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ELECTRIC RAILWAY JOURNAL · Vol. 45, No. 19 · May 8, 1915 · pp 872-880.
The New York Municipal Car -- Brakes and Auxiliaries
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| NEW YORK MUNICIPAL CAR -- INTERIOR SHOWING THE GENERAL SEATING ARRANGEMENT AND VIEW OF SEAT FOLDED UP ALONGSIDE ONE OF THE ACTIVE DOORS; EMERGENCY LAMPS SHOWN OVER DOORS. |
Unusually Severe Conditions Are Set for the Air Brakes, in Which the Braking Pressure Is Varied According to the Load -- The Low-Voltage Coupler Greatly Simplifies Train Operation, Including Automatic Change of Marker and Tail-Lights -- Pneumatically Operated Doors with Spring Shock Absorbers, Automatic Speed Control, Buzzer Train Signals and Correct Posture Seating are Other Features.
In this article, which concludes the series on the multi-side-door car of the New York Municipal Railway Corporation, are described the braking equipment with its empty-and-load brake mechanism, the low voltage coupler, the interoperation of control, door, train light and train signal circuits, the automatic speed control, the heaters, signs and other auxiliaries. (For the preceding articles in this series, see Electric Railway Journal as follows: "Design," June 6, 1914; "Body," June 13, 1914; "Trucks, Brake Rigging and Draft Gear," Dec. 26, 1914; "Motors, Control, Conduit and Collectors," March 13, 1915, and "Lighting," March 27, 1915.)
The air brakes are of Westinghouse automatic type AMUE with electropneumatic control and graduated release. Further, they embody the features of rapid recharge after each brake application and of auxiliary reservoir recharge without releasing the brakes. Emergency application of the brakes is obtained instantaneously and simultaneously on all of the cars of a train from the opening of the motorman's brake valve, the conductor's valve, or rapid reduction of brake-pipe pressure from any other cause. The brake-pipe pressure is 70 lb., and full service application gives 50 lb. brake-cylinder pressure with a fully loaded train. The electromagnet valves of the brake system are operated from the 32-volt storage battery on each car.
As noted in the article of Dec. 26, 1914, all wheels of each truck are fitted with clasp brakes, two shoes per wheel. With 50 lb. air pressure in the brake cylinder, the foundation and truck brake rigging, which is designed for a leverage ratio of 12:1, delivers a combined pressure on each pair of brakeshoes equal to 90 per cent of the weight on each trailer wheel and 110 per cent of the weight on each motor wheel.
The air brakes are to be operated under the local and express run conditions already detailed in the article of March 13, 1915. Broadly speaking, local trains are to make a schedule speed of 15 m.p.h. between terminals of local service and express trains are to make a schedule speed of 25 m.p.h. between terminals of express service. Some trains will operate in local service entirely and others in mixed local and express service. The trains will vary from two to eight cars, weighing 120,000 lb. each when fully loaded. The average lengths of stop for local and express service respectively will be twenty and thirty seconds. The average lay-over at terminals will be three minutes.
One important requirement is that the air brake shall be capable of making full emergency application after, or superimposed upon, ten possible applications with an average interval of 430 ft. when the train is descending inclines over the East River bridges.
On straight, level, clean and dry rail with trains of two to eight cars using cast-iron brakeshoes and with a brake-cylinder pressure of 50 lb. for service and the maximum obtainable for emergencies the following rates of retardation are specified.
Service Stop -- From an initial speed of 50 m.p.h. the average rate of retardation during a service stop must not be less than 2 m.p.h.p.s., provided the product of the efficiency of the brake rigging and the average coefficient of friction of the brakeshoes throughout the stop, expressed in percentage, is not less than 9.5 per cent. The period of retardation includes the time from the instant full service pressure is obtained in the brake cylinder to the instant of stop.
Emergency Stop -- From an initial speed of 50 m.p.h. the guaranteed average rate of retardation during an emergency stop must not be less than 3 m.p.h.p.s., provided the product of the efficiency of the brake rigging and the average coefficient of friction of the brakeshoes throughout the stop, expressed in percentages, is not less than 9.5 per cent. Here the period of retardation includes the period from the instant the brake-valve handle is moved to emergency position to the instant of stop.
