.
- Motors: 4 GE-247
- Controller: G.E. P.C.-B
- Car straps: Rico
- Manufacturer: Pullman Co.
- Number of cars: 40
- [Numbering: 0500 series]
Reducing Weight of Rapid Transit Cars Saves $108,000 a Year
Electric Railway Journal · Vol. 64, No. 8 · August 23, 1924 · pp. 269-274.
The East Boston Tunnel Car. While Narrower Outside than the Standard Elevated Car, Has More Room Inside.
Steps by Which Weight Was Reduced, Carrying Capacity Increased and Strength Maintained in New Rolling Stock for East Boston Service -- Electric Door Openers Give Good Results.
By John Lindal, Superintendent, Rolling Stock and Shops, Boston Elevated Railway.
Styles of cars change and it sometimes seems that these changes are as frequent as the changes in the styles of clothing. For instance, when the famous "hobble" skirt was in vogue, the steps of many of our cars had to be changed to meet the conditions. If it should happen that the "hoop" skirt should again come into style, we should probably have to change the cars to meet that condition! Some people seem to have the idea that when a new type of car is desired, the whole matter is conceived and developed in the brain of the car designer the same as an artist paints a picture. This is not true. There are many requirements which must be met in the design to enable the car best to meet the conditions of service. This may be more fully explained by following out, step by step, the development of our latest type, the East Boston Tunnel rapid-transit car, which has several features quite novel and somewhat radical in design.
SPECIAL CONDITIONS HAD TO BE MET
The East Boston Tunnel was built in 1900 to 1904 for the operation of surface cars run singly. It is probable that at the time when it was designed very little, if any, consideration was given to the question of train operation in the future. The tunnel was put into operation on Dec. 30, 1904, and operated with closed double truck cars with 26-ft. 6-in. bodies. As the traffic increased these cars were replaced with the largest type of car that could be used in the tunnel and on the streets. The increase in carrying capacity obtained in this way took care of the traffic growth up to 1917, when it was found that the capacity of the tunnel with single-car operation had been reached. As a means of further increasing its capacity, the operation of surface car trains was started. The number of cars in a train was gradually increased up to four. While this added materially to the carrying capacity of the tracks, it became evident that the capacity for handling passengers on the station platform also had been reached.
As several car lines were operated througk the tunnel with diverse routing after leaving the East Boston end, it was impossible for each car or train to empty the station platforms, as passengers had to wait for the car or train running on their particular routes. This caused serious station platform congestion.
To relieve this condition and as a means of providing further increase in carrying capacity, it was decided to go to trunk-line service in the tunnel, extend the platforms for six-car trains and provide terminal facilities at Maverick Square, East Boston, for looping the tunnel trains and also the connecting surface cars, with large platforms arranged so that the transfer of passengers could be made at one level.
In operating with this arrangement the use of center-entrance motor-car trains was first considered, but this did not prove advisable for several reasons. The design and construction of the center-entrance cars were not suitable to withstand the buffing and pulling stresses which they might be subjected to when operated in six-car trains; overhead trolley operation had never been very satisfactory in the tunnel and with six trolleys on a train, more trouble was to be expected. It was also evident that the center-entrance cars would require more time at stations during heavy traffic than would a car of the rapid-transit type with three doors on a side. There was a further advantage in the rapid-transit type of car, in the reduction of trainmen required for operation, seven men being needed for a six-car train of center-entrance cars and only four for a train of the same number of cars of the rapid transit type. For these reasons, it was decided to use the rapid-transit type of car.
This question having been decided, the logical thing to do, if possible, would be to use the Cambridge subway type of car which had proved so satisfactory in that service; but when the matter of providing clearance for such a large car was looked into, it was found that the cost would be prohibitive. The next question was to determine how large a car could be operated through the tunnel without necessitating material changes in its construction. From tunnel clearance plans it was found that a car of approximately the length and width of the present elevated lines car could be used if its height could be reduced, and it was further found that on account of the low roof of the tunnel over the station platforms these platforms could only be raised to a certain height. This height determined the height of the car floor, and it was found that the largest diameter wheel which could be used under the cars was 26 in. This meant that to provide proper motor clearance, when wheels were worn down, the largest motor that could be used was one of 40 hp. This forced a departure from previous rapid transit car practice of using two motors per car, as sufficient power could not be obtained from two 40-hp. motors. As a matter of fact, it was a very serious question whether a rapid-transit type of car could be built light enough so that the total load would not exceed the capacity of the four 40-hp. motors, considering the number of stops per mile, grades, etc. We were operating the center-entrance cars of approximately 22 tons weight in that service with four 40-hp. motors. A check indicated that we could not safely go much beyond that weight. So our problem was to produce a fireproof rapid-transit type of car with stronger framing, M.C.B. wheels and heavier trucks, without exceeding the weight of the center-entrance motor car. When we considered that the last elevated cars built by this company weighed approximately 35 tons, the solution seemed quite impossible.
