IMPROVE- MENTS IN PROPELLING VESSELS
Year: 1853

page_text: LETTERS PATENT to John Jones, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVE-
MENTS IN PROPELLING VESSELS."
Sealed the 20th June 1854, and dated the 21st December 1858.
PROVISIONAL SPECIFICATION left by the said John Jones at
the Office of the Commissioners of Patents, with his Petition, on
the 21st December 1853.
I, JOHN JONES, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PROPELLING VESSELS" to be as follows:-
This Invention relates to a new arrangement of screw propeller, and
to an improved form of propeller shaft.
According to one modification of the propeller, it consists of two distinct
portions, each in itself being a portion of a two-bladed screw with its
boss, but of very little length in the direction of the shaft. One of these
portions, the forward one, is firmly keyed or fixed upon the shaft; the
other, and hindmost one, the blades of which may be of the same dimen-
sions and form as the forward blades or not, as found best, is loose upon
the shaft, and is capable of turning round upon it to an extent determined

page_text: by catch pieces within the boss and upon the propeller, shaft respectively.
When at rest, the hindniost pair of blades are made to lie immediately
behind the forward pair, either by the mere action of the water, or by
thrusting down a bar from above, so as to come in contact with the
blade, and then turning the propeller shaft, or by a clutch box or other
mechanical arrangement upon the shaft. When the propeller is turned,
the resisting action of the water will cause the hind blades to turn
round as far as the catches will allow, and assume the position
determined upon. A. clutch box or other mechanical arrangement
may be provided to lock the blades in this position, if necessary, for
backing. It is obvious that the propeller may be made to consist of
more than two sections, in which case, cach section must be arranged
to turn round upon the shaft to a greater extent than the section
immediately before it. The shape of the blades of this propeller is a
particular point in the Invention. The acting surfaces of blades form
portions.cither of what is termed a true screw, or of an increasing pitch
screw, or of an expanding: pitch screw, or, finally, of an expanding and
increasing pitch screw. The blade may stand out at right angles from
the shaft, or it may be inclined or slightly curved, if deemed expedient.
In all cases it is of the same or nearly the saine width throughout its
entire length from the boss to the circumference, as measured upon the
helical or screw surface, or the blade may be slightly tapered in width. It
is proposed to determine the working position of the loose hind section
of the screw, so that the blades shall coincide with the continuation of
the helical surface of the front blades. If this position is adopted, the
propeller will have the appearance of a common two-bladed screw with
a triangular portion cut out from the middle of the blade, the apex of
the triangle being towards. the shaft. The Inventor, however, does
not confine himself to this position; any mechanical arrangement is
to be adopted by which the propeller shall always be stopped with
its blades vertical, and as they are very narrow, they will, in this
position, lic entirely within the dead wood of the ship, the hind
blades being brought immediately behind, the front ones, as already
mentioned. The form of blade already described may be adopted in
propellers which have no moveable parts about them, and whatever may

page_text: be the number of the blades, and also in propellers in which the blades
are made to swivel or feather. In any of the cases alluded to, it is
proposed to add intermediate blades, these to be about one third the
radial length from the boss of the main blades. These smaller inter-
mediate blades are for the purpose of acting upon the water at the
central part of the screw, and they may be of the same pitch as the
main blades, or they may be of a different pitch; they may also be
placed either before or behind the main blades, or immediately between
them, and it is proposed to surround them with a 'drum or hoop, so
as to confine the water at that part.
According to another part of this Invention, the shaft of screw and
similar propellers is made hollow and of large diameter at the part on
which the propeller is fixed, and where it passes through a bush or
bearing into the dead wood of the ship. This plan is to give greater
strength and lightness to the shaft, and to provide a greater surface for
the frictional action at the bearings, so as to prevent rapid wear at
those parts. The larger diameter of the shaft will also admit of the
application of anti-friction rollers at the bearings.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Jones in the Great Seal Patent Office on
the 21st June 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN JONES, of Glasgow, in the County of Lanark, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of December, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Jolin Jones, Her special license
that I, the said John Jones, my executors, administrators, and assigns,
or such others as I, tlie said John Jones, my executors, administrators,
or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,

