IMPROVEMENTS IN THE CONSTRUCTION OF VESSELS OR BOATS AND RAFTS, AND IN THE LAUnching and LOWERING OF BOATS AND RAFTS FROM ON BOARD SHIPS INTO THE WATER
Year: 1877

page_text: LETTERS PATENT to Edmund Thompson, of No. 27, Leadenhall Street, in the
City of London, Ship-broker, also of Sutton, in the County of Surrey, for
the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF VESSELS OR BOATS
AND RAFTS, AND IN THE LAUnching and LOWERING OF BOATS AND RAFTS
FROM ON BOARD SHIPS INTO THE WATER."
PROVISIONAL SPECIFICATION left by the said Edmund Thompson at the
Office of the Commissioners of Patents on the 4th December 1877.
EDMUND THOMPSON, of No. 27, Leadenhall Street, in the City of London,
Ship-broker, also of Sutton, in the County of Surrey "IMPROVEMENTS IN THE
CONSTRUCTION OF VESSELS OR BOATS AND RAFTS, AND IN THE LAUNCHING
AND LOWERING OF BOATS AND RAFTS FROM ON BOARD SHIPS INTO THE
WATER."
This Invention has for its object improvements in the construction of vessels
or boats and rafts, and in the launching and lowering of boats and rafts from on
board ships into the water.
I construct a boat or vessel in the shape of a cylinder, with the ends tapered as
required, and along the opposite sides of the cylinder I form exterior air tubes of
dimensions large enough to give sudicient buoyancy to support the cylinder even
should be become filled with water.
The cylinder is divided into water-tight compartments. The two ends are to
carry no cargo or weight of any kind; the top of the cylinder may if required be
flattened.
At the bottom of the cylinder, floorings of the depth required are to be placed, and
in order to keep the ship upright when cargo is all out, and dispense with ballast
when going into graving dock, in whole or part fixed ballast in the shape of iron and
cement may be let in and carried between the flooringa.
The air tubes which are around the exterior of the cylinder are formed of vertical
frames covered with plates of iron or steel and starting from about the middle of

page_text: the cylinder, rise up to the level of its top or the main deck of the vessel. The air
tubes to be in compartments rendered water-tight. These compartments can be
wholly or in part filled with cork or other light substance so as to prevent the tubes
being injured to any great extent by collision or otherwise.
A spar deck, or deck houses, poop, and forecastle can be placed the whole width
and length of the tubes, care being taken by permanent iron bulkheads that the
+pace for carrying cargo in such spar deck does not exceed in length that of the tubes,
excluding the ends as aforenamed, the remaining space being utilised for crew and
passengers or very light freight; thus excessive pitching will be avoided, and if heavy
cargo is kept from the sides in the 'tween decks of the spar deck a great immunity
from rolling would also be experienced.
All the hatches from the lower hold and lower 'tween decks should be trunked up
separately through the 'tween decks of the spar deck, so that in case of a serious leak
or fire in any hold it could be localised
Where engine power is required it will be arranged in such portion of the cylinder
as is required.
In boats on this principle the thwarts are to be hollow girders, water-tight, and
may be filled with cork or protected by wood casing, and on each space between
them, which would be about 5 feet only, the water would be discharged as fast as
it came in by pipes and valves; each end of the boat to be turtle-backed and fitted
with water-tight doors; these ends can be utilised for cooking and shelter.
In the same way to that above described all classes and forins of vessels may have
applied to them exterior air tubes of sufficient size to support the vessel even should
it become filled with water.
Where the maximum of stability with a minimum of rolling is required, such as in s
ships of war, channel steamers, vessels to bring live cattle from the Continent, or
more distant parts, such as Texas, South America, &c., ferry boats, coast life-boats,
surf boats, fishing boats, and others where it is desired to introduce steam propulsion ;
or for emigrant ships' life-boats I construct a vessel or boat of two single cylinder
air tube boats joined together as far apart as may be found desirable for the special
work they have to do by cross box girders made of iron or steel, to be
joined together in the 'midships and sides if desired by longitudinal girders
between them.
The bottom of the girders or between them, where the boat or vessels are
apart, to be plated over or between so as to present a fair surface to the water.
The girders and plates may be arched in the middle to give additional strength.
In boats the box girders form the thwarts, and should be in air-tight compart-
ments, and may be covered over with a wooden casing or filled with cork Thus
the boat would be divided on deck as the single cylinder one, and the water got rid
of in the same manner.
