Engineers Report on Brooklyn Elevated (1924)
Electric Railway Journal · Vol. 63, No. 18 · May 3, 1924 · pp. 691-692.
Engineers Report on Brooklyn Elevated. Ridgway-Swain-Klapp Committee Discusses Desirable Track and Equipment Standards in Its Report Just Finished on Brooklyn Elevated Functions and Requirements of Guard Rails Considered at Length.
Some suggestions on track and car maintenance, with comments on the condition of Brooklyn's elevated railway system, are contained in a report just made to the Board of Estimate and Apportionment, New York, by George F. Swain, Eugene Klapp and Robert Ridgway. These engineers represented respectively the Board of Estimate and Apportionment, the Brooklyn-Manhattan Transit Corporation, and the New York Transit Commission. This committee was appointed in July, 1923, after an accident on the Brooklyn elevated railways, in which both cars of a two-car train left the track, and the committee was instructed to report on "the present condition of the cars and road equipment in use on all of the elevated railroad lines in the city of New York." The present report relates to the lines of the Brooklyn-Manhattan Transit Corporation, which aggregate 46.861 miles in length. As many of the suggestions contained in the report are of application to other rapid transit lines, a brief summary of these general points will be given:
GUARD TIMBERS AND TIES
The standard elevated railway track construction of the company on tangent calls for longitudinal timbers outside and inside of each rail, known as "guard timbers," of a 6 in. x 6 in. section. The outside guard timber is placed with its inner edge 11 in. from the inner or gage line of the rail; that is to say, about 8-1/2 in. from the outside of the head of the rail, while the inner guard timber is placed 6" in. in the clear from the gage line of the rail. These guard timbers are bolted to alternate ties, the inside guard timber being bolted to the ties to which the outside guard timber is not bolted. If a derailment occurs, the function of the guard rails is to guide the derailed trucks.
The inside guard rail can do this better than the outside guard rail, for two reasons. The first is that if an axle with its wheels is derailed, the wheel which comes in contact with the inside guard rail will have its flange running along that guard rail, while if the other wheel is being guided by the outside guard rail, the outside of the tread will be running along that guard rail. It will be much easier for the wheel running alongside the outer guard rail to climb over it than for the other wheel to climb over the inside guard rail. In the second place, if a derailed wheel is guided by the inside guard rail, it is being retarded, while the other wheel on the same axle, if not against the guard rail, is not retarded. The effect of retarding the wheel which is running against the inside guard rail is to twist the axle in such a way as to turn the wheel toward the rail from which it fell. On the other hand, if the other wheel were running against the outside guard rail, that wheel would be retarded, and the effect of this retardation would be to twist the axle in such a way as to turn the wheels from the rails from which they fell and to facilitate their climbing over the guard rails. To enable the inside guard rail most effectively to guide a derailed truck, it should be smoothed, round and even on the side toward the track rail, no matter how uneven it is on the other side.
If the guiding is to be done by the inside guard rail, the clear distance between it and the track rail should be at least as great as the thickness of a wheel, or 5-3/8 in. To allow some clearance for joints, etc., the inside guard rail should be not less than 7 in. from the track gage line. If so placed, the outside of the opposite wheel, as shown in the engraving, will be 9-1/4 in. from the gage line of track, so that the outside guard rail must be spaced at least this distance away in order that the inside guard rail may guide the derailed wheels. In fact, wherever the inside guard rail is placed, the outside guard rail should be at least 4 ft. 10-3/4 in. distant, measured from the inside edge of the inside guard rail.
Diagrams Showing the Action of Guard Timbers on Derailed Wheels.
What then is the function of the outside guard rail? It is twofold. One function is as a precaution in case the inside guard rail should fail. The outside guard rail also holds the ties at the proper spaces and prevents their becoming bunched. The inside guard rail, however, is more important, and as its inner surface should present a smooth continuous surface to guide a wheel running along the ties, it is better to use steel rails as inside guard rails rather than timbers. These inside guard rails may be used rails and should be spiked and otherwise securely fastened to every tie, and placed at such a distance from the track rail that a wheel can roll freely between the two and will be guided by the steel rail before the other wheel on the opposite side of the same axle touches the outside guard timber.