Full emergency pressure is applied automatically whenever the brake-pipe pressure is reduced below a pre-determined point, whether through leakage or other causes. While possessing maximum sensitiveness to increases in brake-pipe pressure for the purpose of obtaining release, the brake is free from the tendency to "creep on" due to slight fluctuation in brake-pipe pressure. Any failure in service of the electric control of the brake system in service or emergency application results in the automatic application of the brakes, without further manipulation of the brake valve by the motorman.
The D-2-F motor-driven compressor has a displacement capacity of 25 cu. ft. per minute at 600 volts. Its motor will operate the compressor at a minimum line voltage of 300 and a main reservoir pressure of 100 lb., and it will also operate satisfactorily on line voltages ranging from 300 minimum to 750 maximum. The compressor was subjected to a preliminary voltage test of 3000 a.c. for one minute, between windings and ground, while the commutator had to stand a voltage test of 200 a.c. between adjacent bars for one minute.
The compressor motor has ample capacity to operate for three hours continuously with 100-lb. air pressure in the main reservoir, on an average line voltage of 550, with a maximum temperature rise in the motor windings of 65 deg. Cent, above the surrounding atmosphere. Furthermore, the compressor must be capable of supplying the 1% cu. ft. of free air per car which the pneumatic door devices take at each station stop. It must also be capable of supplying the air for the chime air whistles.
One complete synchronizing system is furnished with each set of air-brake apparatus. This system is so designed that the first governor to cut in, after depletion of the main reservoir pressure, will close all compressor switches in the train simultaneously.
The compressor switch opens the motor circuit at a normal maximum of 750 volts, and is capable of opening, without injury, the compressor motor circuit during such current surges as may be caused by crossing gaps in the third-rail.
The governor cuts in and cuts out on a variation of 10 per cent of the main reservoir pressure, and its quick action is not influenced by a slow rate of depletion of the main reservoir pressure. Failure of any governor on the train to cut in does not affect the operation of the compressor switches on any of the cars in the train.
The emergency-valve (deadman's handle) feature in the motorman's cab has already been described in the article relating to motors and control. It is proper to add here that each car is equipped with the usual conductor's valve placed in the deck sill near the middle of the car.
Moreover the speed control equipment hereinafter described is so interconnected with the brakes that if a motorman disobeys a signal the brakes will apply automatically.
In addition to the usual gages, cocks, valves and other air-brake fittings, including American Type J automatic slack adjuster, there is installed the empty-and-load brake attachment described hereinafter.
All reservoirs are made of steel plate enameled inside to prevent corrosion and oxidation. They were tested by a hydraulic pressure of 200 lb. per square inch followed by an air pressure of 160 lb. per square inch.
All pipe used in connection with the air brakes is of iron lap-welded "Sherarduct." The fittings are of malleable iron, each tested under water with air pressure of 250 lb. per square inch. All pipe joints are made with shellac cut in alcohol, and the installation, when completed, was tested with a pressure of 125 lb. per square inch, at which pressure it had to be free from leakage. All unions are of rough brass with ground joints.
An individual spiral-shaft hand brake, especially designed by the railway, is available for contingencies. The ratio of this brake is 4:1, and it is operated by means of a ratchet handle. A drawing of the brake is presented in an accompanying illustration.
The object of the empty-and-load brake mechanism is to vary the braking power, as applied through the brakeshoes, in accordance with the variations in the live weight of the car. These variations are made when the doors are open; in other words, they occur only during the period of passenger interchange. The functions of this mechanism are carried out as follows:
When the doors of a car are opened, interlocks on the door-operating mechanism are in such position that an electropneumatic valve on the car body is energized from the storage battery. The action of this valve permits air to enter a vertical cylinder, which is mounted on the truck truss plank, and to push the piston of this cylinder outward and upward.
As the passenger load on the car increases, the movement of the elliptic springs on the truck tends to force this piston backward. This movement in turn actuates a vertical rack and pinion which are mounted on the body bolster. Any movement of the vertical rack is transmitted to a horizontal rack which in turn causes a connecting pullrod to vary the capacity of the auxiliary reservoir.
In this way the brake-cylinder pressure at full load is increased between 35 per cent to 40 per cent, with a 20-lb. reduction in the brake pipe. In case of an emergency application the braking power is increased practically 42 per cent. In short, the most efficient rate of retardation is maintained for any degree of loading.
