Publication: The Electrical Engineer
New York, NY, United States
A NOVEL ELECTRIC RAILWAY POLE-TOP.
A GLANCE at the electric railways in this country will show a number of poles of different designs now in use. How serviceable the different forms are will depend on the rigidity of the pole and partly on the design of the pole-top. That the pole should stand a great side pull without much bending was early seen, but only lately has due attention been given to the features needed in pole-tops. These should be strongly made, so shaped as to shed the water, and should iinsulate both trolley and guard wires from each other and from the pole. Then there should be ready means of taking up the slack in both of the suspension wires, and two insulators for carrying the feeders. These features seem to be embodied in the new pole-top designed by Mr. Edmund Verstraete, the electrician in charge of the construction of the Union Depot Railway Company's plant in St. Louis.
As shown in the accompanying engravings, it is an iron cap which may be used with either iron or wooden poles. The wooden poles do not need to fit it tightly, as the pull of the guy-wires will keep it pressed against one side of the pole. The pole-top is merely slipped over the end of the wood poles, the top adjusting itself. With iron poles a wooden plug and a wood bushing is used, as shown in the section Fig. 2. These bushings are thoroughly soaked with Simplex paint; and as the iron flange keeps the adjacent part of the pole dry, the top is always insulated from it. The lower end of the pole-top is flared out so as to shed the water, and keep the upper part of the pole dry; this insures the insulation of the trolley wire from the ground.
The suspension wires are wound on a drum, whose enlarged ends have six holes; a pin through one of these holes keeps the drum from unwinding. These pins cannot drop out, yet allow the slack of the wires to be readily taken up. The drums for the guard wires is 9 inches above that for the trolley wire, and is made of insulating material. The insulators for carrying the mains or feeders are above the guard wire; hence if both the trolley and the guard lines are put up before the mains are, the latter need not be slipped through between the suspension wires, but are readily thrown over the top and fastened to the insulators. The pole-top is well built, simple and inexpensive, and seems to be eminently practical. It is made by the Great Western Electric Supply Co., Chicago.
|Date completed:||January 27, 2011 by: Bob Stahr;|