AN IMPROVED TWIN SCREW PADDLE WHEEL
Year: 1871

page_text: LETTERS PATENT to Richard Long, of Liverpool, in the County of
Lancaster, for the Invention of "AN IMPROVED TWIN SCREW PADDLE
WHEEL"
Sealed the 22nd December 1871, and dated the 3rd July 1871.
PROVISIONAL SPECIFICATION left by the said Richard Long at the
Office of the Commissioners of Patents, with his Petition, on the
3rd July 1871.
I, RICHARD LONG, of Liverpool, in the County of Lancaster, do hereby
declare the nature of the said Invention for "AN IMPROVED TWIN SCREW
PADDLE WHEEL," to be as follows:-
The object of my Invention for twin screw paddle wheels is to
construct paddle wheels so as to give a great amount of power and
speed and dispense with the necessity of having to reef the floats, as is
the case in ordinary paddle wheels when vessels are deeply laden; also
the wheel will require about one-third less breadth of paddle box and
sponson.

page_text: A twin-screw paddle wheel according to my Invention is constructed
of a boss and cylindrical casing. On the inside of this cylindrical boss
and casing I bolt or otherwise attach radial arms or blades set with a
right-hand screw pitch, and on the outside of the boss and cylindrical
casing I bolt or otherwise attach radial arms or blades having a left-
handed screw pitch, thus forming what may be termed a twin screw
radial paddle wheel, that is, the propeller is formed of twin radial arms
springing from a common centre or boss, being set at a right and
left-handed screw pitch to the boss respectively. The radial arms or
blades may be stayed together by outside rings, or in any other practical
manner if necessary. The cylindrical casing formed on the boss may
be about one-third the diameter of the wheel, or as found most con-
venient in practise, the object being when partly immersed to throw
the water by centrifugal force on to the radial blades. The twin radial
arms or blades may be merely straight blades set at about angles of
forty-five degrees from the boss, right and left handed respectively. The
blades being set at opposite pitches converge towards each other at the
upper edge, forming an angle to each other. The bosses are mounted
on the paddle shaft in the ordinary manner, but it is preferred that the
brackets supporting the shaft shall be fitted close to the ship's side,
thus enabling the wheel to come as close to the ship as possible and
offering slight resistance to the water when deeply immerged.
•
The action of the wheel is thus:-The wheel revolves in a similar
manner to the ordinary paddle wheel, but the blades take the water
in place of the floats. The blades in going ahead enter the water at an
angle with its apex at the upper edge forcing the water behind as the
wheel revolves and sending the water in parallel lines with the ship's
sides. The radial blades or arms when they are not made to feather
leave the water at an inverse anglé to when entering. The wheel may
be composed of any number of twin radial arms as found expedient in
practise; also the wheel may'in some cases be composed of double or
treble twin radial arms, for instance, such might be expedient in the
case of a wheel being fitted at the stern of a vessel, as is sometimes
adopted in canal and river boats, and barges.
11

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Long in the Great Seal Patent Office
on the 30th December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
LONG, of Liverpool, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of July, in the year of our
Lord One thousand eight hundred and seventy-one, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Richard Long, Her special licence that I, the
said Richard Long, my executors, administrators, and assigns, or such
others as I, the said Richard Long, 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 "AN IMPROVED TWIN SCREW PADDLE
WHEEL," upon the condition (amongst others) that I, the said Richard
Long, 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 performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
.
NOW KNOW YE, that I, the said Richard Long, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :—
The object of my Invention for twin screw paddle wheels is to
construct paddle wheels so as to give a great amount of power and
speed and dispense with the necessity of having to "reef" the floats as is
the case in ordinary paddle wheels, when vessels are deeply laden; also
the wheel will require about one-third less breadth of paddle box and
sponson..
A twin screw paddle wheel according to my Invention is constructed
of a boss and cylindrical casing. On the inside of this cylindrical boss

