IMPROVEMENTS IN THE PROPULSION, STEERING, AND MANŒUVRING Or STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF PROPELLERS AND MECHANISM THEREFOR."
Year: 1881

page_text: "
LETTERS PATENT to John Neil and John Lorimer Corbett, both of the City
of Glasgow, in the County of Lanark, North Britain, for an Invention of
IMPROVEMENTS IN THE PROPULSION, STEERING, AND MANŒUVRING Or
STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF PROPELLERS AND
MECHANISM THEREFOR."
PROVISIONAL SPECIFICATION left by the said John Neil and John
Lorimer Corbett at the Office of the Commissioners of Patents on the 25th May
1881.
JOHN NEIL and JOHN LORIMER CORBETT, both of the City of Glasgow, in the
County of Lanark, North Britain. "IMPROVEMENTS IN THE PROPULSION, STEERING,
AND MANOEUVRING OF STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF
PROPELLERS AND MECHANISM THEREFOR."
This Invention relates to an improved means of propelling, steering, and
manoeuvring steam ships, and to the construction of propellers or propelling
appliances therefor, the object of which is to ensure high speed with a minimum
expenditure of driving power, great facility for steering and manoeuvring vessels,
greater carrying capacity of the vessel, entire absence from vibration, and ready
means of unshipping and refitting the propellers when an accident occurs.
In carrying out the Invention we employ a novel construction of propeller
consisting, according to one modification, of two or more screw blades, the points of
which are broader than the roots or central parts, with the sides converging towards
the central boss in straight or nearly straight lines. A two bladed propeller of this
construction thus resembles a long flat plate narrowed towards the centre and
twisted on either side of the centre to form a screw or oblique blade, preferably
increasing in pitch towards the point. The object of so forming the propeller
blades very broad at the tips or points is to obtain a large acting surface where the
sweep and pitch of the blade is greatest, and thus obtain a very powerful effect.
A four bladed propeller is, by this Invention, formed of two such double blades
with a large central boss cast or fitted between them so that the blades do not all
converge towards each other on the boss as usual, but each pair of blades is distinct
and separate.

page_text: The improved propellers may be fitted on a horizontal propeller shaft or shafts
as single or twain screws at the stern of the vessel as usual, but we prefer to fit the
propellers nearly amidships, one on each side of the vessel, and drive them from
vertical shafts by means of an arrangement of appliances and devices which
constitute an important part of our Invention. In a modification of this arrange-
ment, with which ordinary screw propellers may be used if preferred, each propeller
is fitted on a large stud or spindle fitted at the lower end of a strong bracket piece
formed or fixed on a tubular shaft through which the main vertical driving shaft
passes. The central boss of the propeller, which may form a thrust block on the fixed
stud, has a bevil wheel or pinion fitted or formed on its inner side to gear into and be
driven by a similar pinion or wheel on the lower end of the main vertical driving
shaft. The main shaft on each side of the vessel may be driven separately or both
be driven together, either direct as crank shafts of motive-power engines, or by
means of suitable gearing within the vessel; but the hollow shafts carrying the
propellers at their lower ends are fitted with drums or chain pulleys at their upper
ends, round which chains are passed and connected to a steering wheel, and retaining
screws, ratchets, or clutches are provided for holding the hollow shafts and propellers
in any position. The propellers have a normal position directly astern of the
driving shafts, in which they remain when the vessel is to go ahead steadily; but
for reversing, the hollow shafts are merely turned one half of a revolution by means
of the steering wheel and gear to bring the propellers to a position directly ahead
of the vertical driving shafts. In this reversed position the propellers will drive
the vessel in the opposite direction or astern without the engines being reversed or
stopped. By thus changing the position of the propellers relatively to the driving
shafts, or in a horizontal plane round the driving shafts as a centre the vessel may
be steered in its course, or it may be made to turn on itself as a centre, or with a
sweep; or by turning the propellers through a quarter of a revolution in the same
direction, the vessel may even be propelled broadside on, so that by means of the
improved arrangement described a vessel may be steered and manoeuvred to an
extent never hitherto attained by the use of screw propellers.
