IMPROVE- MENTS IN THE CONSTRUCTION OF SCREW-PROPELLED SHIPS, AND IN THE ARRANGEMENT AND MODE OF DISCONNECTING, WITHDRAWING, AND LIFTING SCREW PROPELLERS
Year: 1863

page_text: LETTERS PATENT to Thomas Edward Symonds, of Adam Street; Adelphi,
Commander in Her Majesty's Navy, for the Invention of "IMPROVE-
MENTS IN THE CONSTRUCTION OF SCREW-PROPELLED SHIPS, AND IN THE
ARRANGEMENT AND MODE OF DISCONNECTING, WITHDRAWING, AND LIFTING
SCREW PROPELLERS."
Sealed the 21st August 1863, and dated the 28th February 1868.
PROVISIONAL SPECIFICATION left by the said Thomas Edward Symonds.
at the Office of the Commissioners of Patents, with his Petition, on
the 28th February 1863.
I, THOMAS EDWARD SYMONDS, of Adam Street, Adelphi, Commander in
Her Majesty's Navy, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-PROPELLED SHIPS, AND IN THE
ARRANGEMENT AND MODE OF DISCONNECTING, WITHDRAWING, AND LIFTING SCREW
PROPELLERS," to be as follows:-
This Invention relates to twin or double screw ships built of iron, and having
one or more keels, each screw being overhung or having no outer bearing.
In constructing ships according to this Invention, I form or insert two'.
transverse bulkheads across the stern part of the ship, the aftermost of these
bulkheads being immediately before the screw, and I form a well-hole for
receiving each screw under the counter and abaft the transverse bulkhead.
For the purpose of enabling overhung screws according to this Invention
to be raised vertically, I mount or fix each screw upon a short length of shaft,

page_text: which is supported by and free to revolve in a long bearing formed by two
half carriages, which when brought together form a tube, which may be fitted
with lignum vitæ strips or other bearing and wearing surfaces. These half
frames when combined form the carriage, and which sliding in a vertical
frame or guides between the transverse bulkheads enables the screw to be
raised vertically, so that the ship may sail without the obstruction offered by
the screw propeller. Each screw may be raised separately. The inner end
of the short shaft, upon which the screw is mounted, may be fitted with the
ordinary form of cheese-head coupling. The withdrawing the screw from
the water or the raising and lowering may be effected by means of chains or
ropes and pulleys, or any of the well-known mechanical means may be adopted
for that purpose. The foremost of the transverse bulkheads is fitted with a
stuffing box for the screw shaft, and one part of the cheese-head coupling
projects therefrom. The apertures for the screws are fitted with flaps or
shutters opening outwards, or they may be made to slide, for the purpose of
closing the opening at the bottom of the screw hole, so as to ensure a clear
delivery of the water, whether under steam or sail. The overhanging end of
the screw or one of the blades may have a hole cast or formed therein for the
purpose of enabling the screw to be fished, or to assist in withdrawing it or
hauling it up.
For the purpose of withdrawing the overhanging screw horizontally from
off the screw shaft in twin screw vessels, I form the after end of the screw
shaft in the following manner:-I make the shaft at the outer end sufficiently
large to enable it to be bored or otherwise made hollow, for the purpose of
receiving the shank of the screw, or a short length of shaft upon which the
screw has been fitted, and by means of a gib and cotter passing through slots
formed in both the screw shank or shaft and the hollow part of the main shaft
within or forward of the stuffing box, or between the outer and inner bulk-
heads, or forward of the stern bearing, the key or other means of securing the
overhanging screw in its place may be withdrawn and the screw released.
By the arrangement of bulkheads forming the after termination of the hull
in the manner described, I am enabled to give additional strength to the ship
as a structure, and by the arrangement and disposition of the stern part
externally and of the rudders in double-keeled vessels I am enabled to avoid
the necessity for any after stern post, upright, or framing piece abaft the screw
propeller, or any opening or void, such as exists in ships of war and other vessels,
between the fore and after stern posts, which impairs the steering qualities of
the ship.
In iron screw vessels having double keels I place a rudder in the line of

