IMPROVEMENTS IN AND RELATING TO PROPELLING NAVIGABLE VESSELS, AND SCREW PROPELLERS THEREFOR."
Year: 1880

page_text: LETTERS PATENT to Joseph Gibbons, of Liverpool, in the County of Lancaster,
for an Invention of "IMPROVEMENTS IN AND RELATING TO PROPELLING
NAVIGABLE VESSELS, AND SCREW PROPELLERS THEREFOR."
PROVISIONAL SPECIFICATION left by the said Joseph Gibbons at the Office
of the Commissioners of Patents on the 21st October 1880.
JOSEPH GIBBONS, of Liverpool, in the County of Lancaster. "IMPROVEMENTS IN
AND RELATING TO PROPELLING NAVIGABLE VESSELS, AND SCREW PROPELLERS
THEREFOR."
My Invention has for its object certain improvements in propelling ships, and
forms of screw propellers used therefor.
According to my Invention I construct a longitudinal aperture or apertures
in the dead working or deadwood in the run of the vessel and immediately above
the keel, commencing from the rudder or stern post and continued for the necessary
distance forward, and of the necessary height. The propeller shaft connected with
the engine is brought through this aperture, and continued to the rudder or stern
post where it rests and works on a suitable bearing. The propeller or propellers
according to my Invention are mounted on, attached to, or form part of this shaft,
and consist of a combination of different or contrasting shaped blades, or pairs, or
series of blades attached to the shaft in alternate positions. When the blades are
attached independently to the shaft they are alternately spaced in contrasting
forms; for example, the first blade has its greatest surface at its root, or where it
springs from the shaft and tapers away to its outer end. The next blade in
succession on the shaft has its greatest surface at its outer end and tapers away to
its root or base, so that each succeeding blade contrasts in form with the preceding
blade. The blades may be cast in the form of ordinary propeller blades with a
pitch to suit circumstances, but must contrast with each other in their position on
the shaft

page_text: My Invention further consists in using screw propellers of ordinary construction,
but having their blades with contrasting surfaces, namely, one propeller has its
blades with their greatest surface at the root, and the other propeller has its blades
with the greatest surface at the outer end. Two or more of these propellers are
mounted in succession in the before mentioned aperture on the screw shaft.
My Invention further consists in constructing a propeller of the type known as
the Mangin screw with duplex blades on one boss, but according to my Invention
I form the blades of contrasting surfaces, namely, one set of blades tapered to their
outer ends and the other set tapered to the root.
In the further carrying out of my Invention I forin a continuous archimedian
screw on the screw shaft. The blade of this archimedian screw I form with an
undulating surface, so that I produce a series of contrasting surfaces in the blade.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Gibbons in the Great Seal Patent Office on the 21st April
1881.
JOSEPH GIBBONS, of Liverpool, in the County of Lancaster. "IMPROVEMENTS IN
AND RELATING TO PROPELLING NAVIGABLE VESSELS, AND SCREW PROPELLERS
THEREFOR."
My Invention has for its object certain improvements in propelling ships, and
forms and positions of screw propellers used thorefor.
According to my Invention I construct a longitudinal aperture or apertures in
the dead working or deadwood in the run of the vessel and immediately above
the keel, commencing from the rudder or stern post, and continued for the necessary
distance forward, and of the necessary height, and of construction similar to the
ordinary screw aperture in vessels, excepting that in my Invention, I reduce the
height of the aperture and extend the length thereof, as and for the purposes
hereafter set forth. The propeller shaft connected with the engine is brought
through this aperture, and continued to the rudder or outer stern post where it is
supported and works on a suitable bearing. The propeller or propellers, according
to my Invention, are mounted on, attached to, or forn part of this shaft, and consist
of a combination of different or contrasting shaped blades, or pairs, or series of
blades attached to the shaft in alternate positions. When the blades are attached
independently to the shaft they are alternately spaced and placed in contrasting
forms; for example, the first from the after end blade, or pair, or series of blades has
its greatest surface at its root, or where it springs from the shaft or boss and tapers
away to its outer end. The next blade, or pair, or series of blades in succession on
the shaft has its greatest surface at its outer end and tapers away to its root or
base, so that each succeeding blade, or pair, or series of blades contrasts in form
with the preceding blade. The blades may be cast in the form of ordinary pro-
peller blades with a pitch to suit circumstances, but must contrast with each other
in their position on the shaft.
