IMPROVEMENTS IN APPARATUS FOR STEERING VESSELS
Year: 1864

page_text: LETTERS PATENT to Robert Ker Aitchison, of Forest Hill, in the County
of Kent, for the Invention of "IMPROVEMENTS IN APPARATUS FOR STEERING
VESSELS."
Sealed the 3rd January 1865, and dated the 5th July 1864.
PROVISIONAL SPECIFICATION left by the said Robert Ker Aitchison
at the Office of the Commissioners of Patents, with his Petition, on
the 5th July 1864.
I, ROBERT KER AITCHISON, of Forest Hill, in the County of Kent, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN APPA-
RATUS FOR STEERING VESSELS," to be as follows:-
The first part of these improvements applies to vessels propelled by the
screw, and consists principally in mounting the screw in the rudder of the
vessel, instead of in the "dead wood" of the stern. An opening of appropriate
size and form is made in the rudder, and the screw propeller (fitted on a short
shaft or spindle) is mounted in suitable bearings therein. This short shaft or
spindle is connected to the propeller shaft driven by the engine by means of a
universal coupling joint, so that whilst the ordinary propeller shaft constantly
revolves on an axis parallel to the central line of the vessel, it drives the short
shaft with the screw on it at the same speed at whatever angle the rudder
(and consequently the short screw shaft) may be moved. It will be evident
that by this arrangement of the screw it will act as a very powerful auxiliary

page_text: 66
to the rudder, for as soon as the latter is turned (however slightly) either to
port" or "starboard," the screw (instead of acting still in the line of the
vessel's course) acts in the direction given to the rudder, and consequently
causes the vessel to answer her helm much quicker than she otherwise
would do.
I propose also to use a screw having two vanes, which are capable of being
set to the required angle, or of being brought into the same plane, so as to fill
up, or nearly so, the opening in the rudder, in order that the latter can be
used in the ordinary manner when the vessel is propelled by the wind alone.
The second part of these improvements is intended to be used in connection
with the first, but it may also be applied to ordinary screw or paddle steam
vessels, and also to sailing vessels. To the tiller of the vessel, which moves
the rudder, a toothed segment is attached, which is acted upon by a toothed
pinion keyed on the spindle which carries the steering wheel. Outside this is
fixed to the deck a second segment furnished with moveable pins or projections
working in radial slots; these pins or projections are all moved simultaneously
inwards or outwards by means of a suitably formed cam attached to the first-
named segment, and the end of the tiller is so arranged that it shall be held
between these pins or projections when they are thrust forward, but shall be
free from the same when they are drawn back; or if preferred the pins or
projections may be moved vertically. The cam which works these pins or
projections is so formed and arranged, that as soon as the steering wheel is
moved it withdraws the pins or projections before acting on the tiller, and
returns them immediately after the end of the tiller has passed, so that the
pins or projections instantly lock the tiller in any position in which it may be
placed, but do not hinder the steering wheel from acting on the same, when
required.
It will be evident that by this arrangement of pins or projections for holding
and releasing the tiller the work of the steersman will be greatly facilitated,
and that fewer men will be required to steer a vessel of any given tonnage
than would be necessary with the ordinary arrangement.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of July, in the year of our Lord One
thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Ker Aitchison, Her special licence that I, the said
Robert Ker Aitchison, my executors, administrators, and assigns, or such
others as I, the said Robert Ker Aitchison, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN APPARATUS FOR STEERING VESSELS," upon the
condition (amongst others) that I, the said Robert Ker Aitchison, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the suid
Letters Patent.
NOW KNOW YE, that I, the said Robert Ker Aitchison, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement in writing, and on reference to the accompanying Sheet
of Drawings, that is to say :-
The first part of these improvements applies to vessels propelled by the
screw, and consists principally in mounting the screw in the rudder of the
vessel (instead of in the "dead wood" of the stern) in the manner herein-after
described. An opening of appropriate size and form is made in the rudder,
and the screw propeller (fitted on a short shaft or spindle) is mounted in
suitable bearings therein. This short shaft or spindle is connected to the
propeller shaft (driven by the engine) by means of a universal coupling joint,
so that whilst the ordinary propeller shaft constantly revolves on an axis
coincident with or parallel to the central line of the vessel, it drives the short
shaft with the screw on it at the same speed at whatever angle the rudder
(and consequently the short screw shaft) may be moved. It will be evident
that by this arrangement of the screw it will act as a very powerful auxiliary
to the rudder, for as soon as the latter is turned (however slightly) either to
"port" or "starboard," the screw, instead of acting or thrusting still in the
line of the vessel's course, acts or thrusts in the direction given to the rudder,