A comparison of the weights of the various parts of cars indicated that for every 1,000 lb. of weight in the car body it was necessary to provide about 1,200 lb. of weight in trucks, motors, control, brakes, etc. It was, therefore, obvious that any weight that could be saved in the car body would more than double itself in the total weight saving. With this in mind, we began consideration of means for reducing car-body weight without sacrificing necessary strength. We had developed the practice of operating rapid-transit cars in units of two, i.e., with one guard in control of the doors of two cars, so that adding or cutting off cars was always done in units of two. This materially reduced the value of absolute interchangeability of individual cars, and by making the cars single-ended and coupling them together semi-permanently, a material reduction in weight could be made by the elimination of duplicate equipment, such as cabs, cab apparatus, markers, tail-lights, door control equipment, etc. This amounted to approximately 1,300 lb. per car.
DOORS ON THE OUTSIDE OF CAR REDUCED WEIGHT
It had been universal practice to slide the doors, in both the sides and ends of the car, into pockets in the walls. This meant double walls, glass, etc., at all such pockets eight per car. These pockets also determine the thickness of the car walls. By placing the side doors on the outside of the car and designing the end doors to swing, we eliminated the necessity for door pockets and were able to reduce the thickness of the walls of the car. This permitted placing the seats nearer the outside line of the car and gave the further advantage of greater passenger carrying capacity. In fact, the distance over side walls of the East Boston tunnel car is less than that of the elevated car, while the aisle space is greater; or in other words, it is a smaller car outside and a larger car inside. This change permitted a saving in weight of approximately 1,500 lb.
The matter of providing suitable fireproof doors on rapid-transit cars has been a serious problem. Sheet steel was generally adopted for this construction, but a number of difficulties developed from its use. The light-gage sheet steel at first used cracked at the corners. There was trouble from condensation of moisture in the interior of the door, and also water would get into the door at the glass rabbet. For these reasons heavier metal was substituted, and in some cases cast aluminum doors were used. Notwithstanding this, the weight and cost of the doors increased. Weight in car doors is doubly expensive. It costs money to carry it on the car and costs additional money on account of having to move that weight twice at each station stop when the door is opened and closed. As is well known, increased weight adds to the danger element of moving objects.
As a remedy and a means of reducing weight, we decided to go back to the wooden door and provide fire-proofing by covering the wood with thin sheet-metal. The Fire Underwriters consider a wooden firedoor covered with tin of no greater firehazard in a building than one made of sheet steel. We arranged to seal the sheet metal covering to prevent moisture from getting to the wood, and we interlocked the sheet-metal covering so that in the event of the doors being subjected to temperatures sufficiently high to melt the seal, the sheets could not be displaced. With such doors, we were able to make a reduction of 800 lb. in weight.
FIREPROOF FLOORS OF LIGHT WEIGHT ADOPTED
The necessity of providing fireproof floors in cars was the cause of a material increase in weight. The method adopted was to lay sheet-steel flooring, pressed in the form of corrugations to give some vertical stiffness over the underframe, and cover this with a cement composition, the combination resulting in a stiff and rigid floor. This met the fireproof requirements and carried the load satisfactorily. Due to the vibrations set up in the floor, the composition material cracked and became loose. To prevent this, floors were laid with thicker composition, which meant additional weight, and there was the further objection that the floors were cold in winter. Our attention was called to a floor that had been invented by a New York engineer, which was called "Truss-plate" flooring. On investigation we found that two cars having this flooring had been in service several years with apparently satisfactory results. By the use of this material in our East Boston Tunnel cars, we were able to save approximately 2,000 lb. in weight, and the floor, being constructed with a dead air space between the upper and lower plates, seemed to be an effective temperature insulator, making the floor warmer during the cold months. The strength of the floor is entirely in the plates and a thin, flexible composition is used for the wearing surface.
REDUCING WEIGHT OF THE SEATS
The wooden slat seats in the rapid-transit cars were designed with the necessary strength entirely in the wood; to meet the Underwriters' requirements for fire-proofing over heaters and electrical apparatus, the undersides of seat-frames were covered with sheet metal. By redesigning the seat and using the sheet metal in a corrugated form we were able to make the metal furnish the necessary strength and stiffness as well as provide the necessary fireproofing. This change enabled a saving to be made in seat weights of 160 lb. per car.
The total of the items of weight saved thus far mentioned amount to 4,460 lb. in car-body weight. As previously pointed out, weight saved in the body would more than double in the total weight saved. This meant a total saving of approximately 5 tons. Having accomplished so much, it began to look as though the problem might possibly be solved.
At about this time a trip was made to a number of large cities to see light-weight cars and to discuss our problem with car builders. From the information thus obtained, we concluded that it would be possible, by careful design and careful following of all details, to produce the car we required. We made drawings and specifications accordingly, one clause reading: "The weight of the car body, as delivered to the railway, must not exceed 19,000 lb."
The weight of the car bodies, as delivered to us by the Pullman Company, was 18,320 lb., or 680 lb. less than the weight specified, while the total weight of the car, complete, was slightly under 22 tons.
The operating costs for way, equipment and power, for these cars in the East Boston Tunnel service, based on $219 per ton per year* [* The derivation of this figure was given in an article in ELECTRIC RAILWAY JOURNAL for July 26, 1924, page 122.], will be approximately $108,000 per year less than if the service were performed by cars similar to those last placed in service on the elevated lines.
