IMPROVEMENTS IN MACHINERY FOR PROPELLING WATER CRAFT
Year: 1868

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough
Park, Brixton, in the County of Surrey, for the Invention of
** IMPROVEMENTS IN MACHINERY FOR PROPELLING WATER CRAFT."-A com-
munication from abroad by Edwin Sabine Renwick, residing at
Beach Street, New York, United States of America.
Sealed the 26th February 1869, and dated the 22nd October 1868.
COMPLETE SPECIFICATION filed by the said George Tomlinson
Bousfield at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 22nd October 1868, pursuant to
the 9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the County
of Surrey, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR PROPELLING WATER CRAFT," (a communi-
cation to me from abroad by Edwin Sabine Renwick, a person resident
at Beach Street, New York, United States of America,) and in what
[Price 8d.]

page_text: manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, that is to say:-
The subject matter of this Patent relates to the propulsion of water
craft by means of screw propellers placed at the sides of the vessel, and
the Invention consists of certain improvements upon the machinery
described in the Specification of Letters Patent granted in England to
me the said George Tomlinson Bousfield, dated the 4th day of
January 1862, No. 36.
The Invention is divided into parts, the nature of each of which will
appear from the following description and the Drawings referred to therein;
Figures 1, 2, 6, 7, 8, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, and 20 of
said Drawings being drawn upon scale of one-eighth of an English
inch to one English foot; Figures 3, 4, 5, 9, 11, 21, 22, and 23 being
drawn upon a scale of three-eighths of an English inch to one English
foot, and Figure 24 being drawn upon a scale of three-quarters of an
English inch to one English foot.
The special object of the first improvement is to enable a screw
propeller arranged at the side of a vessel to receive and discharge the
water with facility although the propeller shaft is connected directly
with the steam engine, and it consists of the combination of the hull
of the vessel with a shaft chamber placed at the outside of the vesse!
and containing the shaft of the screw propeller, and with an overhung
screw propeller arranged at the end of the said shaft chamber. The screw
propeller in this combination has no rear bearing, and as the side of
the vessel in the rear of the propeller does not project within the
cylinder described by the ends of the propeller wings in their revolution
and forward movement a clear water way is afforded for the water upon
which the propeller blades have acted.
The second improvement consists of the combination of the hull of
the vessel, exterior shaft chamber, and screw propeller at the rear
thereof with a stay to sustain a portion of the weight of the propeller.
The stay in this combination may be arranged either forward of the
propeller or in its rear; in the former case it may have the form of a
flattened oval bar, extending upwards from the bearing of the propeller
shaft forward of the propeller to the side of the hull, or to a bracket
projecting from it, or if the stay connects the after bearing of the

page_text: propeller with the hull, the, stay and bearing or pillow block may have
the form of a bracket secured to the side of the hull aft of the propeller.
The third improvement consists of the combination of the said hull of
the vessel, exterior shaft chamber, and overhung screw propeller with a
guard above water to prevent the propeller blades from coming in
contact with a wharf.
The fourth improvement consists of the combination of the said hull
of the vessel, exterior shaft chamber, screw, propeller, and stay with a
guard as aforesaid. The guard in these last two combinations may be
either a fixed guard or a moveable one, hinged or linked to the side of
the vessel, so that it may be turned upwards or so that it may be
turned downwards, and when so turned may be flat or nearly so against
the said side of the vessel. If the guard be fixed the stay used may
depend from it.
The fifth improvement consists of the combination of the hull of the
vessel, exterior shaft chamber, and screw propeller with two cranks (for
receiving the motive power) arranged diametrically (or nearly so)
opposite each other, so that the momentum of one portion of the
propeller engine, connected with one crank and moving in one direction,
is counterbalanced in whole or in part by the momentum of another
portion of the propeller engine connected with the other crank and
moving in the opposite direction.
The sixth improvement consists of the combination of the hull of the
vessel, exterior shaft chamber, and screw propeller with pillow block
frames or brackets of U form arranged with the closed part of the
frame at the exterior of the screw shaft. This combination permits the
crank shaft to be readily inserted or removed from the shaft chamber
while the vessel is afloat.
The seventh improvement has reference especially to the engine for
driving the propeller, and consists of the combination of the crank shaft
with two steam cylinders of unequal size (the smaller working steam of
high pressure and the larger receiving the steam exhausted from the
smaller) and with a single four-ported slide valve which regulates the
admission and exhaust of steam for both cylinders.
The said improvements may be embodied in various forms. Figures 1,
2, 3, 4, and 5 of the accompanying Drawings represent the first improve-
ment (with others). The hull A of the vessel is fitted at each side with
a shaft chamber B which is large enough internally to permit the crank

