IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS
Year: 1878

page_text: LETTERS PATENT to John Isaac Thornycroft, of the Firm of John I. Thorny-
croft and Co., of Church Wharf, Chiswick, in the County of Middlesex, Steam
Yacht and Launch Builders, for the Invention of "IMPROVEMENTS IN STEERING
APPARATUS FOR VESSELS."
Sealed the 31st January 1879, and dated the 27th August 1878.
PROVISIONAL SPECIFICATION left by the said John Isaac Thornycroft at
the Office of the Commissioners of Patents on the 27th August 1878.
JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft and Co., of Church
Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch Builders.
IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS."
According to my Invention, a rudder or paddle, moveable on a suitable joint, has
imparted to it from an engine or motor sculling movement capable of being reversed,
and is able also to assume positions in which its surface will be inclined to the
vessel's course as an ordinary rudder, so that the positions and operation of the
rudder or paddle may be readily adjusted according to the course to be steered.
By my Invention the fore and aft position of a vessel not under way may be
readily changed, and under way the steering power may be greatly increased, the
operation of the rudder or paddle being rendered active as distinguished from the
passive action of the ordinary rudder.
1

page_text: :
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Isaac Thornycroft in the Great Seal Patent Office on the 27th
February 1879.
JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft and Co., of Church
Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch Builders.
"IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS."
According to my Invention, a rudder or paddle, moveable on a suitable joint, has
imparted to it from an engine or motor sculling movement capable of being reversed,
and is able also to assume positions in which its surface will be inclined to the
vessel's course as an ordinary rudder, so that the positions and operation of the rudder
or paddle may be readily adjusted according to the course to be steered.
By my Invention the fore and aft position of a vessel not under way may be
readily changed, and under way the steering power may be greatly increased, the
operation of the rudder or paddle being rendered active as distinguished from the
passive action of the ordinary rudder.
Referring to the accompanying Drawings,
Fig. 1 shews in side elevation part of a vessel, having steering apparatus according
to my Invention arranged in the bow, a portion of the skin of the vessel being
removed, the better to show the apparatus.
Fig. 2 is a plan, and Fig. 3 is a cross sectional view of the vessel, taken aft of
my steering gear, which is partly represented as seen when looking toward the stem
of the vessel, a portion of the skin being cut away to shew where the steering
apparatus passes through the hull.
1 is a rudder or paddle in the form of a blade, somewhat like a fish's fin, capable
of being caused either to lie close against the skin of the vessel, as at 1ª (Fig. 1),
or to protrude into the water in a downward sense, as at 1 (Fig. 1). About this
last-described position the rudder, paddle, or fin-like blade is able to move when
suitably operated in such a way that not only will the course followed by any one
point in the longitudinal centre 1b of the blade (below the centre of the joint 5,
about which it oscillates) as seen in plan, resembles the Figure 8, but moreover
throughout such movement the blade will exert a propelling effect, its faces being
during the whole time at some efficient working angle to the direction of movement,
the angle varying with the position.
In other words, the movement of the blade may be approximately described as
follows Referring to the diagram, Fig. 6, representing approximately the
Figure 8-shaped course of the paddle or blade when moving through the path a orb,
the paddle or blade acts almost as an ordinary paddle float, and when moving
between these points near the centre c of the Figure, the paddle or blade acts some-
what like a screw propeller, being inclined one way in moving from a to b, vid d,
and reversely inclined in moving from b to a, vid e, and vice versa.
At.points in its course, intermediate between c and a and c and b, the action is a
combination of the two, i.e., paddle and screw, gradually changing from one to the
other, while the propelling effect remains nearly uniform.
The active action of the paddle or blade, as just described, is designed for turning
the vessel when not in rapid motion. To turn her when in rapid motion I use the
paddle or blade as passive rudder, for which purpose I turn it to a suitable angle.
The paddle or blade 1 has motion imparted to.it for active steering by a connecting
rod 2, moving it fore and aft, and a second connecting rod 3 constantly turning it
to the angle suited to the point of its travel, motion being given to the connecting
rods 2 and 3 by a cranked shaft 4, which may be turned by any suitable engine or
motor.
In the Drawings I have shewn a pair of oscillating cylinders. The paddle or
blade 1 is supported in a socket in which the spherical surface 5 rests, this being