ELECTRIC DOOR OPERATING MECHANISM USED
There are two other features of note in connection with the East Boston Tunnel car. The Boston Elevated Railway was the first to operate car doors with pneumatic engines. The practice has now become nearly universal. It has made possible great improvement in operation and economy, but the use of compressed air for that purpose has some drawbacks. In the first place, the conversion from electrical energy to mechanical energy is accompanied by considerable loss. Compressed air is hard to confine and to prevent from leaking. The leak may be small at any one point, but there are numerous points and they are not readily accessible for testing or repair. This means that there is a constant leakage of air as long as air pressure is on the car and the compressor capacity must be proportioned to maintain proper pressure notwithstanding the air leakage. In the case of the East Boston Tunnel car, this meant that while a 16-cu.ft. compressor would be ample to provide air for brakes and control, a 25-ft. compressor would be required if air-operated doors were used. The difference in compressor weights was approximately 300 lb. These were important considerations, but the desirability of eliminating the troubles of sticking and slow working doors in cold weather was of greater importance, and if doors could be controlled directly by electric power it seemed that the results should be economical as well as beneficial from a service standpoint.
We built a car door model and equipped it with an electric motor and controlling mechanism. From the results obtained in this way we were satisfied that the scheme was practical. We issued specifications for electric door mechanism and the Consolidated Car Heating Company was the successful bidder. Our experience, so far, with the electric door operators indicates that they will be an improvement over the pneumatic door operators.
The introduction of light-weight cars of large carrying capacity introduced another problem, that of braking. The usual practice has been to adjust the braking pressure to the light weight of the car so as to reduce the liability of wheel skidding. This trouble is not only disastrous to the wheels but it is a well-known fact that sliding friction between wheel and rail is considerably less than rolling friction. For that reason a longer distance is required to stop a car when the wheels skid. This means that with the brake pressure adjusted to the weight of the car without load, there was no means provided for taking advantage of the additional friction or adhesion between wheel and rail due to the additional weight of the passenger load. This necessarily meant longer stopping distances even with maximum braking conditions, as the load was increased. With our steel elevated cars, the maximum passenger load amounts to 33 per cent of the dead car weight, which is not such a serious difference, but with the East Boston Tunnel car the proportion of passenger load to dead weight is 57 per cent and in the interests of safety and traffic capacity, this factor could no longer be ignored.
We had reached a point where some means must be applied for increasing the available braking pressure as the load was increased and conversely reducing that pressure as the load was decreased. Such a device was in use on the New York Municipal subway lines. On investigation, it was found to work very satisfactorily, but the design was such that it required considerable space for installation which could not be provided on our cars, and its weight amounted to 2,000 lb., which we could not afford. However, designs were submitted by the manufacturers showing a device which would accomplish practically all that the Brooklyn device accomplished; which could be installed in the space available and which weighed only 165 lb. This was adopted for both the No. 5 semi-convertible cars and the East Boston Tunnel cars. These brakes are operating very satisfactorily and seem to meet the conditions fully. It is possible to stop a loaded car in the same distance as that in which the empty car can be stopped. This should make for greater safety and materially add to traffic capacity on lines of dense traffic.
If the East Boston Tunnel cars were to be interchanged or operated with the present elevated cars and were to be subjected to the stresses imposed by the heavier cars, it would have been impossible to make any such reduction in weight; i.e., it would be impossible to design cars for our elevated lines with a weight of 44,000 lb. It may, however, be possible in building future elevated cars, by adopting some or all of the new features incorporated in the East Boston Tunnel cars, to make a material reduction in weight without sacrificing strength.
End of a Two-Car Unit. The Inside Ends Have Semi-Permanent Coupling.
The Seat Ends and Supports -- Hollow Metal Reinforced Was Used to Give Rigidity.
Details of Seat Back and Cushion, Showing How the Construction Was Made Light.
Details of Side Framing for East Boston Tunnel Car.
The Floor Framing Shows a Light but Strong Type of Construction.
East Boston Tunnel Changed Over to Train Operation
Electric Railway Journal · Vol. 63, No. 17 · April 26, 1924 · p. 671.
Where Surface Cars Enter Maverick Square Station -- Rapid Transit Tracks Are Parallel and Outside Columns.
By joining forces with the Boston Transit Commission, so as to muster a working crew of about 800 men, the Boston Elevated Railway changed over the service in the East Boston Tunnel between 8 o'clock on the evening of April 18 and 5 o'clock on the morning of April 21 from surface cars to the operation of four-car trains. It was a stupendous job. The tunnel was closed to the public during the fifty-seven hours. Then the crossovers were broken, the guard rails taken down, the third rail installed for a distance of 2 miles and platforms erected at the several stations. This was work which could not be done until the surface cars ceased running. Its completion was accomplished in record time, however, as everything was ready for the work the minute the cars were out of the tunnel. All the platforms had been built in small sections which fitted together like a picture puzzle. The third rail had been welded together in lengths of 400 ft., all ready to set in place.