The empty-and-load brake mechanism is also tied in with the selective acceleration feature of the multiple-unit control. This is accomplished by means of an extra winding on the limit switch whose modification of current input to the motors is controlled from a switch operated in connection with the empty-and-load brake mechanism.
A full appreciation of the great value of this improvement is obtained only when one considers the effect of a 40 per cent increase in the total weight, by means of the live load, upon the stopping distance of multiple unit trains as heretofore braked. The weight of the empty train determines the maximum braking power that can then be applied to it, and under the old conditions an increase of 40 per cent in weight meant lengthening all the stopping distances obtainable with the empty train by about 40 per cent when the same train was loaded. With the empty-and-load brake attachment, all trains can be stopped in the same minimum distances, irrespective of loading. The acceleration also is maintained at a uniform maximum for any given grade condition, irrespective of loading.
These important factors, together with the shorter spacing of block signals involved, permit a remarkable increase in train capacity on any rapid transit railway.
In place of the usual loose-fitting car couplers, double sets of air hose and train-line receptacles with removable jumper connections, the Westinghouse combined car, air and electric coupler was adopted for the following reasons:
1. Less time needed to couple and uncouple the cars.
2. Less hazard in coupling cars.
3. Freedom from possible accidents due to dragging jumpers.
4. Superior contact for train-line connections.
5. Saving in the cost of coupling cars.
6. Simpler installation, because one-half of the trainline terminals are eliminated.
7. No extra provision for housing in the cars or at the terminal for detached jumpers.
8. Simple and safe automatic operation of auxiliary contacts at the end of the train for marker and signal purposes.
9. Greater facility in cutting the train line to locate trouble, thus minimizing possible delays.
10. Material reduction in cost of maintenance.
11. Because there is no wear between car coupler faces, this expense in maintenance is eliminated.
Perhaps the most important feature of the automatic electric coupler is that only one operation is required, namely, that of throwing the coupling valve in the motorman's cab. On the contrary, with the preceding jumper system fully sixteen operations were necessary and only a few of this large number were due to safety gates, chains and other non-train-line devices.
When the motorman throws the coupling valve the main control, the speed control, the air brakes, the signal lights (including the extinguishing of marker and tail-lights between cars), the buzzers, and all other train-line auxiliary circuits are in normal service.
All of the foregoing advantages are made practicable by the fundamental fact that the car coupler, to which the air and electric connections are attached, is of the absolutely tight-lock type. When two of these coupler heads have been united the two parts become as one piece, so that when in service a thin coating of brake-shoe dust extends across the two, there is no crack to indicate the line of juncture.
One junction box near each end of the car and one at the center of the control box with terminal studs are provided to form the train-line connection between the automatic couplers, the master controller, the control box and the brake and auxiliary apparatus.
At the end junction boxes are outlets for all train-line wires, including the main control, speed control, brake, marker and tail-light and signal circuits. At the central junction box separate outlets are provided for the control circuits, the brake circuits and the battery supply connections. Each terminal clip is marked with the number of the wire to which it is to be connected, and the terminal board is usually marked with the train-line numbers on each stud.
As stated in the earlier articles the New York Municipal car has three pairs of sliding doors on each side and a single door at each end. One operator stationed on either side of the car midway between the two middle doors, is able, by means of the push-button board illustrated, to operate all doors on the side nearer to him, and, also to operate both end doors from the same position. He can also operate the doors on the opposite side of the car by manipulating the buttons on the opposite panel. In all, each car has fourteen door engines and eight electropneumatic valves.
All engine valves are equipped with an attachment for opening or closing their respective doors by hand from the inside of the car. The respective valves are also equipped with an attachment for opening and closing from the outside the two end doors and each pair of middle doors, by means of properly-protected push buttons outside the car.
The doors will operate at main reservoir pressures of 80 lb. minimum to 100 lb. maximum. It was specified that all door mechanism must be capable of making 300,000 strokes in service between applications of lubricant. The wear of operating parts during these periods must not cause valves or piston packing to leak. The variation in the time of door opening and closing between applications of lubricant must not be more than 10 per cent with an air pressure of 100 lb. per square inch in the main reservoir with atmospheric temperature ranging from zero to 90 deg. Fahr.
