Improvements in Boats, and in Releasing, Lowering, and Detaching Devices for the same.
Year: 1890

page_text: Date of Application, 9th Oct., 1890-Accepted 9th May, 1891
COMPLETE SPECIFICATION.
Improvements in Boats, and in Releasing, Lowering, and Detaching
Devices for the same.
I, GEORGE MONTGOMERY BIRD, of 265 Meridian Street, East Boston,
Massachusetts, U.S.A., Inventor, do hereby declare the nature of my invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of my invention is to provide a boat of great strength and buoyancy,
and means whereby boats can be safely and rapidly lowered from the deck of a
ship, the top of a wharf, or other place, and whereby the boat can be hoisted out
and instantly detached, thus preventing danger of the boat being stove in or
otherwise damaged, or tipping over.
The invention consists in the improved boat of the novel construction which I
will hereafter describe; and it also consists in the improved mechanism for hoisting
out, lowering, and detaching a boat, from the deck of a ship, or other place, all of
which will now proceed to describe.
Of the accompanying drawings, forming a part of this Specification,
Figure 1 represents a perspective view of the side and deck of a ship or vessel
provided with my improved davits and hoisting and lowering device, and a boat
embodying my improved construction being lowered over the side of the vessel.
Figure 2 represents a cross section of a part of a vessel, and my improved
hoisting and lowering mechanism and boat thereon, the boat being shown as at rest
between the chocks attached to the deck of the vessel.
Figure 3 represents a longitudinal section of a portion of my improved boat, a
portion of the inner skin or ceiling on the farther side of the boat being broken
away.
Figures 4 and 5 represent detailed views of the head or end of the davits.
The same letters of reference indicate the same parts in all the figures.
In the drawings:
a represents the deck, and the side of a ship or vessel of the usual or any
ordinary construction.
c represents my improved boat, the construction of which I will first proceed to
describe. The boat c is made with ribs 22 affixed to the keel at right-angles thereto,
in the usual way, and to said ribs are secured the outer skin and inner skin or ceiling
of the boat. The material of which said boat is made may be either wood or metal,
if the latter, it should preferably be of steel. 33 represent the seats of the boat
which extend cross-wise of the keel and reach from side to side a little below the
rail. Said seats are supported by bulk-heads 4 4, which, together with the ceiling 5
and floor of the boat, and said seats, form compartments or receptacles which are
utilized in a way which I will now point out. In the compartments formed by the
seats and their supports or bulk-heads I place air-tight tubes 77 in an upright
position. Said tubes may be formed to constitute air-tight compartments, or they
may be left with an open top and used to hold food, etc., in case of wreck or casting
away, the seats 3 3 forming lids or covers for the said tubes.
Below the floor 6 of the boat I place thin tubes 8, arranged longitudinally,
which are closed at both ends and form air chambers which give to the boat a great
amount of buoyancy.
In order to give the boat strength and buoyancy, and to protect the tubes or air
chambers 7 and 8, I fill the spaces between the inner and outer skin of the boat,
the space between the bulk-heads 44 and around the tubes 7, and the space between
the floor 6 and the bottom of the boat and around the tubes 8, with a mixture or