Forty new steel cars have been purchased by the Elevated for this service, the trains to run between Maverick Square in East Boston and Bowdoin Square in Boston, meeting surface cars at both ends. The new work cost about $2,500,000. It makes the total cost of the East Boston Tunnel approximately $9,000,000. The Elevated pays the rental on this sum to the city of Boston.
Changing Tunnel for Rapid Transit
Electric Railway Journal · Vol. 64, No. 2 · July 12, 1924 · pp. 39-41.
In 50 Hours with 1,526 Men the Boston Elevated Railway and the Boston Transit Department Converted the East Boston Tunnel from Surface Car Operation with Overhead Trolley to Third Rail Rapid Transit Train Operation -- A New Station Was Built at Maverick Square.
Only a short time ago the local newspapers of Boston carried items announcing that the Boston Elevated Railway had changed its operation in the East Boston tunnel from, surface trolley cars to third-rail rapid transit trains. This information was also published in the news columns of ELECTRIC RAILWAY JOURNAL, issue of April 26, page 671. Behind these bare statements of fact was hidden a story of engineering and construction achievement, a story of railroading, of interest to every railroad man.
On Friday evening, April 18, when the last scheduled trolley car entered the East Boston tunnel, it made its routine trip in the usual way. No ceremonies marked its entrance but feverish construction activity followed the completion of its trip. No formal speeches marked its exit but the curt, forceful language of engineers, superintendents and foremen followed in its trail. It was the last surface passenger car to travel through this twenty-year old hole under Boston harbor.
For two decades, trolley cars operated through this tunnel had met the transportation requirements. To be sure they had been crowded in up to the maximum frequency possible with a modern block signal system. And then they had been coupled together in two and three-car units, so heavy had the traffic become. But at last the fact had to be faced that this service was inadequate. Rapid-transit operation, with high-speed, multiple-unit trains of greater length had to be introduced.
To make the change involved the construction of a terminal station at the East Boston end of the tunnel. Formerly no station had been needed as the surface cars simply ran up the grade out of the tunnel onto the city streets at Maverick Square, the tunnel portal. But rapid transit trains must be kept off the streets hence it became necessary to build a terminal under and around the existing tunnel portal, without interrupting the operation of the cars.
The East Boston tunnel, like other subway and tunnel facilities in the city of Boston, is the property of the city and is leased to and operated by the Boston Elevated Railway. All construction and reconstruction work on such tunnels is handled by a public commission, the Transit Department of the City of Boston.
Reconstruction work was commenced in the fall of 1921. An interesting feature of the undertaking was the employment of needy ex-soldiers on the work. At that time the unemployment situation throughout New England had reached alarming figures and a large proportion of the unemployed were veterans of the World War. With a view to reducing the constantly increasing payroll for soldiers' relief, Mayor Curley issued instructions to have this work done by day labor, preference to be given to former service men. Although many of these men were inexperienced in work of this character, they soon acquired the necessary knowledge under skillful supervision, and this massive structure was completed within the time limit, despite unforeseen construction difficulties and the abnormal weather conditions. Day and night for over two years, crews of men were engaged in excavating below tide water, removing and relocating water, sewer and gas pipes, telephone and telegraph conduits and electric lighting service without even momentary interruption. Night cars operated regularly regardless of the fact that more than 15,000 charges of dynamite were shot off for blasting sections of the old concrete tunnel which had to be removed.
About 125,000 cu.yd. of material had to be excavated, a great proportion being removed from under large buildings which had to be carefully underpinned; 28,000 cu.yd. of reinforced concrete was installed requiring 42,000 bbl. of cement, and more than 1,000 tons of steel reinforcing rods; 1,800 tons of heavy steel for girders and columns were fabricated and erected and 130,000 ft. of saturated fabric for waterproofing the structure was laid. Included in this underground structure is a completely equipped car shop, fitted with all the necessary tools and appliances for making repairs to the cars.
As the Maverick Square terminal station neared completion the problem of making the change-over from trolley car operation to third-rail trains had to be solved by officials of the railway. This involved the raising of all station platform levels to a height of 3 ft. 6 in., or on a level with the floors of the new subway cars. It involved the installation of third-rail construction for double tracks, the entire length of the tunnel. It involved the removal of old guard rail, and the placing of new. It involved the installation of an entirely new block signal system with automatic emergency stop devices. All special work had to be replaced to accommodate M.C.B. flanges. And the whole job had to be done in the shortest possible time, as this tube provided the only convenient means of transportation to thousands of suburbanites in their daily travel to and from the business section of Boston. To interrupt this traffic even for a day would have involved serious consequences. Ordinarily a week's work would have been required to do this job. But a week simply could not be spared. Accordingly a most carefully laid out and elaborate plan was devised by General Manager Edward Dana, Harry M. Steward, superintendent of maintenance and other officials, in collaboration with the Boston Transit Department.
Saturday, April 19, was a legal holiday, Patriots' Hill Day, in Massachusetts. The plan involved suspending operation of the tunnel by trolley cars at 8:30 p.m. Friday, April 18, and resuming operation with third rail trains Monday morning the 21st. And incredible though it may seem this plan went through on schedule, with a few hours to spare.