There are other advantages of steel inside guard rails over wooden rails. The maintenance should be less, and they can be used, if desired, as an additional return circuit. Again, as the company substitutes new running rail for worn rail, the latter can be moved inward and used as a guard rail. At the approach to curves the committee recommends a change from this inside guard rail, 7 in. from the track rail, to the usual form of check rail, bolted to the inside running rail. At its outer ends this check rail should be curved outward toward the center of the track and an inclined casting placed between it and the track rail. This will provide a sort of rerailer to replace a derailed wheel on the track.
Ties may be renewed in two ways. According to the first method, if any single tie needs renewal, it alone is replaced. This method is suitable on steam roads, because the roadbed is elastic and each tie can be tamped to bring its top to the proper level. With the method of complete renewals all ties in a considerable length of track are renewed, though some of these ties may have some service life remaining. In general, this method is better for elevated railroads than the first method. On such lines if a single tie of a standard dimension is put in to replace a decayed one, it will seldom exactly conform to the level of the adjoining ties, and being new and sound, it will be more rigid than the adjoining ones under the application of the load. This means that it will lead to undue wear or deformation of the rails and fastenings, especially if the new tie is a joint tie, where the adjoining tie and others near it are poor.
Where this method is used, some of the good ties removed may be used again in other places, as in yards or footwalks, or where the track is on the ground.
The rigid enforcement of one system of repairs to the exclusion of all others is not advocated in the report. There may be many cases of split ties, burnt ties, or prematurely rotten ties, which it would be advisable to take out and replace during the fifteen or sixteen years of life fairly assignable to any considerable stretch of ties.
CAR EQUIPMENT AND REPAIR
The company's rolling stock consists of 648 wooden motor cars, 259 wooden trail cars and 900 steel motor cars. The present report covers only the wooden cars, and the condition of the steel cars will be considered later. The report is based on an inspection of 10 per cent of the wooden cars, which were taken as typical of all.
The company's rules require that each car shall have a general overhauling once in fifteen months. At such times the trucks are removed from the cars and the motors from the trucks, and all parts of the body and truck are thoroughly cleaned, tested and put in good repair. Each motor car has a regular periodical inspection after 1,000 miles and every trail car after 1,400 miles, with an allowance of 150 miles above and below the specified mileage in each case. If this mileage is not made, the cars are arbitrarily ordered in for inspection, every sixteen days for the motor cars and thirty days for the trail cars. When a condition is found that is considered dangerous, the cars are ordered to be kept out of service until repairs are made.
The shop facilities of the company have not kept pace with its needs. This is shown in the accompanying table:
|Length in linear feet of...||1907||1923||Increase Per
|Track in inspection sheds||6,122||8,192||34|
|Track in repair shops||3,864||4,344||12|
|Track in total shop facilities||9,986||12,536||26|
The company could well consider the matter of offering bonuses to employees who discover defects in any important part of the equipment.
Throughout the report the committee makes certain recommendations of a general nature or specifically in regard to portions of the system.
Under track the committee specifies a number of places at which renewals of rails, ties, guard timbers, etc., should be made. It says that all of the company's track and decking is safe at present, but if not sufficiently maintained some parts will become unsafe. As regards the structures, it says that many of them, having been constructed a number of years ago, involve details which would not be considered good design now. Reinforcement is considered desirable in view of present stresses. Attention should especially be given to the protection of the column bases and to painting the structure. The recommendation for the rolling stock includes the grounding of the frames of all electric heaters, the interconnection of the dead man's button with the brake system to stop a train, a change from clear glass to an opaque material in the side window in the motorman's cab to prevent his attention being diverted by passing objects, more rigid inspection and a hastening of the construction of the proposed Coney Island repair shop.
REPORT OF CITY COMMITTEE
The report of this committee of engineers was transmitted to the Board of Estimate by a committee of city engineers, made up of J. H. Delaney, G. P. Nicholson and A. S. Tuttle, making some additional recommendations. This report declares that a large amount of reconstruction will be required to the structure before it can be used for the operation of steel cars. A number of changes in the equipment were also recommended.