! For the purpose of enabling the propellers to work freely without fitting them at
some distance below the vessel, where they might be injured when the vessel should
come into port or be in shallow water, the vessel is made of extra breadth of beam
with flat bottom, and hollowed on each side amidships where the propellers are
fitted. The keel of the vessel is considerably lower than the centre of revolution of
each propeller, and the bottom is curved to allow of free flow of the water towards
and from the propellers, so that the bottom presents the appearance of their being
two vessels in line united at the keel and near the water line. The propellers are
fitted in the recesses thus formed for them, with the outer shafts by preference
fitted through a movable plate in the ship's bottom at about a level with the
water line, so that by the removal of this plate the propeller and shafting can be
hoisted into the vessel for repair or renewal, and replaced without great risk or
danger.
In order to relieve the driving shaft of the thrust due to the action of the
propeller, a strong forked bracket is jointed to the lower end of the tubular shaft
or bracket carrying the propeller, and extends upwards to the vessel's bottom,
where each forked end is fitted with a small roller or pulley running in a circular
groove or on a rail formed on or fixed to the flat bottom part of the vessel.
bracket or fork moves round in a horizontal plane with the propeller when its
position is altered for steering or manoeuvring and thus takes up the thrust of the
propeller in any position in which it may happen to be.
This
Instead of driving the propellers by means of bevil gearing as hereinbefore
described the propeller shafts may be connected to the main driving shafts by means
of double ball and socket or other universal joints, and driven without the intervention
of toothed gearing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Neil and John Lorimer Corbett in the Great Seal Patent Office
on the 24th November 1881.
JOHN NEIL and JOHN LORIMER CORBETT, both of the City of Glasgow, in the
County of Lanark, North Britain. "IMPROVEMENTS IN THE PROPULSION, STEERING,
AND MANOEUVRING OF STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF
PROPELLERS AND MECHANISM THEREFOR."
Our said Invention relates to an improved means of propelling, steering, and
manoeuvring stean ships, and to the construction of propellers or propelling
appliances therefor, the object of which is to ensure high speed with a minimum
expenditure of driving power, great facility for steering and manoeuvring vessels,
greater carrying capacity of the vessel, entire absence from vibration, and ready
means of unshipping and refitting the propellers when an accident occurs.
And in order that our said Invention and the manner of performing the same
may be properly understood we have hereunto appended for that purpose a Sheet
of explanatory Drawings to be bereinafter referred to, and representing our
improved propelling appliances as fitted to a steam ship, and also in part separately.
In these Drawings the same reference letters are used to mark the same or like
parts where repeated in the several Figures.
Figure 1 of the Drawings is a transverse vertical section of a steam ship as fitted
with our improved propellers and mechanism for driving, steering, and manoeuvring
the vessel, and Figure 2 is a plan of the same showing more particularly the driving
and steering gear; Figures 3 and 4 are respectively a side elevation and a longi-
tudinal vertical section of the steam engine, which is shown as driving the
propelling appliances; Figures 5 and 6 are end and side elevations of a modification
of our improved propellers; Figure 7 is an elevation, and Figure 8 a plan of a
peculiar construction of ship or vessel we have designed, and which is specially
adapted for the application of propellers fitted amidships in the manner hereinafter
described; and Figure 9 is cross section of this vessel taken as at the line 1-1 in
Figure 7.
In carrying out the Invention we employ a novel construction of propeller
consisting, according to one modification, of two or more screw blades A, the
points a of which are broader than the roots or central parts a¹, with the sides
converging towards the central boss in straight or nearly straight lines. A two
bladed propeller of this construction, such as is shown applied in Figure 1, thus
resembles a long flat plate narrowed towards the centre, and twisted on either side
of the centre to form a screw or oblique blade A, preferably increasing in pitch
towards the point a. The object of so forming the propeller blades very broad at
the tips or points a is to obtain a large acting surface where the sweep and pitch of
the blade is greater, and thus obtain a very powerful effect. A four bladed
propeller, of which an example is shown in Figures 5 and 6, is by this Invention
formed of two such double blades A with a large central boss A' cast or fitted
between them, and which is fitted on the propeller shaft A², so that the blades A
do not all converge towards each other on the boss A' as usual, but each pair of
blades A is distinct and separate, although the blades may be made to converge
towards one centre.
