New-York tribune., 1908-06-29
or Mongol. and this railroad development SHOWS
that Russia means II to be Slav.
THE ECONOMY OF STEAM TURBINES.


Ever since the new Cunarders began crossing
the Atlantic last autumn much curiosity has
been entertained concerning their fuel con-
sumption. little light on the subject was
shed in paper recently read before the Bit
ish Institution of Naval Architects. IL was
there announced that on one of her WESTWARD
voyages few weeks ago the Lusitania covered
more than 1000 miles at an average speed OF
"a. 65 knots. At that time she developed 6oooo
horsepower measured at her shafts), ana
burned ] ,090 tons of coal daily.
Every modern steamship has many uses Ior
power besides that demanded for the task OF
propelling her. 1t was estimated that-ior her
lights elevators and other minor service the
Lusitania employed 14.6 per cent OF the fuei
she consumed. After making this discount
dividing the remainder by a. converting long
tons to pounds, 1t is found that each or Tue
65, 900 horsepower applied to the screws Gust
q pound and third Of coaI-1.33o, to be exact
an hour. Few vessels in the merchant MAJ INC
or in any of the navies OF the worlo ee'
horsepower with less than from Id 10 l'o
pounds OF coal an hour. On the race oi .le
returns the Lusitania's requirements on the
occasion mentioned must be regarded as eA-
tremely modest.
In comparing the Cunarders consuilp
with that of any other flyer this fact should
bine Is ascertaned at the shaft. The power
of a reciprocating engine is determined at the
! cylinder In the second instance n card on
which is automatically registered the pressure
behind the piston furnishes the OASIS for tiie
calculation Now between the cylinder anu
the shaft there is always a Ioss ranging SLY
expert engineers, from to 10 per cent. 81.
William H. White a distinguished British naval
architect estimates therefore, that If the Lusl-
tania had been equipped with reciprocating en-
pInes 10000 indicated" horsepower wouiu
have been required to match the work OF her
turbines With only 65 600 at the cylinder she
would have been perceptibly slower Further-
more ii would be necessary to make slsht
addition to the Lustanias consumptlon-ihah
ing the basis of comparison 1.43 or 1.4I POUNDS
TO the horsepower for an hOur-before the ecoi-
omy of any steamship having reclprocatlhe en-
gines could be accurately judged.
Even So the comparison would not be just
or particularly instructive unless speed was
developed as great as that of the Lusitania on
the occasion mentioned With every steamship
the fuel needed to the horsepower varies Win
speed One speed is almost invariabiy more
economical than another. A transatlantic run
at 20 % or % knots, with an hourly coal con-
sumption of from 43 TO Al pounds TO the horse
power would be an interesting ach1evement
no doubt. That the reciprocating engine was
the equal of the steam turbine in economy
would not be demonstrated, though, unless
with the same or lower fuel requirements
voyage should be made at 2465 knots Inc
prospect of such a performance Is at present
extremely remote Indeed, it looks very much
rs If the new Cunarders were fully two knots
faster than their best known rivals.