page_text: and consequently causes the vessel to answer her helm much quicker than she
otherwise would do.
Another advantage is, that by this arrangement the vessel can be turned
round or otherwise manoeuvred without having previously any "way" on her.
If preferred, the screw in the rudder may be used in addition, or as an
auxiliary to the ordinary screw in the "dead wood" of the stern, in which case
a much smaller screw will be required in the rudder.
I propose also to use a screw having two vanes only, which are capable of
being set to the required angle, or of being brought into the same plane, so as
to fill up, or nearly so, the opening in the rudder, in order that the latter can
be used in the ordinary manner when the vessel is propelled by the wind alone.
With regard to the second part of my Invention, I wish to state that since
filing the Provisional Specification which accompanied my petition for the said
Letters Patent, I have ascertained that it would not be desirable to lock or
hold the rudder in the manner therein described, as it is frequently necessary
to let the rudder go "with a run " in a heavy sea, and I therefore propose to
modify that part of my Invention, so as to make the locking motion operate
by the foot of the steersman instead of its being automatic, as previously
described. To the tiller of the vessel which moves the rudder a toothed
segment is attached, which is acted upon by a toothed pinion keyed upon the
spindle which carries the steering wheel. Upon this spindle is also keyed a
notched wheel or disc in connection with which is a sliding stop, which is
thrust into any one of the notches in the wheel or disc, so as to lock the
spindle (and consequently the rudder) whenever the steersman places his foot
on a treadle, which is conveniently placed for that purpose, and on his
removing his foot from the treadle the stop is withdrawn from the notch, and
the spindle and rudder are perfectly free.
It will be evident that by the use of this arrangement for holding and
releasing the tiller by means of the foot the work of the steersman will be
greatly facilitated, and that fewer men will be required to steer a vessel of any
given tonnage than would be necessary with the ordinary arrangement.
Such being the nature and object of my said Invention for "Improvements
in Apparatus for Steering Vessels," I will now proceed to describe more in
detail the manner in which the same is to be or may be performed or
carried into practical effect; and in order that the same may be distinctly
understood, I have annexed hereunto a Sheet of Drawings illustrative thereof,
and have marked the same with figures and letters of reference corresponding
with those in the following explanation thereof, that is to say :-
Figure 1 represents a side elevation of part of the stern of a vessel with one

page_text: modification of my Invention applied thereto, the screw in the rudder acting
as both propelling and steering screw; Figure 2 is a plan view of the same;:
and Figure 3 is a partial section shewing the rudder turned to an angle of
about 45 degrees; Figures 4, 5, and 6 are similar views illustrating another
modification of my Invention, wherein the steering screw fixed in the rudder
is used in addition or as an auxiliary to the ordinary screw placed in the
"dead wood."
In Figures 1, 2, and 3, a, a, is the rudder, in which an opening b, b, is:
formed; c, c, is the ordinary propeller shaft driven by the engine and connected
by a universal coupling joint d, d, to a short shaft or spindle e, e, mounted in
the rudder and carrying the screw f. f. The effect of this arrangement is that
the rotation of the propeller shaft c, c, will still be communicated to the short
screw shaft or spindle e, e, although the latter may be moved out of the right
line and inclined to either side by the action of the rudder, as shewn in
Figure 3, and it will also be evident that the force or thrust of the screw will
always be exerted in the direction given to the short shaft or spindle e, e, by
means of the rudder, as represented by the arrows in Figure 3.
In the modification shown in Figures 4, 5, and 6, the propeller f.f, (and
consequently the opening b, b, in the rudder) is reduced, and a propeller g, g,
in the ordinary position is also employed; by these means the screw f, f, acts
as a powerful auxiliary to the propeller g. 9, so long as the rudder and the keel
of the vessel are in the same line, and it acts as an auxiliary to the rudder
whenever the same is inclined either to "port" or "starboard," as shewn by
the arrows in Figures 5 and 6.
In Figures 1, 2, and 4, h, h, is a toothed segment attached to the tiller of
the rudder, and in gear with a toothed pinion i, i, keyed on the spindle k, k,
which carries the steering wheel 1, 1; on the same spindle is also keyed a
wheel or disc n, m, having notches in its periphery, in which the upper end of
a sliding stop n, n, is capable of fitting. This stop is thrust upwards into the
notches (when it is desired to lock or hold the rudder) by the steersman
placing his foot upon the treadle o, o, and upon his removing his foot there-
from the stop becomes instantly disengaged by its own weight or by means of
a spring.
Having now described the nature and object of my said Invention for
Improvements in Apparatus for Steering Vessels," together with the manner
in which the same is to be or may be performed or carried into practical effect,
I would remark in conclusion that I claim as my Invention the improved
apparatus for steering vessels as hercin-before set forth and shown in the

page_text: accompanying Drawings, or any mere modification or imitation constructed
and operating in substantially the same or a similar manner.
In witness whereof, I, the said Robert Ker Aitchison, have hereunto
set my hand and seal, this Third day of January, in the year of our
Lord One thousand eight hundred and sixty-five.
ROBERT KER AITCHISON. (L.B.)