page_text: suitably packed to be water-tight when this bearing is situated below the water
lino.
The socket and packing may be such as shown in Figs. 4 and 5, wherein 8 and 9
are two principal parts of a socket formed with recesses to receive packing 10.
The parts 8 and 9 are held together by both 11 and the packing; 10 is kept against
the spherical surface 5 of the paddle or blade by glands 12.
In order to guide the paddle or blado it has an upward prolongation beyond the
connecting rod 2, which prolongation is operated by a piston rod 6, or it may be by
a spring exerting a nearly constant pressure towards the port sido or the starboard
side, as the case may be, of the vessel.
The action of the steering gear will be reversed by reversing the direction of the
rotary motion of the shaft 4 and the pressure exerted by the rod 6 or its equivalent.
When the paddle or blade is in use for passive steering after the manner of an
ordinary rudder, only a part of a revolution will be required to be given to the
shaft 4, so as to bring the paddle or blade 1 to the required angle.
7 is a screw, by operating which when desired the paddle or blade 1 may be
placed against the vessel's skin, as at 1, out of use and of danger by the following
arrangement:-13 is an arm fast on the prolongation of the paddle or blade 1; 14
is a part able to turn on the said prolongation; the screw 7 connects the two, being
attached to the arm 13, and working in a nut carried in the part 14. The turning
the screw 7 alters the angular position of the arm 13 in relation to the part 14.
The several bearings in the connecting rods and the bearing surfaces on the pro-
longation of the paddle or blade 1 are made so that the rubbing parts are spherical.
Other suitable bearings, which will allow suitable motion round about their centres,
may be used.
The motion imparted to the paddle or blade is designed to exert a continuous
positive pressure of one of the two faces of the paddle or blade, which face acts in a
direction depending on that of the shaft 4.
Figs. 7, 8, and 9 shew my improved steering apparatus adapted to the stern of a
vessel, where it may, if desired, take the place of the ordinary rudder.
In this arrangement the same reference numbers as in the preceding arrangement
are used to denote like parts of the apparatus.
In the present arrangement the upper part 14 is formed in one with the paddle
or blade, and is guided in a different manner to the part 14, previously described
and shewn.
The cylinder is replaced by a frame, with rollers holding the connecting rod 2, so
as always to pass through the axis 20, 20.
The paddle or blade 1 describes a definite curve, which is always repeated in the
same way as distinguished from the previously-described arrangement, which allows
variations in certain limits and elasticity.
It is not essential that the paddle or blade 1 should be supported at 5; it may
be sometimes advantageous to support the blade from the upper extremity at or
about 21, in which case the connecting rod 2, giving the Figure 8 motion, would be
connected to the paddle or blade at 5, and the connecting rod 3 suitably arranged
to give the proper angle of the blade. The angle of blade given may be varied as
required, but I prefer about 40 degrees as a maximum angle.
The angle of the path or travel in the Figure 8 course, which is the same as the
angle of the connecting rod 2, should be about half the angle of the paddle or blade
to a line passing through the longitudinal centre 22 of the vessel.
In applying this to a vessel, the shaft 4 might be driven by a pair of engines, so
geared to an ordinary steering wheel in any part of the vessel that putting over the
wheel in the ordinary way would first act on the reversing gear of the engines
driving the shaft 4, and then gradually put on the steam in such a way that the
pressure applied would depend on the position of the steering wheel
Figs. 10 and 11 shew a suitable reducing valve for such an arrangement. The
effect would be that the paddle or blade would act simply as a rudder, the increased
pressure of steam giving an increased angle to the rudder, but when the steering

page_text: wheel was so far put over that the pressure of steam was more than equal to bring
the paddle or blade to its maximum angle, then the paddle or blade would begin to
reciprocate and act as a propeller athwart the vessel, thus giving complete control
over the apparatus by an ordinary steering wheel.
As is obvious, the paddle or blade described as applied to the bow may be applied
with suitable actuating gear to other parts of the vessel, as also may the paddle or
blado I have described as applied to the stern.
Having described the nature of my said Invention, and explained how the same
is to be or may be performed or carried into practical effect, I would have it
understood that what I consider to be novel and original, and therefore claim
as the Invention secured to me under the herein-before in part recited Letters
Patent is,-
1. The method of turning or altering the course of a vessel by causing a rudder,
steering paddle, or blade to operate actively on the water, in the manner substantially
as herein-before described.
2. Arranging a rudder, steering paddlo, or blade, so that it may lie up against the
skin or hull of the vessel out of use, or may be caused to operate on the water for
steering in the peculiar manner substantially as herein-before described.
3. The constructing and arranging steering apparatus, substantially as herein-
before described, with reference to Figs. 1, 2, 3, 4, and 5 of the accompanying
Drawings.
4. The constructing and arranging steering apparatus substantially as herein-
before described, with reference to Figs. 7, 8, and 9 of the accompanying Drawings.
In witness whereof, I, the said John Isaac Thornycroft, have hereunto set
my hand and seal, this Twenty-seventh day of February, in the year of our
Lord Oue thousand eight hundred and seventy-nine.
TOUN T
A