INTERURBAN AND CROSS COUNTRY WORK. 211
main feeder here would weigh about 96,000 1bs. and the
short feeder about 20,000.
We may now take up the station F and its connec-
tions. F is midway of its section and the only disturbing
factor is a small one, the town D. Its tendency would be
to move the load center of the scction G F toward F since
a town in such a situation would probably be tributary to
B rather than A.
The section G F would normally contain three or at most
four cars. The worst concentration of load to be expected
would be a pair at G with another pair between D and F.
Allowing 150 amperes for each pair and a maximum of
twenty-five per cent drop to G, we find about 600,000 c. m.
required. But G can draw part of its current from E.
Therefore we can take advantage of this fact and not only
use less copper from F to G, but reduce that from E to G.
Altogether we are unlikely to get more than three cars in
the vicinity of G calling for, say, 200 amperes. This would
call for only about 1,000,000 c¢. m. from both stations.
Since it is desirable to give one station the ability to ex-
tend some help to the other it is desirable not to cut down
the copper too much. One of the most practical ways of
doing this is that shown in the figure. Reducing the
main feeder from E to G to 500,000 ¢. m. we run a similar
feeder from F out to and beyond G, making the two feed-
ers of the same length. This leaves on the section G F
two cars unprovided for. As there may be an occasional
call for extra conductivity toward D, this section may well
be provided for by a 250,000 c. m. cable up to D.
The 500,000 c. m. feeder weighs 1500 1bs. per M feet,
and there is ten miles of it, weighing, say, 30,000 lbs.,
which is also the weight of the revised feeder from E to G.
The 250,000 c. m. feeder weighs 750 1bs. per M feet and
its total weight is about 15,000 1bs.
We may now pass to the final section, F B. Thecon-
ditions at B are similar to those at A. Allowing 200 am-
peres possible demand near B, about 750,000 ¢. m. will do
the work there. ‘There may be, however, a car or two