IMPROVE- MENTS IN PROPELLERS FOR SHIPS AND OTHER NAVIGABLE VESSELS
Year: 1862

page_text: LETTERS PATENT to John Burchall, of St. Helens, in the County of
Lancaster, Merchant, and Edward Borrows, of Sutton, also in the
County of Lancaster aforesaid, Engineer, for the Invention of "IMPROVE-
Sealed the 11th March 1863, and dated the 6th December 1862.
PROVISIONAL SPECIFICATION left by the said John Burchall and Edward
Borrows at the Office of the Commissioners of Patents, with their Peti-
tion, on the 6th December 1862.
We, JOHN BURCH ALL, of St. Helens, in the County of Lancaster, Merchant,
and EDWARD BORROWS, of Sutton, also in the County of Lancaster aforesaid,
Engineer, do hereby declare the nature of the said Invention for " IMPROVE-
MENTS IN PROPELLERS FOR SHIPS AND OTHER NAVIGABLE VESSELS," to be as
follows:-
The object of our Invention of "improvements in propellers," is to prevent
the vibration so justly complained of in ships and vessels fitted with paddle
wheels of the descriptions now in use, to produce or construct propellers less
liable to damage from ice and other hard substances in the water, and
to obtain, by the use of such propellers, increased speed from the employment
of an equal amount of motive power. On both sides of ships and other
vessels, and in similar positions to the ordinary paddle wheels, we place one,
two, or more propellers partially immersed in the water, resembling in form

page_text: the stern submerged screw propeller generally in use. The blades are
sometimes, for small and coasting ships, cast with the boss, which is secured
to the driving shaft, but usually and by preference so formed and secured
to the said boss that the angle and pitch at which the said blades enter and
leave the water, and the depth of immersion, can be accommodated to the
water line. These propelling blades may be secured by bolts or pins to the
boss and strengthened by stays, but in all cases we dispense with rings round
the outer circumference.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Burchall and Edward Borrows in the Great Seal
Patent Office on the 5th June 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
BURCHALL, of St. Helens, in the County of Lancaster, Merchant, and
EDWARD BORROWs, of Sutton, also in the County of Lancaster aforesaid,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of December, in the year of our
Lord One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said John Burchall and Edward Borrows, Her special licence, that we, the
said John Burchall and Edward Borrows, our executors, administrators, and
assigns, or such others as we, the said John Burchall and Edward Borrows,
our 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 "IMPROVEMENTS IN PROPELLERS FOR
SHIPS AND OTHER NAVIGABLE VESSELS," upon the condition (amongst others)
that we, the said John Burchall and Edward Borrows, our executors or
administrators, by an instrument in writing under our, 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 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.

page_text: NOW KNOW YE, that we, the said John Burchall and Edward Borrows,
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement (that is to say) :-
The object of our Invention of "improvements in propellers," is to
prevent the vibration so justly complained of in ships and vessels fitted with
paddle wheels of the descriptions now in use, to produce or construct propellers
less liable to damage from ice, and other hard substances in the water, and
to obtain, by the use of such propellers, increased speed from the employment
of an equal amount of motive power. On both sides of ships and other
vessels, and in similar positions to the ordinary paddle wheels, we place one,
two, or more propellers partially immersed in the water, resembling in form
the stern submerged screw propellers generally in use. The blades are
sometimes, for small and coasting ships, cast with the boss, which is secured
to the driving shaft, but usually and by preference so formed and, secured
to the said boss that the angle and pitch at which the said blades enter and
leave the water, and the depth of immersion, can be accommodated to the
water line. These propeller blades may be secured by bolts or pins to
the boss and strengthened by stays, but in all cases we dispense with rings
round the outer circumference.
That our Invention may be clearly understood we have hereunto attached
a Sheet of Drawings illustrative of several modifications of our improvements.
Fig. 1 is a side elevation, and Fig. 2 a plan or bird's-eye view, both of a
propeller cast in one piece, and suitable for the smallest class of vessels, say,
yachts and canal boats. Four blades or radial arms a, are shewn, but any
desired number may be employed; we have found six give very good results;
6 is the boss; and c the transverse driving shaft. Figs. 3 and 4 are similar
views to Figs. 1 and 2 of a propeller with six blades or radial arms. The
strengthening ribs d, radiating from the boss e, and running up the blades
or radial arms f to any desired distance, but tapering off and merging into
the blades, preferably within the water line, are cast in one piece with the
other parts, and make this form serviceable for a larger class of ships, say,
river and coasting vessels; g is the driving shaft. Fig. 5 is a side elevation
of a propeller, built or constructed of a number of pieces, with five blades
or radial arms, and Fig. 6 is a plan view of the same propellers shewn secured
on the ends of a driving shaft, and having each one of the blades or arms
cut off close to the boss to exhibit the means of altering the pitch and angle
of the said blades or radial arms. This class is serviceable for any size of
ship; represents the driving shaft; i the boss on which there is cast or

