IM- PROVEMENTS IN APPARATUS FOR STEERING VESSELS
Year: 1866

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "IM-
PROVEMENTS IN APPARATUS FOR STEERING VESSELS."-A communication
from abroad by Maurice Aron, Merchant, of 29, Boulevart St. Martin,
Paris.
Sealed the 26th March 1867, and dated the 29th September 1866.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 29th
September 1866.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR STEERING VESSELS," to be as
follows:-
This Invention relates to an improved screw steering apparatus, by the aid
of which a vessel may be guided in its course under all circumstances, and
especially when going at half or slow speed when the rudder has little
effect. This apparatus may be made dependent or independent of the screw
propeller shaft, and can be worked without the aid of the engines or of those
in charge. By moving the steering bar which is placed on the deck to one
side or the other the vessel may be readily turned in the desired direction.

page_text: This apparatus consists of a small auxiliary screw placed in a line with the
keel of the vessel above the screw propeller shaft in the space between it and
the stern post. The diameter of this auxiliary screw varies from three to four
feet, according to the size of the vessel, and may be geared with a shaft in
connection with that of the propeller so as to perform from two to three
hundred revolutions per minute in order to keep up the speed of the vessel
and not retard its progress; if it is desired to add its effect to that of the
propeller, the propulsive power will be thus greatly increased. In case of
damage to the propeller the vessel will be thus provided with a small auxiliary
propeller, which in many cases would be of great service, and renders the
In order to incline the
apparatus superior to any heretofore constructed.
shaft of the steering apparatus to one side or the other in a horizontal plane,
an opening is made in the framing of the vessel behind the stern post, forming
a segment of a circle corresponding to the form of the stern itself. For this
purpose the upper part of the stern post, which is usually made of forged iron
in iron ships, and of brass in wooden ones, is extended laterally in such manner
as not to weaken it in order to provide an opening, as shown in Figure 2 of
the Drawing annexed, which represents the auxiliary screw in line with the
keel, and inclined to starboard. Inside the opening in the round part of the
stern is disposed a metal backing, see Figures 3 and 4, of circular form, also
having a horizontal slot in which the shaft of the steering screw moves, this
backing being provided with horizontal slides C, Figure 3. In these slides,
concentrically to the backing, works a circular guide piece, colored red in
Figures 3 and 4, which projects on each side of the slides to an extent equal
to that traversed by the shaft (till it comes in contact with the guide)
at an angle of 45 degrees. The guide may be kept up to the backing by
means of screw bolts. At the centre there is an opening provided with
a stuffing box through which the shaft of the steerer passes. In order to
prevent water from entering the vessel through the opening before mentioned
I form a raised ridge around the slit a, Figure 3, and in the groove which is
formed by the raised ridge there is a band of india-rubber which projects
a little in front. It will be understood that by causing the guide to bear
with sufficient force upon the india-rubber by means of bolts it will form
a tight packing, and the guide may work in the slide without admitting the
water.
Supposing moreover the shaft of the auxiliary screw to be the radius of a
circle having the same centre as that of the circular parts of the guide and
backing, it will be evident that by turning the shaft on one side or other of
the keel, see Figure 4, the guide will move with it by sliding in the horizontal

page_text: opening, without however allowing the water to enter the vessel. In order
to move the steerer, that is to say, traverse it horizontally to an angle of
45 degrees on each side of the keel, I may employ a sector having on its
circumference vertical teeth gearing with a pinion vertically mounted for the
purpose of turning the same. This pinion is mounted in suitable bearings in
a line with the keel when of cylindrical form, or at right angles thereto if
bevil gearing be employed. Any suitable arrangement of gearing may be
used for imparting motion to this pinion from a wheel on the deck.
Supposing it is wished to impart the motion through a bar or tiller, as
represented in Figure 5, I employ a vertical bent rod supported in bearings,
and passing up through the centre of the slide before mentioned; this
rod is curved at its lower end, through, which passes the steering screw,
or it may, if desired, be fixed in a sleeve piece adapted to the guide.
By moving the bar mounted on the end of the rod from the deck; the
steering screw may be readily moved to the one side or the other, the
screw shaft being mounted in the same centre as the guide, and on the end of
the rod.
The shaft of the steerer terminates at the part opposite to the centre of the
guide, being connected to a joint, see Fig. 6, which shows the steerer in a line
with the keel, while Fig. 7 shows it inclined at an angle of 45 degrees; this
joint is composed of two semicircular jaws forming the ends of the two parts
of the shaft, which are connected together at right angles by means of a hoop
so as to permit of their free oscillation. By means of this joint the rotation of
one part of the shaft is communicated to the other even when inclined at an
angle of 45 degrees. By making the centre of this joint coincide with the
axis of the cylindrical part of the guide it will be seen that if the shaft
driving the steerer is caused to turn, the steerer will turn with it, and if
independently of this rotation, the shaft being inclined on one side or the
other to the horizontal plane of the keel the steerer will be displaced
laterally while still maintaining its rotary motion, and so turn the vessel as
desired.
The annexed Drawing will render the action of this steering apparatus
readily understood, the advantage of which arrangement consists in its
rendering the apparatus as easy in handling as the ordinary rudder, while its
small size enables it to be readily fitted at but small cost. If notwithstanding
the india-rubber joints before described the water might still be liable to
enter, the mechanism being only about three feet in diameter might as a
measure of precaution be enclosed in a spherical sheet iron case fixed to the
slide inside the slot or opening; this case being provided at the opposite