The improved propeller A, A', may be fitted on a horizontal propeller shaft or
shafts as single or twin screws at the stern of the vessel as usual and as is indicated
in Figure 6, but we prefer to fit the propellers nearly admidships, as indicated in
Figures 1 and 2, one on each side of vessel, and drive them from vertical shafts B, B,
by means of an arrangement of appliances and devices which constitute an important

page_text: part of our Invention, and which we shall presently describe. In a modification of
this arrangement, with which ordinary screw propellers may be used if preferred,
cach propeller A is fitted on a strong stud or spindle a fitted at the lower end of a
strong bracket piece formed or fixed on a tubular shaft B', through which the main
vertical driving shaft B passes. The central boss A' of the propeller A (which may
form a thrust block on the fixed stud) has a bevil wheel or pinion C fitted or cast
on its inner side to gear into and be driven by a similar pinion or wheel C' fitted
on the lower end of the main vertical driving shaft B. The main shaft B on each
side of the vessel V may be driven separately, or both be driven together, either
direct as crank shafts of motive-power engines, or by means of suitable gearing
within the vessel, which in the case of small yachts or launches may be operated
by hand or foot power.
In the modification shown in Figures 1 and 2, the shafts B actuating the
propellers are fitted at their upper ends with spur wheels E in gear with a large
spur wheel E' placed intermediately and carried on a vertical shaft e in journal
bearings in a strong bracket or standard F, which also supports the shaft g of the
motive-power engine G from which the spur gearing E, E, is driven by means of
a bevil wheel H on the engine shaft g in gear with a bevil pinion H' at the lower end
of the vertical shaft c. Other arrangements of driving gear may obviously be used
for actuating the shafts B, B, and propellers A. The hollow shafts B', B', to which
the propellers are fitted by means of the studs A', and which form journal bearings
at the top and botton b, b', for the central shaft B, have pinions I fixed at the
upper end, the teeth of which engage in teeth on segments I¹ fixed on centre pins
or studs i, i, and formed with slotted lever arms I', in the slots of which there are
fitted pins on a screw nut j' carried on transverse screw shafts working each
segment I'. The one shaft J has a right hand screw, while the other J' has a left
hand screw, so that while the shafts J, J¹, are turned in opposite directions they
may actuate the segmental arms I and segments I' in the same direction, both
shafts J, J', being driven by a bevil wheel K in gear with bevil pinions K', K², on
these shafts J, J, and actuated by a hand wheel K³ on the shaft on which the
bevil wheel K is fitted. Instead of the arrangement just described, the hollow
shafts B carrying the propellers on the studs A at their lower ends may be fitted
with drums or chain pulleys at their upper ends, round which chains may be passed
and connected to a steering wheel, by means of which the propellers are shifted to
any position round the central driving shafts retaining screws, ratchets, or clutches,
being provided for holding the hollow shafts and propellers in any position. The
action of thus turning the segments I and pinions I on the tubular shafts B', B',
carrying the propellers A, A, is to shift the propellers to any radial position round
the vertical shafts for the purpose of driving the vessel ahead or astern, or for
steering and manoeuvring. The propellers have a normal position directly astern
of the driving shafts B, B, in which they remain when the vessel is to go ahead
steadily, but for reversing the hollow shafts B', B', are merely turned one half of
a revolution by means of the steering wheel and gear to bring the propellers to a
position directly ahead of the vertical driving shafts B, B. In this reversed
position the propellers will drive the vessel in the opposite direction or astern
without the engines being reversed or stopped. By thus changing the position of
the propellers A, A, relatively to the driving shafts B, B, or in a horizontal plane
round the driving shafts B, B, as a centre, the vessel may be steered in its course,
or it may be made to turn on itself as a centre, or with a sweep; or by turning the
propellers A through a quarter of a revolution in the same direction, the vessel
may even be propelled broadside on, so that by means of the improved arrangements
described, a vessel may be steered and manoeuvred to an extent never hitherto
attained by the use of ordinary screw propellers.
For convenience of illustration, the propellers fitted in the vessel, shown in
Figure 1, are placed so that the one is propelling the vessel forward, while the other
is propelling side-ways, the one hollow shaft B being a quarter of a revolution in
advance of the other. To enable the propellers to be shifted simultaneously from

page_text: such a position, or when in the position in which the one is propelling forward
while the other is propelling aft, an additional pin " is provided on the screw nut
actuating the segment I and pinion I, and the lever arm Is is jointed so that it can
be lifted out of action, while by means of the steering wheel the one propeller is
turned round, say, from the aft to the forward side of the shaft B, and the lever
arm 1 is then dropped down to let the slot fit over the second pin " in the screw
nut which by the action of the steering wheel has been traversed under it.
the lever arm I is on this second pin j¹¹ the working of the steering wheel will
turn both propellers together, but the one propeller will be half a complete turn in
advance of the other. Other simple mechanical devices and arrangements may be
used for effecting this change in the relative positions of the propellers.
