IMPROVE- MENTS IN SHIPS' RUDDERS AND IN STEERING GEAR THEREFOR
Year: 1869

page_text: LETTERS PATENT to Charles Godfrey Gumpel, of No. 49, Leicester
Square, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN SHIPS' RUDDERS AND IN STEERING GEAR THEREFOR."
Sealed the 29th April 1870, and dated the 2nd November 1869.
PROVISIONAL SPECIFICATION left by the said Charles Godfrey Gumpel
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd November 1869.
I, CHARLES GODFREY GUMPEL, of No. 49, Leicester Square, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SHIPS' RUDDERS AND IN STEERING GEAR THEREFOR," to
be as follows:-
The amount of power required for deflecting ordinary rudders was the
cause of the adoption of the so called "balanced" or "differential"
rudder, wherein the acting surface of the rudder was situated equally or
nearly so on each side of the rudder shaft. With such rudders experience
has however shown that when the helm is put over to the utmost extent
the vessel refuses to answer the rudder readily, owing to the surface of

page_text: the rudder blade being thrown equally or nearly so on each side of the
line of the keel, thus impeding the headway of the vessel as well on the
port as on the starboard side.
Now my Invention consists in so constructing a balanced rudder that
when deflected it is thrown entirely on one side of the line of the keel,
for which purpose the rudder blade is carried at or near the middle of its
surface by means of a crank or cranks from a vertical shaft supported at
its upper and lower ends by the hindmost part of the vessel, which crank
or cranks when in the fore and aft position points or point towards the
forward part of the vessel, and upon which crank or cranks the rudder
blade is free to turn within the limits herein-after described. On turning
this crank rudder shaft for the purpose of deflecting the rudder blade
(that is, to bring the helm over to port or starboard) the whole of the
rudder blade is carried to either side of the line of the keel, the forward
edge thereof being however caused to remain in such line of the keel
by means of a pin or pins fixed to the said blade sliding in a slot or
slots fixed to the vessel in the line of the keel. Or in place of pins
sliding in slots the forward edge of the rudder blade may be kept in the
line of the keel by being connected to any suitable known form of
"parallel motion. " For actuating this rudder the upper end of either
the crank rudder shaft or the sliding pin attached to the forward edge
may be used by having a tiller or yoke connected to it.
By providing both the crank rudder shaft and the sliding pin with
tillers in the form of cranks, which are joined together at a point
coinciding exactly with the centro line of the crank or cranks on which
the rudder blade turns, and by extending the tiller of the sliding pin
beyond such point of union, this extended tiller may very advantageously
be employed for attaching the usual ropes or chains of the rudder wheel,
such as is commonly employed. Or this end of the tiller may be con-
nected to a nut travelling on a screw spindle placed athwart ships, so
that by rotating such screw spindle the nut and with it the tiller are
moved either to port or to starboard.
In cases where it is desirable to retain the ordinary form of rudder the
following arrangement of steering gear may with advantage be employed
as approaching in its action the above described arrangement of balanced
rudder-The tiller of the rudder shaft is made to point abaft, and is
provided with a slot in which works a pin carried by a second tiller or
crank turning on a pivot placed at a suitable distance behind the rudder

page_text: shaft in the line of the keel. By extending this last-named tiller and
actuating the end thereof by any suitable known means the rudder will
be thrown to port or starboard and at its maximum extent of deflection
when the last-named tiller or crank will be in a position at or near right
angles to its surface, the thrust will consequently be borne more or less
entirely by the pivot on which the last-named tiller turns.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Godfrey Gumpel in the Great Seal Patent
Office on the 30th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CILARLES
GODFREY GUMPEL, of No 49, Leicester Square, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of November, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Charles Godfrey Gumpel, Her special
licence, that I, the said Charles Godrey Gumpel, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Godfrey Gumpel,
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thercafter 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
SHIPS' RUDDERS AND IN STEERING GEAR THEREFOR,' upon the condition
(amongst others) that I, the said Charles Godfrey Gumpel, 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 the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Godfrey Gumpel, 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