In vessels of war, or in any other description of vessels, the girders to be filled in
level with the top by iron plates so as to make a deck which can be covered with
cement, or planks, or armour plating, as required. On this deck batteries or deck
houses, with poop and forecastle, can be erected, or the whole space can be covered
in by a spar deck the entire width and length of the cylinders and air tubes.
In vessels of war means such as valves or sea-cocks to be provided for intro-
ducing when going into action (also for pumping out when required) water into the
ends of the cylinders or air tubes, so that the vessel can be so submerged that the
necessity for side armour plating in whole or to any great extent is obviated, and
the weight or thickness of the batteries can be proportionately increased.
The engine power can be either in the tubes, as named for single cylinder boats or
ships, or when light draught is required the screw or screws can be dropping ones
placed between the cylinders, or can be placed at one or both ends of each cylinder,
or otherwise arranged.
For channel steamers or ferry boats, if paddles are preferred, they can be recessed
in the air tubes amidships flush with the sides of the cylinders, and on the outer

page_text: side the engines for each paddle, which would work separately, being in the cylinder
adjoining such paddle. The air tubes may be flush with the outside of the paddle
boxes.
In order to allow of boats of this construction being lowered or launched into the
water from on board ships I place the boats on a launching platform, provided with
launching ways or transverse rollers The double cylinder boats may be protected
with a keel on each body, and the single cylinder boats are provided with bilge
pieces for stowage on deck, or for safety in beaching. The keels rest in grooves in
the rollers, or in or alongside the launching ways, and the boat is thus kept steady.
The launching platform rests athwartships upon rollers, supported in the centre by
standards which are placed amidships, joined together by a bar of iron, and in or
round which the rollers may be placed, and at the sides of the vessel on rollers
supported by quadrants, joined in same manner as the standards by a bar or rod of
iron, and in or on which the rollers can be placed.
The quadrants are let into the main rail on each side of the ship and secured by
pins, which are removeable at pleasure. The quadrants on each side are joined to
the 'midship standards by hinged frames.
When the boat is to be launched the pins securing the quadrants at each side of
the vessel are withdrawn, and the outer end of the launching frame drops or is
pressed or forced down on the side required, the launching platform then slides over
the rollers before named until its centre has passed up to, but not beyond, the side
of the vessel; its forward motion is then arrested by spring or other buffers affixed
to the bottom of the platform, and the platform tilts downwards to such an angle
as is thought desirable, the after end of the platform being held in check by ropes
or chains to limit the angle to which it can incline, the ropes or chains to be
previously securely affixed to the ship's bulwarks or waterways. The boat which
previously was held by a rope from sliding down the launching platform can then
be let go, and will at once descend into the water.
The launching platform may also itself be converted into a life raft, and after the
boat has been launched from it may be allowed to descend into the water For
this purpose I form the platform of three longitudinal box girders, about 15 inches
square, fastened together by angle irons plated on the underneath side. I also
carry in the vessel a number of loose cross box girders to fit in between the longi-
tudinal girders, and in which provisions can be carried. The cross girders also form
thwarts for rowers. Water to be stored in the ends of the central longitudinal box
girder, in the middle of which a dropping keel or centre board can be carried.
The ends of the launching platform to be fitted with strong iron doors between
the longitudinal girders, which shall be hinged to the bottom of the platform, and
affixed with chains at the top to the girders, so that when the boat has to be
launched the doors may be let down to such an angle, being provided with launching-
ways, as will facilitate the passage of the boat into the water.
The doors when in position to fit into grooves lined with india-rubber or other
substance so as to render them water-tight. The sides of the exterior longitudinal
girders to be raised about 18 inches, so as to form bulwarks and give a higher free-
board.
The outside of the longitudinal girders and the bulwarks to be protected by air
tubes like the boat, filled with cork to prevent injury by collision or otherwise.
The boat and raft, i.e., the launching platform, to be fitted or provided with oars,
masts, and sails, also with nautical instruments, such as a compass, at least.
For the single cylinder boats and other boats falling davits may be used for
lowering them into the water. In this case I control the lowering of the davits by
chains or ropes from their upper end, being led over pulleys carried at the top of
two fixed upright columns placed on the poop or other part of the deck, or on the
spar deck, at a distance apart somewhat greater than the length of the boat. The
boat is to rest on the poop or spar deck between the upright columns or chocks,
the stanchions of the poop or spar deck being moved for the purpose.

page_text: The falling davits consist of an iron frame, in length somewhat greater than the
boat, attached by hinges or roller pins to the gunwale of the main deck outside the
vessel. The chains or ropes being secured to the upper end of this frame or falling
davits after going through the pulleys, as aforesaid, pass round a drum, which is
wound up by a single action of a winch, which can be worked by steam or hand.