page_text: should and lawfully might make, use, exercise, and vend, within
the United Kingdom of Great Britain and Ireland, the Channel
Tslands, and Isle of Man, an Invention for "IMPROVEMENTS IN PRO-
PELLING VESSELS," upon the condition (amongst others) that I, the said
John Jones, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office, within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Jones, do hereby declare
the nature of my said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Draw-
ings, and to the letters and figures marked thereon, that is to say :-
My said Invention relatos to a new arrangement of screw-propeller,
and to an improved form of propeller shaft. According to one modifi-
cation of the propeller, it consists of two distinct portions, each in itself
being a portion of a two-bladed screw with its boss, but of very little
length in the direction of the shaft. One of these portions, the forward
one, is firmly keyed or fixed upon the shaft; the other, and hindmost
one, the blades of which may be of the same dimensions and form as
the forward blades or not, as found best, is loose upon the shaft, and is
capable of turning round upon it to an extent determined by catch
pieces within the boss and upon the propeller shaft, or upon the fixed
portion of the propeller respectively. When at rest, the hindmost
pair of blades are made to lie immediately behind the forward pair,
either by the mere action of the water or by thrusting down a bar from
above, so as to come in contact with the blade, and then turning the
propeller shaft, or by a clutch box or other mechanical arrangement upon
the shaft. When the propeller is turned, the resisting action of the
water will cause the hind blades to turn round as far as the catches
will allow, and assume the position determined upon. A clutch box or
other mechanical arrangement may be provided to lock the blades in
this position, if necessary, for backing. It is obvious that the propeller
may be made to consist of more than two sections, in which case cach

page_text: section must be arranged to turn round upon the shaft to a greater
extent than the section immediately before it. The shape of the blades
of this propeller is a particular point in my Invention. The acting
surfaces of the blades form portions either of what is termed a true
screw, or of an increasing pitch screw, or of an expanding pitch screw,
or, finally, of an expanding and increasing pitch screw. The blade
may stand out at right angles from the shaft, or it may be inclined or
slightly curved, if deemed expedient. In all cases it is of the same or
nearly the same width throughout its entire length from the boss to the
circumference, as measured upon the helical or screw surface, or the
blade may be slightly tapered in width. It is proposed to determine
the working position of the loose hind section of the screw, so that the
blades shall coincide with the continuation of the helical surface of the
front blades. If this position is adopted, the propeller will have
the appearance of a common two-bladed screw with a triangular portion
cut out from the middle of the blade, the apex of the triangle being
towards the shaft. I do not, however, confine myself to this position or
arrangement. Any mechanical arrangement is to be adopted by which
the propeller shall always be stopped with its blades vertical, and as
they are very narrow, they will, in this position, lic entirely within the
dead wood of the ship, the hind blades being brought immediately
behind the front ones, as already mentioned. The form of blado
already described may be adopted in propellers which have no move-
able parts about them, and whatever may be the number of the blades,
and also in propellers in which the blades are made to swivel or feather.
In any of the cases alluded to, it is proposed to add intermediate blades,
these to be of about one-third the radial length from the boss of the
main blades. These smaller intermediate blades are for the purpose of
acting upon the water at the central part of the screw, and they may
be of the same pitch as the main blades, or they may be of a different
pitch. They may also be placed either before or behind the main
blades, or immediately between them, and it is proposed, in some cases,
to surround them with a drum or hoop, so as to confine the water at
that part.
According to another part of this Invention, the shaft of screw and

