New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1906-02-28
COAL ECONOMY WITH TURBINES.

Though the owners and builders Of steam
ships have only recently come to realize that
the turbine requires less steam. and hence less
fuel, than the reciprocating engine it is now
evident that indications of this fact were dis
coyerable five or six years ago. In the expert
ence OF the torpedo boat destroyers Cobra and
Viper on which the Parsons engine had its
first real trial. there probably no sign of
economy Then came, in successive years, two
river boats for service on the Clyde, the King
Edward ana the Queen Alexandra. and ferry
boat designed to cross the English Channel. From
Il paper read before a Liverpool engineering
ciety few days ago ii appears that the King
Edward demonstrates its ability to travel fur
Their with the same allowance of coal than
a boat of the same size which had paddle
wheels and reciprocating engines. The side
wheel craft now gets 773 miles out of a ton
of coal. the King Edward SO and the Queen
Alexandra fully miles. What Is more, the
two turbine steamers travel faster than their
rival. The difference in fuel consumption be-
tween the first Channel boat having turbines
and the best paddle wheel steamer running on
the same route extraordinary. and it looks
now as if it was exceptional also. Tine old
vessel travelled more slowly than the new
one, yet it required "A per cent more fuel per
mlei
At least two reasons can be suggested for
the tardlness with which the economy of the
turbine was recognized. In a measure, no
doubt. this quality Overshadowed by the
increase in speed which the Parsons engine
made feasible. Again, there might have been
doubt about the justice of assigning all of
the gain effected to the engine and not credit
ing the screw propeller which was substituted
for paddle wheels. with any share of it,
much more significant comparison was possible
when the British Admiralty tried the two styles
of engine on cruisers having not only the same
model displacement and boiler capacity. but
also the same mechanism for utilizing the
power generated. The Amethyst and the To
Pare alike in everything except their en-
gines. However, the browning test did not come
until the new Cunerd steamship the Carrnania,
began running. less than three months ago.
She and her sister ship, over which the Car
mania showed her superiority, have a much
greater displacement than the two cruisers just
mentioned.
\ good illustration of the effect of these les
on the minds of practical men is afforded
by the bids recently offered for mail steamer
which is TO run between Constantinople and
Alexandria. The company which wants the boat
prescribed its dimensions and demanded a speed
of eighteen knots and engines of 1000 horse
power. The invitation ELECTED responses from
"A large number of builders, some British, some
Continental In the specifications preference
was shown for reciprOcating engines, but it was
stipulated that for the development of 1000
horsepower not more than 1O,S01 pounds of coal
IAN average of 1.343 pounds per horsepower
should be required per hour. Two or three
bidders proposed TO put in turbines, which
should give the requisite speed with 7,716
pounds per hour, an average of only IL
pounds per horsepower. There was an assur-
ance that nearly 80 per cent would be saved
by the use of Parsons engines. That figure is
not. of course. to be adopted a standard for
steamers of all sizes and speeds. 1t was the
estimated economy attanable with the particu-
lar vessel in question. For a larger or smaller
one. a faster or a slower one different figures
would doubtless have been given. But there
seems TO be no longer any doubt that at veloci-
ties above fifteen knots an hour the turbine
needs less coal than the most modern triple
expansion recipTOcating engine.