When the boat is to be lowered, the chains, ropes, or drum being guided or con-
trolled by a clip, such as is attached to a chain cable, are allowed to run out, and
the falling davits are thus lowered to any angle not exceeding a position horizontal
with the gunwale of the main deck, to which they are attached as aforesaid.
The boat is supported by falls in the usual manner, which pass or lead through
rollers, pulleys, or blocks attached alike to the top of the frame of the falling davits
as well as to the upright columns, and are then secured at the end to a drum having
an action independent of, but running in unison with, the one to which the chains
of the davits are attached.
When the davits are in the desired position the falls of the boat which have run
out with them are continued to be run out or lowered until the boat takes the
water on an even keel. Any disengaging apparatus can be used to fiee the boat
from the falls.
The boat, with or without her passengers on board, can thus be placed into the
water fully 12 feet from the ship's side, thus avoiding all chance of injury from
colliding with the vessel.
The upright pillars if placed on the poop or spar deck should pass through thom
and be secured to the main deck.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edmund Thompson in the Great Seal Patent Office on the 4th June
1878.
EDMUND THOMPSON, late of No. 27, Leadenhall Street, in the City of London,
Ship-broker, now of Sutton, in the County of Surrey, Naval Designer "IMPROVE-
MENTS IN THE CONSTRUCTION OF VESSELS OR BOATS AND RAFIS, AND IN THE
LAUNCHING AND LOWERING OF BOATS AND RAFTS FROM ON BOARD SHIPS INTO
THE WATER."
This Invention has for its object improvements in the construction of vessels,
boats, and rafts, and in the launching and lowering of boats and rafts from on board
ships into the water.
I construct a vessel with cellular sides and bottoms forming air tubes in the manner
herein-after described and shown in the Drawings annexed.
Figure 1 shows a transverse section of a vessel constructed according to my Inven-
tion, and suitable for a merchant vessel.
The floorings and frames a, a, for the midship's body, which by preference will be
fully one-half the vessel's entire length, will be each in one, varying from about
three feet in depth at the centre of the floorings, and from the bilges upwards,
gradually expanding to, say, about five feet at the gunwale of the main deck. They
are placed at distances apart of about six feet, and are stiffened by intercostal
kelsons b and tie plates c about the same distance apart as the frames, so as to con-
stitute a honeycomb fiame. The frame when put together is plated over on each
side with iron or steel plates, the plates of which the frame is composed being bent
at right angles at their inner and outer sides to form flanges for the inner and outer
plating to be secured to.
Openings are formed in the intercostal kelsons b and tie plates c to allow of the
interior of the several cells being painted or examined, and some or all of these
openings may be provided with water-tight covers.
The inner sides of the vessel are, as shown, perpendicular, save at the bilges and
ends, so that the interior of the vessel forms as it were a rectangular tank. The
beams for carrying the lower deck are securely attached to the inner sides, and sup-
ported by longitudinal shelf pieces of angle steel or iron rivetted thereon; or if
desired, they might be continued to the ship's outer side and rest on the tie plates,
and be attached to the frame plates. Above the top of the box girder sides are
transverse box beams to carry the main deck, and above the main deck will be a
spar deck, as shown, formed by similar honeycomb frames of narrower dimensions,
but not necessarily plated on the inner side. The decks are all to be plated with
steel or iron plates, and covered, if desired, with wood or cement. Between the floors
and in the kelsons an ample supply of fresh water can be carried, for the doublo
purpose of ballast and to supply the boilers. The condensed water from the engines
may be returned to these tanks.
The interior of a vessel constructed as above described being for the most part
rectangular, will give great facility in the stowage of cargo; and by reason of the
cellular sides of the vessel and the width of the frames, the cargo cannot be stowed
so close up to the outer sides as heretofore, whereby the tendency to roll will be
greatly diminished. Transverse bulkheads will be placed in the holds, say, at
about every 70 feet, and to the floors and sides longitudinal ribs of wood may be
attached to keep the cargo free of and prevent undue pressure against the sido or
bottom plates.