page_text: and casing I bolt or otherwise attach radial arms or blades set with a
right-hand screw pitch, and on the outside of the boss and cylindrical
casing I bolt or otherwise attach radial arms or blades having a left-
handed screw pitch, thus forming, what may be termed, a twin screw
radial paddle wheel, that is, the propeller is formed of twin radial arms
springing from a common centre or boss respectively. The radial arms
or blades may be stayed together by outside rings or in any other
practical manner if necessary. The cylindrical casing formed on the
boss may be about one-third the diameter of the wheel, or as found
most convenient in practise, the object being, when partly immersed,
to throw the water by centrifugal force on to the radial blades. The
twin radial arms or blades may be merely straight blades set at about
angles of forty-five degrees from the boss, right and left handed res-
pectively. The blades being set at opposite pitches, converge towards
each other at the upper edge, forming an angle to each other. The
bosses are mounted on the paddle shaft in the ordinary manner, but
it is preferred that the brackets supporting the shaft shall be fitted
close to the ship's sides, thus enabling the wheel to come as close to the
ship as possible and offering slight resistance to the water when.deeply.
immerged.
:
The before-going being the nature and object of my Invention, I will
now proceed to describe more in detail the manner in which the same.
is to be or may be performed or carried out into practical effect, and.
in order that the same may be more clearly and readily understood I.
have hereunto annexed a Sheet of Drawings illustrative thereof marked
with Figures and letters of reference corresponding with those in the
following explanation, like letters and figures being used to denote
similar parts.
Figure 1 is an end elevation of a twin screw paddle wheel constructed
according to my Invention, drawn to a scale of half an inch to the foot;
Figure 2 is a sectional end elevation of the same, drawn to the same
scale Figure 3 is a side elevation of the same, drawn to the same scale.
Figure 4 is a section of blades through a, b, Figure 3, drawn to the scale
ofone inch to the foot.
A twin screw paddle wheel according to my Invention is constructed
of a boss or centre A. On the inside of this boss or centre and next
to the ship's side I bolt or otherwise attach radial arms or blades B.
These arms or blades are set with a right-hand screw, pitch, or angle
•

page_text: .
to the boss or centre A. On the outside of the boss or centre A I bolt
or otherwise attach radial arms or blades C, set with a left-hand screw
pitch to the boss or centre A, thus forming, what may be termed, a twin
screw radial paddle wheel, that is, the wheel is formed of twin radial
arm B and C springing from a common boss or centre A, and being
set at right and left-handed pitches to the boss or centre respectively!
The arms or blades are stayed together by means of the stay D and
band stay E. These blades I prefer to be made of two plates of wrought
or malleable iron or steel welded or forged together at their edges, and
leaving a space between them, thus forming the blades hollow, as shown
at Figure 4, the blades being set to the required pitch or angle, during
the process of welding by means of a matrix block. of the required shape.
The blades may be bolted or attached to the boss or centre A in the
manner shown in the Drawings, or as found convenient in practisc.
In some cases a cylindrical casing may be built outside the boss so as
to throw the water by centrifugal force on to the arms. i.
The action of the wheel is thus:- -The wheel revolves in a similar
manner to the ordinary paddle wheel, as shown by the arrow F, but the
blades B and C take the water in place of the ordinary floats, the blades
in going ahead enter the water at an angle with its apex at the upper
edge G forcing the water behind as the wheel revolves and sending
the water in parallel lines with the ship's sides; the blades leave the
water at an inverse angle to when entering. The wheel may be com-
posed of any number of twin radial arms or blades, as found expedient
in practise, also the wheel may in some cases be composed of double
or treble twin radial arms or blades, for instance, such may be expedient
in the case of a wheel being fitted at the stern of a vessel as is some.
times adopted in canal and river boats and barges, and a double or
treble wheel according to this Invention fitted as a stern wheel will
give very good results.
Having now described and ascertained the nature and object of this
my Invention, and the manner in which the same is to be or may be
performed or carried out into practical effect, I would have it clearly
understood that I do not limit myself to the exact dimensions, relative
proportions, and style of the different parts of the paddle wheel as shown
in the Drawings, as it will be well understood by any mechanical
engineer that the same may be considerably varied without departing
from my Invention; but what I claim as the Invention secured to me

page_text: by Letters Patent as aforesaid is:-The construction of twin screw
paddle wheels formed of twin radial arms or blades set at right and
left-handed pitch respectively to a boss or centre, the arms or blades
gradually narrowing towards the centre and decreasing in pitch, thus
compensating for the varying velocity with which the different parts
of the wheel travel through the water, the arms or blades springing
from a common centre, the whole substantially in the manner and for
the purposes as set forth and illustrated in the before-going Specification
and Drawings..
In witness whereof, I, the said Richard Long, have hereunto set
my hand and seal, this Twenty-eighth day of December, in the
year of our Lord One thousand eight hundred and seventy-
one.
Witness,
FREDERICK J. Cheesbrough,
of 15, Water Street, .
Liverpool.
RICHARD (L.S.) LONG.