Improvements in or relating to the Construction of Rudders for Iron or Steel Ships.
Year: 1890

page_text: Date of Application, 18th Nov., 1890
Complete Specification Left, 18th Aug., 1891-Accepted, 19th Sept., 1891
"
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Construction of Rudders for Iron
or Steel Ships.
1, GEORGE WILLIAM SIVEWRIGHT, of 5, Radcliffe Terrace, Hartlepool, in
the County of Durham, Shipbuilder, do hereby declare the nature of this invention
to be as follows:-
My invention relates to an improved method of constructing rudders for sea-
going vessels.
Ships' rudders as hitherto constructed consist of a main piece, cranked to carry
the pintles, provided with a back piece and necessary stays all forged or cast
together in one piece; after the frame is welded together the outside surface is then
covered over with plating on each side and rivetted round. It is well known that
such forgings, which are not always reliable, involve a difficult, laborious, and slow
process, accompanied by great cost and often causing delay in launching and com-
pleting vessels. As a substitute for this, rudders have been manufactured all in
one piece of cast steel.
The object of my invention is to simplify the construction of ships' rudders by
building them up of separate parts consisting of a forged main piece carrying a
blade constructed of plates rivetted together instead of forging or casting the entire
frame in one piece from back to front. Such rudders can in consequence be more
readily varied or altered in form and can be made with the strength and powers of
resistance more equally distributed, and the whole construction can be completed at
less cost and with great saving of time, and at the same time are rendered more
reliable.
In carrying my invention into effect I forge or cast the front part or main piece
of the rudder in one piece which is furnished with the necessary pintles for hanging
the rudder; this main piece is the only portion of the rudder that need be made in
the forge.
1 then build onto this main piece two plates flanged and rivetted
together onto the post and at the middle and the edges, the usual packing being
provided in the space between the plates. If it is found necessary to stiffen up
these two plates.frivet on stays at the outside so as to give more rigidity to the
rudder.
I do not confine myself to the above described method of building up ships'
rudders which is merely given as an example for illustrating the main features of
my invention as the same may be modified as the conditions of use or design of the
ship may require; thus for instance the plates may taper suddenly from the main
picce terminating in a broad flat surface towards their outer edges, or the main
piece being tapered the plates may be evenly tapered therefrom to a line of contact
at their outer edges, or instead of the plates being brought into actual contact they
may be kept apart at their outer edges by distance pieces; or the plates instead of
being evenly tapered from edge to edge may be flanged to fit onto a main piece
which is not tapered to correspond. A further arrangement is to flange the plates
at the back of the post, each plate forming a section, so that they form parallel
surfaces from the back of the post to the outer edge of the rudder which can be
rivetted together and if necessary stiffened by an iron stay at each side.
17 Jon of November 1890
G. J. CLARKSON,
Stockton-on-Tees, Agent for the said G. W. Sivewright.

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to the Construction of Rudders for Iron
or Steel Ships.
I, GEORGE WILLIAM SIVEWRIGHT of 5, Radcliffe Terrace, Hartlepool, in
the County of Durham, Shipbuilder, do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:—
My invention relates to an improved method of constructing rudders for sea-
going vessels.
Ships rudders as hitherto constructed consist of a main piece, cranked to carry the
pintles provided with a back piece and necessary stays all forged together in one
piece; after the frame is welded together the outside surface is then covered over
with plating on each side and rivetted round.
It is well known that such forgings which are not always reliable, involve a
difficult, laborious, and slow process of manufacture accompanied by great cost and
often causing delay in launching and completing vessels. As a substitute for this,
rudders have been manufactured all in one piece of cast steel.
The object of my invention is to simplify the construction of ships rudders by
building them up of separate parts consisting of a forged or cast main picce carrying
a blade constructed of plates rivetted together, and to the said main piece instead
of forging or casting the entire frame in one piece from back to front.
From the foregoing description taken in connection with the accompanying
drawings which form part of this Specification it will be seen that rudders con-
structed according to my invention can be more readily varied and altered in form
and can be made with the strength and powers of resistance more equally or
suitably distributed as the conditions of use or design of the ship may require, and
the whole construction can be completed at less cost and with great saving of
time and control of delivery. Rudders so constructed are also more reliable,
examples of which are illustrated in the drawings and which I will now proceed to
describe.
In the figures the same letters of reference indicate corresponding parts wherever
they occur.
Figures 1 and 2 illustrate a ships rudder as ordinarily constructed with side plating
which is shown in Figure 2 being omitted in Figure 1. A forged main piece a,
cranked to carry, the pintles, back piece a and stays y are all welded together in
one piece; after which the outside surface is covered over with plating 6 on each
side and rivetted round as shewn.
These frames owing to their large dimensions and awkward configuration are
difficult to either forge or cast which is in a great measure due to the back piece
and stays y extending from and forming one piece with the main piece a.
In Figures 3, 4, 5 and 6 which illustrate examples of rudders constructed
according to my invention it will be observed that I have dispensed with the said
forged back picce and the forged stays y the main piece à furnished with the
usual pintles for hanging the rudder being the only portion of the rudder that need
be made in the forge or cast. I then build onto this main piece a two plates bb;
flanged and rivetted together onto the post and at the middle and the edges, a
packing piece e being provided in the space between the edges of the plates at the
top and bottom. If it is found necessary to stiffen up these two plates bb, I rivet
on stays d d at intervals at the outside so as to give more rigidity to the rudder as
illustrated in Figure 6.
My invention is not limited to the precise method of building up ships rudders as
hereinbefore described with reference to Figures 1 to 6 which is merely given as a
convenient example for illustrating the main features of my invention which may be
modified in several details of construction.

page_text: One modification of my invention is illustrated in Figures 7, 8, 9 and 10 in which
the main piece a is in one piece but I taper this post from back to front as shown in
Figures 9 and 10. I then build onto and from the back part of this post the two
plates which are evenly tapered therefrom to a line of contact at their outer
edges and are rivetted to the post and through the back edges in the manner shown,
with packing pieces e provided between the plates at top and bottom edges. If
this form of plating requires to be stiffened up, I fit iron stays d d at intervals on
the outside as shown in Figure 10.
Figures 11, 12, 13 and 14 illustrate another modification of my invention in which
I make the main piece a of the rudder in one piece and fit on a plate at each side
slightly flanged at the back near the main post as shewn in Figure 13, these
plates bb taper suddenly from the main piece a, terminating in a broad flat surface
towards their outer edges which are kept apart by distance pieces or ferrules
through which the rivets pass, with a packing piece e provided between the edges
of the plates. Should these plates require to be stiffened 1 fit iron stays dat
intervals on the outside as shewn in Figure 14.
A further modification of my invention is illustrated in Figures 15, 16, 17 and 18
in which the main piece a of the rudder is in one piece with two plates bb flanged
at the back of the post, each plate forming an section so that they form parallel
surfaces from the back of the post to the outer edge of the rudder, which can be
rivetted together and if necessary stiffened by an iron stay dat intervals at each
side as shown in Figure 18.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
Firstly In the construction of rudders for sea-going vessels, the employment
of a forged or cast main piece carrying a blade constructed of plates rivetted
together, and if necessary stiffened up by iron stays, in substitution of forging or
casting the entire frame in one piece from back to front, substantially as and
for the purpose as hereinbefore described with reference to the accompanying
drawings.
Secondly In rudders for sea-going vessels the particular combination of parts,
as a whole, constructed, combined arranged and fitted together, substantially as and
for the purpose as hereinbefore described and illustrated in Figures 3 to 18 of the
accompanying drawings.
Dated this 17th day of August 1901
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.