IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR RAISING, LAUNCHING, AND LOWERING SHIPS' BOATS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by John Nicholson at the Office of the
Commissioners of Patents on the 20th April 1878.
JOHN NICHOLSON, of No. 2, Dean Terrace, South Shields, in the County of
Durham, Marine Superintendent. "IMPROVEMENTS IN THE MODE OF AND APPARATUS
FOR RAISING, LAUNCHING, AND LOWERING SHIPS' BOATS."
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My Invention relates to the application of mechanical apparatus, by means of
which ships' boats may be safely launched and lowered into the water, or raised out
of the water and brought on board, with or without the crew in them, in any
position of the ship, and either on the lee or weather side, by manual power applied
to the apparatus on the deck of the ship. For this purpose two upright "davits
are fixed in two quadrants which are keyed on shafts working in bearings formed
in standards or frames, which are secured to the ships' deck in positions to suit the
length of the boat to be dealt with. Each of these quadrants, by suitable wheel
and pinion or other gearing, has a motion given to it through any required portion
of a circle by manual power applied to a winch handle or to a large wheel similar
to the steering wheel in ordinary use. Upon the same standards or frames which
carry the quadrants is also carried a rope or chain barrel, which can be acted upon
by suitable wheel gearing independently of the quadrants. To this barrel is attached
one end of a steel rope, which is carried up through proper guides to the head of
each "davit," where it runs over a sheave, and is attached to the end of the boat
by a "slip hook" or other suitable attachment readily disengaged. A brake is
also provided upon the standards or framing which can be worked by the hand or
foot of the man working the apparatus, and by which the lowering of the boat is
controlled.
The boat being supposed to be resting upon the "chocks" provided for her, and
being required to be launched, the operation of the apparatus is as follows:-The
quadrants are put into gear with the hand wheels, at which are stationed one or
more men (according to the weight of the boat), and the wheels being revolved the
quadrants through the intervening gearing are caused to revolve also, by which
motion the upright davits are at first raised a few inches, lifting the boat clear

page_text: of the skeats or framing on which it rested, and the revolution of the quadrants
continuing the "davits "(with the boat hanging on them) are carried out till they
project over the ship's side like crane jibs, and until they rest in suitable "cleats"
provided for them on the rail, the boat being now suspended quite away from and
clear of the side of the ship. In this position the quadrants are put out of gear,
and the rope barrels are connected with the hand wheels, the brakes being at the
same time applied, and the boat is lowered steadily and safely down to the water,
on reaching which (or to within a safe distance) the trigger lines in connection
with the "slip hooks are pulled, and the boat is free.
"
. The process of raising the boat out of the water, and bringing her on board is
the same as in launching and lowering, but the action is reversed, the winch barrels
first raising the boat by the ropes to the "davit" heads, and the quadrants then
being applied to swing the "davits " inboard, and land the boat upon the "chocks."