improvements in or Connected with Twin-sorew Ships.
Year: 1888

page_text: improvements in or Connected with Twin-sorew Ships.
I, GEORGE EDWARD VAUGHAN, of 57, Chancery Lane, in the county of Middlesex,
patent agent, do hereby declare the nature of this invention, which has been com-
municated to me from abroad by Samuel Trott, of Halifax, Nova Scotia, to be as
follows:-
In twin-screw ships, as ordinarily constructed, the propellors are arranged on
opposite quarters of the vessel, and a single rudder is placed at the stern to serve for
steering. Ships constructed on such principle are slow to turn, the back-wash from
the propellors not taking effect on the rudder. In practice it has not been uncommon
for one of the propellors to be stopped, or even reversed, to assist in turning
the ship, thereby not only sacrificing speed, but even bringing the ship to a stand
still.
The defect above noted is a serious one, especially in heavy ships of war or
torpedo boats, in which both quickness of manoeuvering and speed are desirable.
The former quality is so essential in torpedo boats that recent builders have
endeavoured to secure it even at the sacrifice of speed, although that quality also is
hardly less a necessity.
To assist the steering of such ships recourse has been had to the expedient of
cutting away the bow of the ship below the water line and thus shortening the
immersed portion of the ship. This is practically of little advantage and, moreover,
is wrong in theory, as the cutting away of the vessel at the forward end will have
little effect upon its turning as compared with a cutting away at the stern, where the
force of the rudder is applied.
My invention provides means whereby a twin screw-ship can be cut away at the
stern, and also whereby the force of the steering apparatus can be applied more
advantageously than when it is attached directly to the centre of the stern, as
hitherto. In carrying out my invention I use two rudders and attach them behind
With this
the two screws to frames, each screw having a separate rudder behind it.
arrangement of the parts, I am able to cut away the immersed part of the ship at

page_text: the stern sufficiently to effect a great improvement in its manoeuvering qualities, and
I also increase the effects of the steering apparatus by applying my rudders at points
where they can work to greater advantage than at the centre of the stern.
I will now proceed to describe my invention with reference to the accompanying
drawings, in which Figure 1. is a side elevation of a modified form of the after part
of the hull of a twin-screw ship, with the improved steering apparatus, to which this
invention relates, applied thereto, the dotted lines showing the stern as ordinarily
constructed.
Figure 2 is an end elevation of the stern of the ship, and Figure 2* is a similar
view with the rudders, propellors and propellor frames removed.
The said figures illustrate the hull of the ship built down on each quarter so as to
enclose the propellor shafts, the forward part of the propellor frames being secured
to such built down portions whilst the upper ends of the frames are built into or
secured to the hull of the ship, in the position illustrated. It will be observed, by
reference to Figure 2, that the hull of the ship is not built down between the two
portions enclosing the propellor shafts.
Figure 3. is a side elevation of the after part of the hull of a twin-screw ship in
which the built down portions of the hull, above referred to, are dispensed with.
Figure 4. is an end elevation of Figure 3.
Figure 5. is a deck plan of the after part of the ship, showing how the rudder
shafts are connected with cords or chains which control the rudders. It will be
readily understood that means, other than cords or chains, may be employed for
connecting the rudder shafts with the actuating mechanism and that they may be
above or below the deck. Figure 6. illustrates the connection of the heads of the
rudder shafts and the cords or chains, in such a manner that either rudder can be
moved independently, or both rudders can be moved simultaneously.
The same letters of reference indicate like parts in all the figures.
A. is part
of the hull of a twin-screw ship, B. and C. are screw propellors on the ship's
quarters, and L. L. are the rudders.
Figures 1. and 3. show most of the details of my invention as applied to one of
the propellors. The construction on the other side of the ship is similar in all
respects. The dotted lines in Figure 1, show the present construction of ships of
this class in those particulars with which my invention is especially concerned.
In Figure 3. the shaft of the propeller B, traverses a sleeve B¹ which projects
through the ship's quarter at B2. At its outer extremity the sleeve is supported in
the upright D of the frame E. This frame is of an oblong shape and surrounds an
opening F, in which the screw turns. The frame E, is secured at its upper side
between the lips of a massive iron frame, such as G, the two parts of which are
bolted through suitable flanges to the ship's quarter, the parts of the frame also
being bolted together at their lower edges and the whole, forming when secured
together, a strong angular frame rigidly secured to the ship. The bolts which
secure the lips together pass through the upper part of the frame E. In some
cases, I enlarge the frame G. upwards and build the upper portion thereof into the
body of the ship. The frame E. is further supported by three or more braces, such
as H. I.J. The brace H is bolted to the keel of the ship and also to the upright D ;
the brace I. is formed on or secured to the upright D, and is also secured to the
sleeve B¹, and the brace J. is bolted to the ship's keel and also to the post or
upright K. carrying the rudder, which post or upright forms part of the frame E.
The frame E, secured in the manner lastly described, is capable of resisting great
shock or strain. The braces H. and J, extend at different angles from the centre of
the ship to the frame which is supported thereby against pressure from different
directions.
When the hull of the ship is constructed as shown at Figures 1 and 2, the employ-
ment of braces or stays in connection with the frames of the propellor shafts may be
dispensed with.
The post or upright K. of the propellor frame is continued upwards and is suitably
At the lower end of the post K. is a step k. carrying a socket for the toe
secured.

