A METHOD FOR ASSISTING TO RENDER A SHIP, VESSEL, OR CRAFT GOVERNABLE IN ALL THE CASES OF HER MOVEMENTS
Year: 1814

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THOMPSON, of Yarmouth, in the County of Norfolk, Master Mariner, send
greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourth day of August,
in the fifty-fourth year of His reign, give and grant unto me, the said James
Thompson, His especial licence, that I, the said James Thompson, during the
years therein mentioned, should and lawfully might make, use, exer-
cise, and vend, within that part of the United Kingdom of Great Britain and
Ireland called England, the Dominion of Wales, and Town of Berwick-upon-
Tweed, my Invention of "A METHOD FOR ASSISTING TO RENDER A SHIP, VESSEL,
OR CRAFT GOVERNABLE IN ALL THE CASES OF HER MOVEMENTS;" in which said Let-
ters Patent there is contained a proviso obliging me, the said James Thompson,
by an instrument in writing under my hand and seal, to cause a particular de-
scription of the nature of the said Invention, and in what manner the same is
to be performed, to be inrolled in His Majesty's High Chancery within two
calendar months after the date of the said recited Letters Patent, as in and by
the same (relation being thereunto had) may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Thompson, do hereby declare that my said Invention is described as
follows, and Plan hereunto annexed, viz:-
The first part of the Invention is named the dead water releiving piece,
and is designed to be shipped on the after part of a vessel's rudder, to remove

page_text: the dead water which that part of the rudder makes when she has direct
motion, to obviate its counteraction when she makes sternway, and to add to
the effect of the rudder in casting the vessel round.
Fig. 1, a perspective view of the rudder prepared to receive the dead water
relieving piece: a, a plate to turn down to secure it to the rudder; b, an 5
affixed plate into which it is to be shipped; e, a wood lock to prevent it from
slipping upwards or downwards.
Fig. 2, the rudder with the dead water relieving piece attached to it: g, a
rope used for conducting it to its place, which is then to be unreaved; h, a rope
to hand it up when intended to be unshipped, after the plate a, as in Figure 1,
is turned up with a boat hook.
Fig. 3, 4, & 5, transverse sections of Fig. 2, through the lines a, b, c, d,
and e, f, to show the effect of the rudder with and without the Invention, parti-
cularly when the vessel has sternway. The dotted lines doe represent the action
of the rudder (without the Invention) upon a supposition that it has no counter-
action, but the counteraction is shewn by the line g, n, which being deducted
(or its equivalent c, e,) from the supposed action leaves the line d, c, which
represents its real action. Now, by the addition of the dead-water relieving
piece, this counteraction is not only removed, but the positive action of the
rudder is increased by the line g, b, and the additional action gained by the
Invention is represented by the line f, b; the advantage thus gained is, when
the vessel is making stern way, and the rudder set an angle of 45°; when
the ship has head way, the Invention will add but small effect to the general
action of the rudder, except when most necessary, that is, when the helm is
put hard over, as is shewn in Fig. 3, 4, & 5, when its effect in this position is
represented by the line h, b..
Fig. 8 is a diagram, to shew how the rudder may be formed upon an
improved principle, and the thickness of a rudder reduced to a certain pro-
portionate rule: A, the stern post bevelled off on each side 20%, and the
main piece of the rudder bevelled off 25° on each side, which together will
admit of an action of the rudder of 45°, which mode of bevelling has some-
times been the practice of many builders; a, b, the thickness of the main piece
of the rudder at the upper part, where the tail piece is put on; c, a, is of
the thickness at a, b, which will be the proportionate thickness of the forc
part of the keel; e, f, the thickness of the after part of the rudder below at
the keel, which is equal to of c, d, (this reduction may be increased, but
should never be less than of c, d). Having obtained the thickness for these
parts of the rudder, now set off the breadth you propose the rudder to be a
the bottom (which necessarily varies according to the constructions of the ship)

