Improvements in or relating to Ships' Davits and in Holding and Detaching Gear for Ships' Boats.
Year: 1890

page_text: Date of Application, 25th Apr., 1890
Complete Specification Left, 25th Feb., 1891-Accepted, 11th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in or relating to Ships' Davits and in Holding and
Detaching Gear for Ships' Boats.
I WILLIAM ARMSTRONG, of 18, Cromwell Terrace, Belle Vue, West
Hartlepool, in the County of Durham, Blacksmith, do hereby declare the nature of
this invention to be as follows
My invention relates to the construction of ships' davits for lowering ships' boats
at sea, and in the holding and detaching gear connected therewith.
The object of my invention is to design ships' davits on which the ship's boats are
housed in an over-balanced position, so that when the boat is loaded and the davits
are released for action they fall over the ships sides by the action of gravity far
enough to suspend the boat over the open water to be lowered down at will by the
Occupants of the boat.
A further object of my invention is to design a simple, cheap, and effective con-
trivance which can be readily brought into operation for detaching the ships' boat
when the water is reached.
In carrying my invention into effect I construct the ship's davits in the form of
straight bars up to a certain length beyond which they are set off to form the boat
seat by being curved approximately to the outline of the boat as taken from the
keel to the boats side, the said davits then extend to a suitable height above the
boat and are inclined sufficiently to reach beyond the boat's centre; each davit
is free to work on a pin between the sockets or double eyes which are provided
at the bridge deck to enable the said davits to fall over the ship's side to positions
at which the boat to be lowered is suspended above the open water, the proper
working of the davits is provided for by confining them in slots or guides formed in
beams which are erected on the ship's upper deck to pass close under the boat's
keel when housed on board. The upper end of each davit is forked to receive a
roller which is fixed to a spindle which extends from the forked end of one davit to
the forked end of the other davit, and carries a third roller which is also fixed to it
at an intermediate position; all the rollers thus rotate with the spindle in the same
direction. The object of this roller arrangement is to wind a rope onto the inter-
mediate roller at the same time as other ropes wind off the other two rollers as the
boat descends into the water; this enables a man in the boat to regulate its rate of
descent by holding onto the rope which winds onto the intermediate roller. The
davits are so erected that the boat hangs over the centre ready to swing out beyond
the ship's side even when housed on board ship, and is only held back by a rope or
bridle which lashes the davits to a suitable connection or cleat. It is to be under-
stood that by the employment of the above described appliances everything requisite
to swing the boat over the ship's side and lower into the sea can be done from
within the boat.
The operation of lowering the boat is as follows:-The crew having got into the
boat, the davits are unlashed and fall over the ship's side, the boat is then lowered
by unwinding the tackle which is round the two rollers which rotate in the forked
ends of the davits; the descent of the boat being regulated by a man holding the
rope which is simultaneously wound up onto the intermediate roller in the opposite
direction to that of the other two rollers, the tackle is then detached by the means
hereinafter described.
The detaching gear constructed according to my invention consists of the
following parts all connected and operating together within the boat itself;
extending from the underside of a thwart or seat towards each end of the boat and
secured to the keel below, I provide frames with two sides set apart to carry the