As that last trolley car made its way through the tunnel, Friday night, it was followed by construction cars, loaded with men, tools, equipment and material. Inside of fifteen minutes the tunnel became a hive of activity, apparently confused, in reality so well ordered and supervised that about 50 hours of stupendous effort wrought the entire change without a hitch. Gangs at each of the four stations en route threw up temporary wooden platforms to the new level. Other gangs set to work with acetylene torches cutting up and removing the old Z-bar guard rail 20,000 ft. of it in 23 hours. Rail cars followed and picked up the pieces. Third-rail insulators had been placed in advance with third rail laid alongside and bolted up. Now it was picked up and laid in place on the insulators. Special work to the extent of 340 ft. was cut up and removed, and 724 ft. of new special work was installed. Elsewhere, signal crews were at work on the new installation.
In all a total of 1,525 men were employed, with a maximum of 780 on one shift, all in a tunnel 1.7 miles long. Twelve-hour shifts were worked; 2,185 meals were served to the men while on the job. Only two trifling personal accidents were reported during the whole period.
At 1 a.m. Monday morning Mr. Steward told the operating department they could have the tunnel. Power was turned on the third rail, the motorman of a waiting train turned on his controller and the first rapid transit train rolled down through the hole. Others followed, as the transportation and equipment executives hastened to break in their men during the two or three short hours left before the rush of Monday morning commuters was upon them.
The new cars used in the tunnel are unique in that they are always operated in units of two, or multiples of two, with control equipment on one end only of each car. They were built by the Pullman Company and are each equipped with four Westinghouse 514-E motors with Westinghouse electro-pneumatic variable load brakes. Other details of their construction and equipment were described in the ELECTRIC RAILWAY JOURNAL for Jan. 12, 1924.
The personnel of the Boston Transit Department which handled the engineering and construction of the Maverick Square station consists of Colonel Thomas F. Sullivan, chairman, formerly well known as a street railway man and later Commissioner of Public Works, city of Boston; Louis A. Rourke, formerly a division engineer on the Panama Canal and later Commissioner of Public Works, city of Boston ; and Francis E. Slattery, a Boston lawyer. Ernest R. Springer is chief engineer.
An unusual degree of co-operation existed throughout the work between the Transit Department and the Boston Elevated Railway. A further remarkable degree of co-operation was enjoyed from the 1,500 men who labored day and night through a public holiday and Sunday to accomplish this remarkable achievement. Their pride was aroused to win and they did.
Two-Car Units of Type Used East Boston Tunnel.
Cross-Section of Tunnel During Reconstruction at East Boston End.
"Narrow Gage" Electrified for Economy
Electric Railway Journal · Vol. 72, No. 23 · December 8, 1928 · pp. 994-997.
Catenary type overhead with feeder-messenger is suspended from steel bridges.
Quicker, quieter and cleaner service now being given by Boston, Revere Beach & Lynn Railroad. Three-foot gage retained. Special motor constructed. Messenger feeder used in catenary type overhead.
Economy was the paramount consideration in the electrification of the Boston, Revere Beach & Lynn Railroad, Boston, Mass. At the same time the service has been made quicker, quieter and cleaner. As the electric trains move smoothly over the line, murmurs of satisfaction are heard from the passengers on every hand. To make possible this improvement in service, an expenditure of $1,400,000 was required which was divided in the following manner:
Car equipment: $610,000; Substations: $152,000; Overhead structures, lines and feeders: $277,000; Signal changes: $90,000; Miscellaneous construction including engineering, interest charges, etc.: $271,000.
During rush hours, six-car units and express trains have been inaugurated. Throughout the day trains operate at an increased schedule speed and greatly decreased headway. The running time between Boston and Lynn has been reduced about one-third and the comfort and safety of passengers has been materially improved. At the same time, the number of cars in operation has been reduced from 96 to 67 and the 26 steam locomotives have been discarded. The essential principles of steam and electric operation are fundamentally opposite. In steam operation, on account of the cost of locomotives and minimum crews, the whole tendency is toward heavier trains and greater headway. In passenger transportation, shorter headways mean more passengers. With electric operation the trains can be broken up into smaller units running on shorter headways, thus giving faster service with less expense.
The Boston, Revere Beach & Lynn Railroad was planned 56 years ago, primarily to develop the land which now comprises the municipalities of East Boston and Revere. Service was inaugurated in 1875. What is now the Winthrop branch was originally the Boston, Winthrop & Shore Railroad, started in 1877, and merged with the Revere Beach Road in 1891. In November, 1927, the railroad was purchased by the Eastern Railway Associates, controlled by Hemphill & Wells, and American Equities Company.
The Boston, Revere Beach & Lynn Railroad electrified its entire system from the East Boston terminal, which is connected to Boston by ferries, to Lynn including the double-track loop to Winthrop. Substations are located at Orient Heights and Lynn.
