IMPROVEMENTS IN THE CONSTRUCTION Or SHIPS
Year: 1865

page_text: LETTERS PATENT to John Weems, of Johnstone, Renfrewshire, Scotland,
Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION Or
SHIPS."
Sealed the 11th May 1866, and dated the 20th November 1865.
the
PROVISIONAL SPECIFICATION left by the said John Weems at the
Office of the Commissioners of Patents, with his Petition, on
20th November 1865.
I, JOHN WEEMS, of Johnstone. Renfrewshire, Scotland, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF SHIPS," to be as follows:-
My Invention consists, firstly, in preventing wholly or in part the rolling
and pitching motion to which ships or other vessels are subject when at sea;
secondly, in raising, depressing, or canting vessels; thirdly, in floating off
vessels which may strike on sand banks or otherwise; fourthly, in causing
barnacles or other parasites to drop from the sides of vessels.
My Invention will be better understood by reference to the three Sheets of
Drawings hereunto annexed, and forming part of this my Provisional Speci-
fication, than by written detail only. In such Drawings Figure 1, Sheet 1,
represents a diagram of a mid-section of a vessel (taken athwart ship) with
an outer shell or case, the keel acting as a diaphragm to preserve the two sides
Dice Sd 1

page_text: independently air-tight, a number of small holes F being made in the outer
case near the keel for the free ingress and egress of water.
Figure 2, Sheet 2, represents the vessel blown off the perpendicular by the
wind acting in the direction of the arrow, and as a consequence of this move-
ment the air contained in the space A on the storm side is rarefied, and the
water in B acted on by the pressure or weight of the atmosphere outside is
forced up, as shewn, above the level of the sea, and this acts in opposition to
the wind tending to adjust the vessel, whilst the air in the corresponding
space A is compressed and exerts a pressure of buoyancy above the pressure
of the atmosphere, both sides presenting a resistance to the wind. The total
resistance to the wind will, of course, be dependent upon the length and width
of spaces between the cases or hulls. Suppose a vessel constructed as per
section Figure 2, the width of air space being 18 inches, and the length 200
feet, and that an average depth of water, say seventy inches. could be
obtained, this would represent a power equal to about 96 tons on one side of
the ship to resist the force of the wind, balancing the vessel, preventing her
rolling (or nearly so), and keeping her steady. To prevent pitching or heaving
motion it will not be necessary to interfere with the means for preventing
side rolling, but it is effected by having an air-tight partition or diaphragm
midway between the bow and stern of the vessel's length independently air-
tight. When the bow of the vessel rises the air in the spaces at her bow is
rarefied and presents a power of resistance, while the air in the stern com-
partments is compressed, thereby giving a power of buoyancy, the two powers
acting in unison to right her, and prevent or cease the pitching motion of bow
and stern.
The controlling power of raising. depressing, or canting vessels is repre-
sented at Figure 3, Sheet 3, which is a mid-section of a vessel constructed in
a similar manner to that shewn by the Diagram, Figure 1, Sheet 1. The
vessel in this case, however, as shewn at Figure 3, is canted over by having air
forced into the space A, and partially extracted from the space A. E; the
blowing machine (or air pump) being supplied with valves communicating
with the air spaces by means of pipes fitted with taps or slides. The other two
movements are vertical, the one raising the vessel, the other lowering or
depressing her. The first is obtained by forcing air into both air spaces, at
the same time, displacing the water and causing a pressure on the top of the
spaces, and giving power of buoyancy which raises or lifts the vessel. The
second movement is obtained by extracting the air from both air spaces
simultaneously the water rising up in the spaces causes the vessel to sink
lower or be depressed. By this operation the vessel can, as it were, be

page_text: ballasted. If a vessel be aground, and the vertical distance from the small
holes F and the surface of the water be 13 feet, this height of water would
balance a pressure of air in the spaces of 5 and a half pounds per square inch,
and this would give a floating power equal to about 212 tons.
In adapting my Invention to iron clad war vessels, the air spaces can be
arranged below water mark. The vessel can be canted over, faised, or
lowered on either side of the elevation of the guns, and the lowering of one
side assists in moving her round within a smaller circle and more speedily.
In the event of pursuit the water in the compartments may be displaced by
air, thereby raising the vessel and enabling a higher speed to be obtained.
In case of a vessel becoming leaky or in danger of sinking, the water com-
partments may be fitted with a pipe and tap in connection with the sea, and a
communication made with the blowing machine, so that water can be displaced
by air, and assist in keeping the vessel afloat. And in order to cleanse the
outer hull or casing of a ship or other vessel double cased as herein-before
directed, and cause the barnacles or other parasites to fall off, I cant the
vessel by the means already described, and introduce steam into the compart-
ment of the exposed side, the heat causing the barnacles (whether they be
alive or dead) to lose hold and drop from the ship's side or bottom. The
exposed surface may then be painted, and the steam at a lower temperature
used to facilitate the drying of the paint. Or operate on the barnacles
without canting the vessel, and in the manner just above explained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Weems in the Great Seal Patent Office on the
19th May 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WEEMS, of Johnstone, Renfrewshire, Scotland, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of November, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Weems, Her special licence that I, the said John Weems,
my executors, administrators, and assigns, or such others as I, the said John
Weems, 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,

