Improvement in Propulsion of Ships by Screw-propeller.
Year: 1887

page_text: Date of Application, 22nd June, 1887
Complete Left. 22nd Mar., 1888
Complete Accepted, 27th Apr., 1888
PROVISIONAL SPECIFICATION.
Improvement in Propulsion of Ships by Screw-propeller.
1, WILLIAM SCOTT PRICE, residing at 29 Island Road, Garston near Liverpool in
the county of Lancaster, Timber Merchant do hereby declare the nature of my inven-
tion for "IMPROVEMENT IN PROPULSION OF SHIPS BY SCREW PROPELLER to be as
follows:-
"
My invention consists in having two or more shafts for driving ship's propeller.
The after ends of these driving shafts projecting through forward sternpost at different
levels, and all terminating at after side of forward sternpost. The highest shaft
being placed at about same level as is usual in present practice.
The propeller is hung on a short independent shaft, which works in bearings, in a
frame, placed between forward sternpost and after (or real) sternpost, and this frame
is made capable of being lifted up, or lowered down, so that propeller shaft can be
connected with any one of the driving shafts, in a manner similar to that in use for
auxiliary propellers-When ship is in shallow water the propeller can be attached to
the upper shaft, so that propeller blade does not project below level of ship's keel-
But when ship is in deep enough water, propeller can be lowered to lower shaft and
if this for instance should be at level of keel, then half diameter of propeller would
be below keel level. By this I expect to get a very decided increase in power, with
further advantage of making it possible to use a propeller of larger diameter in rela-
tion to ships draft, than is now usually used, and also the advantage of modifying or
obviating the risk, and loss of power caused under present system, by propeller being
often wholly or partially out of water when ship is pitching. To enable propeller to
be lowered in this way it is necessary to have a break or opening in the keel at
forward sternpost and I have various plans to use to make up as far as possible for
consequent weakness and for prevention of vibration. Among these plans are the
following: That after sternpost be made specially strong by increased dimensions
both thwartship and fore and aft; that propeller frame, in which propeller
works, be made particularly strong and its sides or ends be connected at both top
and bottom. The bottom of frame can also be made specially broad; that the after
side or end of frame can be made to entirely, or almost entirely embrace the after

page_text: sternpost against which it slides; that from forward end of bottom of propeller
frame can project one or more stringers which are connected further forward with
keel or ship's bottom or sides, so as to prevent frame being dragged aft and also to
act as fenders to keep wreck &c. from striking against frame; that the propeller shaft
can be made hollow for its entire length, and also the driving shafts for great part or
whole of their lengths, for purpose of enabling a strong stayrod to be passed through
the shafts, the after end of which stayrod can be screwed or otherwise fastened into
after sternpost and the forward end of stayrod either held by suitable means within
driving shaft, provision being made for free working and for accessibility, or, where
possible, as in case of shafts being driven by gearing or by rotary engine on shaft,
then the stayrod can be passed through entire length of driving shaft and fastened
securely at inner end. Many other means may be used for strengthening frame and
after stern post and lessening vibration, according to circumstances of power exerted
and necessity for special steadiness.
The propeller frame may move up and down either in straight line, or, in case of
shafts not being parallel to one another, the frame may be made to follow such a curve
that propeller shaft may be always in direct line with that driving shaft which for the
time is driving it. The propeller frame may also be made capable of being lifted
above upper shaft, so that minor repairs to propeller or its shaft can be done or a
broken propeller replaced by a good one without docking ship.
The driving shafts can be driven either by the same or by separate engines.
The ships rudder may be made to fall down along with propeller frame, if that is
considered desirable for getting increased steering power.

page_text: Improvement in Propulsion of Ships by Screw Propeller.
1 WILLIAM SCOTT PRICE, of 29 Island Road, Garston, Liverpool, in the County of
Lancaster, but at present temporarily residing in Vancouver, British Colombia,
Timber Merchant, 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:-
My invention consists in providing two shafts for driving a ships propeller.
The after end of these driving shafts project through the stern post at different
levels and terminate at the after side of stern post. The upper shaft is placed at about
the same level as usual in present practice. The propeller is carried on a short
independent shaft revolving in bearings carried by a frame placed in the opening
between the stern and rudder posts.
This frame is capable of being raised or lowered to admit of the propeller being
connected to either of the driving shafts in a manner similar to that in use for
auxiliary propellers.
The arrangement is such that when a ship fitted with my improvements is in shallow
water the propeller can engage with the upper shaft, then the tips of the blades will
not project below the line of ships keel, but when the ship is in deep water the pro-
peller may be lowered and attached to the bottom or lower shaft, then nearly one half
of the diameter of the propeller would be below the line of the keel, and by this
method a larger diameter of propeller might be used in relation to the ships draft, and
also the risk and loss of power under the present system by the propeller being often
wholly or partially out of the water when the ship pitches is obviated.
To enable the propeller to be lowered it is necessary to have an opening in the keel
at stern post, and I have various plans to make up as far as possible for consequent
weakness and prevention of vibration, thus for example the rudder post may be made
specially strong by increased dimensions, also the propeller frame in which the
propeller works may be connected at the top and bottom.
The bottom of frame can also be made specially broad, that the after side or end of
propeller frame can be made to entirely or almost entirely embrace the rudder post
against which it slides, that from the forward end of the bottom of propeller frame can
project one or more stringers which are connected further forward with the keel or
ships bottom or sides so as to prevent the frame from being dragged aft and also to
act as fenders to keep wreckage &c. from striking against the frame; that the pro-
peller shaft can be made hollow its entire length and also the driving shafts for great
part or whole of their lengths for purpose of enabling a strong stay rod to be passed
through the shafts, the after end of which stay rod can be screwed or otherwise
fastened into rudder post, and the forward end of stay rod held by suitable means
within driving shaft, provision being made for free working and accessibility, or
where possible as in case of shafts being driven by gearing or by rotary engine on shaft,

