IMPROVEMENTS IN STEERING AND MANOEUVRING SHIPS OR VESSELS OR IN THE APPARATUS EMPLOYED THEREIN
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Dugald Graham at the Office
of the Commissioners of Patents, with his Petition, on the 2nd December
1862.
I, DUGALD GRAHAM, of Edinburgh, in the County of Midlothian, North
Britain, Commander of the Northern Lights Commissioners Steamer, do hereby
declare the nature of the said Invention of "IMPROVEMENTS IN STEERING
AND MANOEUVRING SHIPS OR VESSELS OR IN THE APPARATUS EMPLOYED THEREIN,"
to be as follows, that is to say :-
This Invention relates to the arrangement and construction of the steering
apparatus of vessels. Under one modification or system of arrangement an
opening is formed in the stem or "dead wood" at the forward part of the
vessel, and in this opening is fitted a rectangular or other suitably shaped
rudder, or instead of being fitted in an opening in the ordinary stem the
rudder may be set to project forward beyond this stem: This rudder or steer-
ing apparatus is fitted on a vertical shaft which passes down through the central
part of the rudder, and is stepped in a footstep bearing arranged for the purpose
in the framing of the opening and which extends in a line with the lower
part of the keel. The rudder may however be fitted up and actuated in various
other ways. The shaft is carried up on deck, from which point it is suitably
connected to a steering wheel by means of bevel or other equivalent gearing.
The forward rudder may be made supplementary to the usual one at the stern
or the vessel may be wholly steered by it. As this mode of fitting the forward
rudder admits of its being placed at right angles to the keel it forms a very

page_text: efficient means of quickly checking the progress of the vessel, thus giving the
commander greater confidence in the control which he has of the vessel.
These improvements also comprehend some arrangements of the ordinary
rudder so as to facilitate the working of it, more particularly in large ships.
For this purpose the rudder is formed with an opening in it in which is hung
a secondary rudder corresponding to the shape of the opening; suitable means
are provided for working the secondary rudder either independently or in con-
junction with the main rudder. In this way when the main rudder is placed
in an angular position by the steering wheel the smaller rudder turns upon its
hinges like a door and thus greatly relieves the pressure of the water upon
the larger one. The inner rudder is then moved over to the same plane as the
larger one by means of a secondary wheel or other equivalent actuating con-
trivance. In lieu of this arrangement the rudder may be divided into two parts,
which are so arranged that either part may be put in motion either separately
or conjointly; the object of the arrangement being in both modifications to
lessen the difficulty of steering large ships by causing a portion of the rudder
to be actuated in the first instance, and this to be followed if necessary by the
motion of the second part. The difficulty of moving these duplex or compound
rudders being much less than those of the ordinary kind, the ship will answer
her helm quicker than by the present system, which is frequently a point of
vital importance, at the same time a considerable saving of labour will be
effected.