page_text: side with a stuffing box through which the shaft would pass when the water
which might filter through the slit would there remain with the mechanism
turning in it, which would prevent its heating. A cock might be fitted to the
easing to draw off the water, and two manholes provided to afford access to
the joint and slot opening.
The chief features of the Invention are, 1st, the use of a screw steering
apparatus arranged as described and represented; 2ndly, the arrangement of
water-tight joint and circular guide, enabling the steerer to move to port or
starboard.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
29th March 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of September, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, 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," a communication to me from abroad by Maurice Aron, of
29, Boulevart St. Martin, Paris, upon the condition (amongst others) that I,
the said William Clark, 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 performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after tho
date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following

page_text: statement, reference being had to the two Sheets of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
This Invention relates to an improved screw steering apparatus, by the aid
of which a vessel may be guided in its course under all circumstances, and
especially when going at half or slow speed when the rudder has little effect.
This apparatus may be made dependent or independent of the screw propeller
shaft, and can be worked without the aid of the engines or of those in charge.
By moving the steering bar which is placed on the deck to one side or the
other the vessel may be readily turned in the desired direction.
The apparatus consists of a small auxiliary screw placed in a line with the
keel of the vessel above or below the screw propeller shaft in a space between
it and the stern post. The diameter of this auxiliary screw varries according
to the size of the vessel, and may be geared with a shaft in connection with
that of the propeller so as to make from two to three hundred revolutions per
minute, in order to keep up the speed of the vessel and not retard its pro-
gress; if it is desired to add its effect to that of the propeller the propulsive
power will thus be greatly increased. In case of damage to the propeller the
vessel will be thus provided with a small auxiliary propeller, which in many
cases would be of great service, and this advantage renders the apparatus
superior to any heretofore constructed. In order to incline the shaft of the
steering apparatus to one side or the other in a horizontal plane an opening
is made in the framing of the vessel behind the stern post, forming a segment
of a circle corresponding to the form of the stern itself. For this purpose
the upper part of the storn post (which is usually made of forged iron in iron
ships, and of brass in wooden ones) is extended laterally in such manner as
not to weaken it, and in order to provide an opening, as shown in Figure 2
of the Drawing annexed, which represents the auxiliary screw in a line with
the keel as also inclined to starboard. Inside the opening in the round part*
of the stern is disposed a metal packing, see Figures 3 and 4 of circular
form, also having a horizontal slot in which the shaft of the steering screw
moves, this packing being provided with horizontal slides C, Figure 3; in
these slides concentrically to the backing works a circular guide piece colored
red in Figures 3 and 4, which projects on each side of the slides to an extent
equal to that traversed by the shaft (till it comes in contact with the guide)
at an angle of 45 degrees; the guide may be kept up to the backing by
means of a set screw. At the centre of the guide there is an opening pro-
vided with a stuffing box through which the shaft of the steerer passes. In
order to prevent water from entering the vessel through the opening before
mentioned I form a raised ridge around the slit, Figuro 3, and in the

