IMPROVEMENTS IN APPARATUS FOR DISENGAGING SHIPS' BOATS FROM THE LOWERING TACKLES
Year: 1876

page_text: LETTERS PATENT to Arthur Benjamin Cruickshank, of Dundee, in the County
of Forfar, Merchant, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
DISENGAGING SHIPS' BOATS FROM THE LOWERING TACKLES."
Sealed the 28th July 1870, and dated the 30th May 1876.
PROVISIONAL SPECIFICATION left by the said Arthur Benjamin Cruickshank
at the Office of the Commissionors of Patents on the 30th May 1876.
ARTHUR BENJAMIN CRUICKSHANK, of Dundee, in the County of Forfar, Merchant.
"IMPROVEMENTS IN APPARATUS FOR DISENGAGING SHIPS' BOATS FROM THE LOWERING
TACKLES."
This Invention has for its object improvements in apparatus for disengaging ships'
boats from the lowering tackles.
For this purpose I attach to a boat near each of its ends a shackle by a stop
hinge joint which allows the shackle to full when no weight is upon it, or to stand
up in a position inclining somewhat towards the end of the boat. The blocks at
the lower ends of the ordinary lowering tackles I connect to a ring, to the bottom
of which is jointed a hook which is to hook into the shackles upon the boat. The
hooks are each formed with a counterbalance weight which, whenever the hooks
are relieved of the weight of the boat, turn the hooks up and free them from the
shackles. Each hook being arranged to turn away in the opposite direction to that
in which the shackle into which it is hooked is to fall. The shackles then drop
away as before explained, so as to avoid all liability of the hooks again catching
into them. The point of each hook has a line attached to it which I call a preventive
line; by holding on these lines the hooks can be retained and prevented from dis-
engaging themselves until it is desired to allow the self-acting disengaging hooks to
free themselves. In order to ensure that neither of the hooks shall become dis-
engaged until both hooks are freed from the weight of the boat, the links to which
the two disengaging hooks are jointed are connected by a bridle of wire rope which
retains the links somewhat nearer together than the distance between the shackles
upon the boat, so that if the hook at one end of the boat is relieved of weight by
that end of the boat touching the water whilst the weight of the boat is still upon
the other hook, the bridle is drawn endwise and pulls upon the hook which has
been relieved of weight and so prevents it from becoming disengaged.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Arthur Benjamin Cruickshank in the Great Seal Patent Office on the
30th November 1876.
ARTHUR BENJAMIN CRUICKSHANK, of Dundee, in the County of Forfar, Merchant.
"IMPROVEMENTS IN APPARATUS FOR DISENGAGING SHIPS' BOATS FROM THE LOWERING
TACKLES."
This Invention has for its object improvements in apparatus for disengaging ships'
boats from the lowering tackles.
For this purpose I attach to a boat near each of its ends a shackle by a stop
hinge joint which allows the shackle to fall when no weight is upon it, or to stand
up in a position inclining somewhat towards the end of the boat. The blocks at
the lower ends of the ordinary lowering tackles I connect to a ring, to the bottom
of which is jointed a hook which is to hook into the shackles upon the boat. The
hooks are each formed with a counterbalance weight which, whenever the hooks
are relieved of the weight of the boat turn the hooks up and free them from the
shackles. Each hook being arranged to turn away in the opposite direction to that
in which the shackles into which it is hooked is to fall, the shackles then drop
away as before explained, so as to avoid all liability of the hooks catching into
them. The point of each hook has a line attached to it, which I call a preventive
line; by holding on these lines the hooks can be retained and prevented from
disengaging themselves until it is desired to allow the self-acting disengaging hooks
to free themselves. In order to ensure that neither of the hooks shall become
disengaged until both hooks are freed from the weight of the boat the links to
which the two disengaging hooks are jointed are connected by a bridle of wire
rope which retains the links somewhat nearer together than the distance between
the shackles upon the boat, so that if the hook at one end of the boat is relieved of
weight by that end of the boat touching the water whilst the weight of the boat
is still upon the other hook, the bridle is drawn endwise and pulls upon the look
which has been relieved of weight, and so prevents it from becoming disengaged.
The Drawing hereunto annexed will explain more fully the details of construction
DESCRIPTION OF THE DRAWING.
Figure 1 represents a side elevation of a ship's boat with this Invention adapted
thereto, and as it would appear when ready for use. Figure 2 is a top plan view of
Figure 1. Figures 3 and 4 are detached views of sonic of the parts drawn to an
enlarged scale. At each of the Figures similar letters of reference are placed upon
corresponding parts.
A marks the boat, B, B, shackles fixed thereto and constructed as hereafter
described, and represented at Figure +; C, C, hooks constructed as represented at
Figure 3; D a bridle line or rope connected by its ends to the hooks C, C, E, E,
other ropes also connected to the hooks C, C, by their lower end and to the ship's
"davits" and tackles by their upper ends. The following is the construction of the
shakle represented at Figure 4, where a marks a casting made with cars b, b, with
a hole in each through which passes a bolt at c for connecting the shakle B to the
cars b, b.
e is a stop piece to compel the shackle to fall outwards when in use.
I now proceed to describe the construction of the hook represented at Figure 3,
where C marks a hook with a weight at g and ears h, to which is connected loosely
by a pin a casting with openings 1, 2, therein into the opening 1; one end of
the bridle D is connected, the other end of the said bridle being in like manner
connected to another hook similar to that just described. The length of the rope
or chain D should be such as to be taut or tight when the hooks C, C, are connected
to the shakles B, B, as represented at Figure 1. In opening 2 at each of the
castings is connected one end of the tackle leading to the ship's "davits," so that
supposing the boat to be suspended therefrom in the position represented at Figure 1,

page_text: upon lowering the boat and when both ends thereof rest on the water, by slackening
the tackle the weighted end g wil! descend and thus remove the strain on the shackles
when they will fall outward and become desengaged from the hooks C, C, and the
ship's tackle as before stated. At Figure 16 marks a safety line connected by one
end to the hook C, the other end of this line being held by a person in the boat
whilst it is being lowered to prevent one or other of the hooks becoming accidentally
detached from the shackles, and it is only when the boat is fair on the water that
the safety lines are to be released.
Having now described the nature and object of my said Invention and the means
by which it may be effected, I will state that I am aware that a weighted hook has
heretofore been proposed to be used for boat disengaging gear, but I hereby declare
my Invention to consist in, and I claim-
Firstly. The weighted hooks C for the purpose of enabling the said hooks to
disengage theinselves from the shackles B when combined and arranged substantially
as described.
Secondly. The shackles B with the stop piece e to compel the shackles to fall
outwards from the points of the hooks C substantially as described.
Thirdly. The lines and manner of operating therewith for securely holding the
hooks in their respective shackles and releasing them therefrom substantially as
described.
Fourthly. The combination of the hooks C with the bridle line D, shackles B, and
ordinary lowering tackles substantially as described.
In witness whereof, J, the said Arthur Benjamin Cruickshank, have hereunto
set my hand and seal, this Twenty-eighth day of November, in the year of
our Lord One thousand eight hundred and seventy-six.
ARTHUR B. CRUICKSHANK. (L.S.)