IMPROVEMENTS IN PRO- PELLING NAVIGABLE VESSELS
Year: 1856

page_text: PROVISIONAL SPECIFICATION left by John Norman at the Office of
the Commissioners of Patents, with his Petition, on the 21st November
1856.
I, JOHN NORMAN, of Liverpool, in the County of Lancaster, Merchant, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN PRO-
PELLING NAVIGABLE VESSELS," to be as follows (that is to say) :-
This Invention is chiefly applicable to the class of vessels in which auxilliary
propellors are used, or, in other words, vessels having a small amount of
motive power on board, to be used in light or contrary winds only; and consists
in forming or mounting fat submerged propeller blades upon the driving
shaft in such a way that when out of use they will fall fore-and-aft, so as
to fill up the opening formed in the deadwood of the ship's run, through
which they work merely by the action of the vessel being propelled forward
through the water by means of her sails, which it is proposed to form in such
a.way that she can carry a larger amount of fore-and-aft sail than now usually
practised in that class of ships. To accomplish these improvements, upon
the propeller shaft, at the portion exposed in the opening of the run of the
vessel, at about one-third aft from the fore edge of the opening, fixed radial
arms are formed, upon which the propeller blades are mounted, so that when
their surfaces or flat sides are laid fore-and-aft, or parallel to the driving
shaft. About one-third of the propeller blades are before the radial arms upon
which they are mounted. These propeller blades are free to turn or swivel
a given distance upon the fixed arms upon which they are mounted, so that

page_text: upon the rotation of the driving shaft, the pressure of the water being greater
on the after than the fore part of the blades, they will turn to a given angle
across the driving shaft, where they are prevented turning further by suitable
stops formed upon the propeller shaft, and upon a zone or zones of motal
which passes round the propeller shaft, and connect the radial arms together
at given points equidistant from the driving shaft. The propeller blades
may be formed of metal or metal and wood. When applied to a wooden
vessel it is preferred to use metal and wood combined. If deemed advisable,
additional intermediate propeller.hlades of a shorter kind may be introduced
between the zono and driving shaft. The metal rings used to combine the
radial arms, upon which the propeller blades work, it is proposed to form so
as to present only their edges to the resistance of the water, and one or more
may be used and may be applied at any part of the radial arms, small openings
being formed in the propellers' blades to allow of their turning to the required
angle. In order that the submerged propeller may be called into play as
little as possible, it is proposed to give her a larger amount of fore-and-aft
sail than is now usual in such ship, to accomplish which it is proposed to
increase the size and mode of fitting and setting the "spanker," "the fore-
and-aft mainsail," "spencer," or "trysail," and the "trysail," "spencer," or
"fore-and-aft foresail," and above which it is proposed to set gaff topsails,
the heads of which will extend to the topgallant mast or royal mastheads,
to enable a larger "fore-and-aft mainsail," or "main trysail," or "fore-and-
aft foresail," or "foretrysail," to be set. The gaff is fitted to the " cap" or
mast head by tho well-known "goose-neck," joint or any other convenient
method. The sails are so fitted that they can be hauled in and out upon
their gaf, and the "fore lecch" of the sail is laced or otherwise secured to
the back of the minst or to a "jackstay" fitted abaft the mast. The "slings"
for hanging the gaff are to be secured to the "hounds" or topmast head.