page_text: similar propellers is made hollow and of large diameter at the part on
which the propeller is fixed, and where it passes through a bush or
bearing into the dead wood of the ship. This plan is to give greater
strength and lightness to the shaft, and to provide a greater surface
for the frictional action at the bearings, so as to prevent rapid wear at
those parts. The larger diameter of the shaft will also admit of the
application of anti-friction rollers at the bearings.
And in order that my said Invention may be properly understood, I
shall now proceed to describe the several explanatory Figures on the
two Sheets of Drawings hereunto attached. Figure 1, on Sheet 1 of the
Drawings, is an end elevation of a screw propeller constructed according
to my Invention, looking on the back or acting surface of the blades;
Figure 2 is a front elevation of the same screw, looking on the surface
which acts in backing; Figure 3 is a side elevation, corresponding to
Figures 1 and 2. These three Figures represent the screw in its
propelling position, that is to say, with tho two sections of which it is
composed spread out. Figure 4 is an end elevation, similar to Figure 1,
but with the two portions of the propeller brought into a line, showing
the position they occupy when not acting. When the propeller repre-
sented in these four Figures is in the propelling position, it constitutes,
to all appearance, a screw with two blades, the surfaces of the two
portions being continuations of each other. Figures 5, 6, 7, and 8, on
Sheet 1 of the Drawings, are elevations of a different modification of
my divided screw, Figure 5 representing the forward acting surface,
Figure 6 the backing surface, whilst Figure 7 is a side elevation, all
three shewing the screw in the propelling position. Figure 8 represents
the propeller, with the two portions brought into the same line. The
propeller represented in Figures 5 to 8, differs from that represented
in Figures 1 to 4, in that the two portions do not join each other
towards their extremities when in the propelling position, but have the
appearance of blades with triangular portions cut out. The combined
acting surface, however, is a portion of the samo helical or differential
helical surface of which the propeller represented in Figures 1 to 4 is
part. Figure 9, on Sheet 1 of the Drawings, is an end clovation of
another modification of my divided propeller, looking on the acting sur-

page_text: faces of the blades. When this screw is in the propelling position, the
two pairs of blades are at right angles to each other as represented,
forming a four-bladed screw. Figures 10 and 11, are side and end
elevations of the same instrument, representing it as with the blades
brought into a line, and also shewing the means of locking them in
position. In the three modifications of propeller represented in Figures
1 to 11, the forward section A of the instrument is to be keyed upon
the propeller shaft, whilst the after section B is loose, but is prevented,
in any convenient manner, from moving longitudinally on the shaft.
The boss of the fixed portion A of the propeller bas segmental grooves
C, cut in the face adjacent to the boss of the portion B, and this last
has segmental projections D, which work in the grooves C. This
arrangement, which may be modified in various ways, limits the move-
ments of the after blades B on the shaft, in such a manner that when tho
segments D are each at one end of their grooves C, the sections of the
screw will be in the propelling position, and when the segments are
cach at the other end of their grooves, the two sections of the propeller
will be in a line, so as to lie within the dead wood of the vessel, as when
they are not required to propel. When the vessel is being propelled
n-head, the after section of the propeller is turned into the propelling
position by the resisting pressure of the water. And when the vessel
passes through the water with her propeller not revolving, the water
will act on the back of the after section, and cause it to take up a position
in a line behind the forward section, when the propeller will offer con-
siderably less resistance to the motion of the vessel through the water.
The after section of the propeller may be locked in position by means
of the clutch piece E, as represented in Figure 10. This clutch piece
E consists of a collared ring, which has a short traverse on the pro-
peller shaft F, and carries two bolts which pass through holes in the
boss of the front fixed section A of the propeller, and projecting beyond,
enter holes in the boss of the after section B, when this is to be locked.
The clutch is worked by a forked lever G, the points of which embrace
it between its collars. This lever is actuated from above, and draws
the clutch bolts out of the boss B, or thrusts them into it, according as
it is wished to lock or unlock the after section B of the propeller.