page_text: slip hooks which engage with the links or shackles of the ship's tackle above, which
slip hooks rock or swing upon the fulcrums which support them between the sides
of the frames which are preferably set apart from the same stem or shank, that is
forked shaped fashion, with the stem or shank secured to the keel. These sides are
still further opened out or bell mouthed at their upper ends if necessary to receive
the links or shackles of the ship's tackle above, which are let in through slots
provided in the thwarts or seats of the boat to enable the slip hooks to engage with
them. The slip hooks are so weighted, preferably below the fulcrum, as to have a
constant tendency to return by the action of gravity from any position to which
they may have been tilted to that position in which the point of the hook enters the
link or shackle of the tackle above; an arm or bar extending from the slip hook
serves as a lever to tilt the slip hook in the required direction to draw the point of
the hook out of the link or shackle of the ship's tackle to detach the boat, and to
retain it in that position at will when required to again admit the said link or
shackle below the thwart or seat for the purpose of securing the boat to the ship's
davits. To operate the slip hooks so as to detach or secure the boat simultaneously
at both connections, the slip hooks should have their points turned from the centre
of the boat, that is to bow and stern respectively, and their tilting levers to the
opposite directions. The slip hooks are coupled together by chains or their
equivalents connected to the tilting levers and a ring or the like device is attached
to some intermediate part of the chain which is brought round pulleys along the
keel of the boat for the purpose, so that the chains can be pulled at both ends with
equal force simultaneously, thus tilting each slip hook to the same extent until the
boat is detached at both connections.
It will be understood that when the slip hooks are relieved from the pull of the
chain they return to their original positions by the action of gravity and engage
with the links or shackles of the tackle above if these are inserted through the
thwarts to receive them.
Dated this 24th day of April 1890.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Ships' Davits and in Holding and
Detaching Gear for Ships' Boats.
I, WILLIAM ARMSTRONG, of 18, Cromwell Terrace, Belle Vue, West Hartlepool,
in the County of Durham, Blacksmith, do hereby declare the nature of this inven-
tion, and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
My invention relates to the construction of ships' davits for lowering ships' boats
at sea and in the holding and detaching gear connected therewith.
The object of my invention is to enable boats to be lowered from the ship and
detached from the lowering tackle with the utmost facility.
Part of my invention relates to the design and construction of ships davits from
which the ships' boats are housed so that when the boat is loaded and the davits are
released they swing over the ships side by the action of gravity far enough to
suspend the boat over the open water to be lowered down at will by the occupants
of the boat.
A further part of my invention relates to a simple cheap and effective means for
detaching the ships boat when the water is reached.
Davits constructed according to my invention are supported on pins between
sockets or double eyes provided at the bridge deck to enable the said davits to
swing over the ships sides to an angle at which the boat to be lowered is suspended
above the open water. The proper working of the davits is provided for and side-
ward motion prevented by slots or guides which can be conveniently formed in

page_text: beams which are erected on the ships' upper deck to pass close under the boats keel
to take its weight when housed. The davits admit of being used to form the boat
seat to one side of the keel by being curved immediately above the slots or guides
approximately to the outline of the boat as taken from the keel to the boats side,
the said davits then extend to a suitable height above the boat and are inclined
sufficiently beyond the boats centre to cause the boat to swing out from the davits
when free. Spindles extend between the davits and are furnished with rollers from
which the lowering tackle unwinds as the boat descends and with regulating tackle
which is simultaneously brought into operation and controlled from within the boat.
When the boats are not in use they are housed by lashing them to the davits and
to suitable connections or cleats but in such a manner that all operations requisite
for lowering the boat can be carried out from within the boat itself.
My improved detaching gear which engages with the links or shackles of the
ship's tackle above rock or swing upon their fulcrums between forked standards the
upper parts of which receive the links or shackles through slots or openings in
the thwarts or seats of the boat. These slip hooks return by the action of gravity
from any positions to which they may have been tilted to those positions in which
the hook engages with the links or shackles; the slip hooks are simultaneously
disengaged when no weight is upon them, by a coupling chain and return to their
original positions when free to do so or the slip hooks are so adjusted on their pins
that they fall over on their backs as soon as the weight of the boat is taken off the
tackle that is as soon as the boat floats in the water, in which position they are
readily disengaged from the lowering tackle.
And in order that my invention may be fully understood and readily carried into
effect, I will now refer to the accompanying drawings.
Figure 1 illustrates in longitudinal section a boat slung from and fitted up with
my improved lowering and detaching machinery or gear, Figure 2 being a corre-
sponding end view showing the boat and davits in the housed position or out of
use and in dotted lines the corresponding position when the davits have swung over
the ship's side.
Figures 3, 4, 5, 6, 7 and 8 illustrate in detail and to an enlarged scale modifications
of my improved detaching gear.
In the figures, a, a are the davits, 62 are spindles or shafts extending between
them to which are secured two rollers cc and the regulating gear for controlling
the descent of the boat into the water, d d are the lowering ropes and d' the rope
or chain for controlling the regulating gear; each davit a, is supported from and
works on a pin e between a socket or double eye e¹ provided at the bridge deck.
The action of the davits a a is an essential feature of my invention and is clearly
illustrated in Figure 2 in which the davit is shown both in its position with the
boat housed and in dotted lines in its position when by the action of gravity it has
swung over the ship's side with the boat suspended over the open water.
travel between these two positions is the only motion the davits a are intended to
have, and this is provided for by slots or guides extending along or within the
beams which are erected on the ship's upper deck to take the weight of the boat
when housed.
The
The davit takes a convenient form for the purposes of my invention when curved
at the part above the beam to the outline of the boat from the keel to the boat
side; this form of davit admits of the chock ¹ being placed upon the davit to one
side of the keel whilst the other chock is placed against the other side of the
keel. The rope h which is secured to the beam is carried over the boat's sides
to a cleat or suitable connection on the davit and serves to lash the boat to the
davit when not in usc. When the davit is thrown back and the boat housed they
are in a position of repose or nearly so, but are preferably lashed to a cleat or
some suitable connection for security as for instance by rope k and its connections
but in order to swing the davit over the ship's side the upper part of the davit
extends beyond the centre of the boat consequently when the boat which is slung