page_text: otherwise formed a number of flanges j, corresponding to the number of
bladesk that may be used. In or about the centres of these flanges recesses
are formed to receive studs l, cast with or attached to the. blades. The
flanges m and j are here shewn fastened by screwed bolts and nuts, but
any other means of connecting them may be adopted. In the flanges m,
openings n of segmental form are left, so that the blades or radial arms may be
moved, and a greater or lesser pitch and angle employed as may be desired
or demanded by the depth of immersion of the ship in the water. Filling
pieces, held in position by washers or otherwise, may be placed in the said
openings to keep the blades from moving; o are stays fastened by through
pins or cotters at their outer ends to the blades k, and by screwed nuts p, at
their inner ends to the boss i.
In Fig. 7, which is a side elevation of another modification of propeller,
and Fig. 8, which is a transverse section of a shaft, and a pair of Fig. 7 pro-
pellers, the six blades shewn are so arranged that they may be "reefed," or
moved to suit the "water line," of the ship; p¹, represents the driving shaft
q, the boss made of a large centre piece, to which is revetted or otherwise
secured strong sheets of metal with holes therein for the bolts r, to hold the
blades s, which should be made of wrought iron or steel, on and close to the
side of such boss. The blades s are here shewn "furled," or as close up to
the shaft as they can be brought. The slots or openings t allow the blades
to be "reefed;" filling pieces may be employed to keep such blades more
securely in position. If at any time it should be wished that the "reefing"
system just described should be so constructed or arranged that the angle and
pitch of the blades or radial arms should be capable of alteration and adjust-
ment then this can easily be accomplished by having the blades gradually
increasing in thickness on one side thereof towards their centres, for if the
blades. in the positions shewn on the Drawings were so formed, they would,
on being pushed outwards, and their sides next to the boss being kept close
thereto at all parts, alter their angle and pitch; it would be necessary how-
ever to form in accordance with the thickness of the blades the parts
where the nuts were to be screwed home, so that they would meet a level
surface. We do, however, consider it unlikely that the "
reefing", "and
altering the pitch and angle of the blades would be used together.. The
dotted lines in these two Figures represent parts of a ship, and illustrate a
convenient. position for placing propellers constructed according to Figs. 7
and 8, or any other modification of our Invention, in ships of war; that
position is in the dead wood, towards the stern. If spaces are formed at
either side by carrying straight lines upwards from the dead wood, then tho

page_text: propellers would be within the ordinary out of water lines of a ship, at
parts where it is usual or convenient to affix shield armour.
J
With disconnecting and reversing engines and propellers, according to
our Invention, placed in the spaces pointed out, ships of war could be
manoeuvred with great facility. a', shews the keel; 61, the lines amidship;
c', the dead wood lines; d¹, the gunwale and deck; e, the bulwarks; f¹, the
covers for the propellers." The blades or radial arms, to which any shape may
be given, may be flat throughout in their propelling surfaces and placed that
they will act at any desired and uniform angle on the water, or they may
each have varying pitches of screws, but the form which we prefer combines
both of these, and has the blades of the form shewn in the Drawings, with
both surfaces of such blades slightly convex, and somewhat similar to an oar.
About one-third of the outer ends of the propelling surfaces proper, or those
parts which really enter the water, it is preferred should be placed that lines
or the surfaces, from the leading to the following edges of the blades, would
give an angle of 60° to the water surface line when the former edges were
measured as at or touching such water surface line, whilst the remaining two-
thirds of the surfaces which enter the water taking the blades on the
Drawings as made to an inch scale, would have pitches of about six feet.
The angular, flat, and twisted parts merge into each other. We also prefer
that in "going ahead" the propellers should throw the water away from
the sides of the ship, and not toward the same. Engineers and naval
architects, however, from their practice with the submerged screw propeller
and the results that have been obtained by trials of the same, will readily
understand the requirements of propellers according to our Invention; z, z, in
all the views are lines to represent the water surface.
Having now described the nature of our said Invention, and particularized
the same by various modifications suitable for ships of different sizes, we would
have it understood that we do not confine ourselves to the details laid down,
such as the form and number of blades, the means of securing, strengthen-
ing, staying, and reefing, and altering the pitch and angle of such blades, as
these may be variously altered and modified, but what we claim is,-
Firstly, the use of propellers placed on any part of the sides of ships,
or other navigable vessels, with angular or twisted blades, or angular and
twisted blades without rings or other supports in the parts which enter
the water, as herein set forth, and illustrated by the accompanying Sheet of
Drawings.
Secondly, altering the pitch and angle of the blades mentioned in the
first claim, convenient means of doing so being shewn by Figs. 4 and 5

page_text: on the accompanying Sheet of Drawings, and referred to in this Specifica-
tion.
And, thirdly, "reefing, or altering the blades mentioned in the first
claim, that they shall dip more or less into the water as required, convenient
arrangements for carrying out the same being shewn by Figs. 7 and 8
on the accompanying Sheet of Drawings, and set forth in this Specification.
In witness whereof, we, the said John Burchall. and Edward Borrows,
have hereunto. set our hands and seals, this Twentieth day of May,
in the year of our Lord One thousand eight hundred and sixty-
..three.
(L.S.)
JOHN BURCHALL.
EDWARD BORROWS. (L.S.).
In the presence of
JOHN THOMSON KING,
Patent Agent,
4, Clayton Square,
. Liverpool.