Improvements in the Propulsion of Ships or Vessels and in Machinery therefor.
Year: 1887

page_text: Date of Application, 22nd Feb., 1887
Complete Left, 21st Nov., 1887
Complete Accepted, 23rd Dec., 1887
Improvements in the Propulsion of Ships or Vessels and in
Machinery therefor.
I, WILLIAM MACGOWAN, of Lorne Place, Ardrossan, Ayrshire, Shipmaster, do
hereby declare the nature of my invention to be as follows:-
My said invention has reference to the improved construction of propelling
mechanism, or the arrangement and combination of the parts thereof, for the propulsion
of sailing ships, steamers, or vessels, by auxiliary steam or other motive-power
engines, to be used in the case of sailing vessels during calms, or in lieu of tug
assistance while entering or leaving ports, or during light winds to maintain a mean
speed during a passage from one port to another; to be used also in the case of
steamers or vessels in which sail power is more an auxiliary and the motive power of
engines the principal means of propulsion, when the machinery breaks down. The
propeller at rest and in position would have little or no resistance to the forward
motion of the vessel. To be used also in the case of war vessels so that they may be
used as perfect ships or perfect steamers combined or separately. In this case the
propeller at rest and in position may have no resistance to the forward motion of the
vessel when propelled by sails only; also doing away with the large space forward of
stern post necessary for the revolution of the ordinary propeller, or raising same out
of the water when not in use; the said large space having the effect of almost
neutralising the action of the rudder and rendering war-ships and other auxiliary
vessels more unmanageable while under sail only, than by the present improvements.
My invention comprises a new and improved construction of propeller and propeller
shaft and mode of fitting these to each other and to the stern of the vessel, so that the
propelling blades may be swivelled and set from the inside of the vessel to any desired
angle or pitch to act properly as a screw paddle propeller, to suit the maximum speed
of the ship possible for the time being and in a variable or fixed ratio to the power of
engines available. And further, to set the propelling blades to feather in line fore
and aft with the stern post and line of keel when not required for propulsion; and
also the other parts of the propeller as a whole, in such a position as to present the

page_text: least possible resistance to the forward motion of the vessel, namely, in line with the
deadwood and keel when the vessel is under sail or not using the propeller. My
invention further comprises the arrangement and combination of the parts of the now
and improved mechanism for effecting the said auxiliary propulsion of vessels.
The nature and novelty of my invention consist all as follows:-First, in forming
the propeller of two nearly flat propelling blades, preferably of an improved super-
ficial shape, each formed on or secured to the outer end of its carrying and actuating
radial arm or spindle. These two spindles of the acting blades or propellers are
mounted exactly opposito each other, in a straight radial line at right angles to and
through the axial line of the propeller shaft and its large carrying boss, so as to swivel
within or on bearings in cross arms formed in corresponding right angular radial
line on the boss, which would be overhung outside the stern post and its stern neck
bearing and tube, through both of which the propeller shaft would be passed forward
from the stern outside, to have its forward end coupled to and driven by the thrust
or other shaft connected to the crank shaft of the engine. In this way both the radial
arms of the shaft on the boss and the radial spindles of the propellers, could all be
turned and set in line behind the deadwood and stern post, which would be straight
or nearly so, only having recesses formed in it at the stern edge, to allow clearance
for the forward part of the propeller blades and their radial carrying cross arms formed
on and projecting out from the centre of the boss. The rudder swivelling post or
spindle of the helm would be hung in a usual manner by its pintles in their gudgeons
or carrying blocks secured to the stern post, which would have corresponding recesses
formed in the swivel edge of its franie sufficient (when set to port or starboard) to
clear the blades of the propeller and the rotating parts projecting abaft the stern post.