page_text: packing 9 of cork or light wood, hair, manila, or other strong fibrous material, and
rosin and glue melted to a liquid. In applying this packing I first mix rosin and
glue melted to a liquid with cork about as fine as coarse sawdust, and make the
mixture of such consistency that it can be applied with a suitable brush, this
mixture is then applied to all the surfaces to be covered, and the space between is
filled up by a composition formed by adding to the last-described mixture as much
coarse cork or light wood, hair, manila or other strong and fibrous material as is
necessary to bring it to the consistency required. This coarse mixture can either
be poured into the spaces to be filled when melted, or it can be formed in moulds of
any shape, sawed and fitted to place, and by the use of the thin mixture before
described held in place. This composition or mixture fills all crevices, and adheres
to all surfaces, and forms a good packing which is impervious to water and prevents
rot or corrosion. The rosin and glue give solidity, and the cork and fibrous
material give strength, and buoyancy, and the mixture offers great resistance to
blows tending to break through or bend the boat. Another advantage of this
mixture is its light weight, its weight, when properly mixed, being only about
24 pounds per cubic foot.
I do not limit myself to the tubes 7 and 8, but may place in their stead blocks of
cork, or any other suitably buoyant material.
In Figure 3 I have shown the fore part of the boat as provided with a bulk-
head 10 and a cover or scat 12, the space between said bulk-head and seat and the
fore part of the boat being provided with upright air-tight tubes 7', packed with
the mixture or packing 9, before described. The stern of the boat may be
provided with a similar compartment, and similar tubes similarly packed.
The boat is provided on its sides with lugs 13 13, said lugs being the same
length apart as the distance between one davit and another. A cross-bar 14 is
affixed to said lugs, and a stay or strengthening rod 15 is affixed to the centre of
the cross-bar and to the keel. The lugs 13 are the parts to which the ropes which
lift or lower the boat are attached, and the cross-bar 14 and rod 15 form a
strengthening frame for the boat at these points.
The chocks which hold the boat at rest on the deck of the vessel are in pairs,
one pair being near each end of the boat. The inboard chock d of each pair is
fixed rigidly to the deck, while the outboard chock e is pivoted to an ear d' on the
inboard chock d, and is provided with a handle or lever el by which it can be let down
to allow of the free outward swinging of the boat c, and moved up to hold the boat c
in its position of rest, as shown in Figure 2. A catch is provided on the deck
for the handle or lever e', said catch, when engaged with the said handle or lever
holding the latter in its boat-retaining position.
The davits
1 will now proceed to describe my improved boat-lowering mechanism. g
represent the main sections of the davits. Said sections yg are pivoted at their
lower ends to cars affixed to the deck of the vessel, and are adapted to swing
on their pivots. In order to prevent them from swinging too far inboard they are-
provided with cars or projections ii on their rear or inboard surface which come
in contact with a stop or projection affixed to the deck of the vessel.
are made with two sections, each having an outer section near its upper end
which slides in slots provided for it in the main section 7, said slots being so
arranged that they will permit the outward movement of the upper sections kk to
a certain extent, but provided with stops which will limit said motion and prevent
the upper sections from sliding out of the said slots. The main sections 9 g are
connected by cross-bars m and n, the latter bar n being provided with sockets
grasping the main sections 9 and allowing a sliding motion to the upper sections k k.
Said bars n also form the stops which prevent the said upper sections from sliding.
outwardly too far. The upper sections are connected together by cross-bars o
and p, the latter being tubular for a purpose hereinafter set forth. The shape of
the davits is as shown, and is such that when swung inwardly the boat will rest so
that its side is in the angle formed by the shape of the davits.
I

page_text: To the upper end of the upper sections of the davits are attached the detaching
devices. These consist of a pair of jaws, the upper member 7 of which is fixed,
while the lower member is pivoted to the fixed member. A catch having a
handle is affixed to one end of a rock-shaft, s, said rock-shaft running through
the tubular cross-bar p to the other section of the davit, and being there connected
with a similar catch. It will be seen that by moving the handle or lever r',
through the action of the connecting rock-shaft s, the catches at both upper ends of the
davits are drawn back from the jaw of the detaching device, thus allowing the
boat to be detached from each of the davits at the same moment. The catch r
may be provided with a handle or lever at each davit, so that the boat can be.
The
detached instantaneously by the action of a person at either end thereof.
jaws are adapted to receive a ring 16 which may be attached to ropes 17
which are fastened to the lugs 13 13 on the boat, as shown. It will be seen that the
boat c when attached to its davits is always the same distance from the upper ends
of said davits, and as said distance is made short, the boat is prevented from
swinging too much and thereby damaging itself against the side of the vessel, or
from tipping over by reason of striking the water with one end in front of the
other.
The windlass which is used to hoist and lower the boat consists of two frame
stands tt fastened on the deck of the vessel inboard of the davits, and substantially
At the upper
in the centre of the same, that is, equi-distant from each davit.
portion of the frames tt is journaled a shaft u having two loose rope-guiding
wheels . In the lower portion of the frames is journaled a shaft on which
are two drums ¹¹ which must be of different size.
Part of the raising and lowering device for suspending the davits consists in the
ropes ww, one end of each rope we being attached to one of the upper sections k
of the davits, the other ends of said ropes being attached to the sheave block c'.
The movable rope has one end fastened to the large end of the differential
drum and is wound therearound, thence it runs over one of the guide pulleys "',
through the sheave block wl, back over the other guide pulley and down and
around the smaller end of the differential drum, to which its other end is attached,
the rope running round this smaller end of the differential drum in a
direction opposite to that in which its other end runs round the larger end of
said drum.
The shaft is also provided with a drum to which is attached a lowering
rope, the other end of which goes over the side of the boat, so that a person in
the boat c can, by the use of said lowering rope el, lower the boat down gradually
into the water.
A
The other end of the shaft is provided with a ratchet and dog, which act as a
stop, and are used when raising a loaded boat from the water to the ship.
crank is also provided on the shaft by which the boat can be lowered or raised
by a person on the deck of the vessel.
с
The operation of lowering the boat is conducted as follows:-The handles or
lever el are released from the catches f, thus allowing the outboard chock e to
swing outwardly and downwardly, and allow the boat c to swing outward. The
drums are then caused to rotate so as to let the rope run so as to lengthen the
distance between the sheave block w' and the windlass, thus allowing the davits
and boat to swing outwardly and downwardly in the direction indicated by the
dotted line in Figure 2. If the boat c has not reached the water by the time
the davits have swung downwardly to their full extent, the continued loosening
of the rope will allow the upper sections of the davits to slide outwardly from
the main sections 9. 9 thereof. A pair of davits ten feet high will thus permit of
a boat being lowered a distance of nearly twenty feet below the level of the deck
or surface upon which they are located. When the boat touches the water it may
be instantly detached from its davits by a pressure on the handle or lever at the
end of either davit, as before described.