page_text: each keel, and nearly in a line with each screw shaft, and I connect the tillers
together so as to enable them to work simultaneously, but they may be readily
disconnected for the purpose of being worked separately.
..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Edward Symonds in the Great Seal Patent Office
on the 28th August 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
EDWARD SYMONDS, of Adam Street, Adelphi, Commander in Her Majesty's
Navy, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of February, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Edward Symonds, Her special license, that I, the said Thomas
Edward Symonds, my executors, administrators, and assigns, or such others
as I, the said Thomas Edward Symonds, my executors, administrators, or
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 THE CONSTRUCTION OF SCREW-PROPELLED SHIPS, AND IN THE
ARRANGEMENT AND MODE OF DISCONNECTING, WITHDRAWING, AND LIFTING SCREW
PROPELLERS," upon the condition (amongst others) that I, the said Thomas
Edward Symonds, my executors or administrators, by an instrument in writing
under my
hand and seal, or under the hand and seal of one of them, should
particularly describe and ascertain the nature of the said Invention, and in
to be
what manner the same was to be performed, and cause the same
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 Thomas Edward Symonds, do hereby
declare the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement and accompanying Sheet of Drawings
This Invention relates to twin or double screw ships built of iron, and
having one or more keels, each screw being overhung or having no outer
bearing.

page_text: In constructing ships according to this Invention, I form or insert two
transverse bulkheads across the stern part of the ship, the aftermost of
these bulkheads being immediately before the screw, and I form a well-
hole for receiving each screw under the counter and abaft the transverse
bulkhead.
For the purpose of enabling overhung screws according to this Invention to
be raised vertically, I mount or fix each screw upon a short length of shaft,
which is supported by and free to revolve in a long bearing formed by two half
carriages, which when brought together form a tube, which may be filled with
lignum vitæ strips or other bearing and wearing surfaces. These half frames
when combined form the carriage, and which sliding in a vertical frame or
guides between the transverse bulkheads enables the screws to be raised ver-
tically, so that the ship may sail without the obstruction offered by the screw
propeller. Each screw may be raised separately. The inner end of the short
shaft, upon which the screw is mounted, may be fitted with the ordinary form
of cheese-head coupling. The withdrawing the screw from the water or the
raising and lowering may be effected by means of chains or ropes and pulleys,
or any other of the well-known mechanical means may be adopted for that
purpose. The foremost of the transverse bulkheads is fitted with a stuffing
box for the screw shaft, and one part of the cheese-head coupling projects
therefrom. The apertures for the screws are fitted with flaps or shutters
opening outwards (or they may be made to slide), for the purpose of closing
the opening at the bottom of the screw hole, so as to insure a clear delivery of
the water, whether under steam or sail. The overhanging end of the screw
or one of the blades may have a hole cast or formed therein for the pur-
pose of enabling the screw to be "fished," or to assist in withdrawing it or
hauling it up.
For the purpose of withdrawing the overhanging screw horizontally from off
the screw shaft in double screw vessels, I form the after end of the screw shaft
in the following manner :-I make the shaft at the outer end sufficiently large
to enable it to be bored or otherwise made hollow, for the purpose of receiving
the shank of the screw, or a short length of shaft upon which the screw has
been fitted, and by means of a gib and cotter passing through slots formed in
both the screw shank or shaft and the hollow part of the main shaft within or
forward of the stuffing box, or between the outer and inner bulkheads, or
forward of the stern bearing, thus the key or other means of securing the
overhanging screew in its place may be withdrawn and the screw released.
By the arrangement of bulkheads forming the after termination of the hull
in the manner described, I am enabled to give additional strength to the ship

page_text: as a structure, and by the arrangement and disposition of the stern part
externally and of the rudders in double-keeled vessels I am enabled to avoid
the necessity for any after stern post, upright, or framing piece abaft the screw
propeller, or any opening or void, such as exists in ships of war and other
vessels, between the fore and after stern posts, which impairs the steering
qualities of the ship.
In iron screw vessels having double keels I place a rudder in the line of
each keel, and nearly in a line with each screw shaft, and I connect the tillers
together so as to enable them to work simultaneously, but they may be readily
disconnected for the purpose of being worked separately.
In the accompanying Drawing I have shewn my Invention applied in
both single and double keel ships, and adapted to vessels of deep and light
draught.
a
Figure 1 is a side elevation of the stern part of Her Majesty's iron-plated
frigate "Warrior," which is shewn only for the purpose of comparing with it
ship constructed according to my Invention; Figure 2 is a side elevation of
the stern part of a ship of war of the same dimensions as the "Warrior," con-
structed according to my present Invention, shewing the arrangement of trans-
verse bulkheads, the arrangement for lifting the screw, and the trunk or well-
hole for each screw; this vessel has two screws and a single keel and rudder.
Figure 3 is a longitudinal section, and Figure 4 an elevational stern view in
two sections of a double keel iron ship having two screws and two rudders
fitted according to this Invention in a ship of large size suited for war
purposes.
In the two sectional views in Figure 4, the one is so taken as to show
the screw in its usual position, and also the trunk or space up which the
screw shaft travels; the other section shews the screw raised, the screw
well-hole, and the cheese-head coupling or bearing in the trunk or box projec-
tion which springs from the keel for the purpose of receiving the outer length
of screw shaft.
Figure 5 is a longitudinal section of part of the stern portion of an iron
vessel of light draught with two screws, shewing the mode of fitting any form
of screw which may be preferred to the screw shaft for the purpose of discon-
necting by drawing off horizontally, access to the outer end of the screw shaft
being given by increasing the width of the trunk up to the skin of the ship by
splaying out, so that the gib and key may be readily withdrawn, and the screw
with its short internal shaft or shank may be drawn out horizontally. The
stern lines of the vessel shewn in this view are however only ideal, and
are not intended to convey the exact form which it may be desirable to