To effect the angling and feathering of the two propeller blades, as stated, by one
arrangement the boss would have a large cylindrical recess bored in it from the
outer stern end in line with the axis of its shaft fitted with a screwed-on water tight
end cover. A small tubular hole would be bored from the large hole right through
the whole length of the shaft in its axial line. Through this hole in the propeller shaft
a long bar or spindle is fitted loosely but in guide bushes at each end so as to be
traversed to-and-fro longitudinally for a short distance by a screw wheel working on
its screwed inner end (or other equivalent) within an open part of the coupling to
which the inner or forward end of the propeller shaft is secured. This reciprocating
rod or bar would have a crosshead on its after end working within the large hole in
the propeller boss, and would be coupled by a lateral pin and slot with sliding bush to
a disc made circular on the back to suit the curve of the internal recess of its boss, or
a segment, or lever secured on the inner end of each spindle of the propeller blades
projecting down into the recess in the boss for that purpose on each side of the cross-
head; so that the motion of the crosshead and its rod, as stated, by the screw inside
the ship, would angle the blades equally to give any desired propelling force when the
shaft is turned, or feather them fore and aft in line with the keef to have no propelling
effect when the propeller shaft is held stationary; in which case the cross arms and
propeller blades would be set and held by the engine, in the vertical plane of the
deadwood and end of keel and stern post, and so give little or no resistance to the
motion of the ship when propelled by the wind and its sails. The inner end of
the propeller shaft would be made polygonal, and would be shipped into the open end
of a strong hollow coupling of the same shape, and to prevent motion at the coupling
it might be split at the socket end and have a slight taper outside, with a strong steel
ring driven over it so as to grip the socket close on the polygonal end of the propeller
shaft. The inner end of the coupling would preferably be formed solid with or on the
driving shaft, and have an open recess on one or both sides at the part where the
screw wheel was worked on the inner end of the shifting or feathering rod, this screw
wheel or nut turning in recesses within the coupling, and might be actuated by a
lever inserted into radial holes in the periphery of the screw wheel or nut to angle or
feather the propelling blades as before described. An important improvement of the
invention for this auxiliary propelling gearing, consists in forming or mounting the
flat propelling blades at the outer ends of their swivelling stems and cross carrying

page_text: arms, and in making these arms as long as convenient to give the blades as great a
radial and circumferential action as the draught of the vessel would conveniently allow
to keep the blades fully immersed, to give the advantages of having a small area of
propelling blade and comparatively slower rotation of the propeller shaft and blades
than could be advantageously got by ordinary screw propellers with small auxiliary
engines, and screw propellers of the ordinary construction with numerous blades all
secured close to the boss of the propeller shaft.
An improved construction of the flat propelling blades, consists in making them
nearly circular at the inner propelling part next their stems, gradually increasing
sternways and outwards in a parabolic curve to about a third greater at their outer
extremity, nearly in radial line with their stem, where it might die away from the
curved point to the circle at the forward edge of the blade, so that when these pro-
peller blades are angled and rotated, the water would first meet the forward lower
broad part of the blade, and pass across it in curved lines over the surface towards
the aft and outer extended part of the blade as forced from it. Other forms of blades
may however be adopted, with approximately good results, but in any case these
blades would be formed at the extremity of the cross arms of the propeller to act more
as angled paddle blades than as the ordinary true screw propeller blades, all as herein-
before stated. These blades and their stems would preferably be formed of the best
steel or bronze metal, which would give strength and lightness; and the new cross
arms and boss carrying these, although described as formed in one with the propelling
shaft, might be formed separately of bronze metal, and bolted to a large flange on the
stern end of the steel propeller shaft. And the motive power engines would preferably
be ranged in a compartment of the after part of the ship, as near to the propeller
shaft as possible, whilo the boilers and coal bunkers might be fitted in a compartment
further forward, which would not interfere with the cargo holds of the ship, and have
the steam led back in lagged pipes to the engine.
Although I have only described one simple arrangement of reciprocating rod with
crosshead and disc or segmental levers, with pins within the hollow boss of the pro-
peller shaft for turning the inner spindle end of the propelling blades to angle and
feather these, it is to be understood that any equivalent or other feathering arrangement
heretofore used for so swivelling and setting screw propeller blades from the inside of
the ship, may be employed.
The main or substantive parts of the invention consist in the new construction of
propeller with large boss on stern end of propeller shaft outside stern post, formed
with strong cross head or cross lateral armis, carrying at their outer extremity the
angled paddle or screw acting blades, preferably on spindles swivelling within the
cross arms, all so as to admit of the whole propeller and its blades being set and held
in line with the keel behind the dead wood and stern post to present the least possible
resistance when the vessel is to be propelled by sails alone. And further in the
improved construction of the angled propeller blades, which would be as nearly flat as
possible, only strengthened convexly on one or both sides in the axial line of their
spindles, and tapered away sharp all round towards the outer edges. The superficial
form of cach propeller blado in its new construction would be that of a circle nearest
the cross arms, having a half crescent superimposed aft and outwards beyond the
radial line of its axis to give increased acting surface at an angle of 45 degrees through
the centre of the axis and circle of the blade.