page_text: Figure 12, on Sheet 1 of the Drawings, is an end elevation, looking
on the acting surface of a screw propeller. constructed according to
another portion of my Invention. This propeller is not represented as
divided or in sections, but the peculiarities it illustrates are likewise
applicable to my divided screws. The propeller has two large blades A, 5
which may be of any shape or form, but I prefer to construct them
according to a geometrical method, forming another branch of my
Invention, and herein-after described. At right angles to the blades A,
and in the spaces between them, are a pair of small blades B, which are
intended to secure a more efficient action at the central part of the
propeller. The blades B may be from one third to one half the radial
length of the larger blades A, but I do not confine myself to any precise
proportion. The acting surface of the small blades B, may be similar
to the corresponding portions of the larger blades, or they may be
different in shape or pitch, or both; and they may be arranged to
lic within the same parallel discs as the larger blades, or they may
be placed wholly or partly before or behind the larger blades, as may
be found desirable. Figures 13 and 14, on Sheet 2 of the Drawings,
are respectively an end elevation looking on the acting surface, and a
side elevation of a three-bladed screw propeller, constructed according
to my Invention, both as regards the shape and proportions of the
blades, and the construction of the propeller shaft. The propeller shaft
A is formed of an enlarged diameter towards the end at which the pro-
peller is fixed, as at B, and this enlarged portion is hollow, as indicated
by dotted lines. This mode of construction renders the shaft much
stiffer and stronger at that part than a solid shaft of equal weight, and
the enlarged part being continued to within the bush or stuffing box
bearing through which the shaft issues from the interior of the vessel, a
much larger bearing surface is in consequence obtained.
The acting surfaces of all the propellers represented in my two
Sheets of Drawings, are constructed according to the geometrical
method which I shall now proceed to explain, with the assistance of
the diagrams, Figures 15, 16, and 17, on Sheet 2 of the Drawings.
These Drawings are all drawn to a scale of half an inch to the foot.
In the diagram, Figure 17, the parallelogram A, B, represents a

page_text: cylinder of the same diameter as the screw, and of the same length
in the line of the shaft, and C, D, represents the developement of
the corresponding circumference. The vertical lines 7-7, are made
equal to an assumed pitch, eighteen feet in this instance, the diameter
of the screw being 14 feet; and the parallelogram 7-7 represents the
developement of a cylinder of the length of the pitch. The boss is
assumed to be two feet in diameter, leaving six fect on each side for
the blades. These portions I divide into any number of equal parts,
the number six being selected, in this instance, for the sake of con-
venience, and I imagine so many cylindrical sections, the developement
of which I obtain by dividing the parallelogram 7-7 in a corresponding.
manner. Then by drawing diagonals from the corresponding points
across the centre E, I obtain the developements of the true or right
helices of a pitch of eighteen feet on the several cylindrical sections.
These helices are represented in the diagram by red lines 1-1, shew-
ing the angle at the boss of a true or right helical surface; 2-2, the
angle at two feet from the axis; 3-3, the angle at three feet from
the axis, and the line 7-7, representing the angle at the outer edge of
the surface or blade. By a right or true helical surface, I mean such
as is generated by the uniform revolution of a straight line round an
axis, to which it is at right angles, and along which it has a uniform
longitudinal motion.
In one modification of my propeller, I make about one half of
the blade with angles corresponding to a right or true helical surface,
and I make this the after half of the screw. Thus A, F, in the dia-
gram represents the after part of the scrow, and the blue lines drawn
from it to the centre E, represent the angles on the after half of the
blade, these blue lines coinciding with the red lines representing
the true helical angles. I make the forward half of the blade of
a differential pitch, both increasing and expanding, but merging
at the centre E, into the uniform pitch of eighteen feet, or the
pitch of the after part of the blade. Thus I make the angle at
the boss to correspond to a pitch of twelve feet six inches, or any
other suitable pitch, and I obtain this angle by taking the distance
G, H, equal to the half of this pitch on the line corresponding to the

