ALTERNATING MOTORS FOR RAILWAY WORK. 195 
location. 'The average distance of transmission would then 
be 314 miles, quite nearly 17,000 ft. 
The maximum voltage for standard generators may be 
taken as about 600, giving with fifteen per cent loss 510 
volts at the motors. Each station would have to be able 
to deliver 60oo amperes at a distance of 17,000 ft., with a 
lcss of ninety volts. Falling back on our stock formula 
Wees oy 8 20d X 600 X 289 = 80,920 lbs. 
90 
At current prices (fifteen cents per pound) this would 
mean the expenditure of $24,276 for feeder copper for the 
two stations. The annual output for both stations would 
be about 2,000,000 k. w. hours. 
The operating expense of two stations each of 300 
k. w. maximum output would, of course, be decidedly 
more than if the output were concentrated in a single 
station. The extra expense due to this cause can be esti- 
mated with fair accuracy. With coal at about $3 per 
ton it would probably amount to o.25 cents per kilowatt 
hour, the difference between, say, 1.5 cents per kilowatt 
hour with a single station and about 1.75 cents with the 
two stations. The total extra expense would be then 
about $5000 per year. 
With a booster system the principal gain would be 
the ready use of the extra working voltage on the line. 
The motors could with advantage be run at 575 to 600 
volts giving, say, 700 volts for transmission. The dis- 
tance of transmission would, however, be doubled, as the 
best situation for the station would be the center of the 
line. Taking now the average distance as 34,000 ft. the 
current, reduced by the extra voltage, as 525 and the per- 
missible volts drop as 105, we have as before 
W — 42 X 525 X 1156 
105 
for the transmission in each direction, giving a total of 
double thisamount costing at 15 cents per pound %72,628. 
The boosting apparatus would probably add $2500 to the 
cost of the station, and the cost per kilowatt hour generated 
= 242,760 lbs.