New-York tribune., 1886-08-13
STEAM YACHT RACES.
,EssONs IN THE DEVELOPMENT OF SPEED.
VELOCITY ATTAINED BY PLEASURE CRAFT AND
TORPEDO BOATS.

lCan 1dcnJ CiuD may DO btuuleU WIFI lItcIcSt W
show the development in the speed of steam Yachts
and other small steam vessels and perhaps assist in
making some forecasts IA to the probable improve
ments which will be made in these vessels in the
future. We have had for many years light side
wheel steamers Of the type of what were known as
the Harlem boats" that would easily run eighteen
or twenty miles per hour. but the limit for sea-
going vessels of small size very much less
The naval gunboats during the late Civil War only
ran eight or nine knots with occasional spurts to
ten. The larger class of gnnboats of the Npslc
type considered phenomenal. but they
coud only be forced to 113i knots, which
was about the speed of the smaller soops of
war under favorable conditions. At that time the
larger sloops of war of the Brooklyn class were
about knot or more slower. Speeds of twelve
knots were obtained with number of compar-
atvelv small yachts built soon after the war.
though generally such speeds were reported at
fourteen to sixteen knots. Numbers Of failures TO
obtain even twelve knots for long runs could be
recorded
The manufacture OF light vessels with large
power begun a number of years since by
Thornycroft and Barrow in England and by
Hcrreshoii in this country, all beginning with
fast small launches and gradually increasing the
size of the vessels Herreshof has, | believe
uniformly been able to do little better than the
efficient boiler The speeds obtained with torpedo
boats were phenomenal. Many will recollect the
sensation which resulted from the report that an
English-built torpedo boat, So feet long with 10
feet beam. had attained speed of 2l q knots The
detailed report showed that this speed required
AGO horse power. which was obtained with COM
pound engine having cylinders only II and II
inches in diameter with = inches stroke of rstons.
running about 400 revolutions per minute ste an
beng supplied by a locomotive boiler only Gig feet
in diameter and Il feet long. the fires being urged
by powerful fan blower The whole machinery
weighed only l2l. tons and the boat complete for
trial only 32l2 tons. In previous practice the
machinery alone for that power would have
weighed fully 10 tons. more than twice as much
as the torpedo boat and her machinery complete.
Hereshots Stiletto is about the same size as this
boat ana Is reported to make better speed a. should
be expected from the superiority OF its boiler.
Larger torpedo boats with increased speed have
| since been constructed.
| These torpedo boats indicate limit of speed
which cannot be obtained in practical yachts of the
same size. The hulls are made so light that neceS
sarily the quarters are greatly cramped and there
| is little space available for the comfort re-
| qured for yachting purposes. desirable yacht
must be a compromise between IA comfortably
arranged sailing vessel in which no space or
weight is occupied by machinery and torpedo
boat which is practically built to carry machinery
alone and the better yacht is the one in which the
! compromises have been made so judlciousiy as 10
ob,ain on the whole. the better result The lessons
of the torpedo boat are not to be lost. Their high
speed cannot it is true. be obtained in yacht OF
| the same size as there would be no room for
quarters, but the machinery eau be modified TO
secure some CT the advantages shown by the tor
pedo machinery and thereby save very much of the
/ 1t- te n
construction within the last ten years may be
| found in the adoption of higher steam pressures
and of smaller engines run at higher speeds. with
some reductions of wei ght IN the huls and httings.
As the results of these changes. however the speeds
of yachts have been materially increased.
In comparing the speed of yachts difficulty has
arisen from the fact that larger vessels faster
than small ones, and for time it seemed impracti-
| cable to Tx system of comparison which would
apply to yachts of all lengths. The speed of vessels
ofsimarmodel shOud.t d.theorcticallyvary as thecube
roots of their lengths and the writer found tna the
speeds of individual yachts of tho better class varied
very nearly as 81 times the cube roots of their
lengths which rule was found to apply very closely
to the speed obtained in the regattas of tie AmcTi-
can Yacht Club. and adopted by that club the
basis of time allowance for three of their cups
The Atalanta. DPS feet inches long. last year
ran so kuots in 3 minutes and seconds less than
that alto we'd by this rule AMI the Rival only 81
feet inches long ran the same distance in 3
minutes and 1 seconds less than the time allowed
for her length by the same rule Other vessels ran
even closer TO the time allowance than these,
though at less relative speed. showing clearly the
applicability of the rule. The Atalanta must he
taken as a sample of very excellent compromise
for Yachting purposes, having relatively great
speed and pie accommodations OF course it If
not possible with smaller yachts 10 do quite a
well for gh the yachts may run at the same
relative speed by the rule. the accommodations
decrease with the size of the vessel and become lcss
valuable.
There appears to have been littc done in this
country 70 utilize the experiments of Froude in
modelling yachts; in fact there are differences OF
opinion as 10 what the experiments show There IL
no doubt but that the lines OF vessel may be ~
shaped ~ to permit a much greater displacement
for n given horsepower than was formerly sup
posed possible The new English torpedo cruisers
of the Scout class are of about the same length
as the AtAlanta, but Of 1.43O tons. or more THAI
double her displacement, yet they are driven a
abont the same speed with 5000 horse power
which is some what larger in proportion than theiI
increased displacement. These cruisers have been
made rather too short for their displacement &
secure hardness in manGuvrng so that the full
benefit OF the new principle has not been obtained
In designing the lines of tho Lagonda now th'
flagship OF the American Yacht Club the writer
applied the principles Of Froudes experiments st
tar AS applicable as he understood them. with the
gratifying result that with the same power as thai
due 10 a llerrcshoil boat OF the same length whicl
would have had dlsplaoe ement Of but 80 tons, th'
Lagonda, with "A displacement of $40 tons, wa
driven AT the same speed This result indicatc
that considerable Improvement may be made III th'
future in the modelling of yachts by proper study
C cinle "A
attention except among English naval architects
The times of the Yachts III the regaGtas OF th'
American Yacht Club made over the same conrs'
vary in different years account of differences III
| the tide Last year the start was made on Hoo
tide which was adverse and finished on the ebl
tide which was favorable, 70 IL Was generally con
| IN. Inc Ind yes IIll iLe lIaG hid ND