IMPROVEMENTS IN THE CONSTRUCTION OF SHIPS AND VESSELS
Year: 1861

page_text: LETTERS PATENT to Andrew John Robertson, of 26, Parliament Street,
Westminster, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF SHIPS AND VESSELS."
Sealed the 12th November 1861, and dated the 20th May 1861.
PROVISIONAL SPECIFICATION left by the said Andrew John Robertson
at the Office of the Commissioners of Patents, with his Petition, on
the 20th May 1861.
I, ANDREW JOHN ROBERTSON, of 26, Parliament Street, Westminster, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF SHIPS AND VESSELS," to be as follows:-
This Invention has for its object improvements in the construction of ships
and vessels. In constructing ships and vessels according to my Invention, in
order to decrease as much as possible the resistance offered to them by the
water in passing through it, I make the load water line concave both at the
bow and stern, and beyond these concave portions in passing into the body or
centre portion of the vessel the line becomes convex, and in combination with
this formation of the load water line of a ship or vessel the vertical lines
throughout both the bow and the stern of the ship, in passing from the load
water line on one side to the same level on the other side semicircular, that is

page_text: to say, a vertical transverse section of the ship taken anywhere (the keel of
the vessel being neglected) will be a semicircle beneath the load water line.
A vessel made with all its transverse sections semicircular in combination
with the hollow water line at the load water level, as described, is the best
form for speed; but in order to give other qualities required by a steam or
sailing vessel it may be necessary to employ the forms of transverse sections
which are not semicircular.
In order to reduce as much as possible the resistance to a ship in which all
the transverse sections are not semicircular, I construct the ship in such a
manner that if a midship. section of it be taken, and any normal (or line per-
pendicular to a tangent) to the curve of this section be drawn until it inter-
sects the vertical centre line, then a plane passing through this line, and at
right angles with the plane of the midship section (which is vertical) will,
where it intersects the surface of the ship or vessel, make the line of inter-
section a hollow. curve; both at the bow and stern, and in passing into the
body or centre portion of the vessel, the line becomes convex.
In constructing vessels to navigate very shallow water, I make the vessel
of the same or nearly the same width throughout, and flat-bottomed, and the
ends of the vessel, both at stem and stern, I make to a double curve, that is
to say, from the water line down to about one-half of the draft of the vessel I
make the surface concave, and from thence to the bottom of the vessel I make
the surface convex.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Andrew John Robertson in the Great Seal Patent Office
on the 20th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME,-I, ANDREW
JOHN ROBERTSON, of 26,-Parliament Street, Westminster, send greeting...
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of
Her reign, did, for, Herself, Her beirs and successors, give and grant unto
me, the said Andrew John Robertson, Her special licence that I, the said
Andrew John Robertson, my executors, administrators, and assigns, or such
others as I, the said Andrew John Robertson, 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

page_text: 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 THE CONSTRUCTION OF SHIPS AND VESSELS,"
upon the condition (amongst others) that I, the said Andrew John Robertson,
my executors or administrators, by an instrument in writing under my, or
their, or one of their bands and seals, 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 tho
said Letters Patent.
.
NOW KNOW YE, that I, the said Andrew John Robertson, do hereby.
declare the nature of the 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, that is to say:
.
This Invention has for its object improvements in the construction of ships
and vessels. In constructing ships and vessels according to my Invention in
order to decrease as much as possible the resistance offered to them by the
water in passing through it, I make the load water line concave both at the
bow and stern, and beyond these concave portions in passing into the body or
centre portion of the vessel the line becomes convex, and in combination with
this formation of the load water line of a ship or vessel the vertical lines
throughout both the bow and the stern of the ship, in passing from the load,
water line on one side to the same level on the other side are semicircular,
that is to say, a vertical transverse section of the ship taken anywhere (the
keel of the vessel being neglected) will be a semicircle beneath the load water
line.
.
Figure 1 is a body plan; Figure 2, a sheer plan; and Figure 3, a half
breadth plan of a vessel constructed in this manner. The load water line from
the point a at the bow as far as the point is concave, and from the point c at
the stern as far as the point d the line is also concave, but between the points
b and d in the centre or body portion of the vessel the curve is convex; the
vertical lines, as the body plan shews, are all semicircular, in fact, the portion
of the vessel below the load water line is (the keel excepted) a solid, such as
would be generated by the revolution of the plane bounded by the load water
line a, b, d, c, and the centre line a, c, about the said centre line as an axis;
the form of the load water line may, so long as the curve retains its general
character, be varied; the proportion between the breadth of beam and the
length being made such as the builder may consider most suitable for the
particular case.

page_text: A vessel made with all its transverse sections semicircular in combination
with the hollow water line at the load water level as described is the best
form for speed, but in order to give other qualities required by a steam or
sailing vessel it may be necessary to employ forms of transverse sections which
are not simicircular.
In order to reduce as much as possible the resistance to a ship in which all
the transverse sections are not semicircular I construct the ship in such a
manner that if a midship section of it be taken, and any normal (or line per-
pendicular to a tangent) to the curve of this section be drawn until it intersects
the vertical centre line, then a plane passing through this line and at right
angles with the plane of the midship section (which is vertical), will where it
intersects the surface of the ship or vessel make the line of intersection a
hollow curve both at the bow and stern, and passing into the body or centre
portion of the vessel the line becomes convex.
Figure 4 is a body plan; Figure 5, a sheer plan; and Figure 6, a half-
breadth plan of a vessel constructed according to my Invention, and in which
the midship section is not semicircular. Qis a point in the midship section,
and at the exterior of the vessel the line Q, P, is a normal to the curve at
point Q, and which cuts the centre line of the vessel at the point P. The
form then of the vessel is such that if it be cut by a plane passing through the
line P, Q, and perpendicular to the plane of midship section (which is
vertical), then this plane in cutting the side of the vessel will produce a curve
concave both at bow and stern, and becoming convex as it passes into the body
or centre portion of the vessel; the actual curve is shewn at Figure 7.
Similarly S, R, and T, V, are other normals; the sections made by a vertical
plane passing through these normals are shewn at Figures 8 and 9; it will be
seen that they are curves of a similar character to that of the section, Figure 7.
In-selecting-a-form-for-the-midship-section,-and-in-regulating the proportion
between the beam and length of the vessel the builder will be guided by
similar considerations to those by which these proportions are regulated in
vessels of ordinary form.
In constructing vessels to navigate very shallow water I make the vessel of the
same or nearly the same width throughout, and flat-bottomed, and the ends
of the vessel, both at stem and stern, I make to a double curve, that is to say,
from the water line down to about one-half of the draft of the vessel I make
the surface concave, and from thence to the bottom of the vessel I make the
surface convex. Figure 10 is a vertical longitudinal section; and Figure 11,
a vertical transverse section of the same; the fore end of the vessel is concave
from the water line as far as the point d, and then it becomes convex as far.

page_text: as f, beyond which point the body of the vessel is flat; the after part of the
vessel is similarly formed.
In witness whereof, I, the said Andrew John Robertson, have hereunto
set my band and seal, this Nineteenth day of November, in the year
of our Lord One thousand eight hundred and sixty-one.
Witness,
WILLIAM H. BUTTER.
ANDW. JOHN ROBERTSON. (L.S.)