Immediately upon acquisition of the property by the new owners, steps were taken toward electrification. There was an outstanding capital stock of $850,000 and 4-3/4 per cent first mortgage bonds amounting to $1,000,000. To finance the electrical program, the Massachusetts Department of Public Utilities authorized an issue of additional capital stock in the amount of 1,700 shares with a par value of $170,000 and $1,000,000 in 6 per cent, general mortgage bonds. Additional short-term notes were necessary to complete the financing.
As shown in the accompanying map the railway operates between Boston and Lynn with a branch line forming a loop through Winthrop. To connect Boston with the terminal in East Boston, three ferries are operated across the harbor. The entire system is double track. Last year 13,350,000 passengers were carried. A total of 60 electric cars, seven trailer cars, and two electric service cars are operated over 13.12 miles of line having 34.48 miles of electrified track. The running time between Boston and Lynn has been reduced about ten or fifteen minutes, which is a saving of one-third of the time formerly required by the steam trains.
No new cars have been purchased. Sixty of the 96 passenger cars used in steam service have been remodeled and electrically equipped. Seven additional cars have been remodeled as trailers. The interior of each car has been refinished and small operating cabs built in each end. Each car has been equipped with 30 Consolidated 500-watt truss plank heaters connected fifteen in series on a circuit. The heating circuits are controlled by a Consolidated No. 213 switch mounted at the motor end of the car. Wiring has been installed for a thermostat to be placed in the center of the car. The lighting fixtures furnished by the Electric Service Supplies Company are the 1022 dome type, with short-circuiting sockets. Twenty of these dome fixtures with 32-volt lamps are connected in series in each car. A General Electric J-63 headlight can be attached to the front of each car by means of brackets arranged on the-handrail. These headlights are equipped with 250-watt incandescent lamps controlled by a three-way switch located in the cab through a tapped resistance permitting dimming.
Motive power has been provided by replacing one of the old trucks with a new Brill 177-E2 truck equipped with two General Electric 295-A 600-volt railway motors. Because of the narrow gage these motors were especially designed for this installation. They are the four-pule. direct current, commutating pole railway motors for operation with tapped field on 600 volts. The weight of the motor complete with gear, pinion, gear cover, and axle bearing linings, is approximately 2,770 lb.
The frame of the motor is the box type with bar suspension. Longitudinal ventilating ducts are provided in the armature, which is keyed to the spider. The shaft can be replaced without disturbing windings or the commutator. The commutator is unusually narrow for a railway motor and its diameter is 14-1/2 in. The depth of the segments is approximately 3/4 in., the segments being mica-insulated and grooved 5/64 in. There are four brush-holders per motor, which are adjustable radially. Steel clock spring pressure fingers are centrally located by recessed adjusting sleeves. which are clamped by the first turn of the spring. The carbon ways are renewable and each brush-holder is equipped with a 1-3/4-in. x 5/8-in. brush. Because of lack of space, the commutator overrides the bearing on that end of the motor. Ventilation is produced by a multiple fan integral with the pinion end of the armature head. The air intake is through protected openings in the top of the commutator cover.
The cars are equipped with type M control for multiple-unit operation. Current is collected from the trolley by a Nuttal 11 ft. 4 in. pole. Current is carried down the car at the left-hand corner post on the motor end, to a main switch and a fuse box located underneath the car. This, in turn, is connected to a contactor box which is operated by a C-503-A master-controller located in the cab at each end of the car. A type ML form E-3 master governor is mounted under a longitudinal seat in the front end of the car and connected to a snap switch in the operator's cab.
Cables from the connection boxes mounted under the cars are carried up through the car framing to the roof and all electrical connections between cars are made overhead by means of coupler sockets located in the ends of the car roof. A No. 00 bus line runs from end to end of each car, connecting the trolleys and DA-35G bus line coupler sockets, located in the ends of the cars. With the exception of the heater circuits, no metal conduit is used in these cars. The control cables were grouped, taped and covered with a weather-resisting mulehide. The lighting circuits were run in wood moldings on the interior of the car mounted in the cove of the ceiling. The advertising signs are snapped in place over this molding, completely concealing it.
General Electric electro-pneumatic brakes are installed on each car. This equipment uses a brake valve, having an equalizing piston which functions to give a pneumatic service application if, for any reason, the electric brake is inoperative. There are five positions on the brake valve from left to right as follows: release, holding, lap, service, and emergency. In conjunction with this brake valve is used a pneumatic duplex contactor. In release position of the brake valve the contactor is in neutral position. In holding position it is moved to the right and energizes the holding magnet. In lap, it is again in neutral position and in service or emergency position it is moved to the left and energizes the application magnet, causing the brake pipe reduction to take place at the application valve in service position, and at both the brake valve and application valve in emergency position. In electric operation of the brakes, a service application is made in the regular way, and after the proper brake pipe reduction is made, the handle is returned to the holding position. In this position of the brake valve handle, the triple valve goes to release position, but the release or holding wire is energized by the contactor which, in turn, energizes the holding magnet and retains in the brake cylinder any air that has been admitted. The brake may then be graduated off by moving the brake valve handle between the holding and release position. The graduating actually being accomplished by energizing and de-energizing the holding magnet, which in turn seats and unseats the release valve in the magnet bracket.