Propellers of any contrasting shaped blades in pairs or sets may be placed
alternately along the shaft, the broad ended propellers with an inclination forward
and the narrow ended propellers with an inclination aft, the object of the con-
trasting shaped propellers and inclinations being to obtain as much as possible
independent or solid water for the propellers to act in. The propellers having
opposing inclinations catch or strike the water at different or opposing angles, and
the broad ended propellers thus thrust the water outside of the radius of the
narrow ended propellers, which latter act upon the water that passes the inner or
narrow part of the narrow rooted propellers.
My Invention further consists in using screw propellers of ordinary construction,
but having their blades with contrasting surfaces, namely, one propeller has its
blades with their greatest surface at the root, and the other propeller has its blades
with their greatest surface at the outer end. Two or more of these propellers are
mounted in succession in the before mentioned aperture on the screw shaft.
My Invention further consists in constructing a propeller of the type known as
the Mangin screw with duplex blades on one boss, but according to my Invention
I form the blades of different or contrasting surfaces, namely, one set of blades
tapered to their outer ends and the other set of blades tapered to their root. The
blades may be straight or set with contrasting inclinations, namely, one set having
a front overhang and the other set having a back overhang.
In the further carrying out of my Invention I form a continuous archimedian
screw on the screw shaft. The blade of this archimedian screw I form with an
undulating periphery or outer surface line, so that I produce a series of different
blades, or the blades may be of alternate contrasting sizes and shapes.
The beforegoing being the nature, object, and purposes of my Invention, I will
now proceed to describe more in detail how the same may be put into practical

page_text: operation, and for that purpose I have hereunto attached four Sheets of Drawings
illustrative of my Invention, which are marked with letters and figures of reference
corresponding with those in the following explanation, like letters being used to
denote the same or corresponding parts throughout the various views.
The essential object of my Invention has arisen from the consideration that the
tendency of the steam ship building of the day is to greatly increase the size of
ocean going steamships, and that the depth of the vessel, and consequently the
diameter and surface of the propellers now in common use, is not increased com-
paratively with the size and capacity and weight of the increased size of the vessel;
it is imperative that greater propelling surface should be obtained in order to
counteract such deficiency and attain increased proportionate speed, and that the
slip and ineffective surface of propellers should be reduced as much as possible, and
this I effect by the positioning and formation of propellers as herein described,
which system is equally suitable for steam ships of all sizes.
In the Drawings,-
Figure 1 represents the outline of a screw steam ship, broken in half for the
convenience of space.
Figure 2 is an enlarged view of the screw aperture and screw shown at Figure 1.
Figure 3 is an end view showing contrasting shaped blades of two bladed
propellers according to my Invention.
Figure 4 is an end view showing contrasting shaped blades of three bladed
propellers according to my Invention.
Figure 5 is a view of the screw aperture with three three bladed screws with
contrasting shaped blades.
Figure 6 is an end view of the propellers, Figure 5.
Figure 7 is an elevation of screw aperture with two four bladed propellers with
contrasting shaped blades according to my Invention.
Figure 8 is a modification of Figure 7.
Figures 9 and 10 are end views showing contrasting shaped four bladed propellers
according to my Invention.
Figures 11 and 12 are details showing a method which I employ for attaching
screw blades to the propeller shaft:
Figure 13 ilustrates a continuous archimedian screw, with an undulating
periphery producing blades according to my Invention.
