AN IMPROVEMENT IN THE ARRANGEMENT FOR THE SCREW PROPELLER IN STEAK SHIPS
Year: 1872

page_text: LETTERS PATENT to Reginald Heber Radcliffe, of The Oaks, in Led-
sham, in the County of Chester, and an Assistant in the Offices
of the Inman. Steam Navigation Company, in Liverpool, in the
County of Lancaster, for the Invention of "AN IMPROVEMENT IN THE
PROVISIONAL SPECIFICATION left by the said Reginald Heber
Radcliffe at the Office of the Commissioners of Patents, with his
Petition, on the 26th August 1872.
I, REGINALD HEBER RADCLIFFE, of The Oaks, in Ledsham, in the
County of Chester, and an Assistant in the Offices of the Inman Steam
Navigation Company, in Liverpool, in the County of Lancaster, do
hereby declare the nature of the said Invention for "AN IMPROVEMENT IN
THE ARRANGEMENT FOR THE SCREW PROPELLER IN STEAK SHIPS," to be as
follows:-
-
My Invention relates to the formation and extension of the dead work
from the run of the ship to the sternson, and the formation of the
opening in the dead work for the reception of the propeller.

page_text: I propose that the said dead work, whether of wood or iron, or other
material, should be constructed as thin as may be consistent with the
strength required, and that the breadth of the dead work from the pro-
peller opening to the sternson be increased more or less as may be
consistent with other conditions but still considerably increased, not
as at present the stern post forming the aft curb of the propeller
opening.
I propose the propeller opening in the dead work to be in size and
form in exact correspondence with the size and form of the propeller,
with allowance for free motion and no more.
By means of this condition of the opening or chamber of the propeller,
I neutralize the effect and loss of propulsive power resulting from the
cross action of the blades of the propeller on the water, and by limiting
the thickness and increasing the breadth of the dead work between the
propeller opening and the stern post I very considerably increase the
propulsive force of the machine by directing the operation, and with
accelerated force in the plane of the keel or line of the ship's progress,
the action being more efficient, continuous, and direct, and less disturbing
to the effect of the rudder in the direction of the ship's course.
By these arrangements or some of them, I increase the propulsive
power very considerably, and as measured by accelerated progress at
the least one-eighth part, and without any increased cost of constructed
mechanism or increased consumption of fuel. My Invention therefore
will operate a large economy in the important work of ocean traffic.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Reginald Heber Radcliffe in the Great Seal Patent
Office on the 21st February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, REGINALD
HEBER RADCLIFFE, of The Oaks, Ledsham, in the County of Chester,
sond greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of August, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
3

page_text: and grant unto me, the said Reginald Heber Radcliffe, Her special
licence that I, the said Reginald Heber Radcliffe, my executors, ad-
ministrators, and assigns, or such others as I, the said Reginald Heber
Radcliffe, 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
Ircland, the Channel Islands, and Isle of Man, an Invention for “AN
IMPROVEMENT IN THE ARRANGEMENT FOR THE SCREW PROPELLER IN STEAM SRIPS,"
upon the condition (amongst others) that I, the said Reginald Heber
Radcliffe, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and scals, 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 Scal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Reginald Heber Radcliffe, 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 :-
My Invention relates to the formation and extension of the dead work
for the reception of the propeller in ships moved by steam from the run
of the ship to the rudder post, and to the formation of the chamber or
opening in the dead work for the reception of the propeller.
First. I propose that the dead work astern of the propeller, whether
of wood or iron, or other material shall be constructed as thin as may
be consistent with the strength required, and that the breadth of the
dead work between the propeller opening and the rudder be increased
more or less as may be consistent with other conditions, but still con-
0 siderably increased instead of as at present.
Second. I propose that the propeller opening or chamber in the dead
work shall be in size and form in exact correspondence with the size
and form of the propeller, with allowance for free motion and practical
working and no more.
And I propose that such part of the edges of the dead work sur-
rounding the propeller opening, as it would be possible if the propeller
got out of position for the propeller to grind or come into contact with

page_text: should be so constructed, and of wood or such other material, as that its
being ground or broken by the propeller would not cause any material
injury to the propeller or the ship.
I refer to the two diagrams herewith in illustration of my Invention.
Diagram No. 1 shews the present form of propellor chamber or
opening, and the relative position of the rudder post and rudder, and the
general condition of the propeller in reference to the chamber. The
dead work is marked A, A, the rudder post B, the rudder C, the propeller
chamber or opening D, and the lines within the chamber shew the edges
of the propeller.
Diagram No. 2 shews the arrangement according to my Invention,
the dead work being marked A, A, the rudder pintles B, B, the rudder C,
and the propeller chamber or opening D. The lines within the chamber
represent the edges of the propeller blades, which may be of any form,
my Invention requiring that whatever the form of the propeller blades
the chamber or opening should conform thereto.
By means of this condition of the propeller chamber or opening I
diminish the effect and loss of propulsive power resulting from the cross
action of the blades of the propeller on the water, and by limiting the
thickness of the dead work and increasing the breadth of the dead work
between the propeller and the rudder I utilise more of the propulsive
force of the machine by directing the water in the plane of the keel or
line of the ship's progress.
By these arrangements or some of them I increase the effective pro-
pulsion very considerably, and without any increased cost of constructed :
mechanism, and as I obtain more uniformity of action in the propeller,
an economy of steam will result and a consequent economy in the
consumption of fuel. My Invention will therefore and as compared
with results operate an important economy in the great work of marino
traffic.
I have now described the nature of my said Invention, and the manner
of performing the same, but I do not restrict myself to the precise
details I have herein and in my Drawings herewith specified and
represented. Variations in detail may be expedient to peculiar con-
ditions, and practical application may suggest modifications without at a
all departing from the objects and principles of my Invention, but that

page_text: which I consider to be new, and therefore claim as the Invention to be
secured to me under the Letters Patent is, the closing up of the propeller
chamber or opening in the dead work to the size and form of the pro-
peller, with the allowance only for the free motion and the prolongation
backward of the plane of the dead work, substantially as herein-before
described.
In witness whereof, I, the said Reginald Heber Radcliffe, have here-
unto set my hand and seal, this Eighteenth day of February, in
the year of our Lord One thousand eight hundred and seventy-
three
REGINALD HEBER RADCLIFFE. (L.S.)
Signed, scaled, and delivered by the
said Reginald Heber Radcliffe, in
the presence of
SAM¹. BELCHER,
44, Bedford Road,
Rockferry,
Cheshirc.
CHARLES O. FRANCIS,
8, St. Paul's Road,
South Tranmere,
Cheshire.