An Apparatus for Facilitating the Computation of the Stability of Ships.
Year: 1896

page_text: Date of Application, 5th Mar., 1896
Complete Specification Left, 9th Sept., 1896-Accepted, 5th Mar., 1897
An Apparatus for Facilitating the Computation of the Stability
of Ships.
ALEXANDER GULLILAND RAMAGE No. 9 Derby Street Leith Scotland
Shipbuilder do hereby declare the nature of this invention to be as follows:-
An apparatus for facilitating the computation of the stability of ships. It is as
follows.
A tank to hold water or other fluid. An arrangement attached to the side
of the tank, by which an arm or projection for attachment of the sections of the
vessel can be raised or lowered, also turned through any angle. An indicator,
which may be balanced on a knife edge the indicator to have a long end and a
short end. A float placed in the water is connected to the short end of the
indicator, & the changes in the level of the water are made visible by the long end
of the indicator. Sections of the vessel whose stability is to be ascertained, are
attached to the moveable arm, which is turned so that the sections are in the
upright position. They are then lowered into the fluid to the required water line
& the displacement is shown by the long arm of the indicator.
The sections are then raised, turned round to the required angle & then
immersed to the depth at which the lever or indicator shows the same change of
level of the fluid. A mark is then made round the sections & the immersed part
can be cut off & the centre of gravity ascertained.
Dated this 3rd day of March 1896.
ALEXR. G. RAMAGE.
COMPLETE SPECIFICATION.
An Apparatus for Facilitating the Computation of the Stability
of Ships.
1, ALEXANDER GULLILAND RAMAGE 9, Derby Street, Leith, Scotland,
Shipbuilder do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
This invention relates to an apparatus for facilitating the computation of the
stability of ships.
But in order that my said invention may be readily understood and easily carried
into effect I will proceed to describe the same with reference to the accompanying
drawings in which
Fig. 1 is an elevation
plan and

page_text: Figs. 4, 5, 6 and 7 are enlarged views of various details shewn in Figs. 1, 2
and 3 and
Fig. 8 is a view shewing needle points with sections of ship balanced thereon.
Referring to the said drawings, the apparatus consists of a small tank a,
containing water or other fluid, to the side of which a frame is attached for
guiding a sliding block c capable of being raised or lowered by the screw rod d.
An arm a', to the outer part of which sections A of the vessel in wood or other
material are attached, passes through the block c. The said arm a¹ can be turned
through any angle by means of the worm E, which is rotated by the hand wheel e,
engaging with a spur wheel e' secured upon the arm a'. A platef provided with
a scale is secured to the sliding block c in order that the angle made by the arm a¹
can be recorded thereon by the finger. An indicating arm G balanced on a
knife edge H is also provided so that its free point g multiplies the vertical motion
imparted to its short end g' by the float, M through the rod L, the indications
being marked on the index board Q.
Sections A of the vessel are attached to the arm a¹ so that they are vertical
when the finger points to zero on plate, and the water line to which the sections
are to be immersed is kept parallel to the surface of the water.
The sections are then screwed down into the fluid till they are immersed to the
required line. The float M will then have risen owing to the displacement of the
water by the immersion of part of the sections, and the free end g of the indicating
arm G will have moved through a certain angle p which will be marked on the
index board Q. The draught of water, of the sections A inclined at any angle,
corresponding to the displacement of the sections when immersed in the vertical
position can be ascertained by turning the sections A to the required angle by
means of the worm or screw E and raising or lowering the sections till the free
end g of lever G again indicates the angle p. The water line can now be marked
on the sections, which can then be cut through at this line and the immersed part
being balanced on the needle points N Fig. 8 the centre of gravity or centre of
buoyancy of this immersed part is ascertained, which known the righting arm
can readily be found by calculation and measurement. The float M may be
enclosed in a bay to lessen its disturbance by the water in the tank without
the bay.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
The apparatus for facilitating the computation of the stability of ships whereby
the waterline of the sections in the inclined position at which they have the
required displacement, is ascertained by magnifying the vertical motion of the
surface of the water so that small changes may be noted, substantially as herein-
before described and shewn in the accompanying drawings.
Dated this 11th day of Feb 1907
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicant's Agents.