Middlebury register. (Middlebury, Vt.) 1886-1937, 1908-04-17

ascertained with great accuracy; and
since the losses in the motors, the trans
mission line. and the generating plsnt
were well known, 1t was a simple matter
to figure back to the power house and
determine the amount of kilowatt capac-
ity that would be required to operate
predetermined schedule Of trains. 1t
was assumed that the machine efficiency
of the steam locomotive was about equal
to the machine efficiency of the electric
motor. The broad difference in economy
between the two systems, steam and
electric, lies, of course, in the superior
efficiency of the water tube boilers of the
power house over the fire-tube boilers of
the locomotive.
The estimated saving in fuel, due to
power house boiler efficiency, when the
whole of the New York division is in op.
Grafton, was given by Mr.. w. s. Murray
at recent meeting of the American In
stitute of Electrical Engineers. The fig.
ures represent the saving of fuel on the
New York division when all freight and
passenger trains, now operated by steam,
are drawn by electric motors. TO haul
the express, local and freight trains of
this division by steam locomotives, in
| wolves the consumption respectively of
| 81. 900, 80 900, and $4,000 tons of coal
| When the whole division is operated
electrically, the amount of coal burned
at the power station for the respective
classes of service will be 10000, 90, 900,
and 10000 tons of coal; and the saving
in cost of fuel consumed by the electric
over the steam traction will amount in
one year to S341 ,470. In express service
by steam locomotives. 2,055 indicated
horse -power-hours are developed in the
evaporation of 1854 pounds of water.
which gives an average of % pounds of
water per indicated horse power hour
On local trains the evaporation works
out at 80 pounds of water per indicated
horsepower hour. The builders of tur-
bine generators are always ready to guar
antee the evaporation of 20 pounds of
water per kilowatt hour, which is the
equivalent OF 10 pounds of water per in
dictated horse power hour. From these
figures Mr.. Murray deduces that by the
electric method of traction twice the
draw bar pull can be developed for coal
burned under the boilers of stationary
plants, as compared with coal burned in
the fireboxes of locomotives.
In the same discussion the figures of
cost and repairs of twenty steam freight
and passenger locomotives on the New
Haven road were given, which show an
|
for freight engines, and SO cents for
passenger engines. The engine mileage
of the New York division of the New
Haven road amounts, per year, to 1886,
992 miles; and on these figures the oper-
ating cost of the locomotive service is es-
tablished at 1916, 962 per annum for the
maintenance and repairs. Compared
with this, the available figures on the
cost of electric locomotive repairs show
it to be about 9 cents per locomotive
mile. Increasing this by 25 per cent
and assuming that an equal number of
electric locomotives will do the same
work as the present steam locomotives,
it is found that on the item of mainten-
ance and repairs there would be a saving,
due to the adoption of electric traction
of $500 per annum. Hence the COM
bined net saving on coal and on locomo-
tive rep irs, by the adoption of electric
traction on this division of the road,
would amount annually to a sum of
1862, 470, which at per cent represents
a capitalization of 81 ,249,000.