IMPROVEMENTS IN SCREW PROPELLERS OF STEAM VESSELS AND IN THE ARRANGEMENT THEREOF
Year: 1862

page_text: LETTERS PATENT to Roderick Grogan, at 22, Westbourne Gardens,
Bayswater, for the Invention of "IMPROVEMENTS IN SCREW PROPELLERS OF
STEAM VESSELS AND IN THE ARRANGEMENT THEREOF."
Sealed the 21st January 1863, and dated the 22nd July 1862.
PROVISIONAL SPECIFICATION left by the said Roderick Grogan at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
July 1862.
I, RODERICK GROGAN, at 22, Westbourne Gardens, Bayswater, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SCREW PRO-
PELLERS OF STEAM VESSELS AND IN THE ARRANGEMENT THEREOF," to be as
follows:-
By attaching one or more of any of the present description of screws now in
use to a seperate shaft or shafts made with cranks or eccentrics and fixing said
shaft in stern of vessel in a vertical or upright position, and connecting said
shaft (so vertically placed) with machinery by a horizontal shaft, one end of
which will be attached to crank or eccentric of said vertical shaft, and the
other end to machinery, and also by fixing two such screws on horizontal
shafts, one on either side of vessel (similarly as paddle wheels are placed on
either side of vessels, and connected with machinery in same manner as they are
connected; by this arrangement the screws on separate shafts placed vertically

page_text: in stern of vessel, and those on each side of her can be used or worked conjointly
or separately as may be found best adapted to size of vessel and power required
to propel her.
It will be noticed by the above that I claim as my Invention the attaching
the same kind of screws as are at present in use to a seperate shaft or shafts
with crank or eccentric (by passing said shaft through boss of screws), and
the fixing said shaft or shafts in stern of vessel in a vertical or upright position,
and also the placing two such screws, one on each side of vessel (similarly as
paddle wheels are placed one on either side of vessels).
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Roderick Grogan in the Great Seal Patent Office on the
22nd January 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RODERICK
GROGAN, of No. 22, Westbourne Gardens, Bayswater, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of July, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Roderick Grogan, Her special licence that I, the said Roderick
Grogan, my executors, administrators, and assigns, or such others as I, the
said Roderick Grogan, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN SCREW PROPELLERS OF STEAM VESSELS AND IN THE ARRANGEMENT THEREOF,"
upon the condition (amongst others) that I, the said Roderick Grogan, my
executors or administrators, by. an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the samo 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 Roderick Grogan, do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
statement (that is to say):-
My Invention has for its object improvements in propellers for ships and
otber vessels, and consists of certain vanes or blades of a flat, spiral, or other
suitable form, two or more of which are mounted upon or attached to shafts,
cranks, or beams, and wholly or partially submerged at or in or partially
within the sides, bottom, or stern of the vessel, where the same, when fitted
to the required mechism, can be made to act as a paddle or take the place
of a screw propeller. The propeller is two-bladed, and its general form
is that of a segment of a disc or a parallelogram, which is made to rotate
transversely upon or about an axis which traverses the blade or upon. which
the blade traverses longitudinally. In constructing the propeller the ends
of the blades may be made of a spiral form. One or more of these blades may
be fitted, either entire or in sections, so as to form a screw or paddle with twoj.
three, four, or more propelling vanes; by preference, however, I use a simple
two-bladed propeller, the two vanes of which are in the same plane or in planes.
at right angles or inclined to each other. When the two vanes or blades.
are not in the same plane with each other they are mounted so as to turn
partially upon or about their respective longitudinal axis or axes, so that as one.
paddle or vane enters the water flatways the other vane leaves it edgeways, or.
so as to enter and leave the water angularly, more or less as circumstances
may require. As these blades rotate about their transverse axes they have a
transversing motion longitudinally, in order to increase their stroke and dipping
or-propelling surfaces.
The propeller, and mode of fixing and working the same, and principle
upon which the propellers are constructed are shewn upon the accompanying
Drawings, to which the following explanation refers:-
EXPLANATION OF DRAWINGS..
Fig. 1 illustrates its application at the sides of a vessel, where it may be.
used in lieu of a common paddle, in which application the axis of the rotation.
is horizontal.
a, a, are the vanes, both ends of which describe the lines marked b, b, b,. &c..
under the water line A, B, and the lines marked c, c, c, &c. above the water.
line, the vanes being mounted upon and driven by the shafts e,. e', e; in

