Brennan Trolley hanger

ELECTRIC RAILWAY DEPARTMMENT.

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THE BRENNAN TROLLEY WIRE HANGER.

The accompanying illustrations show a trolley wire hanger designed by Messrs. M. F. Brennan and P. F. Begley, of Lowell, Mass., and manufactured by the American Bolt Co., of the same place, of which Mr. Brennan is the general manager. It is designed for use on bracket arms and bridges, also under elevated railroad structures, its chief object being to furnish an elastic and yielding support for the trolley wire. It is made of iron, the lower part being in the form of a cylinder and containing a spring and spindle, the former made the proper tension to support whatever weight is required, and kept in place by means of a bushing fastened in the lower part of the cylinder with set screws. The spindle passes through the bushing and spring, its head resting on the upper end of the latter, and the lower end is threaded and screws into the top of the insulator to which the ear and trolley wire is fastened.

The weight of the trolley wire, ear and insulator varies from 30 to 40 pounds on each hanger, according to the distance the poles are set apart, and this weight on the hanger sets the spring. The pressure of the trolley on the under side is anywhere fiom eight to twelve pounds, according to the speed of the car and the condition of the track. When, therefore, the trolley is passing the hanger, with its pressure of eight, ten or twelve pounds, as the case may be, the spindle moves up, aided by the tension or strength of the spring, forming a cushion and saving the blow which the trolley would give to a rigid hanger.

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