The Thomas A. Edison Papers Digital Edition

Transcription

LIST OF REQUIREMENTS FOR ELECTRIC RAILWAY MOTOR. 
Weight on driving wheels 60,000 lbs. 
Speed required 30 miles per hour, but motor must work with high efficiency at all speeds from 0 to say 100 miles per hour. 
Weight behind motor 450 tons. 
Rate of grade 26 feet per mile virtual. 
Diameter of driving wheel must not exceed 6 ½ ft. No rigid wheel base. 
It is desirable to cushion weight of armatures and fields on journals. 
Driving journals to be coupled together by a frame allowing sufficient latitude to permit axles to assume a radial position on curves of 20 degrees maximum. 
Load should be distributed on not less than two driving axles and a wheel base of sufficient length to prevent longitudinal rocking of car. Minimum length not less than 15 ft. 
Motor should be designed with a view of having the center of gravity as low as possible. 
Minimum clearance between top of rail and lowest part of motor (except pilot) to be not less than six inches. 
Gauge of track 4 ft. 8 ½ in.
Motor wheel thread and flange in accordance with the standard established by the Railway Master Mechanics Association. Motor to be provided with the usual air pump [illegible text] by the special motor for the purpose. 
All drivers to be furnished with Westinghouse standard brakes to be applied on horizontal axis through the center of wheels. 
Provide two shoes for each driver. 
In addition to the Westinghouse air brakes, electric brakes are suggested for engine but with reference to future extension to train use. 
Armatures should be wound directly upon the driving axles if possible and the use of gears, sprocket wheels and belts of any kind should be avoided. 
The cab should be equipped with Westinghouse standard train signals and arrangements provided for electric circuit throughout the train to conduct current for lighting, signals and for an alternate contact at the rear of train. Also suitable Alarm Bell and Whistle Trolley for rear contact to be under care of brakemen, and allow control as to current by the motorman. This rear contact is provided for the purpose of bridging gaps of any nature. (at street crossing etc.) 
Provide proper means for starting motor gradually and smoothly from state of rest to full speed. 
The extreme width of motor must not exceed 10 ft. Extreme height 14 ft. 
Cab [seats?] must be as high and command some view of track and train as are present in use on the American R. R. Steam Locomotive. 
The cab to be provided with glazed openings on all sides to permit unobstructed view in every direction. 
Establish position of motorman in center of cab and arrange for mirrors at sides or corners to show by reflection the sides of the train from front to rear. 
Arrange for air signal or bell signal in each coach to enable motor driver to signal trainmen. (Calls for brakes, etc. in case air does not work.) 
Head light for oil and to be located preferably on top of the cab and pivoted so that it can be turned in any direction at will. 
Motor must be provided with pilots at both ends with suitable buffers for protection of ends of motor. 
The Motor machinery, armatures and field magnet should be encased or “iron clad” and should be dust and water proof. Frame bearings and oil boxes to be provided for on the outside of the wheels. Bearings for field magnets to be inside or between the wheels. 
Particular attention should be paid in the construction of the motors to avoid overheating of bearings. 
Provision must also be made for heating the cab. 
Contact by trolley wheels must be set positively on either side of motor and at both ends to allow current to be picked up at will from either side and to permit motor to bridge gaps of any kind. It must engage and disengage with the trolley bar with facility and certainty. 
Center and trolley bar should be 6 ft. 6 in. from center of track and from 4 ft. in height to three inches in height above top of rail, and should be designed to form contact from either side for double track use. The trolley bar should generally be placed from 3 to 4 ft. in height. Lesser heights to be used only in special cases – in yards and other locations where a greater height is not permissible. 
The form of contact between the cars should be such as to dispense with the necessity of a separate operation and should be arranged in connection with the couplings air or stem hose connection so contact is made at single operation. 
If possible a high tension current either alternating or direct, with transformers should be used, provided that the expense is not prohibitive, in order to reduce first cost of conductors,. Taking into consideration the necessity of high velocities of local trains between city stations and for through trains traveling within city limits, a difference in the potential of the current supplied to the trolley bars for city and country use seems inexpedient. It is recommended that the track be divided into electric blocks of economical length so arranged that the traveling motor approaching any station will automatically turn the current on to that suction and shut off the current from the section which it has left. This suggests the possibility of establishing a safety block system by means of suitable indicators on the motors and at stations, by which the presence of two trains on the same section could be instantly detected. 
Pilots, couplings, buffers and draw gear attachments are to be provided for both ends and must conform to the standard railroad requirements. 
J. W. Kendrick. 
G. W. Dickinson. 
K. [L.?] Hilgard. 
Julius Meyer. 
J. C. Barber. 
F. W. Fratt. 
Dr. W. T. Barnard. 
E. H. McHenry.