page_text: The
of the rudder L. which is hinged to the said post by any ordinary means.
rudder shaft e. extends upwards and forms, as shown, the axis of a quadrant M.
(see Figures 5. and 6). The quadrants at the heads of the two rudder shafts are
placed in connection, with the steering engine or wheels, by the usual cords or
chains or other means.
In some cases, in order that each rudder may, when desired, be operated indepen-
dently of the other, I connect two cords or chains to each quadrant in the manner
illustrated in Figure 6; or, when the rudders are only arranged to be operated
simultaneously, I dispense with two of the cords or chains, and connect the two
quadrants, as shown in Figure 5. In the former case, I employ two pulleys n, at
each side of the ship and in the latter only one.
It will be understood, that there are many means and methods, other than those
above described, which will be found suitable for moving the rudders.
Comparing the improved construction above described with that shown by dotted
lines in Figure 1, it will be observed that the improvements constituting the
subject of this invention allow of a considerable portion of the ship's stern below the
water line being cut away, whereby the adaptability of the ship, for making rapid
evolutions, is greatly increased. It will also be observed that the advantageous
effects of the back-wash of both the screws is secured. Moreover, owing to the fact
that the rudders are placed at a greater angular distance from the ship's line of
motion than in the case of a central stern rudder, the effects of their action are
correspondingly greater.
Dated this Fifth day of May 1888
VAUGHAN & SON,
Agents for the Applicant

page_text: COMPLETE SPECIFICATION.
Improvements in or Connected with Twin-screw Ships.
I, GEORGE EDWARD VAUGHAN, of 57, Chancery Lane, in the County of Middlesex,
Patent Agent, do hereby declare the nature of this invention which has been
communicated to me from abroad by Samuel Trott, of Halifax, Nova Scotia, and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
In twin-screw ships, as ordinarily constructed, the propellors are arranged on
opposite quarters of the vessel, and, generally a single rudder is placed at the stern to
serve for steering. Ships constructed on such principle are slow to turn, the back
wash from the propellors interfering with the proper effect of the rudder. In practice,
it has not been uncominon for one of the propellors to be stopped, or even reversed,
to assist in turning the ship, thereby not only sacrificing speed, but even bringing the
ship to a standstill.
The defect above pointed out is a serious one, especially in heavy ships of war or
torpedo boats, in which both quickness of manoeuvring and speed are desirable. The
former quality is so essential in torpedo boats that recent builders have endeavored to
secure it even at the sacrifice of speed, although that quality also is hardly less a
necessity.
To assist the steering of such ships, recourse has sometimes been had to the
expedient of cutting away the bow of the ship below the water line and thus
shortening the immersed portion of the ship. This is practically of little advantage,
and, moreover is wrong in principle, as the cutting away of the vessel at the forward
end will have little effect upon its turning as compared with a cutting away at the
stern, where the rudder exerts its influence.
It has also been proposed to cut away the deadwood aft in order to facilitate the
turning, but, in this case, the vessel has been built down under each quarter to carry
the propellor shafts and a rudder has been mounted aft of each propellor.
My invention provides means whereby a twin-screw ship can be still further cut
away at the stern, whereby the action of the steering apparatus will exert a more
powerful influence than heretofore. In carrying out my invention 1 also use two
rudders but I attach them behind the two screws to skeleton frames, projecting from
the hull of the vessel, each screw having a separate rudder behind it. With this
arrangement of the parts, I am able to cut away the immersed part of the ship at the
stern sufficiently to effect a great improvement in its manoeuvring qualities, and I also
increase the effects of the steering apparatus. I also employ a peculiar arrangement
of steering gear for giving motion to said rudders as hereinafter described.
I will now proceed to describe my invention with reference to Figures 3. 4. 5.
and 6 of the drawings accompanying my provisional specification.
Figure 3. is a side elevation of the after part of the hull of a twin-screw ship
having my invention applied thereto.