The ends of the vessel are formed with a longitudinal central bulkhead supported
by transverse ones, and extending not less than 20 feet of the vessel's length in-
board, as shown in the horizontal section at Figure 2. In these spaces no cargo
should be stowed, nor should there be any communication with them except by
man-holes for the purpose of repairs or painting. This will have a tendency to
prevent the vessel pitching, as the weight will be kept free of the ends,

page_text: To secure economy in construction the body of the vessel for fully half her length
should have frame plates of identical form. In the after ends I do not propose to
have air chambers or cells, but frames either of the ordinary description or con-
structed of a similar honeycomb description, but not plated over on the inner side,
and with three transverse water-tight bulkheads. The bulkheads of each compart-
ment should come up to the spar deck. The hatches from each compartment should
also in like manner be trunked up to the top of the spar deck. The keels are in the
form of box girders to give strength for facility of beaching or dock purposes.
Figure 3 shows a transverse section of a war ship constructed according to my
Invention; and Figure 4 shows a section partly in perspective of the cellular frame
of a similar vessel.
The frame of the vessel is, as shown, constructed in the same manner as that
above described, and the parts are marked with the same letters of reference as in
Figure 1. The air tubes or cells increase in width up to the level of the main deck,
and there is no communication with them save by man-holes at the top; these
should never be open save for repairs, and then only under proper circumstances.
The exterior of a war ship should be covered with wooden sheeting, and coppered.
The armour plates 1 carry away from the outer sides of the ship; this I do for the
following reasons:-
The placing of heavy weights at the sides of any vessel is quite opposed, not only
to known laws, but to the customary mode in which dead weight cargoes are carried
in merchant vessels. I allude especially to copper ore or other metals. These cargoes
are built up like a cone, and kept as free from the sides and ends of the vessel
as possible; and so well is this understood in stowing railway iron that it is
notorious that vessels with such cargoes are generally as easier as with almost any
other.
Adopting this well-known practice as a basis, I therefore carry the armour plates
alongside of the inner plating of the air tubes or cells, as shown, and properly support
them by a cellular girder frame. In this way a greater thickness of armour plating
may be carried than at present.
In some cases I provide means for filling some of the air tubes or cells of the
cellular sides with water before the vessel goes into action, so as to considerably
submerge the vessel, and thereby diminish the chance of the vessel being struck by
projectiles, and rendering it practically impossible that she should be struck below
the armour plating.
To protect the vessel from what are known as fish torpedoes and torpedo boats I
provide falling davits d at intervals all round the sides, and to the outer ends of the
davits I attach an effective torpedo net e weighted with grapnels, which may be
used in case of need for picking up torpedoes.
When the davits are lowered into the position shown at Figure 5, the net will
hang down at a distance, say, of about 15 feet or more clear of the ship's side. The
way in which the davits are raised and lowered is similar to that herein-after
described with reference to davits for lowering boats.
Vessels built, as heiein-before described, may be propelled in any suitable manner,
but I prefer to use a scrow propeller placed about one-fourth the vessel's length
from the stern. To allow of this I form a tunnel along the lower part of the after
body of the vessel, as shown in cross section at Figure 5, thus forming the after
body into two bodies, with a channel of uniform width between them; or the after
bodies might each be formed like an ordinary vessel, and the bodies be connected by
transverse box girders. The central channel will in this case increase in width at
the stern; I place the rudder midway between the two after stern posts, as shown
in the horizontal section, Figure 6. By placing a screw propeller to work in a
channel along the lower part of the after body I gain comparative absence of
vibration, a shorter screw shaft, absence of racing, diminution of slip, and the
screw when disconnected and running free will offer no impediment to the vessel
when sailing.
The tunnel might, if desired, commence at a short distance from the bow, whereby

page_text: ncreased stability can be obtained. If the vessel is & double bodied vessel I place
the propeller, if only one is required, about one-fifth the vessel's length from the
stern, and with the screw shaft slanting somewhat downwards. In a long vessel,
when great speed and facility for manoeuvring are required, I place another screw
propeller at the bow; other screws might also, if required, be carried more amid-
ships, all propelled by separate engines.
For yachts, or other boats or vessels, when it is desirable, the screw shaft may
be fitted with an universal joint, and hoisted out of the water into a well fitted for
the purpose.
The same principles herein-before set forth of frames, and flooring, and general
construction, apply to boats. A cross section of a double cylinder boat built in this
manner is shown at Figure 7. When the boat is a single cylinder boat, and is to
be propelled by a screw propeller, the propeller may, as herein-before described,
with respect to a vessel be placed in an open hollow tunnel at the after end of the
boat. A boat so fitted with a screw propeller is shown at Figure 14.
To allow of a double cylinder boat, such as shown at Figure 7, or it might be
any other boat of large dimensions being launched into the water from the deck of
a vessel, I carry the boat on a launching platform, provided with launching ways
or transverso rollers. The keels of the boat rest in grooves in the rollers, or in
grooves, or alongside of rails on the launching ways, and the boat is thus kept
steady.