When
For the purpose of enabling the propellers to work freely without fitting them
at some distance below the vessel, where they might be injured when the vessel should
come into port or be in shallow water, the vessel is by preference made of extra
breadth of beam with flat bottom, as indicated by the dotted lines in Figure 1, and
hollowed on each side amidships at VI, where the propellers are fitted, as indicated
in Figures 7, 8, and 9. The keel of the vessel may be lower than the centre of
revolution of each propeller, and the bottom is curved to allow of free flow of the
water towards and from the propellers, so that the bottom presents the appearance
of there being two vessels in line, united at the-keel and near the water line.
propellers are fitted in the recesses thus formed for them, with the outer shafts by
preference fitted through a movable plate or a well formed through the ship's
bottom at about a level with the water line, or with the upper end of the well above
the water line, so that the propeller and shafting can be lifted into the vessel for
repair or renewal, or when the vessel is under sail, and replaced without great risk
or danger..
The
In the arrangement shown in Figure 1 for thus withdrawing the propellers, a
deep cylindrical or other well L is formed through the ship's bottom for cach
propeller and fitted with a cover L', which forms a journal bearing and stuffing box
for the shaft B¹ which passes through it. A plate L2, also forming a journal bearing
for the shaft B, is fitted at the bottom of the well L to prevent the inflow of water.
The propellers and their shafting may either be bodily lifted out through these
wells L, L, or a rack and pinion or a screw nut may be fitted at one side of the
stuffing box journal through which the shaft passes, and have a screw working
through it to raise and lower the propeller shafts and propellers. When the
propellers are lifted out a plug may be fitted at the bottom of the well L.
The propellers are shown as driven by means of a peculiar construction of engine,
which is illustrated in Figures 3 and 4, and which is actuated by means of steam
admitted alternately at both ends of a long cylinder fitted with two pistons con-
nected together by rods, and also fitted with connecting rod to a crank shaft passing
through a chamber in the centre of the cylinder, through which chamber also the
steam is exhausted. This engine does not however form part of our present
Invention, and the propellers may be driven by any ordinary construction of
motive-power engine.
In order to relieve the driving shaft of the thrust due to the action of the
propeller, a strong forked bracket may be jointed to the lower end of the tubular
shaft or bracket carrying the propeller, and when fitted would extend upwards to
the vessel's bottom, where each forked end would be fitted with a small roller or
pulley running in a circular groove or on a rail formed on or fixed to the flat bottom
part of the vessel. This bracket or fork would move round in a horizontal plane
with the propeller when its position is altered for steering or manoeuvring, and
thus take up the thrust of the propeller in any position in which it may happen to
be. When the keel of the vessel is lower than the tips of the propeller blades,
stays may be led from the keel to the lower ends of the driving shafts and form
bearings for them.
Having thus particularly described our said Invention, and the manner of
performing the same, we desire it to be understood that we do not restrict our-

page_text: selves to the precise details herein described or delineated, but what we believe
to be novel and original, and therefore claim as the Invention secured to us by
the hereinbefore in part recited Letters Patent is,-
First. The construction of ships' propellers, of which the blades are formed with
the screw pitch increasing towards the points, and with or without a central
separating boss, substantially as herein described and as shown in the accompanying
Drawings.
Second. The general arrangement or construction and combination of the parts of
apparatus for propelling ships or vessels, in which the propellers are arranged
amidships, and driven by rotating shafts passing through hollow shafts which
carry the propellers, and which can be turned to bring the propellers into any
position in relation to the driving shafts and to each other for the purpose of
steering the vessel, substantially as herein described in reference to the accom-
panying Drawings.
Third. The construction of ships or navigable vessels driven by propellers, with
the sides hollowed or cut away amidships to form recesses for the working of the
propellers on each side of the vessel, the bottom and sides being so formed as to
allow the water to flow freely towards and from the propellers, substantially as
herein described, and as illustrated in Figures 7, 8, and 9 of the accompanying
Drawings.
In witness whereof, we, the said John Neil and the said John Lorimer
Corbett, have hereunto set our hands and seals, this Twenty-second day of
November, in the year of our Lord One thousand eight hundred and eighty-
one
JOHN NEIL.
(L.S.)
Witness,
WALLACE FAIRWEATHER, C.E.,
Of W. R. M. Thomson & Co.,
Patent Agents,
Glasgow.
JOHN LORIMER CORBETT. (LS.)