page_text: Improvements in the Propulsion of Ships or Vessels and in
Machinery therefor.
I, WILLIAM MACGOWAN, of Lorne Place, Ardrossan, Ayrshire, Shipmaster, do
hereby declare the nature of my invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following state-
ment in writing, reference being had to the accompanying Two Sheets of Drawings,
and to the letters and figures marked thereon, that is to say :-
My said Invention has reference to the improved construction of propelling
mechanism, or the arrangement and combination of the parts thereof, for the
propulsion of sailing ships, steamers, or vessels, by auxiliary steam or other motive-
power engines, to be used in the case of sailing vessels during calms, or in lieu of
tug assistance while entering or leaving ports, or during light winds to maintain a
mean speed during a passage from one port to another; to be used also in the case of
steamers or steam yachts or other vessels in which sail power is more an auxiliary
and the motive power of engines the principal means of propulsion, when the
machinery breaks down. The propeller at rest and in position would have little or
no resistance to the forward motion of the vessel. To be used also in the case of war
vessels so that they may be used as perfect ships or perfect steamers combined or
separately. In this case the propeller at rest and in position may have no resistance
to the forward motion of the vessel when propelled by sails only; also doing away
with the large space forward of stern post necessary for the revolution of the ordinary
propeller, or raising same out of the water when not in use; the said large space
having the effect of almost neutralising the action of the rudder and rendering war-
ships and other auxiliary vessels more unmanageable while under sail only, than by
the present improvements.
My invention comprises a new or improved construction of propeller and propeller
shaft, and mode of fitting these to each other and to the stern of the vessel so that the
propelling blades and their crosshead may be swivelled and set from the inside of the
vessel to any desired angle or pitch to act properly as a screw paddle propeller, to
suit the maximum speed of the ship possible for the time being and in a variable or
fixed ratio to the power of engines available. And further, to set the propelling
blades to feather in line fore and aft with the stern post and line of keel when not
required for propulsion; and also the other parts of the propeller as a whole, in such
a position as to present the least possible resistance to the forward motion of the
vessel, namely, in line with the deadwood and keel when the vessel is under sail or
not using the propeller. My invention further comprises the arrangement and com-
bination of the parts of the new and improved mechanism for effecting the said full
propulsion or auxiliary propulsion of vessels.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended two explanatory Sheets of Drawings, in which the same reference letters
are used to indicate corresponding parts in all the Figures where shown. Figure 1
on Sheet 1 is a sectional elevation to a small scale of the stern end of a steam ship S,

page_text: showing the general arrangement of the steam boilers T, and motive power
engines T', T3, T, in their respective compartments S1, S2, near to and for driving
the new screw propeller and its shafting A A' and B B¹ and fittings, all constructed
in accordance with and illustrative of one modification of my invention and its
improvements. Figures 2 and 3 on Sheet 2, are a sectional elevation and end view
respectively of my new or improved screw propeller and its driving shaft and fittings
to a larger scale, to show the details of construction of the improvements more
clearly than can be seen in the general view in Figure 1. Figure 4 shows a sectional
end view of the crosshead B, of the propeller through its boss B³, on the line 1--1
in Figure 2, to show the mode of feathering the blades; while Figure 5 is a horizontal
section taken on the line 2--2 in and corresponding to Figure 2; and Figures 6
and 7 are transverse sections on the lines 3--3 and 4--4 in Figure 2.
