IMPROVEMENTS IN STEERING OR MANIPULATING STEAM SHIPS AND OTHER VESSELS, AND IN APPARATUS THEREFOR."
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Robert Bell at the Office of the
Commissioners of Patents on the 25th September 1878.
ROBERT BELL, of Egremont, in the County of Chester.
"IMPROVEMENTS IN
STEERING OR MANIPULATING STEAM SHIPS AND OTHER VESSELS, AND IN APPARATUS
THEREFOR."
"
In manipulating the long ocean screw steamers and others in narrow waters
great difficulties are experienced in turning sharply, and several collisions have
occured in the Mersey and elsewhere from this unmanageableness. Accordingly at
various times numerous auxiliary rudders have been designed, but have not come
into general use owing to their taking up too much room or being otherwise
unsuitable. Now my Invention is designed to overcome this difficulty in steering,
and also give an additional means of arresting the progress through the water
when required, without taking up valuable room. It consists in placing one or
more flaps, preferably of the form of a broad letter D or doors on each side of the
vessel below the water line; the number of fins depend on length of the vessel;
screw steamers drawing more water aft require fins placed well aft, as well as
forward, swinging on vertical or nearly vertical axes, and which when closed fit.
tight against their casings with their exterior surfaces flush with the sides of the
ship. When slightly opened they are forced wide open at once into a positson at
right angles to the axis of the ship by the force of the water meeting them as the
ship ploughs through the water.
The doors are pivoted on axes or hinges as close as possible to the vessel's side,
permitting of an opening to the extent of 90° and no more.
Each door is fixed in
and is part of an iron plate, the fin being sunk in a hollow till quite flush with the
vessel's run when not in use, and not therefore liable to any damage when in docks
or when vessels are alongside. The frame is bolted to the ship's ribs and plating,
the ribs being formed with a bend to admit the thickness of the fins and casing,
the hinge end of fin being placed near a bulkhead where possiple. The whole is
thus rendered one mass perfectly water-tight, and the same as if no fins were there,
they being flush with the vessel's sides. Each door is connected by a chain in a
tube bent at foot with rollers or sheaves to ease friction with a windlass above, and

page_text: there is also a bell crank with a handle going up through the bent tube to give the
door the initial push necessary to open it sufficiently for the current of water
flowing past to catch it and force it wide open. Or in place of the bell crank and
chain, the one to open and the other to close the door, an arrangement of links or
rigid chain of jointed links would be used that could accomplish both motions, or
a spring would take the place of the bell crank, but this would be liable to get out
of order. These fins only require to have the starting lever used to be in action
instantaneously, and with the proper inhauling gear can be closed to the side of the
ship immediately. I do not limit myself however to these modes of opening the
door as it could be worked with hydraulic, steam, or pneumatic power, but in all
cases is should be arranged to work from deck, and for there to be no communi-
cation between the casing round the flap and the interior of the vessel. The mode
of working is as follows:-If the vessel is to be suddenly retarded let loose all doors,
they fly out and retard the ship; if you want to turn hard-a-port let go the port
flaps; if hard-a-starboard the starboard flaps must be shot out. When the purpose
is effected the doors are closed by windlass or other power.
If at any time these fins should be broken off they would only break the
inhauling chain, or if torn off at the hinge end would not make any leak in the
ship's side.
The great merit of these check fins consists in being almost instantaneous in
their effect.