page_text: adopt, but this Figure is given solely as an illustration of a mode of fitting
screws in double screw ships, and of the combination of a rudder or rudders
therewith.
Figure 6 is a transverse section of the view Figure 5, shewing an arrange-
ment of engines for driving the two screws independently, to admit of
manoeuvring the vessel with or without the aid of the rudders; and although
in this section a peculiar arrangement of engine is shewn, in which it is
intended to employ two pairs of engines (each of two cylinders), and wheel
gearing is also intended to be employed for allowing of the engines working
slow, I have only shewn such an arrangement by way of illustration, and not
as a plan which I prefer to employ in ordinary cases either in commercial ships
or in vessels of war.
Figure 7 is a detached view shewing the mode of fitting the screws to screw
shafts, so as to enable them to be drawn off horizontally; and although in this
Figure no screw is shewn as mounted upon the short shaft or shank fitting
into the hollow end of the outer length of screw shaft or shaft for communi-
cating the motion of the engine to the screw, any form of screw may be
adopted, as a two-bladed screw, such as shown in Figure 2, or a four-
bladed screw, such as shewn in Figures 3 and 4, or any other form of screw
which may be considered better suited for the purpose.
In the several Figures in the Sheet of Drawings, A is the transverse bulk-
head herein-before referred to in the stern portion of the hull, and which is in
every case carried up above the deep load line, and in vessels of light draft it
is proposed to carry it up to the deck line in screw ships where the screw is
raised vertically; B is the narrow trunk or space in which in double screw
ships having overhung screws the short shaft and the main bearing are made
to slide or travel up and down as shewn ; C, the well-hole, in which the screw
is raised and withdrawn when out of use from its working position; D, the
screw, which may be varied in form; E, the shaft upon which the screw is
mounted, and which shaft may be fitted and moved and detached from the
screw in either of the manners herein-before described, and in each case the
mode or method of fixing the screws, and of connecting the short shaft to the
main shaft, and the mode of lifting or moving it, as also of connecting and
disconnecting the screw, is shewn in accordance with this Invention; F, the
keel of the single keel double screw ship, and F, F', the keels of double keel
ships; G, G, the rudders of double keel double screw ships, the mode of
working these rudders being shown; H, an aŕrangement of horizontal engines
and gearing for driving the two screws, which may or may not be adopted;
a, a, are flaps for closing the screw well-hole, and b, the long bearing and

page_text: carriage containing the short length of screw shaft, and which is fitted as to
slide vertically into and out of gear with the cheese-head coupling on the
screw shaft; c and c are the pulleys or sheaves for lifting and lowering
the screw; d, the tiller of the rudder; e, the thrust block of the screw
shaft.
Having now described my Invention of "Improvements in the Construction
of Screw-propelled Ships, and in the Arrangement and Mode of Disconnecting,
Withdrawing, and Lifting Screw Propellers," as also the mode of applying the
rudders in double screw ships, what I claim is,-
First, the mode or method of constructing ships, as herein described, for
receiving two screws, and enabling them to be readily lifted or raised in the
manner shown.
Second, the mode of applying or fitting screw propellers in double keeled
double screw ships, as herein described, and as shown in the accompanying
Sheet of Drawings.
Third, the mode or method herein described, and as shown in the accom-
panying Drawings, of applying, mounting, and fitting two screws to singlo
keel ships, so that the screws may be readily raised when out of use.
Fourth, the mode or method of constructing the stern portion of double
screw ships, and of combining therein and therewith the arrangements for
propelling and steering, as described and illustrated.
In witness whereof, I, the said Thomas Edward Symonds, have hereunto
set my hand and seal, this Twenty-fifth day of August, in the year
of our Lord One thousand eight hundred and sixty-three.
5
Witness,
JAMES STEVENSON,
THOMAS EDWARD SYMONDS. (L.s.)
19, Salisbury Street,
Strand. W.C.