page_text: ;
iz, from a to e and b to f, and drawn the lines a, e, and b, f; then set off the
proposed breadth for the top of the rudder, viz, from a to g and b to
the distance therefrom between these lines a, e, and b, f, when they are cut
by the line
g, h, will be the thickness of the after part of the tail piece at the
top; the breadth of the dead-water relieving piece must be made equal to
1 times its thickness, as is shewn in Fig. 2, 3, 4, & 5, & 8, marked R,
unless formed with the solid rudder in its original constructions.
Fig. 8, No. 2, is a section of the rudder D and stern post C, with chocks
or cleats k, k, of metal or wood bound with iron attached to them, to support
the twist of the gudgeon, which may be let into the rudder and stern post and
bolted through; they are again shewn on the rudder, Fig. 2, marked k, k, k.
The next part of the Invention is called a rowing paddle, and is intended to
be applied to several purposes, but more particularly to the two following;
1st, to supply the place of a rudder to a small vessel, if any accident should
happen to her rudder; and by increasing the number of these paddles, and
using them out of the quarter posts and stern posts, or both, a vessel of any
size having met with a similar accident may be made governable. 2d, in light
winds the paddles are intended to be used to impel the vessel forward, by
being fixed on the sides of the ship.
Fig. 9 represents the rowing paddle k, as it is attached to the side of a
vessel by the mainpiece m; b, a rod to raise and depress it when in use, by
its connection with the lever d; e, a rope used to adjust it to lock it to the
height of the vessel; the part a (shewn separately at a 2,) is so made, that it
may be separated from the other part; it is secured to it by means of a
groove, the gudgeon band h and a share band g. f, an iron plate with
shoulders, that screws on the main piece of the paddle, for the same to work
on, unless it is made to work in a mortice formed in the main piece.
double bar for the lever to work between, with a plate on the top fastened
with screws and nuts. ; is a continuation of the iron plates from each side of
the head of the main piece, with a plate on the top fastened with screws and
nuts for the lever to act upon.
e, a
Fig. 10, a lever to support the paddle, and to admit of its being worked by
a greater number of hands, which may be elevated or depressed by shifting
the bolt on which it acts; the holes described by dotted lines.
5 Fig. 11, a perspective view of the paddle (with a different formed head)
and the lever, the guy ropes attached to it prepared for use.
Fig. 12, a view of the head of the main piece of the paddle as at No. II.
(on a larger scale) adapted for showing how Fig. 13 may be fixed in the top
when used out of a ship's quarter post to steer her.

page_text: Fig. 14, the crow foot by which the main post of the paddle is attached
to the side of the ship, which may be shipped and unshipped at pleasure.
The next part of the Invention is the steering paddle, to be affixed to the
after part of the rudder, to add to its effect when entering a port with a cross
tide, and when it is doubtful the vessel will not answer her helm so speedily as
is necessary to secure her from danger. Fig. 6 shews the form of the paddle:
a, a block to bouse it up by a rope, when intended to be unshipped; b, a lever
by which it is secured to the rudder, and turned down into the locks c, c,
Fig. 1, 2, and 7; c, a rope to haul it to the locks, after which it is to be
unreaved; d, d, are spring plates to lock of themselves on. c, c, on the rudder,
Fig. 7; fff, bolts with screws and nuts to attach the lever to the paddle,
which may be taken apart when it is unshipped. Fig. 7 shews the rudder
with the steering paddle shipped in the locks, in which a is the upper plate
of the dead water releiving piece turned up.
The last part of the Invention is a new form for cast iron ballast, to be
used in lieu of common ballast, by which many sharp built vessels in parti-
cular, as well as others, will be made governable with a clean swept hold.
This ballast, the form of which is represented by Fig. 15, the end view A, and
the side view B, (although they may be made of other forms as found most
convenient for the construction of the vessel,) is intended to be placed in the
situation, and instead of the timber boards now in use, by which means the
vessel will become stiff governable, and a considerable portion of stowage
obtained which would otherwise be occupied by ballast.
In witness whereof, I, the said James Thompson, have hereunto set my
hand and seal, this Twenty-eighth day of September, in the year of our
Lord One thousand eight hundred and fourteen.