page_text: and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF SHIPS," upon the condition (amongst others) that I, the said John
Weems, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands 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 the
said Letters Patent.
NOW KNOW YE, that I, the said John Weems, 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, reference being had to the accompanying Sheet of Drawing,
forming part of this my Specification, and to the figures and letters of
reference placed thereon, similar letters denoting similar parts in each of the
Figures respectively.
My Invention may be said to consist in the construction of vessels, with air-
tight or partially air-tight compartments, in such a manner that, among other
advantages, the following are obtained: First, preventing, my self-acting
means wholly or in part the rolling and pitching motion to which ships are
subject when at sea; second. raising, depressing, or canting vessels when
afloat; third, floating off vessels which may run aground; fourth, enabling
vessels of heavy tonnage to cross bars and traverse rivers which they cannot
now enter; fifth, affording easy access for the workmen to repair shot holes
or other damage to the sides of vessels while at sea; sixth, enabling vessels
to turn within a smaller circle more speedily; seventh, keeping sinking vessels
afloat; eighth, causing barnacles or other parasites to drop from the sides of
vessels.
I construct my ship with an outer casing, between which and the inner shell
or hull of the vessel I leave a space of, say, for example, eighteen inches.
This casing is divided into two parts by the keel, so that I have a separate com-
partment on each side of the vessel extending entirely fore and aft, and from
keel to deck, or only part of the length and depth of the hull, according to
circumstances, for example, the requirements of a war vessel differing from
those of a trader, the position and construction of the compartments will
necessarily be modified to suit them. The two compartments or chambers
thus formed between the inner and outer casing of the hull are made perfectly
air-tight, or partially so, with the exception of a series of holes or openings
with which the outer casing is pierced at intervals along its length, such

page_text: orifices being made by preference at the bottom of each chamber and near the
keel of the vessel, which is the diaphragm separating the two chambers.
Further, the top of each chamber is connected by a tube or tubes, conduit or
conduits, to an air or other elastic fluid generator, receiver, or containers, or to
a single or double acting air or other fluid pump or other suitable contrivance
for forcing or exhausting air or other elastic fluids, these conduits being opened
or closed by ordinary taps or cocks, or by any suitable valve or regulated
opening.
Figure of the Drawing represents mid-section of a vessel constructed as
above described with an outer shell or case a, the keel b acting as a diaphragm
to preserve the two sides independently air-tight; c, c', the holes or openings
for the free passage of water into and out of the two chambers A, A', formed
by the space left between the outer casing and hull a' of the ship. Figure 2
shews a vessel of the same construction with openings e, e¹, communicating by
tubes or conduits with one or more air or other elastic fluid receivers or con-
tainers, or one or more air pumps or other suitable contrivance for forcing
fluids or for generating or exhausting elastic fluids.
The vessel being placed in the water on an even keel, as shown in Figure 1,
the water will enter the chamber A, A', by the orifices c, c', and rise therein
to the same level as the water in which the vessel floats, and as the air con-
tained in the chambers cannot escape (the conduits e, e', being closed, each
chamber will be filled above the line d, d', with compressed air. Now,
supposing the action of the wind and wave coming from the direction indicated
by the arrows, the vessel would naturally have a tendency to incline over to
the opposite side, as shown in Figure 3 of the Drawing; but this tendency is
here checked, firstly, by the weight of the water in chamber A, which resists
every effort to raise it above the outer water level; secondly, by the buoyancy
of the air in A', which resists any further submersion of that side; thus, when
the vessel attempts to roll both sides will present a resistance to the power of
the wind and wave, as the air in the chamber A, or windward side, will be
rarefied, and that in A', or leeward chamber be compressed, thereby preventing
her rolling and keeping her steady. The total resistance to the wind or wave
will of course be dependent upon the length and width of the spaces or cham-
bers between the casing a and hull a'; but I will take, for example, a vessel
constructed as shown with an air chamber on each side eighteen inches broad
by two hundred feet in length, and presume that an average depth of water,
say seventy inches, could be obtained; this would represent a downward
pressure on the one side of the ship equal to about ninety-six tons, and an
equal upward pressure on the other side of the ship, presenting, therefore, a

