Year: 1886

page_text: I, JOHN ISAAC THORNYCROFT, of Church Wharf, Chiswick, in the County of
Middlesex, a member of the firm of J. I. Thornycroft and Co. Steam Yacht and
Launch Builders do hereby declare the nature of this invention to be as follows:-
In the Specification of Letters Patent granted to me the 3rd April, A.D. 1879
(No. 1330), is described the use in apparatus for propelling and steering ships or
vessels of a propeller having behind it and arranged in line with its boss a body
having a gradually increasing diameter or width for a short distance, and afterwards
a gradually diminishing diameter or width to its rearward end. This body, which
I will call the rearward body, is furnished with guide plates or blades for gradually
deflecting and directing the water projected from the propeller into a direction
approximately parallel with the body axis. Around the propeller and body behind
it is a pipe, tube, case, or hollow guide.
In the specification of Letters Patent granted to me the 29th day of April A.D.
1881 (No. 1853) is described the making of the said body in two or more lengths,
and mounting the rearward part of the same on pivots or axes so that it can be
moved to port or to starboard after the manner of a rudder.
Now my present invention has for object to enable vessels fitted with propellers
of this kind to go astern and give them manoeuvering qualities independent of
endwise motion, the propelling engines not being reversed but only varied in speed.
The arrangement I adopt for this purpose is such that for going ahead the
operation resembles that of the apparatus described in my previous specifications;
but to go astern the stream of water from the propeller is caused to pass to some
extent through the vessel by means of curved passages and is projected forwards
at a more or less acute angle with the keel. The water in this case may be
delivered above water mark or the plane of flotation and by suitable valves at or
near the points of discharge the amount at either side of the hull may be regulated
and the direction may be varied so as to give great control whether one or two
propellers be used. When two propellers are used these valves may be dispensed
with the quantity of water discharged being regulated by varying the speed of the
respective propeller engines. For conducting the stream from the propeller to the
discharge orifices when going astern according to one arrangement a portion of the

page_text: concave surface of the hull and the rearward body are carried in bearings so as to
rotate on an axis in rear of and making a small angle with or coinciding with
that of the propeller. The arrangement is such that by turning this combination
through half a rotation a smooth passage is formed and there is a suitable hole in
the bull to admit water to the curved passage or passages leading to the discharge
orifice or orifices, when two or only one propeller respectively are or is employed.
The exit passages may be provided with an outer door or valve to be opened by
the current, and arranged to close from without and to keep out air.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Propelling and Steering Apparatus for Ships
or Vessels.
I, JOHN ISAAC THORNYCROFT, of Church Wharf, Chiswick, in the County of
Middlesex, a member of the firm of J. I. Thornycroft and Co. Steam Yacht and
Launch Builders, 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 :--
In the Specification of Letters Patent granted to me the 3rd April A.D. 1879
(No. 1330), is described the use in apparatus for propelling and steering ships or
vessels of a propeller having behind it and arranged in line with its boss a body
having a gradually increasing diameter or width for a short distance and afterwards
a gradually diminishing diameter or width to its rearward end. This body, which
I will call the rearward body, is furnished with guide plates or blades for gradually
deflecting and directing the water projecting from the propeller into a direction
approximately parallel with the body's axis. Around the propeller and body
behind it is a pipe, tube, case, or hollow guide.
In the specification of Letters Patent granted to me the 29th day of April,
A.D. 1881 (No. 1853) is described the making of the said body in two or more
lengths, and mounting the rearward part of the same on pivots or axes so that it
can be moved to port or to starboard after the manner of a rudder.
Now my present invention has for object to enable vessels fitted with propellers
of this kind to go astern and give them manoeuvering qualities independent of
endwise motion, the propelling engines not being reversed but only varied in speed.
The arrangement I adopt for this purpose is such that for going ahead the
operation resembles that of the apparatus described in my previous specifications;

