The Savannah morning news., 1900-08-06
ELECTRICITY ron SHIP POWER.

In a recent magazine article Mr.. Niko-
la Tesla discussed electricity as the pro-
pelling power for ships, in a manner that
indicated his belief that at no very dis
tant day the steam engine would be dis
placed at the propeller shaft, and the
electric motor would take its place. Mr..
Tesla spoke of employing steam to gem
crate the electricity with which to turn
the shafts and also suggested that gas
engines might be employed in the place
of steam engines. The probabilities are
that the article in question did not en-
nance Mr. Teslas reputation among the
engineering profession. Technical experts
have had no difficulty in picking what
they believe to be fatal flaws in his the
cries. Mr.. W. F. Durand, a marine con-
structor, is one of the experts who take
issue with Mr.. Tesla. In the Marine
Engineering magazine Mr.. Durand points
out how ship propelled by either of
the Tesla plans would be both slower
and more expensive than a steamship.
Surprising, he says. that steam appa-
ratus were used to generate electricity
with which to actuate motors driving the
propellers; the process would necessitate
two transformations of the power before
il reached the propellers involving a loss
of not less than 10 to 10 per cent. of the
energy That would require correspond
ing increase in the consumption of coal
and the increased weight carried by the
ship would make her travel slower for a
given coal consumption. The storage bat
terry plan would be impractcable, for the
reason that batteries capable of running q
ship across the ocean, would be heavier
than the ship itself. 1t has, of course,
been demonstrated that light launches can
be run with storage batteries where they
can be re-charged every five or six hours,
but it is quite a different matter when
one comes to consider the running of a
great ship for two hundred to two hun
dIed and fifty hours continuously with
out touching a station for re-charging.
No engine and no battery is at present
in sight which would change the facts
as stated above.
With respect to gas engines as the ins-
tial source of energy, Mr. Durand points
out that the gas would have to be manu-
featured from coal aboard ship. That
would require the carrying of heavy gas
plant, and an increased staff of expert
opera tives. The loss of power in the trans
formation into electrical energy would be
as great as if steam instead of gas were
used. Gas engines of stated horsepow-
er are always heavier than steam engines
of similar power. Thus a gas establish
ment, besides costing more for opera ton,
would sink the ship deeper in the water
and make her progress slower and more
expensive. Furthermore, no gas engine of
more than a few hundred horsepower has
ever been constructed, and it might prove
difficult to get any builder to contract for
gas engines that would develop the 10000
or more horsepower required by the mod
ern ocean-going vessel. 1t is possible
that gasoline might be employed, as in
automobiles, but il would prove so ex-
pensive that it could not be made profita.
Bile. Gas. gasoline and electricity are I'M
questionabiy good things, according to Mr..
Durand, but there is limit to their avail
ability. The time may come when inven-
ton will adapt them to ocean going ships;
but that time is not present, nor is i,
in sight.