On the side and upper roofs, over
these conduits for the lighting circuits, a strip of sheet iron is
securely nailed to the roof boards before the canvas is applied. The
wires under the floor are carried in ducts moulded into suitable forms
of asbestos compound. Special precautions have been taken with the
insulation of the wires, the specifications calling for, first, a
layer of paper, next, a layer of rubber, and then a layer of cotton
saturated with a weather-proof compound, and outside of this a layer
of asbestos. The hangers supporting the rheostats under the car body
are insulated with wooden blocks, treated by a special process, being
dried out in an oven and then soaked in an insulating compound, and
covered with 1/4-inch "transite" board. The rheostat boxes themselves
are also insulated from the angle iron supporting them. Where the
wires pass through the flooring they are hermetically sealed to
prevent the admission of dust and dirt.
At the forward end of what is known as the No. 1 end of the car all
the wires are carried to a slate switchboard in the motorman's cab.
This board is 44 x 27 inches, and is mounted directly back of the
motorman. The window space occupied by this board is ceiled up and the
space back of the panels is boxed in and provided with a door of steel
plate, forming a box, the cover, top, bottom, and sides of which are
lined with electrobestos 1/2-inch thick. All of the switches and
fuses, except the main trolley fuse and bus-line fuse, which are
encased and placed under the car, are carried on this switchboard.
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