page_text: combined resistance of 192 tons to the pressure of the wind and wave, and this
will be further augmented by the leverage power obtained from the height of
the vessel and by the rapid motion with which the weight is acted on by the
wave. If desired, the resistance can be still further increased by forcing air or
other elastic fluid into the leeward chamber, thus adding to the power of
buoyancy.
To prevent pitching or heaving it is not necessary to interfere with the
means for preventing side rolling. For this purpose I place an air-tight
partition or diaphragm in each of the chambers A and A' midway between
the bow and stern of the vessel's length, so that I have four chambers inde-
pendently air-tight, or nearly so. When the bow of the vessel rises the air in
the forward compartments right and left of the vessel is rarefied, while the air
in the sterm compartments is compressed, thus we have a power of resistance
forward and a power of buoyancy aft, these two powers acting in unison to
prevent or case the pitching motion of bow and stern; it need scarcely be
observed that when the stern of the vessel rises the action is reversed.
To raise the vessel when in an upright position as at Figure 1, air or other
elastic fluid is forced in equal proportions at the same time into the chambers
or compartments A, A', displacing the water from the level d, d', and causing
it to issue at c, c', until the pressure shall give a buoyancy sufficient to raise
the ship out of the water to the height required, thereby enabling vessels to
cross bars and traverse rivers which they cannot now enter. It will be evident
that by this means I could easily and safely float off a vessel which may have
struck upon a submarine bank or rock, even if the rock have torn or fractured
her outer casing, for suppose the vessel to be aground, and the vertical
distance from the small hole c, c', to the surface of the water be thirteen feet,
this height of water would balance a pressure of air or other fluid in the
chambers of 5 pounds per square inch, and this would give a floating power
equal to about 212 tons, and as she got into deeper water the power of
buoyancy would increase in a corresponding ratio by the greater compression
of the air or other fluid in the chambers.
To cant or careen a vessel as at Figure 2, I exhaust or withdraw the air
or other fluid from the chamber A¹, and at the same time force air or other
fluid into the chamber A, consequently the chamber A' will be filling with
water while the water in the chamber A is being displaced by the air or other
fluid, and this simultaneous increase of buoyancy on the one side and weight
on the other will careen the vessel as shown, thereby affording easy access for
workmen to repair shot holes or other damage to the sides of vessels while at
When I desire to re-establish the equilibrium I reverse the process,
sea.

page_text: that is to say, 1 force air or other fluid into A¹, and exhaust it from A, and it
will be evident that if I continue this action after the vessel is on an even
keel it will careen over to the opposite side. If the vessel were forced
over into the position shown at Figure 3 by the shifting of the cargo or other
cause, it could be righted in the same manner, that is to say, by forcing air
or other fluid into the submerged compartment, and exhausting it from the
other, in other words substituting weight for buoyancy, and vice versa.
In adapting my Invention to iron clad or other war vessels the air chambers
can be placed below the water line, and the vessel can be canted over on
either side for the elevation of the guns, and the lowering of one side will be
found to assist in moving her round within a smaller circle, and more
speedily than when on an even keel, and in the event of pursuit the water in
the chambers may be displaced by air or other fluid, thereby raising her out
of the water and enabling a greater speed to be attained, or air or other fluid
or water may be admitted or displaced from one or other suitably arranged
chambers to bring the vessel down by the head or stern, or otherwise alter or
improve her trim, and the vessel can also be sunk to the water level if it be
desired to present little or no mark for attack.
The principle of this Invention may be applied to the air or water tight com-
partments, and water tanks of ships constructed as previously described, or in
ships constructed in the ordinary manner by fitting such compartments or
tanks with a tap and pipe or other suitable contrivance communicating with
the water in which the vessel floats, so that should the vessel become leaky or
in danger of sinking the water in the tanks may be displaced by air or other
fluid, and the air or other fluid in the water-tight compartments be compressed,
and both powerfully assist in keeping the vessel afloat.
The principle of said Invention is not confined to vessels built as shewn
in Drawings, but is applicable wholly or in part to all vessels.
When I desire to cleanse the outer hull or casing a from barnacles or other
parasites, I displace the water in the chambers A. A', by the introduction of
steam, and thus raise the temperature of the casing a to such an extent that
the barnacles will instantly drop off the ship sides, and for this purpose it is not
therefore necessary to dock the vessel; further, the ship may then be canted,
and the exposed side painted while warm.
In constructing ships with an outer casing or double hull a great increase
of strength and safety is obtained, as the outer casing may be tied to the
inner, to which it affords great protection, and to the ribs of the vessel by tie
pieces placed where the greatest strength is required.
Having now described the nature of my said Invention, and in what manner

page_text: I carry it into practical effect, I would here observe that the proportions and
the position of the air-tight compartments in the vessel will be regulated by
the size and construction thereof, and the object more especially sought to be
obtained, for example, the position of the compartments will, as herein-before
mentioned, mostly differ in war vessels from that adopted in trading vessels;
also, that I do not limit myself to the use of any particular description of
pump or other machine or contrivance for forcing or exhausting, or apparatus
for generating or containing air or other fluid, or the use of steam, gas, or
other fluid for obtaining the various motions or advantages, but using such as
I may find in practice most suitable; nor do I limit myself to the advantages
herein-before set forth, as many more may accrue therefrom.
In witness whereof, I, the said John Weems, have hereunto set my hand
and seal, this Fifteenth day of May, in the year of our Lord One
thousand eight hundred and sixty-six.
JOHN WEEMS. (L.s.)