Improved Davits and Appliances for Carrying and Launching Ships' Boats.
Year: 1892

page_text: Date of Application, 11th Mar., 1892
Complete Specification Left, 26th July, 1892-Accepted, 27th Aug., 1892
PROVISIONAL SPECIFICATION.
Improved Davits and Appliances for Carrying and Launching Ships'
Boats.
We, JOHN WOTHERSPOON, Engineer, of Rossbank, Forest Hill, Kent, and
JOHN WEIR, Joiner, of Byron Cottage, Helensburgh, North Britain, do hereby
declare the nature of the said invention to be as follows:-
This invention relates to improved davits and appliances for carrying and
launching ships' boats.
The davits are connected together and are separately hinged to the deck or other
convenient part of the ship or vessel, and are made of a curved formation (curving
in-board of the ship) and so arranged as that the boat, when aboard, will be carried
by suitable tackle suspended from the davit-heads with its keel and longitudinal
centre slightly in-board of the axis of the hinges, upon which the davits are
adapted to turn outboard for the purpose of launching the boat or taking it aboard
from the water, clear of the ship's side.
The lower edge of each davit is made with two planes angularly disposed
relatively to each other, and respectively extending inboard and outboard relatively
to the hinges upon which the davits turn as aforesaid. Those of such planes
which extend inboard, serve to limit the motion of the davits inboard, and when
resting on the deck or other support, such planes support the davit in their normal
position, with the boat carried thereby as aforesaid. Those of such planes which
extend outboard, serve to limit the motion of the davits outboard, and when resting
on the deck, such planes support the davits in a position for launching the boat
or taking it aboard by the lowering and raising tackle, clear of the ship's side.
Each davit is formed of a flat metal plate or of two of such plates bolted
together, with suitable distance-pieces, if required, and in the head of each davit
is formed an inclined slot rising from its inner end which terminates inboard of a
vertical plane passing through the hinges of both davits, so that the weight of the
boat, when being carried aboard, normally tends to keep the davits in their carrying
position but as the davits are turned outboard in launching the boat, the rings
supporting the hoisting tackle traverse the slots to the outer end thereof, so that
the boat can be launched and taken aboard clear of the ship's side.
:
When inboard, the davits are, however, further secured by removable pins to
eyes let into the deck or other support or which may rise from the same plate as
that from which the said hinges rise.
The pair of davits are connected by tie-rods which run parallel with the boat,
and cause the two davits to be of a rigid formation and to work together, so that
both ends of the boat will be caused to have an equal movement.
The davits may be fitted with conveniently arranged chocks for berthing the
boats when aboard, or canvas or rope belts with netting can be used and secured to
the davits and connecting rods; affording a ready means of releasing the boats for
launching and of securing them.
The davits are operated, so as to carry and lower the boat outboard and to bring
it aboard, by means of a barrel fitted to the outer side of each, and around each
of which barrels is passed a wire rope, the ends of which are made fast to suitably
spaced eyebolts let into the deck or other support. Or, in lieu thereof, chain
wheels and chains, or screwed spindles working in nuts pivoted to the davits, may
be used, the necessary motion being given by hand-power.
The improved davits require no standards, nor cross bars, and occupy but little
space and are very strong and of simple construction.

page_text: Their movement being straight outward, all fore and aft swinging gear is
dispensed with, and boats can be placed close together in a fore and aft direction.
The falls of the hoisting tackle may be carried to the said barrels, which may
thus also be used for lowering the boats into and raising them from out of the
water, but any suitable raising and lowering tackle may be used.
Dated this 11th day of March 1892.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.

page_text: Each davit is also formed with a head 24, overhanging its centre of movement,
such head being made of an inclined formation (declining inboard when the davit
occupies its normal position, vide Fig. 2,) and being slotted or equivalently formed,
at 25, so as to permit of the hoisting and lowering tackle and the suspended boat
having a traversing movement independently of but occasioned by the outboard
or inboard movement of the davits.
The inboard end of the slot or travelling-way 25, terminates inboard of a
vertical plane passing through the centres 9, of both of the davits, so that the
boat 10, when aboard and supported by the tackles 27, (which are suspended from
travelling shackles 28, adapted to traverse said slot) will be suspended from the
davit-heads with its keel and longitudinal centre slightly inboard of said
vertical plane, and its weight will consequently tend to keep the davits in their
normal carrying position.
The outboard ends of the slots 25, may terminate any desired distance outboard,
so that on the davits being turned outboard, as aforesaid, (during which the suspended
boat will gradually traverse to the outboard ends of the slots, vide the dotted lines
Fig. 2,) the boat may be carried and caused to traverse to the desired distance
outboard, clear of the ship's side.
The travelling-way 25, is preferably formed by upward extensions 29, 30, rising
from the top side of the davit-head and connected by a top plate 31, bolted to each
such extension, at 32.
Each davit is also formed or fitted with a cleat 33, or the like, for securing the
falls from the tackle 27.
.
Each davit is formed of a metal plate preferably of the section represented in
Fig. 6, with strengthening webs where advisable, or it may be formed of two plain
metal plates (preferably cast steel) bolted together with intervening distance-
pieces.
The pair of davits are connected by one or more tie-rods and angled bars 34,
disposed parallel with the axes of the centres 9, and which cause the two davits
to co-act so that both ends of the boat will be caused to have an equal movement.
The davits may be fitted with chocks for berthing the boat when aboard, and
the boat may be secured by canvas or rope belts and netting secured to the davits
and connecting rod or rods, and bars 34, in any readily releasable manner.
In lieu of using hand-spikes for turning the davits about their centre pins 9, a
barrel may be fitted to the outer side of each davit and around each barrel a wire
rope may be passed, the ends of which may be secured to suitably spaced eye-bolts
secured to the sole-plate 16; or chain wheels and chains, or screwed spindles
working in nuts pivoted to the davits may be used for such purpose, the necessary
motion being given by hand power.
If the said barrels be used, the falls of the hoisting tackles may be carried
thereto, so that such barrels may also be used for lowering the boats into and
raising them from out of the water; but any suitable raising and lowering tackle
may be used.
The movements of the davits being straight inboard and outboard, permit of
boats being placed closely together in a fore-and-aft direction.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The hereinbefore described improved davits and appliances for carrying and
launching ships' boats.
2. The construction of a davit of a metal plate or plates, with a boss serving as
a centre of movement, with inboard and outboard angularly-disposed planes at the
base limiting the inboard and outboard movements and supporting the davit in such
positions, with a head overhanging its centre of movement slotted and inclined so
as to be adapted to cause the raising and lowering tackle and a suspended boat to
have a traversing movement determined by the overhanging length of the head,

page_text: independently of the davit, with a boss adapted for securing it when inboard, and
with a boss adapted for operating it, as set forth.
3. The combination with such a davit, of a flanged sole-plate adapted to centre
the davit and to locate and secure it when inboard, as set forth.
4. The combination of a pair of such davits so mounted and connected as to
co-operate, as set forth.
Dated this 29th day of June 1892.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.