Referring to these Drawings, the nature and novelty of my invention consist all as
follows: First, in forming the propeller of two nearly flat propelling blades A A,
preferably of an improved superficial shape, each formed on or secured to the outer
end of its carrying and actuating radial arm or spindle A¹ A¹. These two
spindles A¹, A', of the acting blades or propellers A, A, are mounted exactly opposite
each other within bushes in a hollow crosshead B, in a straight radial line at right
angles to their propelling shaft B' to cause these propeller blades A and crosshead B
to clear the stern post s of the vessel S, and their after projecting parts clear of the
rudder R. To effect the angling and feathering of the two propeller blades A, A, as
stated and as shown dotted in in Figure 5, by one arrangement the boss B2 of the
crosshead B, has a large cylindrical recess b bored in it from the outer stern end, in
line with the axis of its shaft B¹ preferably spheroidal at the inner end and fitted
with a screwed-on water tight cover b¹ at the outer end. A small tubular hole is
bored from this large hole 6 right through the whole length of the shaft B' in its axial
line and partly into its coupled driving shaft D D'. Through this axial hole in the
propeller shaft B¹, a long bar or spindle Cis fitted loosely, but in guide bushes at
one or both ends so as to be traversed to-and-fro longitudinally for a short distance
by a screw wheel D2 working on its screwed inner end C (or other equivalent) within
an open part D11 of the coupling end of the shaft D¹, as seen particularly in
Figures 2, 5 and 7, to which the inner or forward end of the propeller shaft B¹ is
secured. This reciprocating rod or bar C has a crosshead C¹ on its after end working
within the large hole 6 in the propeller boss B' and is coupled by a lateral slot c and
pin c¹ in and to a spheroidal disc or boss A² screwed or otherwise secured to the inner
ends of each of the oscillating or feathering spindles A¹; the discs being spherical or
circular on their back to suit the curve of the internal recess b, of the boss B² and a
retaining block 62 in two parts, secured in position by the outer water tight cap b', a
slot or recess being formed between the end discs A³ for the crosshead "C" to
reciprocate to-and-fro longitudinally with the bar C, within the hollow boss b, all as
seen particularly in Figures 2, 4, and 5. Or otherwise instead of the disc bosses A², A²,
a segment or lever with links or other equivalent may be used, secured on the inner
end of each spindle A' of the propeller blades A projecting down into the recess b in
the boss B for that purpose on each side of the crosshead C, all so that in either
case the motion of the crosshead C¹ and its rod C, as stated, by the screw wheel D'
fitted in the driving shaft D D', of the propeller shaft B' would angle the blades A
equally in opposite directions to give any desired propelling force when the
shafts B B are turned, or feather them fore and aft in line with the keel to have no
propelling effect when the propeller shaft B is held stationary as indicated particularly
in Figure 5; in which case the crosshead B, B, and propeller blades A, A, would be
set and held by the engine, in the vertical plane of the deadwood and stern keel,
and so give little or no resistance to the motion of the ship S when propelled by
the wind and its sails as seen in this position in Figure 1. The inner end of the
propeller shaft B¹, is preferably made polygonal at B", and shipped into the open
end of a strong hollow coupling D₁, of the internal motive shaft D from
the engine, and to prevent motion at the coupling D it might be split
at the socket end and have a slight taper outside, with a strong steel ring D'

page_text: driven over it so as to grip the socket D¹, close on the polygonal end B₁ of the
propeller shaft B¹. The inner end of the coupling D¹ is preferably formed solid
with or on the driving shaft D, and has a recess in the shaft at D¹¹, open at one
or both sides at the part where the screw wheel D³, is worked on the inner
screwed end of the shifting or feathering reciprocating rod C. This screw wheel
or screw nut D2 is turned in its recess D" within the coupling D¹, by a lever
inserted into radial holes d in the periphery of the screw wheel nut D2, to
reciprocate the rod C and so angle or feather the propelling blades A us before
described. An important improvement of the invention for this auxiliary propelling
gearing, consists in forming or mounting the flat propelling blades A, A, at the
outer ends of their swivelling or feathering stems A¹, A¹, and cross carrying
arms B, B, and in making these arms as long as convenient to give the blades A
as great a radial and circumferential action as the draught of the vessel S would
conveniently allow to keep the blades A fully immersed, to give the advantages
of having a small area of propelling blade and comparatively slower rotation of
the propeller shaft B₁ and blades than could be advantageously got by ordinary
screw propellers with small auxiliary engines, and screw propellers of the ordinary
construction with numerous blades all secured close to the boss B³ of the propeller
shaft.