The door-operating mechanism, which was built by the Consolidated Car Heating Company, embodies some valuable improvements to meet the New York Municipal requirements. Probably the most important of these requirements was that relating to the time of the door-operating cycle.
The railway company felt that in a service with the short station stops specified a rapid yet absolutely safe door mechanism was essential. It therefore specified that all door engines should be capable of opening the doors in one and one-half seconds from the time that the operator pushes the button. This speed, however, is too high for door closing; consequently the time allowed for closing is two seconds. Thus by adding one-half second to the period of closing the entering passenger is not subjected to severe shock should he come in contact with the door. Still further to insure non-injurious closing a spring has been interposed between the piston and the door whereby the door is operated with a cushioning effect in addition to employing the usual rubber cushion at the edge of the door.
On the whole, this door-operating mechanism is a notable improvement over earlier designs.
At one of each pair of side doors is a folding seat which is so connected to a three-way cock in the air feed to the door engine, that when the seat is in use the respective door engine is cut out of action. Thus it is impossible to open the door until the seat is folded up to clear the door.
A buzzer-signal circuit replaces the slow and obstructive bell cord. The buzzer push buttons are mounted just above and on the same panel as the door-control buttons. This signal circuit is so wired that the guard who pushes his buzzer button transmits the signal no further than to the buzzers in the forward cab of his own car and the rear cab of the car ahead. In this manner the signal is transmitted ahead from car to car. The wiring is so arranged that it is impossible to skip a car. This circuit, which is fed from the storage battery, is closed by means of interlocks mounted in the door pockets, the interlocks being operated by means of attachments on the doors themselves.
The motorman depends upon the buzzer circuit only at such times as the light signal in the operating master controller is out of order. These lights burn only when all the doors in the train are closed. The light signal consists of two lamps of 6-volt automobile type, and as but one is in use at a time the possibility of total failure is very remote. The second lamp goes automatically into circuit when the first one burns out.
The circuit for the signal lights is so connected through the reverse drum of the master controller that the signal is displayed only in that master controller which is in the operating position, thereby avoiding waste of energy and unnecessary indications.
Between each pair of doors is mounted one 10-watt, 34-volt frosted-bulb tungsten lamp. The positive circuit of these lamps is connected to one blade of a double-pole, single-throw lighting switch. The negative side is connected to contacts on the voltage relay which is always energized when power is on the line. In the energized position the relay disconnects the negative side of the emergency lighting circuit. Therefore, when normal lighting is in service the main lighting switch will be in the closed position. On any failure of the traction circuit the voltage relay drops and the negative side of the emergency lighting circuit is completed to the storage battery.
The marker and tail-lights are interconnected with the control circuit in such a way that when the motorman changes train ends his tail-lights automatically change from white to red as soon as he throws the reverse handle to the center position; vice versa, the red lights turn to white on throwing the handle to the operating position. Should the train be broken up en route in any way, the tail-lights will go red at the point of breaking. This is accomplished by combinations in the automatic coupler and control as previously stated.
The two marker lights provided in each hood of the car have stationary white semaphore lenses. Colored disks of the Railway Signal Association standard colors are arranged inside of the hood, connected so that any desired color may be placed between the lamps and lens. The marker lights on each side of the hood are operated independently.
The tail-lights consist of one white and one ruby 4-in. diameter 2-3/4-in. focal length semaphore lens as per the Railway Signal Association standard colors in each set. They are lighted from the storage battery by incandescent lamps placed behind each lens. The lenses are held permanently in place by pressed steel retainers riveted to or pressed in the end sheet with removable retainer rings.
The heating equipment per car totals 21 kw capacity divided among thirty heaters with two coils per heater. All coils are interchangeable. The three-point system is used, twenty coils being in series on each point. Piping and wiring connections for thermostatic control have been installed in view of the possible later use of thermostats.
Destination signs are displayed in every car in the windows alongside the central pair of side doors. These signs are of double curtain type, as furnished by the Electric Service Supplies Company.
In concluding the description of this car it is fitting to add some details on the radically different type of rattan car seating. From the first the engineers of of the company had planned a seat which would not only be of the transverse type where practicable but which would also permit a more comfortable bodily position than previous designs. With the assistance of the American Posture League, an organization of experts on hygiene and anatomy, the design was improved still further by certain modifications in the angularity of the back and in the height of the seat cushion. In the seat as finally adopted, the distance from the highest point of the unoccupied seat cushion to the floor is 17-5/8 in. The league's ideal figure of 17-1/4 in. is approximated when the seat is depressed by the weight of the passenger. This height, as compared with the usual one of 18 in., permits good footing for all but very small children.