page_text: groove which is enclosed by the raised ridge there is a band of india-rubber
which projects a little in front. It will be understood by causing the guide
to bear with sufficient force on the india-rubber, by means of screws, to form a
tight packing, and so that the guide may work in the slide without admitting
the water.
Supposing the shaft of the auxiliary screw to be the radius of a circle
baving the same centre as that of the circular parts of the guide and backing,
it will be evident that by turning this shaft on one side or other of the keel,
see Figure 4, the guide will move with it by sliding in the horizontal opening
without however allowing the water to enter the vessel. In order to move
the steerer, that is to say traverse it horizontally to an angle of 45 degrees on
each side of the keel, 1 may employ a sector having on its circumference
vertical teeth gearing with a pinion vertically mounted for the purpose of
turning the same; this pinion is mounted on a shaft in suitable bearings in a
line with the keel when of cylindrical form, or at right angles thereto if bevil
gearing be employed. Any suitable arrangement of gearing may be used for
imparting motion to this pinion from a wheel on the deck.
Supposing it is wished to impart the motion through a bar, as represented
in Figure 5, I employ a vertical cranked shaft supported in bearings in a
vertical line with the axis of the slide and centre of motion of the universal
joint, before mentioned; this rod describes a quarter circle at its lower end,
through which passes the shaft of the steering screw, or it may, if desired, be
fitted in a sleeve piece adapted to the guide. By moving the bar mounted
on the end of the rod from the deck the steerer may be readily moved to the
one side or the other, the screw shaft oscillating on the same axis as the
guide and the steering cranked shaft.
The shaft of the steerer is connected to a universal joint, see Figure 6,
which shows the steerer in a line with the keel, while Figure 7 shows it
inclined at an angle of 45 degrees; this joint is composed of two semi-
circular jaws or forks forming the ends of the two parts of the shaft, which
are connected together at right angles by means of a hoop so as to permit of
their free oscillation. By means of this joint the rotation of one part of the
shaft is communicated to the other even when inclined at an angle of 45
degrees. By making the centre of this joint coincide with the axis of the
cylindrical part of the guide it will be seen that if the shaft driving the steerer
is caused to turn the steerer will turn with it, and if independently of this
rotation the shaft be inclined on one side or the other to the horizontal
plane of the keel the steerer will be displaced laterally while still maintaining
its rotary motion, and so turn the vessel as desired.

page_text: The annexed Drawing will render the action of this steering apparatus
readily understood, the advantage of which arrangement consists in rendering
the apparatus as easy in handling as the ordinary rudder, while its small size
enables it to be readily fitted at little cost. If notwithstanding the india-
rubber joints before described the water might still be liable to enter, the
mechanism being only about three feet in diameter might, as a measure of pre-
caution, be enclosed in a spherical sheet iron casing fixed to the slide inside the
slot or opening. This case being provided at the opposite side with a stuffing
box through which the shaft would pass, any water which might filter through
the slit would there remain with the mechanism turning in it, which would
prevent its heating. A cock might be fitted to the casing to draw off the
water, and two manholes be provided to afford access to the joint and slot
opening.
Sheet 2 represents the following modifications which are intended to obviate
any objections which might result from the position of the screw steerer in
the after stern post, which requires to be cut through for the passage of the
driving shaft of the steerer. Figure 8 is a longitudinal vertical section of the
stern of a ship fitted with a screw steerer; Figure 9 is a sectional plan of
the same, and Figure 10 is a transverse vertical section on the line e, e,
Figure 9.
I fit the steerer in a frame in front of the stern post and about five feet
below the water line in order to increase its effect and allow of its being
placed below the plating of armour-plated ships; the machinery may thus be
placed in a much more convenient position, the form of the vessel at that
point being much more adapted to the purpose. The surrounding frame is
fitted in the dead wood of the stern post, the end of the planking cut
through being united to a concave frame of brass fixed on the one part to the
stern post and on the other to the planking and dead wood abutting on the
frame; this frame is made in two parts bolted or rivetted together in a line
with the keel, as shown in the Drawing.
The circular traversing bearing r of the steerer shaft is furnished with a
segment of teeth on its upper edge gearing with a spur pinion s fixed on the
shaft t communicating by bevil gearing with an upright shaft in communi-
cation with the steering wheel; the apparatus is in this case shown enclosed
in a water-tight compartment u, u, the shaft t and main screw shaft v passing
through suitable stuffing boxes; this renders the packing or water-tightness
of the circular traverser of little consequence; w, a, show the gearing con-
necting the steerer shaft t with the main propeller shaft v. The screw steerer
may be so connected with the propeller shaft as to be readily disconnected,

page_text: and driving gear provided and connected with the screw steering shaft, so that
it may be driven by hand power and the vessel so manoeuvred while the screw
propeller is at rest.
The chief features of the Invention are,-
First, the use and application of a screw steering apparatus arranged as
described and represented in the Drawing annexed.
Secondly, the arrangement of water-tight joint and circular slotted guide,
enabling the steerer to move to port or starboard as described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twenty-ninth day of March, in the year of our
Lord One thousand eight hundred and sixty-seven.
Witness,
W. G. E. SWINNOCK,
53, Chancery Lane,
London.
W. CLARK. (L.S.)