Figure 14 is an end view of Figure 13.
Upon reference to the Drawings it will be seen that in carrying out my
Invention I construct a screw aperture A in the dead working or dead wood in the
run of the vessel, of construction similar to the ordinary screw aperture in vessels,
except that I reduce the height of the aperture and extend the length thereof for
the purposes hereafter set forth. B is the propeller shaft passing through the
aperture A and continued to the stern post C. The propellers consist of a com-
bination of different or contrasting shaped blades; for example, in the propellers
shown at Figures 1, 2, 3, and 4, the propellers D have the greatest surface at the
root of their blades, and the propellers E have their greatest surface at the
extremity of their blades. The blades of the propellers D taper from the root to
the extremity, and the blades of the propellers E taper from the extremity to the
root. It will thus be seen that each succeeding blade, or pairs or series of blades,
contrasts in form with the preceding blade. The propellers shown are cast in the
form of ordinary propellers, pitched and positioned according to my Invention.
I prefer that the broad ended propellers E should have an inclination forward, as
shown, and the narrow ended propellers D should have an inclination aft, as shown,
so that the propellers E thrust the water outside of the radius of the propellers D,
and the propellers D act upon the water that passes the inner part of the
propellers E.
The Drawings, Figures 5 and 6, illustrate a further carrying out of my Invention,
in which three three bladed propellers are used; and the Drawings, Figures 7
and 8, illustrate the application of two four bladed propellers. The two propellers

page_text: may be positioned as shown at Figure 7, or as shown at Figure 8, or the two
propellers shown at Figure 8, namely D and E, may be cast together like a Mangin
screw with the duplex blades on one boss, but the blades E must contrast in shape
with the blades D. The blades or propellers D and E may be attached to the
shaft B, as shown at Figures 11 and 12, namely, the shaft B under the boss is
formed of an octagon shape or other flat shape, and the bosses of the blades
are formed with lugs which bolt together onto the shaft, as shown at Figures
11 and 12.
Upon reference to Figures 13 and 14 it will be seen that the archimedian screw
forming part of my Invention consists in forming the screw F on the boss or
barrel H with an undulating periphery and blade. The face of the blade F where
it meets the water is slightly convex, and has a receding inclination forwards
throughout from the base to the extremity so as to thrust the water outwards. The
blades F may be of any suitable shape and pitch, and are not limited as to length
longitudinally, and may be of alternate contrasting sizes and shapes. The blades
may be cast in one piece or in sections, and the propeller aperture A may be
provided with stanchions between the sections to form extra bearings for the
shaft B if required. An example of these stanchions is shown in dotted lines at
Figure 2, and it will be understood that they can be applied where found necessary
throughout my Invention.
Although I prefer that the contrasting shaped blades should be placed or
positioned alternately longitudinally along the shaft, the propellers may also be
formed by the contrasting shaped blades being placed or positioned alternately
around the shaft, say, each propeller combining contrasting shaped blades.
I propose that the shaft underneath the bosses be reduced to octagonal form for
two and four bladed propellers, and that each blade with its proportion of boss being
cast in one piece, the inner part of said boss be also of octagon form so as to clip
on to the shaft, and the propellers would thus be secured on the shaft by bolts
through the boss, or through lugs which form part of the boss. Three bladed
propellers would be fastened onto the shaft in like manner, excepting that it would
be inore convenient for the shaft to be reduced to a nine sided polygon form, with
the inner part of the boss to correspond. By this arrangement one or other of tho
propellers might be altered to the extent of one eighth or one ninth of a circle, as
the case might be, to the position producing the best results as regards speed.
Amongst the advantages attendant upon my system of constructing and positioning
propellers may be mentioned,-
Better or deeper immersion of the propellers, especially when the vessel is
pitching or rolling in a seaway or swell, such being the normal conditions
experienced by ocean going steamships; indeed, it may be said complete immersion,
excepting under the exceptional circumstances of the very heaviest weather; conse-
quently increased speed and or economy in engine power and consumption of fuel,
with similar results in smooth water.