page_text: but to go astern the stream of water from the propeller is caused to pass to some
extent through the vessel by means of curved passages and is projected forwards
at a more or less acute angle with the keel. The water in this case may be
delivered above water mark or at or near the plane of flotation and by suitable
valves at or near the points of discharge the amount at either side of the hull may
be regulated and the direction may be varied so as to give great control whether
one two or more propellers be used. When two propellers are used these valves
may be dispensed with the quantity of water discharged being regulated by varying
the speed of the respective propeller engines. For conducting the stream from the
propeller to the discharge orifices when going astern according to one arrangement
a portion of the concave surface of the hull and the rearward body are carried in
bearings so as to rotate on an axis in rear of and making a small angle with or
coinciding with that of the propeller. The arrangement is such that by turning
this combination through half a rotation a smooth passage is formed and there is a
suitable hole in the hull to admit water to the curved passage or passages leading
to the discharge orifice or orifices, when two or only one propeller respectively are
or is employed. The exit passages may be provided with an outer door or valve
to be opened by the current, and arranged to close from without and to keep
out air.
Referring to the accompanying 4 sheets of drawings Fig. 1 is a longitudinal
sectional elevation of the stern portion of a vessel provided with propelling and
steering apparatus according to this invention, set for going ahead. Fig. 2 is a
similar view to Fig. 1 with the apparatus set for going astern. Fig. 3 is a plan
or top view of the stern of the vessel with curved water passages the deck being
omitted. Fig. 4 is a transverse section on the line z z, Fig. 2. Figs. 5 and 6 are
detail views hereinafter referred to.
1. is the hull of the vessel; 2 is a screw propeller the boss of which is secured
to a driving shaft 3. Behind the propeller 2 is a rearward body formed in two
parts 4 and 5, whereof 4 is of a gradually increasing diameter or width towards
the stern of the vessel and 5 is of a gradually diminishing diameter or width to
its rearward end. 6 is a pipe, tube, case, or hollow guide hereinafter called the
tube encircling the propeller 2 and the part 4 of the rearward body. The part 4
is connected by guide plates or blades 7 to the tube 6, the office of such guides or
blades being to gradually deflect and direct the water projected from the propeller
in a direction approximately parallel to the axis of the fixed part of the rearward
body. The part 4, the guide plates or blades 7 and the tube 6 are rigidly connected
together and are attached to the vessel 1 in any convenient manner. The part 5 of
the rearward body is rigidly connected by plates or blades 8, 8 to a curved plate or
cover 9 hereinafter called a cover which when in the position shown in Fig. 1 forms
a continuation of the lower concave surface or bottom 9* of the hull of the vessel
and closes the inlet orifice 10° common to the connected curved passages 10, 10,
which extend through the vessel to its sides as clearly shown in Fig. 3. The
part 5 is provided with a pivot 11 having a bearing in the part 4 as shown; the
cover 9 is connected to a shaft 12 working in a water tight, bearing at 13 and in
any suitable bearing at 14, the arrangement being such that the connected cover 9
and part 5 may be rotated on an axis, which in the example shown, makes a small
angle with the driving shaft 3. A convenient arrangement of apparatus for
effecting the desired rotation or partial rotation of the connected cover 9 and
part 5 of the rearward body is as follows:-15 is a worm wheel secured to the
shaft 12 and arranged to receive motion from a hand wheel 16 through the inter-
mediary of a chain wheel 17, endless chain 18, chain wheel 19, shaft 20 and worm 21
which gears with the worm wheel 15 as shown. When the propeller is in operation
to cause the vessel to go ahead the several parts of my apparatus will be in the
relative positions represented in Fig. 1. The stream of water from the propeller 2
will then be caused to pass rearward through the tube 6 and away in the direction
of the arrow x Fig. 1. If it be desired that the vessel should go astern the con-
pected cover 9 and part 5 of the rearward body are rotated in their common axis