In making an electric service application, the equalizing piston does not move as brake pipe air is being taken from the under side of the piston, past the application magnet valve, as rapidly as the equalizing reservoir air is being taken from the top of the piston. In making a pneumatic service application, no brake pipe air is taken from the underside of the equalizing piston, while equalizing reservoir air is depleting to atmosphere and consequently the higher brake pipe pressure raises the equalizing system, allowing the brake pipe air to escape to atmosphere at the brake valve. Brill brake rods and brake beams are used.
The cars, completely electrically equipped, weigh approximately 52,000 lb. In addition to the 60 electric cars and seven trailer cars, two service cars were equipped with two double motor trucks and using the type K-35-JJ control.
Power is furnished through two substations, one located at Orient Heights and the other at Lynn. The Orient Heights station is supplied by the Edison Electric Illuminating Company and the Lynn station by the Lynn Gas & Electric Company. The Orient Heights station furnishes power to all lines. The two 600-volt trolley wires from this station to East Boston are furnished with power by this station only, when under normal operation. The two trolleys from the Orient Heights station to Lynn are furnished power by both stations. The two trolleys on each of these sections are bonded about every 1/2 mile. The Winthrop loop is furnished power by the Orient Heights station and each trolley wire is completely insulated from the other. Any section of the line may be supplied by either station or a portable station. A 2,300-volt line parallels the track furnishing power to the signal system and other power apparatus.
The substation at Orient Heights is of the automatic type and contains two synchronous railway converter sets, of 650-volt, 1,000-kw. capacity. This station has four d.c. stub multiple-feed reclosing feeders, 650 volts, 2,000 amp., and one d.c. stub feed reclosing feeder 650 volt, 2,000 amp.
The two a.c. 13,800-volt incoming lines are provided with, manually operated breakers which are tripped only on reverse current overload, indicating a line fault or a severe overload on the 13,800-volt bus or transformers.
An unusual feature in this substation is the system of ventilation. A steel housing is constructed over each machine, similar in shape to a blower housing. The rotation of the converter causes a draft of air to flow through this housing into a cavity in the floor. The air passes from this to a funnel leading to the ceiling. The warm air from the converter freely rises through the funnel and is expelled through the roof. A damper regulates the degree of temperature maintained. These housings are built in sections and bolted together so that they can be dismantled easily without disturbing the machine. The framework is built up of angles and covered with No. 8 sheet steel. The stack is covered with No. 18 sheet steel.
The substation at Lynn consists of a 1,000-kw., 650-volt converter set which is housed in the power house of the Lynn Gas & Electric Company. This substation is arranged for manual operation only, and is operated by the electric company's forces at a fixed charge.
A portable substation is arranged to be connected to the line at either Orient Heights or the Lynn substation, as the 13,800 feed is available at these points. This substation consists of a 1,000-kw. unit of the manually operated type mounted in a cab on a steel car. The transformer and oil circuit breakers are mounted on the car outside of the cab, making it a complete portable unit. The estimated power consumption per year for the line is about 10,000,000 kw.-hr. The Lynn Gas & Electric Company will furnish 2,500,000 kw.-hr. of this and 7,500,000 kw.-hr. will come from the Edison Electric Illuminating Company.
The line installation presents a number of unusual features. The actual construction work performed under many handicaps and in record time without seriously interfering with the normal flow of traffic. Throughout the day trains operated on a fifteen-minute schedule, and during the morning and evening rush hours, work was interrupted by passing trains every ten minutes. For this reason, a large part of the construction program was carried on at night. Between the hours of midnight and 6 a.m. the trains operate on an hourly schedule, thus permitting the delivery of materials and equipment by a special night work train.
The catenary supporting structure consists of 262 corrosion-proof steel bridges, spaced at a maximum distance of 300 ft. The towers of the four-track bridges consist of 10 in. channel, 15.3 lb., tapering from 6 ft. centers at the base to the center of the top bridge channel at a height of 22 ft. 6-1/2 in. above the rail. The towers are trussed with 2-1/4 x 2-1/4 x 2-1/4-in., and 2 x 2 x- 1/4-in. angles. The top channel of the four-track bridge is 12-in. 20.7-lb steel, and the bottom channel is 10-in. 15.3-lb. steel. They are spaced 3 ft. 2 in. apart and trussed with 6 x 5/16-in. crimped bars. The general dimensions of the towers on the three-track bridges are the same, except for the upright channels which are 8-in. 11.5-lb. steel. The upper channel of this bridge is 10-in. 15.3-lb. steel, and the lower channel is 8 in. 11.5-lb. steel trussed with 5 x 5/16-in. crimped bar. The signal and power wires are run on steel crossarms supported at a height of 5 ft. above the top of the bridge by 2-5-in. 6.7-lb. channels attached to the upright channels of the towers.