More propelling surface obtainable, and from its working in greater solidity of
water enhanced propulsion power thereby secured.
Exemption from racing of the engines and non necessity for governors, thus
securing great diminution in vibration, and as a natural consequence in the wear
and tear of the vessel; increased comfort for passengers and crew; greatly reduced
violent and acute strains on the engines, shaft, and propellers, thereby lessening the
chances of a break down.
The risk of disablement from a break down being greatly diminished insurance
ought to be effected on easier terms.
The deeper immersion and reduced diameter of the propellers would render them
less exposed to destruction or damage from passing or floating wreckage, logs of
timber or ice, and less liable to become deranged in other ways from their working
with greater regularity and steadiness; in the improbable event of one or more
blades being carried away there would be a better chance of some remaining intact
to propel the vessel.

page_text: The strain and weight of the propellers not concentrated on the end of the
shaft, but modified by being distributed along it longitudinally.
The propellers being constructed in section, say each blade with its proportion of
boss in a section, would be more easily handled, repaired, or replaced in case of
damage, and besides they would be considerably less costly than a propeller cast in
one piece, particularly in the larger class of steamers.
The action of the rudder more reliable from less of its surface being acted upon
in consequence of the reduced diameter and wash of the propellers, more especially
when the latter are reversing or stopped with way on the vessel.
Material saving of space in the body of the vessel from the position of the shaft
tunnel being lowered to nearer the kelson. This advantage alone represents a gain
of about three per cent. in the cargo capacity of a largo steamer, so that assuming
eight Atlantic voyages in twelve months it would be equivalent to a gain of about
twenty four per cent. per annum.
The lowered position of the propellers and as a consequence the deeper immersion
of the same would admit of the vessel being built of less depth, thus avoiding or
minimising in the case of the larger class of steamers, as at Liverpool, the extra
expense of loading or discharging in the river and other inconveniences; also an
important consideration as regards all steamers trading to shallow water ports.
The non necessity for water ballast construction so far as regards the deeper
immersion of the propellers. This consideration, combined with outside bilge keels,
bearing in mind the ballasting, anti rolling, strengthening, and protective properties
of the latter would go far to supplant the utility of water ballast construction
without its attendant sacrifice of hold space, and besides would be much less
costly.
The lowered position of the propellers would admit of the vessel being built with
better or fuller upper after bearings above the aperture, which would assist her to
lift and fall easier in a seaway or swell, and at the same time compensate for the
oncroachment on the lower after part of the hull by the longitudinal length of the
aperture.
Numerous self evident advantages as compared with the twin screw propellers
and adapted to war steam ships as well as to the merchant service.
Having now described my Invention, and shown how the same may be put into
practical operation, I would have it clearly understood that my Invention is not
limited to the precise size of screw aperture shown, nor to the identical design
or number of propellers illustrated, as the same are capable of various
modifications.
What I claim as secured to me by Letters Patent as aforesaid is,―
First. The use of two or more propellers (mounted on, attached to, or forming
part of the propeller shaft) with contrasting shaped blades, or pairs, or series of
blades attached to the shaft, as herein described and shown in the Drawings hereto
annexed.
Second. The positioning of screw propellers, as herein described and shown in
Figures 1 to 10, inclusive, of the Drawings hereto annexed.
Third. The method of attaching screw propeller blades, as herein described and
shown at Figures 11 and 12 of the Drawings hereto annexed.
Fourth. The form and construction of archimedian propeller, as herein described
and shown in Figures 13 and 14 of the Drawings hereto annexed.
In witness whereof, I, the said Joseph Gibbons, have hereunto set my hand
and seal, this Nineteenth day of April, in the year of our Lord One
thousand eight hundred and eighty one.
JOSEPH
CIRRONS