page_text: by the following statement thereof, reference being had to the accom-
panying Sheet of Drawings, and to the figures and letters marked thereon,
that is to say:-
The amount of power required for deflecting ordinary rudders was
the cause of the adoption of the so-called "balanced" or "differential "
rudder, wherein the acting surface of the rudder was situated equally
or nearly so on cach side of the rudder shaft. With such rudders
experience has however shown that when the helm is put over to the
utmost extent the vessel refuses to answer the rudder readily, owing
to the surface of the rudder blade being thrown equally or nearly so on
each side of the line of the keel, thus impeding the headway of the
vessel as well on the port as on the starboard side.
.
Now my Invention consists in so constructing a ship's rudder that
while the rudder blade when deflected is thrown entirely to the one or
the other side of the line of the keel, as in ordinary rudders, the power
for so deflecting it is applied through a crank or its equivalent con-
nected thereto at or near the middle of the surface of the blade, whereby
the pressure of the water against the blade on one side of such point of
attachment will to a certain extent balance the pressure on the other
side of such point. For this purpose the rudder blade is carried at or
near the middle of its surface by means of a crank or cranks from a
vertical shaft supported at its upper and lower ends by the hindmost
part of the vessel, which crank or cranks when in the fore and aft position
points or point towards the forward part of the vessel, and upon which
crank or cranks the rudder blade is free to turn within the limits herein-
after described. On turning this crank rudder shaft for the purpose of
deflecting the rudder blade (that is, to bring the helm over to port or
starboard) the whole of the rudder blade is carried to either side of the
line of the keel, the forward edge thereof being however caused to
remain in such line of the keel by means of a pin or pins fixed to the
said blade sliding in a slot or slots fixed to the vessel in the line of the
keel. Or in place of pins sliding in slots the forward edge of the rudder
blade may be kept in the line of the keel by being connected to any
suitable known form of "parallel motion." For actuating this rudder
the upper end of either the crank rudder shaft or the sliding pin
attached to the forward edge may be used by having a tiller or yoke
connected to it. By providing both the crank rudder shaft and
the sliding pin with tillers in the form of cranks, which are joined

page_text: together at a point coinciding exactly with the centre line of the crank
or cranks on which the rudder blade turns, and by extending the tiller
of the sliding pin beyond such point of union this extended tiller may
very advantageously be employed for attaching the usual ropes or chains
of the rudder wheel, such as is commonly employed. Or this end of
the tiller may be connected to a nut travelling on a screw spindle placed
athwart ships, so that by rotating such screw spindle the nut and with
it the tiller are moved either to port or to starboard.
Having thus set forth the nature of my Invention I will now proceed
more particularly to describe the manner of performing the same, for
which purpose I shall refer to the accompanying Sheet of Drawings,
showing some of the various arrangements by which my Invention may
be carried into effect.
Figure 1 shews diagrams of the action of the rudder; Figures 2, 4,
and 8 shew sectional elevations of three different arrangements of my
improved rudder; Figure 3 shews a sectional plan on line X, X,
Figure 2; Figure 5 shews a sectional plan on line Y, Y, Figure 4;
Figure 9 shews a sectional plan on line Z, Z, Figure 8; and Figures 6
and 7 shew arrangements of steering gear.
In all the Figures a, a, is the rudder blade, which may be made of
any suitable material or configuration. This rudder blade is divided by
its vertical axis (u, u, Figures 2 and 8, and n, n, Figure 4) into any
suitable proportion of surface before and abaft the same. This vertical
axis may be formed either by means of a cranked rudder shaft, as at
b, u, u, b, Figures 2 and 8, or by pins carried by cranks, arms, or levers
(k, k, Figure 4) fixed to a vertical shaft (b, b, Figure 4). Such cranked
shaft or cranks when the rudder is in midships (that is, in a fore-and-aft
position) points or point towards the bow of the vessel, and when the
shaft is turned to either side the crank or cranks or arms carry the
rudder blade also over to the same side; thus Figures 3 and 5 shew in
plan the crank shaft and rudder deflected to the port side, and Figuro 9
shews them deflected to the starboard side of the vessel. While being
so deflected the fore edge of the rudder blade is maintained in the
line of the keel or nearly so either by means of one single arm e, e,
Figure 8, fixed thereto, and working with a journal f(coinciding with
the fore edge of the rudder or nearly so) in a slotted frame h fixed in
the line of the keel, the journal being made to turn in the sliding
block in the slot; or the blade is provided with two such arms, one

