IMPROVEMENTS IN SHIP BUILDING
Year: 1854

page_text: LETTERS PATENT to James Sedgwick, of Lewisham, in the County of
Kent, Master Mariner, for the Invention of "IMPROVEMENTS IN SHIP
BUILDING."
Sealed the 12th January 1855, and dated the 21st July 1854.
PROVISIONAL SPECIFICATION left by the said James Sedgwick at the
Office of the Commissioners of Patents, with his Petition, on the 21st
July 1854.
I, JAMES SEDGWICK, of Lewisham, in the County of Kent, Master Mariner,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN SHIP
BUILDING" to be as follows:-
My improvements consist in making the floor timbers and first futtocks
convex fore and aft, whereby greater strength and speed are secured, together
with larger carrying capacity. The floor timbers and first futtocks being
convex fore and aft, there is no concave side in that portion of the vessel
which is immersed, and every line parallel to the keel up to the loading
mark both before and abaft the round of the midship section forms a
wedge in sharp vessels.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Sedgwick in the Great Seal Patent Office on the
20th January 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
SEDGWICK, of Lewisham, in the County of Kent, Master Mariner, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Ier Letters
Patent, bearing date the Twenty-first day of July in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Sedgwick, Her special licence that I, the said James
Sedgwick, my executors, administrators, and assigns, or such others as I,
the said James Sedgwick, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN SHIP BUILDING," upon the condition (amongst others) that
I, the said James Sedgwick, by an instrument in writing under my hand
and seal, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Sedgwick, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say :-
curve.
My improvements consist in making the floor timbers and first futtocks of
vessels convex fore and aft, that is, throughout the entire lengths of the vessels,
so that that portion of every transverse vertical section of a vessel constructed
according to my improvements which lies near to the keel shall be a convex
For the same reasons that have induced me to make these improve-
ments, I deem it very desirable that the transverse vertical sections should
maintain their convexity from the keel quite up to the load water line, but as
would in some cases be impracticable entirely to avoid concavity near the
the load water line, in some of the extreme sections the convexity of only the
lower portions of them forms the subject of my Invention.

page_text: The advantages of the convex principle of construction are, increase of
strength and of carrying capacity, together with superior speed and manage-
ableness, arising from the entire absence of that clinging action of the fluid
which is universally experienced in vessels, part of the sections of the
submerged portions of which are concave, and which action is known to be
exceedingly injurious to their sailing and manoeuvring qualities.
In carrying my Invention into effect, the only changes that will necessarily
require to be made will affect the operation of draughting or laying down the
lines of vessels, although important practical modifications of existing methods
of framing them will in some cases arise from it, such as dispensing with a
considerable portion of either the fore or after deadwoods, or of both; but
these cases will present no difficulty, and introduce no new mechanical opera-
tions to the shipwright. The alterations which the draughtsman will require
to make, consist merely in supplying to the shipbuilder convex moulds for all
the lower timbers, and in doing this he will proceed exactly as heretofore,
after the original design on a diminished scale has been prepared in the usual
manner. I may also observe that the section of greatest breadth may be
situated at, before, or abaft the middle of the length, as the constructor shall
determine.
In constructing vessels upon my improved principle, I prefer, when great
speed is to be obtained, combining with the convex vertical transverse sections
horizontal water lines, which are straight from the stem and stern post respec-
tively to where they round off and fall into the midship section, so that the
bow and the after part of the vessel shall in such cases severally form wedges
of considerable length. But this feature is not at all essential to my improved
system of construction, and there are many cases (when the vessel is intended
to carry large or heavy cargoes, for example,) in which this arrangement would
be incompatible with other necessary qualities.
Figure 1 of the Drawings hereunto annexed represents the body plan of a
vessel designed with my improvements; and Figure 2, a half breadth plan of
the same. In these Figures the sections and water lines are all taken at tho
outside of the plank. By an inspection of Figure 1, it will be seen that the
lower portion of every section 1, 2, &c., A, B, C, &c., is of a convex form,
according to the foregoing description; and from Figure 2 it will also be seen
that the straightness of the horizontal water lines at their fore and aft parts,
already referred to, is maintained. As these Drawings in all other respects
resemble those usually employed by naval architects, no further description of
them is necessary.

page_text: And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim is, construct-
ing vessels in such manner that that portion of every transverse vertical
section which is adjacent to the keel shall be a convex curve, as herein-before
described.
In witness whereof, I, the said James Sedgwick, have hereunto set my
hand and seal, this Seventeenth day of August, One thousand eight
hundred and fifty-four.
JAMES SEDGWICK. (L.B.)