page_text: through half a revolution by turning the hand wheel 16, so that they shall assume the
position shown in Figs. 2 & 4 when the opening 10° in the under part of the vessel's
hull communicating with the curved passages 10, 10 is uncovered. The stream of
water from the propeller, which continues to rotate in the same direction as before,
will now pass rearward through the tube 6 as in the previous case, but it will then
be deflected and guided by the cover 9 and part 5 in the direction of the arrows y, y,
(Figs. 2 and 3) so as to pass through the curved passages 10 in a forward direction
at a more or less acute angle with the keel of the vessel, and by its re-action, will
cause the vessel to move astern as will be readily understood.
To enable the connected cover 9 and part 5 of the rearward body to be rotated
to the required extent with accuracy and afterward to be held in the position to
which they have been moved until it is desired to alter it, the shaft 22 (Fig. 6) of
the hand wheel 16 is provided with a worm. 23 which gears into a worm wheel 24.
The shaft 25 of the worm wheel 24 carries a disc 26 provided with a notch 27 in
which a catch or pawl 28 engages when the connected cover 9 and part 5 are in
either of the positions shown respectively in Figs. 1 and 2. The pawl 28 is
pivotted to a standard 29 which supports the shaft carrying the worm wheel 24
and disc 26. 30, 30 (Figs. 3 and 5) are valves situate in the curved passages 10
near their outer ends; they are provided with handles 31 (Fig. 5) in order that
the quantity of water discharged at either side of the hull may be regulated, and
its direction varied so as to give great control over the manoeuvring powers of the
vessel whether one or two propellers be used. At 31* (Figs. 4 and 5) are a screw
and nut for holding the valve handle 31 in position. 32, 32 are doors or valves
so arranged at the outer ends of the curved passages 10 as to be opened by a flow
of water there-through and to close automatically when such flow ceases and thus
prevent the entry of air into the said passages. 33 is the vessels rudder which
may be of ordinary construction as shewn for use in conjunction with the propelling
and steering apparatus hereinbefore described.
When two propellers are used side by side the rearward body 4-5, tube 6, cover 9,
and means for rotating it should be in duplicate. In such an arrangement when
the vessel is required to go astern the stream of water from the port side propeller
will be passed through the curved passage 10 situate at the port side of the vessel,
and that from the other propeller through the passage 10 at the starboard side or
the curved passages may for convenience in some cases be crossed. The valves 30, 30,
employed when the vessel is fitted with one propeller only, may be dispensed with
when two propellers are used, the quantity of water discharged through the
passages 10 being then regulated according to requirement by varying the speed
of the respective propeller engines. In some cases there may be three propellers
the centre one being simply a screw propeller not provided with means for directing
the water from it through a passage or passages.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a vessel having a screw propeller or propellers arranged with its or their
axis or axes fore and aft of the vessel providing passages and means whereby water
thrown aft by the propeller or propellers can when desired be caused to flow through
the said passages in such a manner as to propel the vessel astern without changing
the direction of rotation of the propeller or propellers.
2. In conjunction with a screw propeller and a passage or passages extending
through one or both sides of a vessel in a forward direction the use of an adjustable
plate or cover and means for operating the same, the arrangement being such that
in one position of the plate or cover water thrown aft by the propeller will be
caused to flow through the said passage or passages so as to propel the vessel astern,
whilst in another position of the said plate or cover the inlet to the said passage
or passages will be closed and the propeller will act to propel the vessel forward
substantially as described.

page_text: 3. In a vessel apparatus comprising a screw propeller with a rearward body
having a movable part such as 5 and in combination therewith a curved plate or
cover such as 9 these being so arranged that they may be rotated about a common
axis and so be caused to open or close as required communication with a passage
or passages extending to one or both sides of the vessel substantially as described
for the purpose specified.
4. Apparatus substantially as described and shewn whereby a vessel can be
caused to move either ahead or astern by the action of a rotary propeller without
changing the direction of rotation thereof.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.