New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1911-05-28
Anti Trolling
Tanks Danish
the Mal-de-mer
SHIPS MADE STEADY
Efforts of Inventors to Counter
act Wave Action Have at Last
Produced Practical Device.

ITHOUGH the fore and aft motion
~ (pitching) OF ship IS more dis
1 n tressing TO many passengers than
the rolling motion. the latter is the cause
O, such general discomfort. 10 say nothing
Of seaslckness, as TO render the elimination
OF rolling a most desirable object. Further
more. since most OF the naval engagements
of the future will be fought broadsde 70
troadside. with the guns trained athwart
the ship, any device which will eliminate
rolling must have a most important erect
upon the accuracy of gun fire. For the
above reasons, il is not surprising to find
that anti-rolling devices have been made
the subject Of much theoretical investiga-
ton and some very costly practical ex-
periments
The best known Of these-bilge keels-are
10 be found on every oceangoing steamship
The bilge keel is fnlike plate-steel struct-
ure. which projects AT right angles 10 the
ships plating. and extends at the biges
Ohe point where the bottom OF the ship
rounds up to the Sides for about two-thirds
of the length of the ship. They are ar
ranged parallel to the longitudinal axis Of
the ship. so as TO present the least posi-
tl' RESISTANCE w HIDSifSss AllHpuSh bie'
keels reduce rolling. they by no means elm
mate it. and. of course. their large sur
lace develops considerable amount Of
skin-frictlon resistance to the progress of
the ship through the water
Several years ago the distinguished en-
gineer Thorneycroft designed and built an
anti-rolling device. consisting of a very
heavy weight pvoted on vertical axis
and controlled by hydraulic power, which
was moved from side to side in such way
as to counteract the heeng effect of the
waves II was fairly efficient in the ship in
which it was installed, but its high cost
and the considerable dead weight which
had TO he carried prevented its adoption in
commercial service.
That wonderful mechanism the gyro-
scope mas also been called into service for
the steadying of ships at sea In this case
the resistance Of the gyroscope to a change
of its plane OF motion is utilized to resist
the tendency OF the ship to heel under the
action of the waves. \ recent improve
ment in gyroscOpe control is that of Sperry.
whose invention of what he calls the "ac-
tive" gyroscope promises TO provide. for
given weight OF gyroscopic apparatus,
vastly greater controlling effect than is
possible with the Schlck gear. Tests re-
Gently made by Naval Constructor Taylor
AT the naval testing tank Washington.
seem To prove that this device will give a
very complete control of rolling.
The earliest anti-rolling devices were OF
that type which forms the subject of the
present article. namely closed tanks OF wa
A.. u-itl,ip 10 hui Of LII Ia,
It's simplest and earliest form the anti
rolling tank consisted II large. closed.
rectangular chamber. built across the ship.
and filled with water. The theory of these
tanks was that when the ship. under the
action of the waves. rolled. say. to star
board the water in the tank would rush
over to starboard. and that. as the ship.
under wave action. rolled back to port.
the body OF water in the tank would lag to
starboard. and tend To damp or check the
roll OF the ship to port.
Now IT can he seen that the action ot
the water In the tank would he effective
only II it's rushing from side to side took
place in "A definite relation to the rolling
of the ship. In other words, 10 check the
ships rolling the motion of the tank
water must always lag certain amount
behind the rolling Of the ship
Now this was just what failed To occur
in the early rolling tanks; and 1t soon be-
came evident that some system of control
OF the tank water was necessary, which
would insure that there should always he
"A surplus Of water on that side OF the ship
on which the heeling effect OF the wave.
At any given time. was being felt
As far back as lSSl-'& Sir Philip Watts
read before the Institute of Naval Archi-
tocts. Great Britain, some papers descrlb-
ing experiments with an athwartship
water-hlled chamber. which was installed
OH The old ironclad Inns xible The trial of
these tanks gave promising results: but Il
was impossible To control the water. ana
the size OF the tanks was So great that
they encroached upon space greatly needed
for other purposes.
OF late years the investigation has heen
taken up by Herr VI. Frahm. a German
member of the Institute Of Naval Arch,
,ects and who read At the last mee,irg
= most valuable paper, IN which he p,va ,
lucid account Of the theory 81 the rolling
tank. and exhibited diagrams M tho A.
vices by which he has overcome the ann.