page_text: or cranks C to revolve. An exterior diameter of from one-third to four-
ninths that of the propeller is generally sufficient for this purpose. The
shaft chamber is by preference made to taper aft of the crank, and is
gradually reduced in size forward of the crank so as to vanish with easy
water lines into the water lines of the hull. The screw propeller D is
overhung from a bearing E (Figure 4) at the after end of the shaft
chamber B and terminates by preference in a conical boss or hub a.
The shaft bearing E projects in the form of a bracket from the hull, and
is, by preference extended into the hull. In order to afford an easy
passage of the water to the screw propeller blade at the inner side of
the shaft chamber the after end of the latter is made smaller (at)
between the propeller shaft and the hull, so that its vertical longitudinal
section there is of V form, as shown by the dotted lines in Figure 1. The
propeller shaft extends forward longitudinally through the shaft chamber
B and is connected with one or more engine cranks C, C¹. Between the
cranks and the after bearing a thrust bearing E¹ is provided for the
propeller shaft H, and this thrust bearing is by preference formed at the
outer end of a strong bracket which extends into the hull of the vessel.
The second improvement is obtained by applying the stay F (Figures 6
and 10) to the bearing E of the propeller, the propeller and shaft
chamber being constructed as represented in Figures 1, 2, 3, and 4. Or
this improvement may be carried into effect by applying the stay F in
the form of a bracket to a bearing E2 (Figures 10 and 11) which is placed
aft of the propeller and holds a journal at the end of the propeller
shaft or at the butt of the propeller hub; the shaft chamber used in this
improvement is constructed as represented in Figures 1, 2, and 3.
In the foregoing examples of the Invention the lines of the vessel
represented (exclusive of the shaft chamber) do not vary materially
from those of ordinary vessels, but if the propeller is to be placed further
forward than is shown in Figures 1, 2, and 3, and the shaft chamber is
to have the same projection as is shown in said Figures, the hull may
be hollowed at the sides, as represented at Figures 6 and 7, so as to give
room for the propeller blades to revolve, and this form of hull may be
used with or without a stay F as preferred.
In the Figures thus far described the shaft chamber is represented as
arranged for horizontal propeller engines whose central lines correspond
with the dotted line d, d, Figures 3, 5, 7, 9, and 11; the engines inay
however be inclined and the shaft chambers may be arranged in corre-

page_text: spondence therewith, as represented at Figure 12, where the dotted lines
d', d', represent the central lines of the engines.
The guard, which is employed to prevent the propeller blades from
coming in contact with a wharf, and which constitutes a member of
the third and fourth combinations before specified, is represented as fixed
to the hull at G, Figures 13 and 14, and may then be constructed in the
ordinary manner of constructing guards in paddle wheel vessels. In
steamboats for still waters these guards may be decked, but in sea
steamers they should be skeleton frames constructed of iron or of wood as
found expedient. The guard when moveable is constructed by preference,
as represented at Figures 15 and 16, in the form of a skeleton frame G¹
hinged or linked to the side of the hull, so that it can be turned up, as
represented in red lines in Figure 16. When it is turned up it is secured
in place by strong hooks or by other means, and when it is let down its
outer side is suspended by chains for by rods from the side of the vessel
or from posts or davits secured thereto.
In the Figures thus far described the screw propeller is represented as
arranged at the after end of the exterior shaft chamber; it may however
be arranged at the forward end of the exterior shaft chamber, as repre-
sented at D, Figures 17, 18, 19, and 20; or a screw propeller may be
arranged at each end of an exterior shaft chamber, as represented at D, D',
in the said last-mentioned Figures. In the latter case, as four propellers
(two at each side of the vessel) are used to propel the vessel, each
propeller may be of small size and may be arranged deep in the water;
the engines also may be slightly inclined, as represented by the dotted
lines d, d, in Figure 19, or may be horizontal, as represented by the dotted
lines d, d, in Figure 20, as preferred. The screw propeller or propellers
represented in these Figures may be protected by a guard either moveable
or fixed secure to the side of the vessel above the level of the water as
previously described. The arrangement of the screw propeller at the
forward end of the exterior shaft chamber will it is believed facilitate
the passage of the latter through the water, because the centrifugal
action of the propeller tends to open a passage for the shaft chamber.
In the Figures thus far described the screw propeller is placed so
closely to the end of the exterior shaft chamber that the hub of the
propeller is an extension of the said chamber; the improvements may
however be used with the propeller arranged at some distance from the
end of the shaft chamber.
A representation of such an arrangement is

