38 POWER DISTRIBUTION FOR ELECTRIC RAILROADS.
shown in section by Fig. 122, and an elevation of a single
shoe in Fig. 123.
The supply rail weighs ninety-four pounds per yard
and is of rather odd shape, to secure sufficient weight
without making the rail too high, and to shelter the in-
sulating blocks. ‘The shoes are a little more than one rail
length apart, and are supported, as shown in Fig. 123, by a
double toggle joint having a rather limited play. The
weight of the shoe, about twenty pounds, is enough to
give good contact.
FIGS. 122 AND I23.
The return circuit is, of course, through the track
rails, which weigh about ninety pounds per yard, and are
thoroughly bonded with short lengths of copper cable. As
a matter of fact, during some weeks of successful operation
the bonding was incomplete, and contact was furnished by
the fishplates at many of the joints. The system has now
been working several months with entire suceess. The
cars, which run over the entire Nantasket Beach road, are,
of course, equipped with an overhead trolley as wellas with
the contact shoes, and from Nantasket Junction to the
Pemberton terminus the overhead trolley line is in use.
A KA 1 A AL S e