The Washington herald., 1908-05-31

From the Scientific American.
At the recent meeting OF the Institu-
tlon Of Naval Architects a paper was pre-
sented by Thomas Bell on the speed Of
the Lusitania, which made public, for
the first time, the facts concerning that
discussed matter. the coal con-
sumption Of the new turbine liners.
In view OF the great secrecy which has
been maintained by the builders and own
ers Of recent turbine-driven ships, and
particularly those of large horsepower it
is decidedly gratifying to have. not only
the matter OF coal consumption, but also
all the principal data Of the PERFORM
ance Of one Of these ships. published for
the benefit of the profession. Among the
various tables given in the paper, the
moss valuable is the abstract Of the en-
gine room log for the third voyage west
from Queenstown to New York, which
commenced at noon, November 3 ast,
and finished of Sandy Hook at 1:l4 a.
m. on November s.
Thousand Tons n Day.
The total distance run was 27Sl knots:
the time days. IS hours. 40 minutes; the
longest days run, 61s miles. and the aver
age speed Of the whole voyage. 2425 knots.
The average daily coal consumption for
the four complete days Of about twenty
five hours each was 1850 tons.
Just here It is interesting to note how
exact is the art Of designing fast steam
ships. as shown by the fact that the es-
timated coal consumption, when the de-
signs were drawn I'D. was LOO tons
average per day. The total bunker ca
pacity Of the Lusitania is $500 tons, or
sufficient, at this rate Of coal consump-
ton. 10 carry the ship 800 miles farther
than the distance from Queenstown 10
Sandy Hook.
On the voyage referred 10. the actual
amount OF ccal consumed for the engines
was 1876 tons. while eighteen tons was
consumed IN the galleys. sc. II should
be noted that the mean draught OF the
ship was about thirty-two feet: and her
displacement about 5000 IONS. The
weather throughout the trip IS described
as having been the average mid-Atlantlc
winter weather, with strong winds and
boisterous seas.
During the first half OF the voyage the
mean speed was A65 knots; but a furi-
Gus southwesterly gale served 70 reduce
the speed for the last twenty-four hours
below 2 knots. and to bring down the
mean average OF the whole trip to PAS
knots
or great interest. also. are the figures
offered by Mr. Bell OF the data secured
on the 1.2O0-mile trial The horsepower,
as determined BY the shaft torsimeter.
was 6s,SJO. giving an average speed OF
25.4 knots. The total consumption OF
steam In the turbines in pounds per hour
was $3.50 and the total consumption Of
| the auxiliaries was 1850 pounds per
hour. The steam consumption Of the
turbines in pounds per horsepower hour
was 12n and the total steam consump-
ton for all purposes was 144S pounds
per horsepower hour.
Same ms German Liners.
The coal consumption per horsepower
hour worked out at LS. including. OF
course the auxiliaries. Now, this con-
sumption Is about the same as that of
the high-speed German liners. using null
tiple expansion reciprocating engines,
Howden's forced draught, and other mod
ern refinements. Mr.. Bell and those re-
spOnsible for the Cunard ships are 70 be
congratulated on having published these
data and thereby set at rest the absurd
rumors, to the effect that the coal con-
sumption on these big ships was SO
great that they had, at times, difficulty
in making port.
During the discussion OF the paper the
| builders both OF the Mauretania and
Lusitania expressed their confidence that
when the working stan had become thor
oughly conyersant with the ships. speeds
equal to those obtained on trial would
be realized. under favorable weather con-
ditiOns on the Atlantic passage. IN this
connection II is interesting 70 note that
on trial the Lusitania averaged 25.4 knots
and the Mauretanie 26.0l knots over a
course Of 200 knots.