A couple of days ago Rupert sent me a link to a Nov. 12, 1901, Railroad Gazette report on the heating and ventilation system of the then-new Seventh Street shops of the C&S in Denver. And what should appear directly below it but this interesting bit of trivia:
A New Third-Rail System.
The Rapid Traction Construction Co., Marquette Building, Chicago has been formed to market an electric third-rail system invented by Mr. E.W. Farnham, Superintendent of Car and Special Freight Service of the Chicago, Burlington & Quincy. The company proposes to equip steam railroads and street car lines with this system and also to build and operate suchelec tric roads. To show the working of the system a party of railroad men and others were taken tocly De, Ill., on the Chicago, Burlington & quincy, last Saturday, where a long siding has been equipped with Mr. Farnham's apparatus and an electric car was operated along this track. The third-rail is divided into sections anda section is charged only while a car remains in that particular section. The sections can be of various lengths.
The third-rail and feeders in the installation at Clyde are caried on supports alongside the track and are all enclosed in wooden trunking. Each truck of the motor car carries a contact shoe which always bears against the third-rail and mechanically sets the switches which charge the sections of third-rail. At the ends of a section a short piece of the third-rail is suspended on knife edges and a feeder switch is placed at either end of this swinging rail; one switch being operated when the car moves in one direction and the other switch when the car moves in the opposite direction.
When the forward contact shoe engages the swinging section of third-rail, the friction is enough to carry the rail forward, closing a switch and charging the section of third-rail ahead of the car and before the contact shoe of the rear truck has left the section back of the car. The switch points are held in contact by a shunt-wound solenoid, one winding carrying current for the motors and the other a small current for lights or heaters. When the car leaves a section the arm carrying the carbon contact points falls by gravity, leaving the third-rail dead. By using the shunt winding and always taking a small current for lights or heaters, the contact at the switch is not broken when the current through the motors is thrown off.
The principal claims made for this system are that dangers from a charged third-rail, as now used, are avoided and leakage losses are greatly reduced. The location of the feeders and third-rail, whether alongside or between the running rails, can be made to suit condition. The car at Clyde was operated satisfactorily last Saturday.