APPARATUS FOR ASCERTAINING APPROXIMATELY THE TRIM AND INITIAL STABILITY OF SHIPS AND OTHER VESSELS
Year: 1882

page_text: LETTERS PATENT to Alexander Taylor of Newcastle upon Tyne in the County
of same name, Engineer for an invention of APPARATUS FOR ASCERTAINING
APPROXIMATELY THE TRIM AND INITIAL STABILITY OF SHIPS AND OTHER
VESSELS
PROVISIONAL SPECIFICATION left by the said Alexander Taylor at the
Office of the Commissioners of Patents on the 26th June 1882.
ALEXANDER TAYLOR of Newcastle upon Tyne in the County of same name,
Engineer, APPARATUS FOR ASCERTAINING APPROXIMATELY THE TRIM AND
$5
INITIAL STABILITY OF SHIPS AND OTHER VESSELS
"
My invention relates to appliances for ascertaining and indicating the distance
between the "meta-centre" and "centre of gravity in ships or similar vessels,
when in, or near, the upright position, with a view to determining their stability
and detecting improper trimming or stowage of cargo.
In any ship or vessel of known (or approximately known) displacement, I
propose to construct or place a tank or tanks, of known capacity in any convenient
position. The most efficient position will be in the cross-section in which the
longitudinal centre of displacement is contained, or generally amidships, between
the fore and aft ends and on either the "port" or "starboard" side at an extreme
and known distance from the centre vertical plane of the ship. This tank or other
vessel I prefer to be filled with water, but any convenient arrangement of known
weight may be adopted.
On deck or in the cabins or other convenient position, well towards the ships
"port" and "starboard" sides, I fix a tube of glass or other transparent material
graduated (or in a graduated case) which will shew a considerable portion of the
tubes and I connect the lower ends of these tubes, by a pipe running across the
ship from side to side, and fill the tube up to a "zero "mark which will be level in
each tube when the ship is exactly upright.
The displacement of the ship, and the capacity of the tank or tanks, and their
effective distance from the fore and aft centre vertical plane of the ship all being
approximately known, the vertical tubes or their cases being graduated to shew

page_text: various angles of "heel" and corresponding meta-centric heights, calculated for the
disturbing weight contained in the tank or tanks for the particular ship, the mode
of procedure is as follows:-
"
The ship being cleared of bilge water and all loose self-moving material and
standing upright (or nearly so) so that "zero on each of the graduated scales is
opposite the line of liquid in the vertical tubes, the vessel (or vessels) of known
capacity is, or are, filled with water. The "heeling" of the ship will cause the
angle of inclination and the meta-centric height, above the centre of gravity to be
approximately indicated upon the graduated scale marked for the extreme load
draft or displacement of the ship. For other drafts or displacements removeable
graduated scales may be provided by which the meta-centric height above the
centre of gravity may be measured.
The vertical tubes may be of equal areas so as to indicate equally in each or
they may be so proportioned as to indicate principally in one tube only. As an
alternative arrangement, instead of vertical tubes, a system of levers, or a spirit
level, a plumb and line or other well known contrivances may be used to indicate
the angle of "heel" and the meta-centric height but for simplicity I prefer the
apparatus I have described, consisting of vertical tubes containing liquid with
graduated scales. I also prefer a tank or tanks of known capacity placed at a
known distance from the fore and aft centre vertical plane of the ship on either
side, though a weighted box or accumulated weights would effect the same objects.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Taylor in the Great Seal Patent Office on the
18th December 1882.
ALEXANDER TAYLOR of, Newcastle upon Tyne in the County of same name,
Engineer APPARATUS FOR ASCERTAINING APPROXIMATELY THE TRIM AND INITIAL
STABILITY OF SHIPS AND OTHER VESSELS
My invention relates to appliances for ascertaining and indicating the distance
between the Meta-centre and centre of gravity in ships or similar vessels, when in
or near the upright positions, with a view to determining their stability and
detecting improper trimming or stowage of cargo. In any ship or vessel of known
or approximately known displacement I propose to construct or place a tank or
tanks of known capacity in any convenient position. The most efficient position
will be in the cross-section in which the longitudinal centre of displacement is
contained or generally amidships between the fore and after ends and on either or
both the port and starboard side at an extreme and known distance from the
longitudinal central vertical plane of the ship. This tank or other vessel I prefer
to be filled with water, but any convenient arrangement of known weights may be
adopted
On deck or in the cabins or other convenient position well towards the ships
port and starboard sides I fix a tube of glass or other transparent material
graduated (or in a graduated case) which will show a considerable portion of the
tubes, and I connect the ends of these tubes by pipes running across the ship, and
fill the tubes with liquid up to a "zero" mark which will be level in each tube
when the ship is exactly upright
The displacement of the ship and the capacity of the tank or tanks and their
effective distance from the fore and aft central vertical plane of the ship, all being
approximately known the vertical tubes or their cases being graduated to show
various angles of "heel" and corresponding Meta-Centric heights calculated for the
disturbing weight contained in the tank or tanks for the particular ship
The mode of procedure is as follows:-
The ship being cleared of bilgo water and all loose self moveable material and
standing upright (or nearly so) so that "zero" on each of the graduated scales is
opposite the line of liquid in the vertical tubes; if then the vessel or vessels of
known capacity is or are filled with water. The "heeling" of the ship will cause
the angle of inclination and the Meta-centric height above the centre of gravity to
be approximately indicated upon the graduated scale marked for the extreme load
draft or displacement for the ship. For other drafts or displacements moveable
graduated scales may be provided by which the Meta-centric height above tho
centre of gravity may be measured
The vertical tubes may be of equal areas so as to indicate equally in each or
they may be so proportioned as to indicate principally in one tube only. As an
alternative arrangement, instead of vertical tubes, a system of levers, or a spirit
level, a plumb and line or other well known contrivances may be used to indicate
the angle of "heel" and the Meta-centric height but for simplicity I prefer the
apparatus I have described consisting of vertical tubes containing liquid with
graduated scales-I also prefer a tank or tanks of known capacity placed at a
known distance from the fore and aft contral vertical plane of the ship on either
side, though a weighted box or accumulated weights would effect the same object
The various modes of carrying out my invention will be easily understood
without the assistance of drawings which I have therefor not considered necessary
to illustrate it

page_text: Having now described my invention and the mode of carrying it into practical
operation I would have it understood that I am aware that the stability of vessels
has been and is now tested by the use of dead weights and a plumb line or
equivalent means of measuring the extent of inclination or "heel," but what I
consider as novel and constituting my invention is
The application of a known weight, acting with a known leverage to "heel"
over a vessel, the angle of the heel or inclination and the meta-centric height being
recorded upon an index graduated in divisions calculated for the known
displacement of the vessel
In witness whereof I the said Alexander Taylor have hereunto set my
hand and seal this sixteenth day of December in the year of our Lord one
thousand eight hundred and eighty two.
Witness:
T. J DANSON F. Inst. P.A
Consulting Engineer & Patent Agent
Newcastle on Tyne
ALEXANDER TAYLOR (L.S.)