page_text: cylindrical section at the boss, when the line drawn from the point I,
to the centre E, will have the required angle. To obtain the angles at
the other sections I join II, I, and divide the portions cut off by it of
the vertical lines 2-2, 3-3, 4-4, 5-5, and 6-6, each into six equal parts.
Then on the line 2-2, I take a division below the line H, I; on the
line 3-3, I take two divisions; on the next three, and so on. Thus I
get the curve II 4, I, which defines a gradually expanding pitch from
the boss to the outer edge of the blade, where the pitch is eighteen
feet, or uniform from the leading to the after edge of the blade. By
drawing the blue lines from the points obtained in the manner
described to the centre E, I obtain the angles corresponding to the
several cylindrical sections. In the diagram, Figure 15, the arcs
drawn in red correspond to the cylindrical sections already referred
to, and the radial line E, J, is what in ordinary circumstances would be
the centre line of the blade, or the section made by a disc at right angles
to the shaft, and passing through the blade at the centre of its length
on the shaft. Instead, however, of adopting this centre line, I curve
back the blade near the central part, and take the curved line J 4, 1,
as the centre line, and as the section of the blade made by a disc at the
longitudinal centre of the blade on the shaft. This line may be curved
in a variety of ways, but I prefer a parabolic or similar curve, the
quickest part of the curve being at the inner part. I form the blade in
such a manner that the angles at the several sections shall be those
described in the diagram, Figure 17, whilst at the same time the surface
passes through the curve J 4, 1. The diagram, Figure 16, is a projec-
tion of the angles at the several sections, as brought into coincidence
with the curve J 4, 1, in the diagram, Figure 15. Thus the blue
angular line 2-2, cuts the vertical line K, L, at a distance from the
point E, which is the projection of the line J, E, in Figure 15, equal to
the distance from that line of the intersection of the curve J 4, 1, with
the arc 2.
I make the blades of the same or nearly the same width throughout
their length, as measured on the helical or acting surface, which gives
them the peculiar outline represented in the Drawings, the only difference
between the form shown in Figures 1 to 4, and that shewn in Figures

page_text: 5 to 8;. consisting in that the former is measured with reference to a
single centre line for the combined blade, whilst, in the latter, ench
portion or section is shaped with reference to a separate distinct centre
line.
The details of the geometrical construction may be varied 'in many
ways. Thus various curves may be adopted instead of the curve J 4, 1,
in Figure 15, or this curve may be made to terminate at the circuni-
ferential edge of the blade, either nearer to the leading or to the after
edge, and the angles of the leading part of the blade may be made to
merge into those of the after part at various distances from either edge.
In obtaining the form of the blades it is to be understood that the entire
sector or portion of the disc of the screw corresponding to its length is
to be shaped to the angles given in the diagram, Figure 17, and the
actual outline of the blades is obtained by cutting away the superfluous
portions. Thus in the modification Figure 1, the corners are cut away,
whilst in the modification Figure 5, a triangular piece is cut out of the
middle, and less is taken away at the corners, so that these two forms
of blade are different portions of surfaces exactly alike. It is also to be
understood that the forked form of blade, as well as any form repre-
sented in my Drawings, may be adopted in solid undivided propellers.
I would also further remark that the several points comprehended in
my herein described Invention may be used in combination with each
other, or with elements already well known. Thus the method of con-
structing the angles, as explained in reference to Figure 17, may be
used for screws of the ordinary kind in other respects, and the same
may be said with regard to the curve J 4, 1, explained in reference to
Figure 15, to the outline shape of the blades, and also with regard to
other points.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried or into effect, I may observe, in conclusion, that I do not
confine or restrict myself to the precise details or arrangements which
I have had occasion to describe or refer to, as many variations may
be made therefrom without deviating from the principles or main
features of my Invention; but what I consider to be novel and original,

page_text: and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is,―
First, the general arrangement, construction, and form of mecha-
nism, apparatus, or means for propelling vessels, as herein-before
described.
Second, the system or mode of forming screw and similar propellers
in two or more sections, one portion being fixed to the shaft, whilst the
other or others can turn upon it, so as to assume different positions when
propelling, and when not propelling, as herein-before described.
Third, the systems or modes combined or separately of determining
the curves, angles, and outline forms of the propeller blades, whether
such blades be solid or divided, or in sections herein-before described,
more particularly in reference to the diagrams, Figures 15, 16, and
17, on Sheet 2 of the Drawings hereunto attached.
Fourth, the system or mode of forming the shaft or a portion of the
shaft of screw and similar propellers hollow, in order to obtain greater
strength and stiffness, and a greater bearing surface as compared with
the weight, as herein-before described.
Fifth, the application and use in screw and similar propellers of
intermediate blades of smaller diameter than the main blades, as herein-
before described in reference to Figure 12, on Sheet 1 of the Drawings
hereunto attached.
In witness whereof, I, the said John Jones, have hereunto set my
hand and seal, this Nineteenth day of June, in the year of our
Lord One thousand eight hundred and fifty-four.