An improved construction of the flat propelling blades A A, consists in making
them nearly circular at the inner propelling part next their stems A¹ A¹ gradually
increasing sternways and outwards in a parabolic curve to about a third greater
at their outer extremity a nearly in radial line with their stern, where it might
die away suddenly from the extreme curved point a to the circle at the forward
edge a² of the blade A and gradually with a larger radius or curve to the rear
edge of the blade a¹, so that when these propeller blades A A, are angled and
rotated, the water would first meet the forward inner broad part a³, of the blade, and
pass across it in curved lines over the surface towards the aft and outer extended
parts a, a, of the blade as forced from it, and as indicated in dotted lines at a* in
Figure 2. Other forms of blades may however be adopted with approximately
good results, but in any case these blades would be forined at the extremity of
the cross arms A¹ A¹, of the propeller to act more as angled paddle blades than
as the ordinary true screw propeller blades, all as hereinbefore stated. These
blades A, A, and their stems A¹, A¹, are preferably formed of the best steel or
bronze metal, which will give strength and lightness; and the cross arms A¹, A¹,
and boss B2 and crosshead B, B, carrying these, although described as formed in
one with the propelling shaft B', might be formed separately of bronze metal,
and bolted to a large flange on the stern end of the steel propeller shaft B¹ in
line with the deadwood round the shaft B¹, to give the least possible friction in
passing through the water. And the motive power engines T¹, T2, T³, are preferably
of the triple cylinder expansive class, ranged in a compartment S2 of the after part
of the ship S, as near to the propeller shaft as possible, while the boilers T and coal
bunkers might be fitted in a compartment S₁ further forward which would not
interfere with the cargo holds of the ship, and have the steam led back in lagged
copper pipes to the engine. Figures 8 and 9 show a sectional elevation and end
section of a solid close ended coupling D¹ on the end of the driving shaft 1), slightly
different in construction from that shown in Figures 2 and 5 for securing the inner
polygonal end B11 of the propeller shaft B¹ by means of a split disc or ring D,
bolted to the flange end of the coupling D¹¹.
Although I have only described one simple arrangement of reciprocating rod C
with crosshead and discs or segmental levers A2 with pins within the hollow
boss B2 of the propeller shaft B₁ for turning the inner spindle ends of the propelling
blades A A, to angle and feather these, it is to be understood that any equivalent or
other feathering arrangement heretofore used for so swivelling and setting screw
propeller blades from the inside of the ship, may be employed.
The main or substantive parts of the invention consist in the new construction of
propeller A A, with large boss B' on stern end of propeller shaft B¹ outside stern

page_text: post, formed with strong cross-head or cross lateral arms B B carrying at their
outer extremity the angled paddle or screw acting blades A, A, on axial spindles A¹A¹
swivelling within the cross arms B B, all so as to admit of the whole propeller and its
blades A A being set and held in line with the keel behind the deadwood and stern
post to present the least possible resistance when the vessel is to be propelled by sails
alone. And further in the improved construction of the angled propeller blades A A,
which would be as nearly flat as possible, only strengthened convexly on one or both
sides in the axial line of their spindles A¹ A, and tapered away sharp all round
towards the outer edges a to a³. The superficial form of each propeller blade AA
in its new construction would be that of a circle nearest the cross arms A¹ A¹ having
a half crescent superimposed segment aft and outwards beyond the radial line of its
axis to give increased acting surface at an angle of 45 degrees through the centre of
the axis and circle of the blade.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is
First. The construction, or general arrangement and combination of the parts of a
duplex feathering screw propeller, crosshead and fittings, for the propulsion of ships
or vessels, substantially as herein described, in reference to and shown in the
accompanying Drawings.
Second. In screw propellers for the propulsion of ships or vessels, the mounting of
their propelling blades A A, at the outer extremities of a crosshead B B, of their
driving shaft B¹, so as to feather at an angle for propulsion or be feathered in line
with the keel, when not used for propulsion, all substantially as herein described, in
reference to and shown in the accompanying Drawings.
Third. In screw propellers for the propulsion of ships or vessels, the mounting of
their propelling blades A A by long stems A¹ A¹, in line in a crosshead B, so as to
be feathered by a bar C carried into the ship through the axis of the driving shaft B1,
all substantially as and for the purposes and advantages herein described in reference
to and shown in the accompanying Drawings.
Fourth. In screw propellers for the propulsion of ships or vessels, the mounting of
a transverse crosshead B B, for carrying the propelling feathering blades A A, all
substantially as and for the purposes and advantages herein described in reference to
and shown in the accompanying Drawings.
Fifth. In screw propellers for the propulsion of ships or other vessels, the con-
struction and use of the propelling blades A A, of a circular disc shape, with extended
half crescent part at their outer extremities a a¹, all substantially as and for the
purposes and advantages herein described, in reference to and shown in the
accompanying Drawings.
Sixth. In screw propellers for the propulsion of ships or other vessels, the
feathering of the propeller blades A A, by discs at the inner ends of their swivelling
stems, by a simple reciprocating rod C, and crosshead C" with slotted pin con-
nections c, c¹, all substantially as and for the purposes and advantages herein
described, in reference to and shown in the accompanying Drawings.
Dated this 21st day of November 1887.