page_text: from the davits by the ropes d d is unlashed it swings out beyond the vertical plane
of the pins e and brings over the davits with it.
C
The lowering ropes d d then unwind from the rollers cc by the weight of the
boat, the rate of descent being regulated by the rope or chain d¹ which controls
the regulating gear and can be restrained at will by the occupants of the boat.
The regulating gear may be of any suitable mechanism to afford an occupant
of the boat sufficient purchase from the chain to control the rotation of the
shaft b¹.
When the boat reaches the water my improved detaching gear is brought into
operation in the following manner: Referring to Figures 3, 4 and 5 in which
detaching gear is illustrated which consists of the following parts all combined and
operating together; within the boat extending from the underside of a thwart or
seat towards each end of the boat and secured to the keel below, I provide
frames,, with the two sides 111 set apart to carry the slip hooks m, which
engage with the links or shackles n, of the lowering tackle, which slip hooks, rock
or swing upon the fulcrums which support them between the sides of the frames
or standards which sides are preferably set apart in the manner shown more
particularly in Figure 5, that is fork-shape fashion, with the stem or shank secured
c the keel. These sides are still further opened out or bell mouthed at their upper
ends if necessary to receive the links or shackles of the lowering tackle which are
let in through slots or openings in the thwarts or seats of the boat as shown more
particularly in Figures 4 and 5 to enable the hooks to engage with them.
An arm
or lever extends from each slip hook towards the centre of the boat so that
the both hooks can be simultaneously disengaged by pulling the coupling chain
or cord P which is brought round pullies and connected together in any suitable
manner for this purpose.
To enable the slip hooks to gain the positions in which they engage with
the links or shackles n, balance we'ghts m² are provided on or form part of
them preferably below the fulcrum. It will thus be seen that by pulling the
coupling chain the boat is detached simultaneously at both connections, but
when relieved of any pull from the chain the slip hooks again return to the position
in which the boat can be readily secured to the tackle above.
In Figures 6, 7 and 8 I illustrate a modification of my improved detaching gear
in which the coupling chain p, is dispensed with, each slip hook m being so adjusted
on its own pins that it falls on its back as soon as relieved from the pull of the
lowering tackle which can then be readily disengaged therefrom, to prevent the
slip hooks from falling over when required to remain erect a chock
inserted into the opening in the thwart into which the slip hook falls.
7 may be
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be carried into effect, I declare that what
I claim is -
Firstly The general arrangement and combination of parts constituting
machinery or apparatus for lowering and detaching ships' boats all combined and
operating together substantially as hereinbefore described with reference to the
accompanying drawings.
Secondly-In means or apparatus for lowering ships' boats the use of davits
constructed to swing over the ship's side by the action of gravity so as to suspend
the boat over the open water substantially as described and illustrated in Figures 1
and 2 of the accompanying drawings.
:-
Thirdly The general construction and arrangement of parts for swinging the
boat over the ship's side and lowering it into the water, operated under the control
of the occupants of the boat, substantially as described and illustrated in Figures 1
and 2 of the accompanying drawings.
Fourthly The use and application of detaching gear in which slip looks m
are simultaneously disengaged by the coupling chain or cord p and are so weighted

page_text: as to regain the positions in which they engage with the lowering tackle by the
action of gravity, as described and illustrated in Figures 3, 4 and 5.
Fifthly: The use and application of detaching gear in which the slip hooks m
when relieved of the weight of the boat fall back for detaching the boat from
the lowering tackle as described and illustrated in Figures 6, 7 and 8 of the
accompanying drawings.
Dated this 24th day of February 1891.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.