page_text: Figure 4. is an end elevation thereof.
Figure 5. is a deck plan of the after part of the ship, showing how the rudder shafts
are connected with cords or chains which control the rudders.
Figure 6. illustrates the connection of the heads of the rudder shafts and the cords
or chains, in such a manner that either rudder can be moved independently, or both
rudders can be moved simultaneously.
The same letters of reference indicate like parts in all the figures.
A. is part of the hull of a twin screw ship, B. and C. are screw propellors on the
ship's quarters, and L. I. are the rudders.
The shaft of the propellor B. traverses a sleeve B', which projects through
the ship's quarter at B2. At its outer extremity the sleeve is supported in the
upright D. of the frame E. This frame is of an oblong shape and surrounds an
opening F. in which the screw turns forming a skeleton frame. The frame E. is
secured at its upper side between the cheeks of a massive iron. frame, such as G, the
two parts of which are bolted through suitable flanges to the ship's quarter, the cheeks
of the frame also being bolted together at their lower edges and the whole forming,
when secured together, a strong angular frame rigidly secured to the ship. The bolts
which secure the cheeks together pass through the upper part of the frame E. In
some cases, I enlarge the frame G. upwards and build the upper portion thereof into
the body of the ship, in order to obtain greater strength. The frame E. is further
supported by three or more braces, such as H. I. J. The brace H. is bolted to the
keel of the ship and also to the upright D; the brace I. is formed on or secured to
the apright D. and is also secured to the sleeve B¹; and the brace J. is bolted to the
ship's keel and also to the post or upright K. carrying the rudder, which post or
upright forms part of the frame E. The frame E. secured in the manner lastly
described, is capable of resisting great shock or strain. The braces H. and J. extend
at different angles from the centre of the ship to the frame which is supported thereby
against pressure from different directions.
The post or upright K. of the propellor frame is continued upwards and is suitably
secured. At the lower end of the post K, is a step k. carrying a socket for the toe of
the rudder L. which is hinged to the said post by any ordinary means. The rudder
shaft e. extends upwards and forms, as shown, the axis of a quadrant M. (see Figures 5.
and 6). The quadrants at the heads of the two rudder shafts are placed in connection
with the steering engines or wheels by cords or chains as shown.
In some cases, in order that each rudder may, when desired, be operated inde-
pendently of the other, I connect two cords or chains to each quadrant in the manner
illustrated in Figure 6, or, when the rudders are only arranged to be operated
simultaneously 1 dispense with two of the cords or chains, and connect the two
quadrants, as shown in Figure 5. In the former case, I employ two pulleys n. at
each side of the ship and in the latter only one.
It will be observed that the improvements constituting part of the subject of this
invention allow of a considerable portion of the ship's stern below the water line being
cut away and the skeleton frame offering no obstruction to the steering the adaptability
of the ship, for making rapid evolutions, is greatly increased. Moreover, owing to
the fact that the rudders are placed at a greater angular distance from the ship's line
of motion than in the case of a central stern rudder, the effects of their action are
correspondingly greater.
I would here remark that the points of invention shown and described in my said
provisional specification with reference to Figures 1. 2 and 2ª of the drawings do not
possess sufficient novelty to warrant my making any claim thereto and I therefore
desire to disclaim and I do hereby disclaim such points of invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First. In a twin-screw ship in which the deadwood is cut away at the stern
encasing that part of each propellor shaft which projects from the vessel's quarter in a

page_text: tube and supporting the extreme end of such tube and such shaft in a skeleton
bearing which also carries a rudder all in manner substantially as herein shown and
described and for the purpose stated.
Second. In a twin-screw ship in which the deadwood is cut away at the stern
encasing that part of each propellor shaft which projects from the vessel's quarter in a
tube and supporting the extreme end of such tube and such shaft in a skeleton bearing
which also carries a rudder and strengthening such frame by means of an additional
frame formed of solid metal plates firmly bolted together and built into the hull of the
vessel, all in manner substantially as herein shown and described and for the purpose
stated.
Third. In a twin-screw ship of the character hereinbefore referred to the peculiar
arrangement of steering gear substantially as herein hown and described and for the
purpose stated.