Due to the marshy ground along most of the track, unusually large foundations were needed for the catenary supporting structures. The foundations are of concrete, being 7 ft. 6 in. deep, sunk 6 ft. below the surface, 8 ft. long, and 2 ft. wide. The foundations on the three-track towers are 6 ft. deep, 8 ft. long, and 2 ft. wide. All towers are anchored to the foundation by means of eight 1-in. bolts of 4 ft. 6 in. length. Signal and power supply wires are carried on crossarms supported at a height of 5 ft. above the top of the bridge by two 5-in. 6.7-lb. channels attached to the upright channels of the tower.
To hold the trolley wire over the track on curves, steel pull-off poles were installed. These were set on concrete foundations at an angle, and laterally braced, no backbracing being used. In all, 161 of these poles were used ranging in height from 18 ft. to 23 ft. 6 in.
For the reason that the required feeder cable had sufficient strength to support the No. 0000 grooved trolley wire, a 500,000 c.m. copper cable was used as both messenger and feeder for the entire system. Hitenso trolley wire was used, consisting of 99-1/2 per cent bronze and 1/2 per cent cadmium. The messenger and trolley wire are bonded about every 600 ft. All hangers and castings are of non-ferrous material.
In the yards and siding, the overhead is direct suspension type. To prevent corrosion, all span wires are of red brass. No copper ground return is used on the system, the track being depended upon for the return. This is possible because all of the tracks are on a private right-of-way and there are few paralleling pipe lines to cause electrolysis.
The insulators supporting the messenger are G-E No. 294698, consisting of General Electric metal parts cemented to Locke insulators. The insulators supporting the short feeders running from the Orient Heights substation to the Winthrop branch lines are supported on this same type of insulator. The span wire insulators are Locke guy strain insulators No. 7664. The 2,300-volt signal and power supply line is carried on Locke 8,000-volt pin-type insulators No. 12. Due to the large number of overhead highway bridges crossing the track, about mile of wood troughs for the trolley wire had to be installed.
No more alterations than necessary were made to the track. The rails, which are 4 1/4-in. 60-lb., A.S.C.E. type were bonded with GE.H-3, No. 0000, 7-1/2-in. bonds, acetylene welded. The curves were graded for speeds of from 35 to 40 m.p.h. Under the bridges, where additional clearance was needed, the tracks were lowered.
The signal equipment furnished by the Union Switch Signal Company, included the installation of automatic block-color light signals operated from the 2,300-volt line through type H, 60-cycle, 3/4-kva. transformers.
The prepayment system is installed in all of the principal stations using General Electric turnstiles. Prepayment areas were fenced off around the station and before the electrification of the lines was completed, motor-generator sets were installed at each station to operate the new turnstiles. In the Boston station, which is across the harbor from the rest of the line, only 250-volt d.c. current is available. Therefore, two 5-hp. motor generator sets delivering 600-volt current to the turnstiles are used.
The actual construction of the electrification was started on April 2, and is now complete in every detail. The entire construction, installation, which was done under the supervision of Hemphill & Wells, New York City, was completed in seven months almost to a day.
- Trucks: Brill 177-E2
- Motors: General Electric 295-A, 600-volt
- Trolley: Nuttal. Trolley wheel No. 48. Harp-- Form 30
- Trolley base: U. S. 14
- Main switch: MS-118-A
- Fuse box: MA-13-F
- Contactor box: SB-72-A3
- Master controllers: C-503-A
- Reverser: DB-431-A1B
- Field control switch: ME-67-C1
- Grid resistors: Type BG-Form G
- Heaters: Consolidated Truss Plank
- Lighting fixtures: Electric Service Supplies Company, 1022 Dome Type
ELECTRO-PNEUMATIC BRAKE EQUIPMENT ON MOTOR CARS
- Master governor: ML Form E3
- Contactor (compressor switch): DB 937
- Feed valve: M3
- Motorman valves: A-Form D14 (modified to omit release pipe and to include the contactor pipe connection)
- Equalizing reservoirs: Two 10xl4-1/3 in.
- Contactors: duplex pneumatic
- Brake cylinder: Type S 12x12 in.
- Triple valve: M2A
- Supplementary reservoir: 16x42 in.
- Conductor's valve: B3A
- Slack adjuster: Form J
Because of the 36-in. gage the motors were specially designed by the General Electric Company.
A two-motor Brill truck is provided for on each car.
All electrical connections between cars are made by means of coupler sockets located in the ends of the car roofs.
This portable substation may be connected to feed any section of the line.
At left, the old cars before electrification. At right, the same type of car refinished and electrified.
The motor trucks are each equipped with two 60-hp. specially built motors.
Characteristic curves of the motor operating with a gear reduction, of 3.77 and 30 in. wheels. FS-1, full field and FS-2, tapped field.
In conjunction with the brake valve of the electro-magnetic brakes a pneumatic duplex contactor is used which energizes the holding or application magnets.
The Orient Heights substation houses two automatically controlled 1,000-kw. synchronous converters. Note the exhaust ventilators in the roof.
A housing is built over each rotary converter in the Orient Heights substation, making possible proper control of ventilation and temperature.
Automatic block-color light signals were installed.
The prepayment system using turnstiles was installed in the stations. Exit turnstiles were placed outside the station.
The yard at the east Boston Terminals where the ferries connect with the trains.