page_text: Figs. 2, 3 & 4, shew similar propellers placed at the stern of the vessel
so as to rotate on verticle axes.
a, a, &c. are the vanes; 6, 6, the axes; c, c, (Fig. 4) the curve described by
the ends of the vanes as they rotate, motion being transmitted thereto from an
engine of any suitable construction fixed for that purpose in the vessel. Figs.
5 & 6.shew the vanes, also placed at the stern of the vessel, mounted on the
horizontal axis a, b; in this case a recess is formed at a, a, Figs. 5 & 6, in
the bilge for the ends of the vanes c, c, to clear. The form of the vanes in
this case is that shewn at Fig. 5, the motion being transmitted at d, d.
Fig. 7 shews the propellers placed at the side of the vessel and submerged,
one end working in a recess, as shewn at Fig. 8, and the other projecting
from the sides of the vessel working upon the axis a, a, and turned by an
engine. Two or more of these blades may be thus used in this way, and, if
necessary, both the sides and stern may be fitted therewith. The blades or
vanes are flat in the centre where they are traversed by the shaft or
axis, upon which they move longitudinally, and may also be made flat or more
or less inclined at the ends or edges b, b, where they may be formed like a
screw blade of considerable pitch, and this form, namely, that approximating
to the screw blade, may be given to the ends of the vanes of propeller blades
Fig. 1 is a development shewing the position of a propeler vane or Diade
and the lines described thereby as it rotates about the axis of the engine shaft,
shewn by the circle a, colored pink.
A, B, is the water line in all cases; b, c, the double-acting blade or pro-
peller, and c, e, the dip or extreme depth of stroke. The lines e¹ and c',
e² and c², e³ and c³, and e' and c', shew the relative positions of the blades as they
pass through the water. The small blue circles 1, 2, 3, and 4 shew the centre
of effort or centre of gravity of that portion of the blade immersed, and tho
distances, indicated by the dotted lines 6, 7, 8, and 9, the corresponding
velocities of the said centres of effort or the effective propelling power in
equal times. The line f, b,'g, is that described by the end of one of the
blades, while the other describes the line 9, c, f. This peculiar motion of the
blade when both ends pass through the water is obtained in the following
manner, see Fig. 2. a, b, is the blade, the two ends of which a' and b¹ may
be either made perfectly flat or formed like a screw, the centres from a¹ to b
being enlarged and traversed by the slot colored pink; the centre may be formed

page_text: upon
as shewn in the section at Fig. 3, having a groove or recess on one side.
This blade is mounted upon a shaft, as shewn at Fig 4. A is the shaft,
which is flattened at b, where it passes through a slot in the centre of
the blade; at the opposite end of this shaft a crank c is fixed which is driven
by a steam engine or other power. This shaft may be also driven by
a spur wheel in lieu of the crank, by a pulley, or by any other mechanism for
transmitting rotary motion thereto. On one or both sides of this blade the
shaft which it is mounted works in suitable bearings d, d, and on one
or both edges of the double blade where the same is enlarged a web e is
fixed, being either cast with the blade or bolted thereto; round the periphery.
of this web a flange f is formed standing at right angles thereto. The form
of this flange is determined by first developing the curve described, as before
explained at Figs. 1, f, b, g, and then setting off the inner curve parallel there-
with, shewn by a dotted line h, i, k, which gives one half of the flange. In
practice this flange may be formed to a circle flattened at y, z, or to any
other curve the chords of which measured through the centre a are equal.
Fig. 5 shews a double-bladed propeller which I intend to use either in place
of the screw at the stern or at the sides of the vessel as a paddle. The two
blades of this propeller stand at right angles to each other, and are connected
in the centre by a strong shaft, the length of which is made sufficient to allow
for the expansive stroke as in the cases before described. This double vanc
is mounted in a suitable shaft having an enlargement bored to receive the
sliding shaft which connects the two vanes. Round the driving shaft and
eccentrically therewith I fix two curved flanges so as to form a groove, and
on the edge of one of which flanges next to the propeller a number of
bevelled teeth are formed. At one side of the propeller I mount another
bevelled wheel, the teeth of which gear with the wheel above described upon
a strong dead pin; also at the side of the propeller I mount a running wheel
or pulley, which travels between the two eccentric fixed flanges. As this
propeller is turned by the driving shaft about its axis, the vanes thus
fitted receive a double motion, turning once round upon their connecting
shaft or own axis while they rotate in or upon the driving shaft, the eccentric
groove and running pulley also giving the expansive stroke; the vanes, which
are formed with more or less pitch or helical surfaces, are thus caused to
5 enter the water, or to rotate therein when submerged, with one vane flatways
when propelling, while the other leaves or passes through the water edgeways
or nearly so.
The expanding stroke of these propeller vanes may be obtained by the

page_text: rotation in equal times of two cranks of varying radii, or by sun-and-planet
gearing, or any other known mechanism by which a bi-circloidial motion
can be transmitted thereto by a shaft rotating in fixed bearings. A single-
bladed propeller with the same expansive stroke rising out of and making the
return stroke above the water may be substituted, when required, for the
double blade.
Having thus described and ascertained the nature of my said improve-
ments, and illustrated the same by Drawings, I hereby further declare that
I do not restrict myself to the precise modes of applying the principle thereof
shewn and explained, as the details may be varied in the application of the
said principle in practice.
In witness whereof, I, the said Roderick Grogan have hereunto set my
hand and seal, this Twenty-second day of January, One thousand eight
hundred and sixty-three.