The launching platform is placed athwart ships upon rollers carried by a launching
frame, as shown at Figures 8 and 9. The launching frame is at its centre free to
turn on a pivot carried by standards, and at its ends is supported by quadrants,
which are let into the main rail on each side of the ship, and secured by pins which
are removeable at pleasure.
When the boat is to be launched the pins securing the quadrants at each side of
the vessel are withdrawn by a single lever action, and the outer end of the launching
frame is forced down on the side required. The launching platform then slides over
the rollers or ways before named until its centre has passed somewhat beyond the
side of the vessel, its forward motion is then arrested by ropes or chains pre-
viously affixed. The boat which previously was held by a rope from sliding down
the launching platform can now be let go, and will at once descend into the water as
shown at Figure 9.
In case of need the launching platform can afterwards be itself launched into the
water and will serve as a life raft. The platform is for this purpose formed as a
girder frame, with two or more pontoons on its under side, as shown in the cross
section of a launching platform at Figure 10.
This plan of raft is applicable to war ships when light draft of water is required,
the vessel being propelled by screws placed between the bodies.
By the above-described arrangement of a lifeboat carried athwart ship upon a
launching platform, which will itself serve as a life-raft means of safety in case of
need, are provided for a great number of persons, whilst at the same time the plat-
form and boat are carried clear of the deck and do not interfere in any way with
the working of the ship.
For lowering into the water single cylinder boats and other boats of smaller
dimensions than the double cylinder boat before described, I employ falling davits,
as shown at Figures 11, 12, 13, and 14. These falling davits are attached by hinges
or otherwise to the vessel's side, and capable of being raised from a horizontal to a
O vertical position by ropes or chains passing over pullies attached to the heads of
upright stanchions upon the upper decks, and passing down from thence and
through leading sheaves or pullies attached to the deck to a horizontal drum or
windlass, upon which drum or windlass the said ropes or chains proceeding from the
respective davits will be wound in opposite directions so as to enable the respective
5 davits to be simultaneously and equally raised or lowered by the rotation in the
required direction of such drum or windlass.
To the outer end of the falling davits I attach the boats by means of falls or

page_text: tackles in the ordinary manner; such falls or tackles may be of rope, chain, or
other suitable material, the ends thereof being led inboard along their respective
davits by means of sheaves or pullies attached to such davits, and thence by other
sheaves or pullies attached to the vessel's side or deck in such positions as may be
required to and around a drum or windlass similar to that used for raising or
lowering the falling davits, as hereiu-before described, and wound thereon in opposite
directions as before described for securing the simultaneous and equal raising or
lowering of the respective falls or tackles. I place the said respective drums or
windlasses upon one axis or spindle, but working independently of each other;
to such drums or windlasses I attach spur wheels respectively capable of being
thrown into or out of gear, with a pinion regulated by a clutch or other well-kown
mechanical motion for attaining the desired effect; and further, when desirable, I
attach to the respective drums or windlasses friction brakes worked by levers for
the purpose of controlling by such means the lowering of the davits, and boat-falls,
or tackles.
and
Netting, as shewn at Figures 12 and 14, will be fitted between the two lower
frames of the davits, which being six feet apart, will, in case the passengers have
not been got into the boat previous to lowering, enable them to embark without
any risk to her by collision with the side of the vessel.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,-
First The manner substantially as herein-before described of building up the
frames of vessels and boats with transverse ribs or fi ames a, and longitudinal tic
plates b and c, to form exterior air tubes or cells to the cargo or central body
Second. Forming the sides of vessels with air tubes or cells increasing in width
from the bottom upwards, substantially as described.
Third. The construction of vessels substantially as herein-before described with
reference to Figures 1 and 2.
Fourth. The construction of war ships substantially as herein-before described
with reference to Figures 3 and 4.
Fifth. Forming the after bodies of boats and vessels with an open tunnel along
their bottom for a screw propeller to work in, substantially as described.
Sixth. The means of launching_boats into the water, substantially as herein-
before described, with reference to Figures 8 and 9.
Seventh. Forming what I have herein called the launching platform in such a
manner that it may in case of need servo as a life raft.
Eighth. The combined anangement, substantially as herein described, of fixed
pillars, lowering davits, and controlling chains or ropes for lowering boats into the
water, also applicable in ships of war for carrying strong nets to serve as a pro-
tection against torpedoes.
In witness whereof, I, the said Edmund Thompson, have hereunto set my
hand and seal, this Third day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.