The sun. [volume] (New York [N.Y.]) 1833-1916, 1898-01-09
ELECTRICITY AND STEAM.
A COMPARISON OF THE rive MEANS
OF SUPPL ZINC POWER.

OF SUPPL ZINC POWER
Ecsnomies or Electricity over Steam fse
Traction Purposes and Its Iimitations-The
Question Of Csal Connunpucn-A suGEess
tion for ExteudipE the Uses OF Eiectricity.
at is remarkable what a number Of persons
Of intelligence thero arc who have tho impress
sion that by tho use Of electricity fvo or six
horse power will do tho work Of fifty or
sixty horse power produced by steam" said an
electrician only a few days ago such n person
said to me in good faith that he believed that
electric motors would soon take tho place OF
steam locomotives for general railroad use.
because a little electric motor Of FIVE or six
horse power would be able to do the work OF
the heayicst engine. A lot Of clever inventors
have also been at work with this same idea, and
every once in n while some newspaper tells
about ono of their schemes and adds that the
invention is to rovolutionize railroading.
"The real economy Of the electro motor does
not lic in its being able to do any more work for
each horse power than could DO done by the
steam engine, but In the fact that tho power
for many motors can be generated at ono cen-
trail station under conditions of much greater
economy than can be secured in the locomotive
or in small separate plants, and also in the
greater efficiency for certain purposes OF a ro-
tary motor over the DISQUALIFICATION of the
ordinary steam engine. Speaking generally.
the power all comes from coal originally ana !
tho steam engine is used to drive the ~electriot
generators or dynamos, as they are called. ns
there are q hundred machines to be driven and
each of those would take Eve horse power they /:
would zach REQUIRE an electric motor Of the
same power as II the motor were q steam en- I
gine and the whole would require n central
station engine, which could furnish to them 800
horse power in the aggregate. The loss OF
power in good practice amounts to from 9 to
10 per cent. so that the central station must
actually produce. in such q case. fifty horse
power perhaps, more than the separate steam
engines to perform tho same work would bo
required to do.
You wonder, then, where the economy Of
using electricity liesi Let us consider this az
applied to the running of locomotives for in
stance. An express locomotive, running under
favorable conditions, will use about four pounds
Of coal an hour for each horse power produced.
Some runs have been made upon a consumption
of 36 pounds an hour for each horse power.
An engine drawing a local train will burn five
pounds OF coal ever hour for each horse power.
while the usual consumption of a freight loco
motive IL from six to ten pounds. Even this
does not take in the coal wasted while the en-
CINE is getting up steam, or that burned when
the fires are banked or thrown away when the
fires are drawn. Compare this with the re-
suits attained in good stationary plants. Some
OF t0eSC Will pTOuuCe power 1T III eApoHoo VI
1.5 pou nds Of coal for each horse power an hour,
while 1t is a roor plant which requires more.
than two pounds. In the new steamship
Kaiser Wilhelm dor Crosse the engines pro.
duce $1,000 horse power upon an average con-
sumption of 1Ls. pounds of coal for each horse
Coal can also be delivered and handled cheaper
at large central stations. and the other expenses
trio roads Is about 5 per cent. of the operating
expenses, while on steam roads it is ABOUT 10
1.-The real reason why the electric locomotive
does not at once take the place of the steam
the electric current for long distances without Q
great loss Of current through the electrical re-
roads operated by electricity, are divided up
into short sections, and separate copper feeder
ton. This Would not entail 50 much. expense
II 1t were not for the. fact that each feeder
MaTs as i in rs s lRere or tSer re w te%Sidhb @ a great sasG loss ss'
OF power. and the cost of the copper soon gets
e %b DC too ips great sshem no warrant far bnjl 5he in tbe Bpo IN s,zs;
underground, rapid transit railroad was being
investigated by a Sqgresme Court commisstiSSn
enormous amount of power which would be re-
CURED for the proposed train service would take
power ali came from one Station"
These antiquities we're very clearly set forth,
before the Chicago Electrical Association. and
Mr.. Marshall also points out a WY in which
'n sAs may FAY as ps a Ese engineer c aie see sass into ito the IHsf future
it is improbable that electricity will supplant
steam for general railroading purposes. but
there are some departments OF the work whore
the adoption of electricity will be q great adj
vanceInent. In thickly settled communities.
as parts of the New England, North Atlantic
and Central States. the railroads will be forced
to make changes in their service to successfully
compete with the parallel trolley lines.
with the present equipment 1t seems that
500 or 600 volts at most Is the limitation OF the
direct current motor. and long lines can only
be operated by placing power stations at FREE
quent intervals, say ten or twelve miles apart.
The transmission at this voltage involves enor->
nous losses or great expense for copper. On
one road recently tested the voltage varied
from 525 volts near tho station to 240 volts at
the end of a line seven miles distant. 1t Is OBJ
vious that for transmission alternating, cur
rents must be employed. How necessary. high
~voltages are may be seen from a little calcula-
Stillwell gives the cost of copper required to
deliver one horse power at motor shaft ten
miles from the generator. allowing n 20 per
cent. drop and copper Is cents per pound, All
500 volts. $7sO.75. and at 10000 volts, $1.95.
Thus 1t is seen that it costs 100 times as much
TO furnish copper at 500 volts as 1t does at
10000. A voltage of 10000 Is well within the
present engineering practice.
1T Is generally believed that alternating cur
rent motors are out Of consideration for trac-
ton purposes. and II is true that the expert
ments have not been successful on account OF
the low starting torque and lack Of regulations;
but the improvements which have of late been
made go far in perfecting this machine
~ rEDr