page_text: then the stay rod can be passed through the entire length of driving shaft and fastened
securely at inner end.
Many other means may be used for strengthening frame and rudder post and
lessening vibration according to circumstances of power exerted and necessity for
special steadiness.
The propeller frame may move up and down either in a straight line or in case of
shafts not being parallel to one another the frame may be made to follow such a curve
that the propeller shaft may be always in a direct line with that shaft which for the
time is driving it. The propeller frame may also be made capable of being lifted
above upper shaft, so that minor repairs to propeller or its shaft, can be done, or a
broken propeller replaced by a good one without docking ship.
The driving shafts can be driven either by the same, or by separate engines.
The ships rudder may be made to fall down along with propeller frame if that is
considered desireable for getting increased steering power.
Referring to the accompanying sheet of drawings Fig. 1. represents partially in
section a side elevation of my apparatus shewing sufficient of a stern frame post and
driving shafts to clearly illustrate my invention, the propeller being raised for working
in shallow water.
Fig. 2. is a similar view to Fig. 1. with the exception that the propeller is lowered
down and attached to the other shaft for working in deep water.
For sake of clearness the thrust bearings and stern tubes are omitted; also the
driving gear and disengageing Couplings and the apparatus for raising or lowering
the propeller and frame work.
Two main driving or propeller shafts A. and B. are provided the upper one A. is
placed in the position a propeller shaft would occupy in a modern steam ship, whilst
the lower one B. is placed diagonally as shewn in Figs. 1 and 2. the length and angle
of same depending on the available space and positions of engines. The propeller C.
is carried by a short shaft, ( rotating in bearings D. D. provided on or made
with a sliding frame E. E. At one end of the shaft, the usual disengageing
Coupling F. is fixed having a suitable recess cut in it for a projection on the end of
the main shafts A. or B. to take.
The sliding frame E. E. is made with projections on each side to slide down and be
guided by the rudder post G. and the stern post G¹. These posts G and G¹ are made
parallel to each other, and are curved to such a radius that the disengaging coupling F.
on the short shaft C may thrust evenly on the face of the other portion of coupling
whichever shaft it is geared to.
With some classes of ships the shafts A. and B. may lay parallel with each other
instead of diagonal as illustrated, then the edges of the stern and rudder posts G¹ and G.
will require to be straight.
In putting this invention into practice the stern and rudder posts will require to be
made very much stronger than usual, as the two sides cannot be coupled together at
their bottom ends, and also to be sufficiently strong to withstand the vibration caused
by the rotation of the propeller when driving the ship.
The rudder post G. is provided with a cavity or slot way in which the end of the
propeller shaft slides up or down as required.
The stern frame may be made in a variety of ways to suit different circumstances,
thus for example with some classes of ships the rudder post G. may be constructed
so as to allow the end of the short shaft C¹ to slide therein and also a similar
opening may be provided for the same purpose in the stern post G₁ which as illus-
trated is provided with guides to take on each side of the shaft C. as well as having
a suitable rib G2 for carrying the stern tubes and ships plating, sufficient space
being left between the post G and rib G to allow of the before mentioned disen-
gaging coupling working.
The shafts A. and B. may each be provided with the usual thrust bearings and
may also have friction or other classes of disengaging couplings thereon, so that
either shaft to which the propeller is engaged may be driven independently of the
other one.

page_text: The shaft may be driven by separate engines or one may be rotated from the other
by toothed gearing or other suitable means.
I would have it understood that I may modify the general arrangement of the
various parts to suit different classes and builds of ships without departure from
the essential features of my invention.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I would have it understood that 1
make no general claim to the idea of being able to raise or lower a ship's propeller
below the line of keel as I am aware this has been accomplished before but what I do
claim is :-
1. In propelling steam ships by a screw propeller the application of a framework
sliding and guided between the rudder post and stern post carrying a short propeller
shaft provided with a disengaging coupling capable of gearing with an upper or lower
shaft substantially as described and for the purpose specified.
2. In the propulsion of steam ships by a screw propeller the combination of a
second or lower lying shaft placed either diagonally or parallel with the shaft A.
having a disengaging coupling for actuating a screw propeller capable of being raised
or lowered as required for the purpose specified substantially as described and
illustrated.
Dated this 21st day of March 1888.
WILLIAM SCOTT PRICE.
Per pro Hector McLean,
By power of Attorney dated 24th February 1888.