A still more important feature is that the back is so shaped that the rattan section begins at a height of about 5 in. above an inwardly curved metal section which forms the base. As shown in the several accompanying halftones and drawings, this formation of the back allows the lower part to fit the natural curve of the human spine, while the upper part gives a proper support for the back. The result is to place the passenger in the most restful position. Since his body is properly balanced he is also less likely to be disturbed by any sudden lurching of the car. The league has affixed its approval plate to the seats in the New York Municipal car, and will gladly co-operate with other railways to achieve scientific seat design. The seats are of the Hale & Kilburn Company's manufacture.
In lieu of the usual signal system employing fixed signals and automatic stop devices placed at certain intervals along the track, each car is equipped with a cab signal system so designed as to give the motorman necessary information as to when to apply the brakes, when to resume normal speed, the permissible speed, the available braking distance, and such other information as is necessary properly to control the train. In addition to the signals, each car will be equipped with a speed-control system which automatically applies the brakes if the motorman fails to obey the cab-signal indications. Also, the system is arranged so as to enforce obedience to fixed interlocking signals by automatically applying the emergency brakes if a train should attempt to pass such signals in the stop position.
Cab signals, one of which is shown in an accompanying halftone, are located in both ends of each motor car and are so arranged that their indications are visible only in the cab from which the train is being operated and controlled. Cab-signal indications are given by two lights as follows : A green light indicating "proceed" when the next two blocks ahead are clear; and a yellow light indicating "caution" when the next block ahead is clear and the second block ahead is occupied or is governed by an interlocked signal indicating "stop," or when the train is on a down grade or curve or when it has some other fixed hazard.
The audible signal, provided in each motorman's cab, is so designed and interconnected with the speed-control mechanism, that it sounds sufficiently long in advance of the automatic speed-control application of the brakes to permit the motorman to control his train so as to avoid the automatic application of the brakes. An indication is given in each motorman's cab to show the maximum allowable speed and the distance within which, succeeding the giving of a caution signal, the speed of the train must be reduced to the prescribed minimum to avoid the automatic application of the brakes.
The speed-control apparatus is so arranged that when a train runs into an unsignaled section of track a distinctive indication is displayed in the motorman's cab, and the cab signals and speed-control equipment are automatically put out of service and automatically return to service when the train again enters the signaled section of track.
The speed-control equipment does not interfere with the operation of the train so long as the motorman runs his train according to the indications of the cab signal, but, if the motorman fails to obey the "caution" signal, the speed-control apparatus enforces obedience by automatically applying the brakes, but only when and if the speed of the train, at any point, exceeds that prescribed by the predetermined braking curve.
When a train, running at a speed not exceeding the prescribed minimum, approaches a clear block, its speed-control apparatus is, prior to entering the block, automatically reset in such a manner as to permit the train to accelerate. If a clear block is succeeded by an occupied block, the train is permitted to accelerate, slowing down should the speed thus acquired exceed that established by the predetermined braking curve. If a clear block is succeeded by another clear block, the train is permitted to attain normal speed.
Suitable means are provided whereby, in the event of its failure, the speed-control mechanism on any car can be safely cut out of service in such manner as not to interfere with the operation of the speed-control apparatus on the remaining cars of the train.
The speed-control and cab-signal equipment is actuated by means of ramps located adjacent to the tracks at such points as provide the required track capacity and facility of operation.
The cab signals are block signals and indicate the condition of the blocks in advance; at crossings, junctions, terminals, etc., fixed signals, which are of the light type, are used to indicate the route set up. The indications of interlocking signals are given by one light as follows:
| Indication | Aspect |
| Proceed on same track | One green light |
| Proceed on diverging light | One yellow light |
| Stop | One red light |
The speed-control apparatus on each car is arranged so as to enforce obedience to the interlocking home signals by automatically applying the emergency brakes if a train should attempt to pass such signals in the stop position.