page_text: The weight of the boat is sufficient to unwind the rope a from the drums v¹, and
the too rapid descent of the boat may be checked by the lowering rope a. In
hoisting the boat, if the differential drums are made in proper proportion to each
other, the boat may easily he hoisted in by one man at the crank or handle v³.
Chains may be used instead of ropes, and various other changes may be made
in the construction and arrangement of parts, as I do not limit myself to the exact
construction here shown and described.
Having now particularly described and ascertained the nature of my said inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1st. A boat with the sides of the seats attached to the ribs 2 2 forming bulk-
heads, and having lugs 13 13 for attaching the suspending ropes secured on the
top and sides of the boat at four opposite points, the cross-bar 14 between the lugs
and the bolt 15 going from the cross bars to the keel, as set forth.
2nd. A boat having the spaces between the outside skin and ceiling, and around
the air chambers, filled with a composition consisting of cork or light wood and a
resinous substance, said material having glue and a fibrous substance mixed therein,
as set forth.
3rd. In combination with boat c, the releasing chocks de, the chock d secured
to the deck, the combined chock and lever e pivoted on chock d, and held in place
by catches, as set forth.
4th. The swinging davits made in two sections, the lower section g forming an
obtuse angle from the stands to the top and inboard side of boat and from the
top and inboard side of the boat to the top of the davit, the upper portion of the
main sections g g having slots in which the upper sections kk are adapted to slide,
combined with horizontal bars nm, forming a frame, and the upper sections k k
having cross-bars op, which combined with the main sections gg form the swinging
davits, as set forth.
5th. In a boat-lowering device, in combination with davits, the fixed stands tt,
the shaft journaled in the stands tt, and having a ratchet and lever on one end
and drum on the other end, provided with a crank 3, the differential drums
on said shaft r, the shaft journaled in the upper part of the stands, the guide
wheels turning loose on said shaft u, all arranged substantially as described
and for the purpose set forth.
6th. In a boat lowering device, the combination of the stands tt, drums
and on shaft journaled in stands, loose guide wheels u u¹ on shaft u, the
davits, sheave block w', ropes ww fastened to sheave block and to davits, with
the rope a, one end of which is fastened to one drum e, wound around and going
from the inboard side of said drum over wheel u around the wheel in sheave
block, then over other wheel is wound around and fastened on the out-
board side of the other drum e, all being arranged substantially as described
and shown.
7th. In a boat-lowering device the combination of the windlass provided with
the differential drums, and the drum, the davits, the ropes fastened to
the davits and to the sheave block ¹, rope a fastened to the drums and
arranged to pass around the sheave in the block and over guide wheels u¹ u',
with the rope. fastened to and wound around drum and arranged to go from
the inboard side of said drum 2 upward to the top of the boat e, all arranged as
described and substantially for the purpose set forth.
8th. In a boat-lowering device the combination of the windlass provided with
drums and v2, and guide wheels u u', the rope e arranged as described on said
drums and passing over the sheave in the sheave block w', rope arranged
as described on the drum 2, the davits provided with bars n
mop, and with
ropes ww, one end of each rope being fastened to the sheave block c¹ and then
each chain extending to and fastened on tops of davits, as specified.

page_text: 9th. The bars going through tubular cross-bar p, having detaching lever r
fastened on each end, the suspending hooks pivoted on the end of the davits, the
ring 16, and ropes 17 that go from ring 16 to the lugs 13 on the boat, as
described and specified.
Dated this Thirtieth day of September 1890.
GEORGE
MONTGOMERY BIRD.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.