page_text: at the upper and one at the lower extremity, as shewn at e, e, Figure 2,
also working in slots h, h, in the line of keel; or again the fore edge of
the rudder blade may carry a pin at any one or more points in its
vertical height, as at i, i, Figure 4, working in slotted arms h in the line
of the keel; or the maintaining and guiding the motion of the fore edge
of the rudder blade in the line of the keel might also be effected by
connecting the arms, journals, or pins to any suitable known arrangement
of parallel motion. By these arrangements it will be seen that as the
rudder is carried over to the port or starboard side by the rudder shaft
the fore edge thereof is made to remain in or nearly in the line of kecl,
and at the same time to slide to and fro in such line, and thus the
rudder blade will be deflected from that line to an extent determined,
first, by the amount of rotation given to the rudder shaft; secondly, by
the proportion existing between the length of the crank or cranks, or
arms, which carry the rudder blade and the distance of the vertical axis
on which the rudder rotates from the centre of the pin or pivot pins or
pivots which guide the fore part of the rudder, that is, referring to
Figure 1, in which 6 is the rudder shaft; o, the crank pin, and f, the
sliding pin or pivot; the angle of the rudder with the line of the kecl
is determined by the proportion existing between the length b, o, and
the length o, f. From this Figure, representing the rudder blade a, f,
as being deflected to different angles, it will be seen that the pressure
of the water at right angles to the rudder surface will in its direction
approach nearer to that of the crank of the rudder shaft until it arrives
at a certain angle, when this pressure will be directly in a line with
and consequently borne by the shaft, removing thereby all or nearly
all strain from the steering gear. When the proportion of the crank
arm b, o, is to the fore part of the rudder blade o, f, as 4 to 5, the rudder
blade will be at right angles to the crank or arms of the rudder shaft
when the rudder blade is deflected to an angle of about 38°. This
proportion, although by me considered the best, may be varied, as also
may the fore edge of the rudder blade be made not to correspond with
the sliding pin or pins or pivots, the latter being if desired made to
extend further from the axis of the rudder blade than the fore edge of
such blade. In case the rudder blade is carried by cranks or arms fixed
to a vertical shaft, as shewn in Figure 4, it may be advisable to reduce
the fore part of the rudder blade, as indicated by the dotted lines,
whereby the after part can be made to overbalance the fore part of the
rudder blade to any desirable extent, which will give a greater tendency

page_text: to the rudder to right itself, that is, to be forced into the position of the
line of the keel by the water which presses upon the rudder surface,
either in consequence of the vessel moving ahead or the screw propeller
driving a column of water astern. When it is desirable to throw part
of the strain which results from the pressure of the water against the
rudder on the sliding pin or pivot f (Figure 1) the after part of the
blade a, o, can be reduced in surface, whereby the fore part o, f, of the
blade will overbalance it, and part of the strain being taken by the pin
or pivot there will be less strain on the rudder shaft, which latter will
hence require less power to be turned. Altogether I do not limit myself
to any proportion existing between the fore and after part of the blade.
The rudder blade may be strengthened if desired by means of ribs
applied either externally or internally; in the latter case in place of
making the blade of a tapering transverse section on cach side of the
rudder shaft, as shewn on the Drawing, it may for affording increased
strength be made of a hollow or box-shaped section.
Figures 2, 3, 4, 5, and 8 show how by means of a plate d, d, the lower
part of the rudder shaft may be held in position, the said plate d, d,
projecting abaft and being provided with a suitable bearing surrounding
the end of the shaft at c. The upper part of the shaft where it enters
the body of the vessel may in a similar manner be held in a bearing, as
shewn in Figures 2 and 4, and may besides be supported on friction
rollers, as shewn in Figures 8 and 9, where v, v, v, are the friction rollers
resting on the surface of the bearing w. Immediately above and resting
on the friction rollers is the arm or tiller t, which latter is firmly secured
to the shaft, and serves also to support the weight of the rudder and
the shaft by resting on the friction rollers. The turning of the rudder
shaft b may be effected by simply fixing upon it the tiller t, as shewn
in Figures 2 and 4, which tiller can be actuated by any suitable known
arrangement of wheel and ropes; or the pin or pivot f may be provided
with an arm or lever r, r, Figures 6, 7, and 8, this latter arm or lever
being firmly secured to the said pin or pivot and extending towards
the bow of the vessel to any suitable length, to be moved by the hand
like the tiller of any small vessel or boat. Or this last-named tiller ", ",
Figure 7, may be extended abaft and be provided, firstly, with a suitable
hole or bearing to embrace and work on a pin o (Figures 6, 7, and 8)
firmly secured to the tiller (or the pin o may be fixed to r, r, and work
in a hole or bearing provided for it in the tiller t); and, secondly, the