An accompanying drawing shows speed and braking curves for a typical block, which in this case is 1200 ft. in length. The emergency braking curve A represents the distance within which, succeeding an emergency application, a train is brought to stop before reaching the end of the block. The design of the speed control system enforces obedience to this curve by automatically applying the brakes in case the speed of the train, at any point, exceeds that indicated by this curve. The automatic application of the brakes takes place at varying distances from the end of the block, depending upon the speed, this being one of the essential features of the system. The usual system employs automatic stops with an overlap, the length of which is always based on maximum speed, and failure to obey a stop indication would cause an emergency application at the same point, regardless of speed. This requires that trains must be spaced apart a distance equal to the length of the overlap, which is usually a full block or more, whereas in the speed-control system trains can close up, provided always that the speed has been reduced to a point within the braking curve. In the speed-control system greater facility is provided, owing to the fact that trains can close up instead of being spaced a full block apart.
Curve B is the normal braking curve and represents the retardation which results from a service application of the brakes. Curve C is the audible-signal curve. The audible signal is given sufficiently in advance of the service-braking curve so as to avoid an emergency application if the motorman obeys the audible indication and applies the brakes. This curve is an important factor in facilitating traffic in the case of a train entering the block at less than normal speed as follows:
If a train enters an unoccupied block at low speed it can accelerate, as shown by curve D, until the curve intersects audible-signal curve C, at which point, if the brakes are promptly applied, curve D merges into curve B and an emergency stop is avoided.
Curve E shows a train proceeding at less than maximum speed, in which case the audible signal is given at the intersection of the speed line and curve C. If the brakes are promptly applied an emergency stop is avoided as in the preceding case.
A train can enter an occupied block, as shown by curve F, but cannot exceed the prescribed minimum speed. Curve G is a continuation of curve D and shows the acceleration attained if the block in advance is clear.
If two blocks in advance are clear, in which case the cab signal would show a green light, a train entering the block shown in the diagram mentioned could proceed at normal speed without interference from the speed-control apparatus. If the block in advance was clear but the second block in advance was occupied, the cab signal would show a yellow or "caution" indication and, if the motorman does not apply the brakes, an automatic emergency application of the brakes occurs, bringing the train to a stop before reaching the end of the block.
The diagram on page 880 shows the principles of the signal system. At one end of the track circuit a transformer, T, supplies electric energy which flows through the track circuit and, when the block is unoccupied, energizes track relay R, and its front contact closes a circuit from battery, B, or some other source of electric energy. Hence when a car is at a ramp, as in this case, current flows through the ramp, through the contact shoe S, and then through the car relay C, causing its armature to pick up, and back to the common return by way of the car axle and one of the track rails. In this condition current from the battery D flows through and energizes the green light G of the cab signal, which gives the "proceed" indication. Energy from battery D also flows through and energizes magnet E.
After the train has passed an energized ramp a retaining circuit is established by way of contact A, so that current from the battery D energizes the car relay C and the green light or "proceed" signal continues until the next ramp is reached.
If the track circuit was occupied, track relay R would be de-energized, and as a result the ramp, also the car relay C and the magnet E would be de-energized. In this condition current from the battery D flows through and energizes the yellow light Y of the cab signal to give the "caution" indication.
Magnet E controls the speed-control apparatus, which operates in the following manner: The rotating motion of the car wheels is transmitted by means of the bevel gears shown in the drawing, to shaft J, on which is mounted a centrifugal device or governor which is so arranged and connected that, as the speed increases, the arms K and L are moved to the left. The worm H is driven through the medium of shaft J and is held out of engagement with the worm sector N by the attraction of the magnet E. When the magnet E is de-energized, the worm H engages with the worm sector N, causing the cam M to move forward against the action of gravity. The shape, speed and general arrangement of cam M are such that if the speed of the train is not reduced, succeeding the giving of a caution indication, the surface of cam M, coming in contact with the lever L, opens the contact Q and the audible signal warns the motorman to apply the brakes.
If the motorman promptly applies the brakes arm L moves to the right, away from the cam M, thus preventing the opening of the contact U and the consequent application of the brakes. If, however, the motorman fails to obey the audible signal, the contact U opens and an emergency application of the brakes occur.
Upon reaching the next energized ramp the magnet E is energized, which disengages the worm H and the sector N, and cam M is restored to its normal position by the action of gravity, thus restoring the speed-control system to the normal condition which allows the train to accelerate. If the next ramp is de-energized, the train may proceed through the block only at minimum speed, which minimum speed is determined by the maximum radius of the cam.
