New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1917-05-13

designed these boats for foreign ser
vice, and wishing TO stimulate an inter
est among private owners who might
build boats which would be suitable
'or patrol work in the event of war.
the department solicited designs for
two such boats.
The first was to have speed Of 25
miles an hour and cas- TO cost not
more than $4,000. The second was to
be a 3O-miler. 10 cost not more than
$4,000. The designs which were &C
cepted were 45-footer. by A. Loring
Swasey, and 66-footer, by A. T..
Luders. from both which boats were
built.
Further TO stimulate interest among
yachtsmen, the Navy Department or
gained manpuvres for motor boats,
which were held last fall in the several
naval districts along the Atlantic Coast,
and number of enthusiastic yachts
men. mostly from Boston. the habitat
of the species, built boats for these
man9uvres. Notably among them was
a fleet of seven uniform 40footers
from Mr. Swasey's design, which were
prominent in the operations of the I'd
Naval District. These little boats
proved all that could be expected, but
were too small for the more strenuous
ofshore work.
Extreme Speed Idea
The early idea was that a submarine
swatter should be very fast and easily
maneuvred above all else, and while
extreme speed is no longer considered
worth the price in comfort and sea-
worthiness which must be paid for its
attainment. the latter quality is de-
cidedly essential and should not be lost
sight of in our tendency toward bigger
and bigger boats.
Another idea, dear to the hearts of
the newspaper writers, was that the
boats should be so shoal of draft that
they would be immune from torpedo
attack. And less Importance was
placed in the armament, il being popu-
larly supposed that any sort of gun
would do to shoot up the periscope of
\ defenceless Uboat.
Then. when it was appreciated that
shoal draft was more of talking point
,han anything else. for the reason that
no sane submarine skipper would chance
was seen that the U-boat was no longer
defenceless, vulnerable thing, but
had become an armed and armored
fighter, the tendency was toward larger
boats. But some designers chung to
form of hull with much faster lines
than the available power and the usual
condition of the sea would permit them
TO use.
Forms of Hull
II is not necessary to employ the
same extreme form of hull to attain a
given speed in large boat that 1t is
in a small one. Take, for instance, the
V-bottom form made famous by w.
II. Hand, jr., a form of unchallenged
merit for boats up to a moderate size.
George Crouch has found that the crit
ical speed at which the V-bottom form
becomes more efficient than well de-
signed hull with rounded bilges is in
miles an hour numerically equal to
four times the square root Of the over
all length in feet. That is to say, TWEEN
ty miles an hour for a 25-footer and
forty miles for a 100footer.
For extremely high speed there is, OF
course. another advantage in the
Worm besides it's easy driving quail
ties, and that is what might be called
its kinetic stability. In other words,
the faster it goes the greater its sta
bilitv. whereas a round bilged boat
driven at great speed is wabbly.
But for sea work the requirements
are different. What is necessary is
plenty of underwater body of a shape
with considerable deadrise--that is,
wedge shaped in section, rather than
fat. The boats should not be designed,
AS are most of our fast express cruis-
ers, with broad, fat afterbody or
run" and fine water lines at the bow;
II is obvious that the great bulk aft and
the lack. of it .forwaId. makes. for .er-