New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1894-01-03
SPEED TRIALS FOR NEW CRUISERS

1KIal<S tOR NEW CRCISflLS.
ADVANTAGES CLAIMED FOR DIFFERENT
METHODS OF TESTING.
To the Editor Of The Tribune.
Sir: read with much interest the editorial refer
ence to the cruiser Marbeheads speed trial, and
the fact that the revised record OF data taken at
the trial showed that her speed was half-knot
below that first reported The reports show that
the trial was run at the wrong time. as the tide
turned during the run, something which must al
ways be avoided IL the present system Of making
the trials IS to be followed. The defects OF the
measured thirty or forty miles course system OF
determining speeds Of ships. followed in the trials
Of some of The vessels well known. and where
SO many thousands OF dollars depend upon minute
accuracy IN the determination Of the t6es and cur
rents alone a better system should be followed.
one important feature of the speed trials or the
new vessels Of the Navy Is that they must be abb
solutey accurate. the premiums or penalties
amount to, in the case Of vessels like the Marble
head 1900 for each hundredth Of knot; there
fore It Is manifesy to the interest OF the Govern
ment that the builders shall not be paid for any
speed not maintained The standardized screw
methods"-that u.s. making several trial runs over
a measured mile course to obtain a constantine
actual Of revolutions Of the screw required 10
run a knot-has been maintained by experts In this
and other countries to be the fairest and most ac-
curate. in that 1t enables the speed to be deter
mined within a hundredth Of knot on the other
hand the method of running In opposite directions
over long course has been objected to on the score
Of accuracy. 1t has been stated bv officers or the
Navy on more than one occasion that 1t Is dlihcut
TO lay off the long courses without the possibility
great enough 10 affect the results OF the
trial by several thousand dollars CnIess such d
Is steered exactly parallel 10 the me i}oinne
the beacons the vessel may run a greater distance
than credit is given to her for Then as mas some ONE,
times occurred. should the weather pecoine r,I
after running part Of the trial the vessel wout
be compelled t. lose the whole trial. nd 6efaI se9
be unsafe to run al high speed at such tme Cn
the measured long courses 1t Is as1 ea
IRE the force of the current. and the mater oi
lion to the speed as determined has been criticised
because the direction Of the current ma! hot De ne
comes necessary to correct for the angle which the
direction Of the current makes win me rhe eme
have been IN the trat oil ' c her
behead where The current % % a knots as
'et0' PRACTICAL objection 10 this method has been
raised by builders who when the trial is com
pleted know nothing definitely as TO the speed me
meanwhile they must keep their trial crews ddg
but under pay until they knoW ine in Iex he cases
OF the a nfm rg ChaT RI Sewar Olympia
Concord ana Bennngon sIme OF Wh aG ,a ma ,r sI
under the standardized screw method NO extra
Observers were necessary besides those o T or ore
All the observations were made by InenDe,rs Oh
a ahe beng 0 taken in duplicate check each
There are no tidal observaons or other data taken
for which hafe 70 pec o has been made
for good and all. Having completed Inc record
showing the relation Of speed and revolution inc
trial can be made anywhere, and thick weather or
fog will not interfere with 1t. unless the place OF
trial Is on a frequented route When the -FOUR,
hours run is made the results can be determined
within an hour afterward. and II Is then settled az
once for there corrections TO be applied ana
Tho result IA absolute and accurate This method
was fully considered and was unanimously recon-
rnendcd for adoption s the standard lnethoa by
~. Toa I'd on Construction composed Of i've chiefs
of bureaus and the Chief Intelligence officer OF ne
NAVY Department Another advantage or the
atandardzed screw system Is that II. after an
hours run the vessel should be stopped for rev
n,inutes on account Of hot journal or some other
cal:se the trial can be resumed anew whereas. II
On the measured course, the vessel would nave 70
return TO the beginning and go all over again. mus
losing two hours instead Of one. NJ
New-YCrk. Dec, is. 1873