OR IMPROVED MACHINERY OR APPARATUS FOR RAISING, LOWERING, AND DISENGAGING SHIPS' BOATS, AND FOR LOADING AND DISCHARGING THE SHIP'S CARGO, ALSO USEFUL AND PARTLY APPLICABLE FOR OTHER PURPOSES ON BOARD SHIP
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by James Scott at the Office of the
Commissioners of Patents on the 30th September 1880.
JAMES SCOTT, of Helensburgh, in the County of Dumbarton, North Britain, Ship
Carpenter and Engineer. "NEW OR IMPROVED MACHINERY OR APPARATUS FOR
RAISING, LOWERING, AND DISENGAGING SHIPS' BOATS, AND FOR LOADING AND
DISCHARGING THE SHIP'S CARGO, ALSO USEFUL AND PARTLY APPLICABLE FOR
OTHER PURPOSES ON BOARD SHIP."
This Invention has reference to a new or improved construction of machinery
and apparatus for raising and lowering ships' boats, which is also designed to act
as hoisting gear, cranes, or winches for loading and discharging the vessel's cargo,
and when out of action for such purposes, to serve as a look-out bridge, and for
displaying the side or signal lights of the ship.
These improvements also comprise certain novel arrangements of disengaging
tackle, or hooks and gear, for the safe and instantaneous letting go and dropping
the boat into the sea. The improved apparatus and appliances are specially
arranged to facilitate the safe and speedy lowering of the ship's boat, or several
boats in succession, with less risk than heretofore of loss of life in heavy seas.
Under one modification of the improvements, the hoisting apparatus or lifting
gear consists of two strong swivelling cranes, or open frames somewhat like cranes,
and constructed with a vertical part mounted to swivel on a strong pillar, fixed to
the deck frames near the sides of the ship, each having an overhanging horizontal
jib at the top, preferably made of wrought iron, or steel side frames strongly
secured together at some distance apart; but these may be made partly of cast iron
or of wood, and fitted to swivel on their said strong posts or pillars secured to the
deck heams or continued down to the lower deck, one on each side, so that the jibs
or horizontal frames can be swivelled or turned to meet transversely over the
vessel's deck, and hold, or main hatch. The crane frame can thus be swung round
on its central pillar or post to reach over the vessel's side as a crane, either for
lifting and launching the boats, or for raising and lowering heavy loads in
loading and discharging the cargo. The vertical frame of each crane is fitted with
a crab or winch barrel and gearing at a convenient height from the deck, actuated
either by motive power engines, or by hand cranks and gearing, and preferably
fitted with a single chain to each crane, carried up over pulleys to the horizontal

page_text: part of the jib, where double chains are joined and carried along over pulleys at the
end of the jib, to suspend the disengaging beam and lift the boat in a parallel manner.
These swinging cranes when arranged to meet in the centre of the vessel can be
conveniently used for loading or discharging the cargo at either side of the vessel;
and when intended to be used for launching or lowering a boat, the crane,
preferably on the lee side of the ship, is swung round at right angles, or nearly so,
when the lifting chains and hooks are attached to the disengaging beam fitted to
the boats, as will hereinafter be described, and the boat with the crew or passengers
seated in it is lifted and swung over the vessel's side in a position transverse or
inclined to the longitudinal centre line of the vessel, in which position the boat is
lowered and disengaged or launched, instead of alongside or parallel to the ship, as
heretofore, thus enabling the men to be seated with the oars out, on both sides of
the boat to pull out clear of the ship. The swinging cranes are formed or fitted
with a foot bridge above, having a protecting railing, so that when not in action
for launching the boats, they may be locked together and used as a look-out bridge;
for access to this bridge the central frames of the cranes are each made or fitted
with a stair or ladder, and the central vertical part of the swinging frames are also
carried up above the bridge and formed with recesses to receive the ship's port and
starboard side lights or lamps.
The improved disengaging appliances comprise a horizontal lifting bar or beam
suspended by links near each end from the two chains of the crane, and this beam
is fitted with a jointed hook, bar, or lever at each end, on which the boat is hung
by a link and rod fixed to the boat, so that the longitudinal centre of the boat is
immediately under that of the lifting beam. The said jointed hook bars extend
inwards from thier joint pins and have forked ends, which being heavier than the
outer hook ends lie horizontally on a stop in the lifting beam, and these forked
ends of the hook bars are locked to retain them in a horizontal position, when they
sustain the weight of the boat, by means of jointed locking bars, which are attached
to a central swivelling disengaging lever on opposite sides of its centre, and are
shot into or out of the forked ends of the hook bars by drawing a cord or pulling
a handle attached to the upper end of the disengaging lever.
The outer hooked ends of the jointed levers are arranged to close up against a
reverse hook or horn fixed to each end of the lifting beam, for the purpose of
preventing the links by which the boat is suspended from rising and dropping off
the hooks if the boat should be lifted by a wave.
Instead of the bridge cranes described, a derrick jib swivelling on the mast and
stayed from the mast head, as is commonly used for loading purposes, may be used
for raising and lowering or launching the boats, or a gaff or the main boom of
smaller vessels may be employed for this purpose in cases where a look-out bridge
and crane are not required; also any of the lower yards of square rigged ships may
be similarly used for lifting and launching the boats from the deck of the ship as
described in reference to the bridge crane, all otherwise as hereinbefore described.
Other arrangements of disengaging apparatus than that described may be used
with the improved construction of raising and lowering or launching machinery or
cranes described, and these cranes might be considerably modified to suit different
circumstances.