page_text: represented at Figures 20 and 20º. In this example the end of the
exterior shaft chamber B terminates in a tubular case B¹ of about the
same diameter as the hub e of the propeller D, and the weight of the
screw propeller is sustained principally by the stay or bracket F which
sustains the after bearing E2, in which a journal formed near the end of
the propeller shaft revolves. In this arrangement the length of the
exterior shaft chamber may be reduced to the smallest amount compatible
with the proper application of power to the propeller shaft and the
formation of the ends of the chamber of the suitable sharpness.
The fifth improvement is represented at Figures 4, 5, 21, and 22.
The hull of the vessel A, the exterior chamber shaft B, and the screw
propeller D are represented in these Figures as constructed in the same
manner as herein-before described. The propeller shaft H passes through
the outer bearing E and through a stuffing box J into the exterior shaft
chamber B, and its inner or forward extremity is supported by the thrust
bearing or pillow block E. The forward end of the propeller shaft is
coupled to the crank shaft K of the engines. The crank shaft has two
cranks C and C', each of which is connected with the piston of a steam
cylinder by means of a connecting rod and by piston rods. The cranks
are set nearly opposite each other, as represented at Figures 4 and 22,
so that the momentum of one piston and its appurtenances moving in
one direction is nearly counterbalanced by that of the other piston and
its appurtenances moving in the opposite direction. The steam cylinders
used by preference are of different sizes, the smaller M' using the steam
at the full boiler pressure and exhausting into the larger cylinder M.
The reason of setting the cranks not exactly opposite to each other is to
permit the exhaust from the smaller cylinder to commence slightly
before the end of the stroke of its piston. If two cylinders receiving
their steam directly from the boiler are used in place of the two shown
in the Drawing, the cranks should be diametrically opposite each other,
to neutralize the effect of the momentum of the pistons and their
appurtenances. In order that the crank shaft K may be put in place in
the exterior shaft chamber and be removed while the vessel is afloat, the
pillow block frames N, N, N, are constructed of U form, with the caps g
of the pillow blocks at the side of the crank shaft nearer the steam
cylinder. Hence, when these caps are removed the crank shaft may
be drawn into the huil of the vessel, and then if the crank be set
diametrically opposite or nearly so the crank shaft may be withdrawn
endwise from between the horizontal legs of the frames. The removal

page_text: of the caps of the pillow blocks is facilitated by constructing the pillow
block bolts with T heads s, and by placing them in grooves formed in
the sides of the pillow blocks.
The construction of the improved slide valve is shown in Figures 21,
23, and 24. The smaller steam cylinder M' and the larger steam cylinder
M are provided with steam passages terminating at the valve seat in
valve ports, n, m, being the valve ports of the smaller cylinder,
and m, m, being the valve ports of the larger or expansion cylinder.
The valve P is constructed to slide parallel with the axes of the cylinders
over these ports. This valve has a central steam port n', which when
over either port m¹, m³, of the smaller cylinder M₁ admits steam to it.
The valve, has two connecting ports t, t, and when one of these is over
the ports, l, m, of the adjacent ends of the two steam cylinders it
forms a passage way from the smaller to the larger cylinder, and permits
the steam to exhaust from the former to the latter. The valve has also
a central exhaust port,, which when in communication with either port
m, m, of the larger cylinder forms a passage therefrom to the exhaust
port of the valve seat, and permits the steam from the larger cylinder
to exhaust. The back of the valve may have any suitable contrivance
applied to it to relieve the pressure, one such being shown in the
Drawing, and consisting of a valve chest cover of thin flexible metal
linked to a plate a against which the back of the valve slides. The
valve is operated by the usual link motion used for moving and reversing
the valves of steam engines, and the eccentrics of the link motion may
be secured to the crank shaft of the steam engine and may be connected
with the valve rods by means of rods or links, a rock shaft, and arms, all
constructed in the usual manner. In the present example the steam
pistons have a stroke of twenty-seven inches. The arrangement and sizes
of the ports of the steam cylinders and valve are such that the exhaust
commences from the smaller cylinder to the larger when the piston of
the former has arrived within one inch of the end of the stroke, and the
exhaust from the larger cylinder commences when its piston has arrived
within five-eighths of an inch of the end of its stroke. The steam at
the exhaust side of each piston is cut off from exhausting before the
piston reaches the end of its stroke by the operation of the valve in
covering the ports, so that the steam is compressed by the advancing
piston for the purpose of neutralizing a portion of its momentum.
When a condenser and air pump are used in connection with the seventh
improvement I prefer to work the air pump by a crank applied to the