page_text: tiller r, r, being sufficiently extended abaft for that purpose the said
tiller r, r, may have attached to its end by any suitable means the
ropes or chains, by means of which the steering wheel may be made to
pull the tiller r, and with it the tiller t, and also the rudder to either
port or starboard, as indicated by the arrows p and 8, Figure 7. Or the
end of the tiller r may be formed into a circular segment q (Figure 6)
round the pivot o as a centre, the circumference of the said segment
mecting the circumference of a pulley m (Figures 6 and 8), which
pulley fits loose on the projecting part of the rudder shaft b, or it may
be fitted loose on a boss of the tiller t, the said boss being carried up
high enough on the shaft to extend through the pulley, there to bear
against a nut or a cotter screwed on or driven through the end of the
shaft (this latter arrangement is not shown on the Drawings). Both the
segment q, as also the pulley m, are provided with two grooves, as shown
in section in Figure 8, so that the chains or ropes coming from the
steering wheel may be slung round the pulley and the segment, one
end of the chain or rope in the upper, the other in the lower groove,
both ends being fastened to the tiller r. In Figure 6 the two arrows p, p,
and 8, 8, indicate the direction in which the ropes or chains have to be
pulled for the purpose of bringing the helm to port or starboard, that
is, tl.c rudder to starboard or port. Or the chains or ropes may be
fastened to the pulley m, instead of being carried to the steering wheel;
the latter may then be placed immediately above or in front of the
shaft b, and made to act on the pulley by any known suitable
mechanism or steering gear as at present frequently applied to the shaft
of the ordinary rudder.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
do not limit myself to the arrangements thereof shown on the accom-
panying Drawing, as these may be variously modified without departing
from the nature of my Invention; but what I claim is,—
First. So constructing ships' rudders that while the power for de-
flecting them is applied by cranks or their equivalents at or near the
middle or at some other intermediate point of the surface of the rudder
blade the rudder when deflected is thrown entirely to the one or to the
other side of the line of the keel, the fore edge thereof being made to
remain in or nearly in the line of keel, substantially as set forth.
Second. The arrangements of ships' rudders wherein the rudder

page_text: blade is carried and actuated by a cranked shaft or by cranks or their
equivalents connected thereto at such a point of its surface as to divide
such surface into any desired proportions on each side of the point
of attachment, substantially as and for the purposes herein-before set
forth.
Third. The arrangements whereby the rudder blade while being
deflected by the aforesaid cranks or cranked shaft is enabled to remain
with its fore edge in or nearly in the line of keel, such edge being at
the same time caused to slide or move to and fro in or nearly in such
line of keel, substantially as herein-before described.
Fourth. The arrangements of tillers and steering gear for actuating
the rudder hercin-before described.
In witness whereof, I, the said Charles Godfrey Gumpel, have
hereunto set my hand and seal, this Twenty-ninth day of April,
in the year of our Lord One thousand eight hundred and
seventy.
Witness,
CHA. D. ABEL,
20, Southampton Buildings.
C. G. GUMPEL. (L.S.)