Year: 1887

page_text: Date of Application, 31st Aug., 1887.
Specification Accepted, 4th Oct., 1887
I, JAMES HARPER LAIDMAN, of 18 East Parade, Hull, in the County of Yorkshire,
Head Foreman Plater 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 :-
The object of my Invention is to construct a rudder for iron or steel ships in such
a manner as to materially reduce the weight comparatively with that of rudders as
hitherto usually made and at the same time without impairing the structural strength;
whilst on the other hand effecting economy in labour and material and facilitating the
operation of repairing when rendered necessary.
In accordance with my Invention I employ a combination of solid, forged, or cast
metal pieces with "profile bars of various suitable sections, such for instance as
channel and angle bars; and connect the same firmly and rigidly by means of
rivetting; or in cases where rivetting is impracticable, screw studs.
In order that my Invention may be the better understood I have appended the
accompanying sheet of drawings in which Figure 1 represents a front elevational view
of a rudder frame built up according to my Invention; Figure 2 is an end elevation
of the same Figures 3, 4, 5 and 6 are respectively transverse sections on the
lines a b, c d, ef, and g h, Figure 1: Figure 7 is a vertical section of the horizontal
stays F, F, F, F, drawn on line j, k, Figures 3, 4, 5 and 6; Figure 8 is a detached
view of the solid, forged, or cast rudder post; Figure 9 is a detached view of the
solid heel piece and pintle forged or cast in one; Figure 10 shews a detached view
of one of the solid pintles (C, C, C, C, Figure 1); Figure 11 is a transverse
section of a rudder of somewhat lighter construction hereinafter described; Figure 12
is a transverse section of the main frame on line l, m, Figures 1 and 2 ; and Figure 13
is a similar section on lines n, o Figures 1 and 2 shewing rudder check pieces.
The inner or main part of the rudder frame A, A¹, Figure 1, is formed of a

page_text: continuous piece of single channel bar. Said channel bar being cranked at B, B¹,
B, B, and B, to form the apertures for the reception of the gudgeons upon the
stern post. Suitable internal and external corner pieces are welded upon the cheeks or
flanges of the channel bar A, A, where it is cranked so as to preserve a rectangular
outline and maintain the strengh of the material. At D, D', the channel bar A, A',
is bent round the flanges being welded up in the form shewn. The rudder post E
(a detached view of which is shewn at Figure 8) is a solid forged, or cast piece of
metal flattened and tapered toward the lower end, and forked or divided into two
tongues G and H, which serve as supports for the main channel bar A, A¹, the cheeks
or flanges of which are closed in upon it and rivetted or otherwise firmly attached
thereto. Upon the tongue H is formed the "woodlock "I, the square metal being
simply rounded down at the proper part, so that the "woodlock" occupies the
aperture B when the rudder post is in position. A solid cast, or forged heel piece J
(shewn detached at Figure 9) carrying the heel pintle C, is formed with two
tongues K, L, bent to a suitable angle. The tongue K aforesaid fits within the
main channel bar A, A', at D¹, to which it is rivetted or otherwise firmly attached.
The solid pintle pieces C, C, Cu, C, are of rectangular formation, as shewn in the
detached view Figure 10, and are rivetted or otherwise fixed within the cheeks or
flanges of the channel bar A, A', so that the axial line of the pintles is co-incident
throughout with the centre of the rudder post, and each pintle is properly situated
within its respective aperture. The outer or bow portion of the rudder frame is
formed of a continuous single channel bar M, M', which is bent in such a manner as
to form the "bow" outline of the rudder, the cheeks or flanges of the channel bar
being outwards. Said outer or "bow" channel bar M, M', is fitted to the tongue G
of the rudder post E, and to the tongue L of the heel piece J, the flanges being closed
in upon said tongues and these are then rivetted or otherwise firmly attached within
the channel of M. M'. The flanges or cheeks of the channel bar M, M', form a butt
joint with the corresponding flanges of the cheeks of the main channel bar A, A¹,
P and 9 respectively.
at
The horizontal stays F, F1, F", F, are formed of a taper angle bar, rivetted to a
reverse angle bar, shewn more particularly in the vertical section at Figure 7, while
in the transverse sections Figures 3, 4, 5 and 6, the lap of the two angle bars afore-
said is shewn by the oblique line 7, 1, 1, 11. The horizontal stays constructed in
this manner, form single taper channel bars, and may be attached to the main channel
bar A, A, and the "bow "channel bar M, M³, by means of welded box ends, or forged
or cast knees rivetted or attached by means of screw studs in both cases.
in the manner hereinbefore described,
After the rudder frame has been built usual method, with the exception that
the whole may be plated over according to
the plates are preferably increased in thickness to the extent of one fourth more than
obtains in the case of those generally used. This plating is shewn in the various
transverse sections Figures 3, 4, 5, 6, 7, 12 and 13 at s, and Figure 13 shews the
rudder check pieces t, t, which are rivetted or otherwise attached to the cheeks or
flanges of the channel bar A, A', through the outer or skin plates. These check
pieces engage against a similar pair of check pieces fitted upon the stern post to
prevent unnecessary movement of the rudder.
If it be required to construct a lighter rudder than that above described, I prefer
to use a bulb bar as shewn at u Figure 11-instead of the "bow" channel bar M. M-
and to simply cause said bulb bar to abut against the tongues G and L of the rudder
post and heel respectively, and plating over all, in the ordinary manner.
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 :-
Firstly In the construction of rudders for iron or steel ships the combination of
solid metal forgings or castings with sectional or "profile" bars of various suitable
sections substantially as herein described and set forth.
:
Secondly In the construction of a rudder for iron or steel ships the formation of
a frame composed of vertical and horizontal channel and angle bars combined with

page_text: solid portions of either forged or cast metal rivetted or otherwise firmly attached
thereto, the whole constituting a base frame for the reception of the plating
substantially as herein described and set forth.
:
Thirdly In a rudder composed of a combination of solid forgings or castings with
channel, angle, bulb, or other suitable "profile" bars, the method of forming, arranging,
and attaching horizontal cross stays with vertical frame bars, connecting and securing
the same to form a light, yet strong and rigid framework to support the plating,
substantially as herein described and set forth.
JAMES STEVENSON,
Gray's Inn Chambers,
20, High Holborn, London, W.C.,
Agent for Applicant.