page_text: end of the crank shaft furthest from the propeller; also to arrange the
largest steam cylinder between the air pump and the smaller steam
cylinder, setting the crank that works the air pump diametrically
opposite the crank of the larger steam cylinder so that the momentum
of the pistons of the smaller steam cylinder and air pump and their
appurtenances counterbalance the momentum of the larger steam
cylinder moving in the opposite direction. Instead of working the air
pump by a crank, it may be worked by one of the pistons of the steam
cylinders by placing the air pump behind the said steam cylinder and by
connecting the piston rod of the air pump with the said steam piston,
the piston rod of the air pump being passed through stuffing boxes in
the head of the air pump and the butt of the steam cylinder for this
purpose. When the cranks of the steam cylinders are set diametrically
opposite each other or thereabouts, for the purpose of balancing the
strains upon the crank shaft, a third and smaller steam cylinder may be
connected with the same crank shaft, its crank being set at right angles
or thereabouts with the cranks of the other two, so that the turning of
the crank shaft when the engine is first started or is moved with great
slowness may be ensured. As the object of using this third cylinder is
merely to carry the cranks of the main steam cylinders past their dead
points with certainty, it may be of small dimensions so that its operation
will not materially affect the balancing of the power upon the crank
shaft due to the diametric arrangement of the cranks of the larger two
steam cylinders. The smaller cylinder will of course require a special
valve gear to operate its valve, and this gear may be constructed in the
usual manner.
The improvements thus described enable screw propellers to be placed
at the sides of vessels in the positions previously occupied by paddle
wheels. They thus obviate all the objectional features of a propeller
arranged at the stern of a vessel, relieving the stern of the weight and
vibration caused by applying the propeller at that place, and dispensing
with the employment of a shaft alley in the interior of the vessel. The
propellers also are placed much nearer the steam engines and the friction
due to the employment of a number of supporting bearings between the
propeller and the engine frame is obviated. The exterior shaft chambers
act as bilge kelsons to obstruct and reduce the rolling of the vessel, so
that a propeller steamer may be as comfortable a ship for passengers as a
paddle-wheel steamer; moreover, the propellers being at a distance from
the stern post are not pitched out of the water when the vessel is in a

page_text: head sea, consequently the propellers will work with full power under
such circumstances. The improvements afford a convenient means of
converting paddle-wheel ships into propeller ships, as the exterior shaft
chambers may be built upon the outsides of the ships; the engines may
be placed in the saine part of the ship as the paddle-wheel engines, and
may communicate with the propeller shafts in the shaft chambers
through ports cut in the sides of the ship.
What is claimed as the Invention to be secured by Letters Patent is,―
First. The combination of the hull of the vessel, exterior shaft
chamber, and screw propeller overhung at the end of the said shaft.
chamber, the whole operating substantially as before set forth.
Second. The combination of the hull of the vessel, exterior shaft
chamber, screw propeller, and stay, the whole operating substantially as
before set forth.
Third. The combination of the hull of the vessel, exterior shaft
chamber, overhung screw propeller, and guard therefor, the whole
operating substantially as before set forth.
Fourth. The combination of the hull of the vessel, exterior shaft
chamber, screw propeller, stay, and guard, the whole operating substan
tially as before set forth.
Fifth. The combination of the hull of the vessel, exterior shaft
chamber, screw propeller, and two cranks, arranged diametrically opposite
each other, the whole operating substantially as before set forth.
Sixth. The combination of the hull of the vessel, exterior shaft
chamber, screw propeller, and pillow block frames of U form, arranged
as before described.
Seventh. The combination of the crank shaft of the screw propeller,
two steam cylinders of unequal size, and a four-ported slide valve, the
whole operating substantially as before set forth.
In wituess whereof; I, the said George Tomlinson Bousfield, have
hereunto set my hand and seal, this Fourteenth day of October,
in the year of our Lord One thousand eight hundred and sixty-
Light
GEO. T. BOUSFIELD. (L.S.)