The selector, shown at the left of the drawing below, in its proper position on the car, sets up the various "block combinations" and indicates the same to the motorman. Combinations are set up by selector ramps, in the center of the track, which lift up one or more of the tappets shown on the lower part of the selector. When lifted by the selector ramps the tappets latch up and are so held until a new combination is set up, at which time the former combination is knocked down by the center tappet. Complete information is given in the cab as to the point at which speed reduction must take place, in order that a lower speed combination may not be set up prematurely and apply the brakes. For example, if the change is to be from a combination of 50 m.p.h. and 1600 ft. braking distance to a combination of 20 m.p.h. and 400 ft. braking distance, first, a "caution" signal is given to the motorman so as to allow him to reduce speed, and, after the speed is properly reduced, the new combination becomes effective, and a "proceed" signal is given, provided that conditions in advance are proper. If the motorman fails to obey the indications shown in the cab, an automatic application of the brakes occurs.
The speed-control mechanism in proper position on the car is also shown in the cut. The operation of this mechanism is described in connection with the simplified diagram. The drawing of the speed-control mechanism shows the contact shoe in the proper position on the car, also the ramp. The contact shoe is of the lifting rotary type, in which the disk contacts with a ramp. The disk, which is inexpensive and easily replaced, travels over the ramp with a scrubbing movement which maintains a smooth contacting surface. The lifting of the contact shoe opens a circuit which de-energizes the car relay, if current is not flowing through the ramp, as described in connection with the simplified diagram. The cab-signal and speed-control system requires comparatively a small amount of simple, substantial and efficient apparatus, and affords maximum traffic capacity consistent with safety. The system is being installed by the General Railway Signal Company, Rochester, N. Y., under the Simmen patents for speed control.
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| NEW YORK MUNICIPAL CAR -- LOW-VOLTAGE AUTOMATIC COUPLER AS INSTALLED. |
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| NEW YORK MUNICIPAL CAR -- DETAILS OF HAND BRAKE. | NEW YORK MUNICIPAL CAR -- PUSH-BUTTON BOARD FOR DOOR CONTROL; HAND BRAKE BELOW. |
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| NEW YORK MUNICIPAL CAR--VIEW OF PANEL BOARD FOR AUXILIARY CIRCUITS. | [Top] NEW YORK MUNICIPAL CAR -- DOOR-CONTROL MECHANISM UNDER SEAT. [Bottom] NEW YORK MUNICIPAL CAR -- THE HUMAN BODY AND THE CAR SEAT. Fig. 1 -- The natural curve of the backbone. The proper points where a seat should give support are at the lower part of the shoulder (a) and the small of the back (b). Fig. 2 -- The prevailing style of street car and Pullman car seat, which, being padded at the wrong place, pushes the pelvis out and affords no support for the back. Fig. 3 -- The new "correct posture" seat which allows an opening for the lowest part of the back and is made to fit the natural curves of the human spine. |
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| NEW YORK MUNICIPAL CAR -- MARKER LAMP LAYOUT AND OPERATING MECHANISM. |
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| NEW YORK MUNICIPAL CAR -- VIEWS SHOWING CORRECT POSTURE SEATING OF DIFFERENT TYPES. |
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| NEW YORK MUNICIPAL CAR -- CORRECT POSTURE LONGITUDINAL AND CROSS-SEATS. | NEW YORK MUNICIPAL CAR -- VIEW OF CAB SIGNAL AS INSTALLED. |
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| NEW YORK MUNICIPAL CAR -- DETAILED DIMENSIONS OF CORRECT POSTURE CROSS-SEAT. | NEW YORK MUNICIPAL CAR -- TYPICAL SPEED AND BRAKING CURVES FOR SPEED CONTROL. |
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| NEW YORK MUNICIPAL CAR -- DIAGRAM SHOWING OPERATION OF SPEED-CONTROL SYSTEM. |
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| NEW YORK MUNICIPAL CAR -- SPEED-CONTROL SELECTOR; CONTACT SHOE AND SPEED-CONTROL MECHANISM. |
Sources: Electric Railway Journal, McGraw Hill Company, Digitized by Microsoft, Americana Collection, archive.org.
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