IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLER CANAL BOATS AND OTHER VESSELS
Year: 1871

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW
PROPELLER CANAL BOATS AND OTHER VESSELS."-A communication from
abroad by Thomas Main, of Piermont, New York, United States of
America.
Sealed the 28th July 1871, and dated the 9th February 1871.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, on
the 9th February 1871.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION
OF SCREW PROPELLER CANAL BOATS AND OTHER VESSELS," a communication, to
be as follows:-
To overcome the objection to the use of screw propellers as ordinarily
applied to canal boats, I construct a cavity in the forward end of the
boat, and in this cavity I place the propelling screw, by the operation of
this screw in drawing the water into the cavity and forcing it under the

page_text: boat I obtain the desired motion of the boat and prevent the settling of the
rear end as would be the case if the screw were placed astern. I provide
a grating over the screw to prevent the entrance of floating objects into
the cavity and the entanglement or clogging of the screw by the same.
The screw is driven by a steam engine or any other suitable motor.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Scal Patent
Office on the 8th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of February, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence
that I, the said William Robert Lake, my executors, administrators,
and assigns, or such others as I, the said William Robert Lake, 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 “IMPROVEMENTS
IN THE CONSTRUCTION OF SCREW PROPELLER CANAL BOATS AND OTHER VESSELS,"
a communication to me from abroad by Thomas Main, of Piermont,
New York, United States of America, upon the condition (amongst
others) that I, the said William Robert Lake, my executors or adminis-
trators, 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 immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification :-
The use of steam vessels on canals or narrow rivers has been hitherto
attended with serious difficulties, the most important of which are the
wash on the banks caused partly by the action of the propeller or motor
on the water, and partly by the passage of the vessel itself through the
water, or as it is usually termed the "bow wave," the necessary
diminution in the width of the boat when side wheels are used, the,
settling of the stern of the boat when it is driven by an ordinary screw
propeller at the stern and the churning action against the bottom of the
canal by a propeller so placed. Attempts have been made to overcome
these difficulties by placing shields outside of the paddle wheels or by
placing the wheels or propellers in channels extending under or through
the boat, but these contrivances diminish the cargo bulk, and produce a
more injurious action on the banks by the increased divergence of the
waves directed against the sides, and hitherto no means have been suc-
cessfully devised for obviating the difficulties which have proved such
formidable obstacles to canal steam navigation.
For the purpose of overcoming these difficulties I construct the bow
or forward end of the boat with a cavity or channel whose lines merge
into those of the boat's bottom, in which cavity I place the propelling
screw. By the operation of this screw in drawing the water into the
cavity and forcing it under the boat, I obtain the desired motion of the
boat and prevent the settling of the rear end which would take place if
the screw were placed astern. I provide a grating over the screw. to
prevent the entrance of floating objects into the cavity and the en-
tanglement or clogging of the screw by the same. The screw is driven
by a steam engine or any other suitable power.

page_text: modification of form may be adopted, and the said propeller may be
arranged to work either horizontally, perpendicularly, or in any inter-
mediate angular position so long as the said propeller is placed and
operated in a cavity in the bow of the vessel of similar form to the
cavity c herein described and most clearly shown in Figure 1. This
arrangement of the propeller prevents any settling at the stern and
gives an even keel when the boat is in motion. The sides of the cavity
or channel prevent any lateral movement of the water as it passes the
propeller, and by so constructing the said cavity or channel that its lines
are merged into those of the vessel at d the water is deflected downward
in the line of least resistance under the vessel's bottom along which it
passes to the stern where its lateral force is dissipated before it reaches
the surface. The passage of the water under the boat tends to lift it
and aids the propulsion of the boat in shallow water, thereby allowing
the carriage of more cargo than would otherwise be practicable. And
as the space at the bow is less available for cargo than any other part of
the boat by arranging the propeller in a cavity at the bow I leave intact
space more valuable for cargo and which would otherwise be lost, and
thereby effect an object of great importance in a vessel of such limited
capacity as a canal boat. Moreover, drawing in the water from the bow
of the boat neutralises a great portion of the bow resistance and reduces
the "bow wave " to a minimum. These advantages cannot be obtained
by having a channel entirely through a boat, as in that case much cargo
space is lost and a torrent of water passes through the channel, spreads
laterally against the banks at a greater angle to them and causes more
injury by its undermining action than the waves produced by an ordinary
screw propeller. The position occupied by the engine being near the
bow, as shewn in Figures 1 and 3, the propeller shaft a¹ is in consequence
extremely short and therefore works with little friction. Very little
space is taken up by the engine 6 and boiler e, which may be of any
suitable form or kind. In Figure 2 I have shown the coarse grating f,
placed in front of the cavity c, for preventing the entrance into the said
cavity of large objects which might injure or obstruct the propeller.
This grating will effectually protect the propeller without in any way
interfering with the free entrance of the water to the same.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and shown how the same may be
conveniently and advantageously carried into practice, I claim,-

page_text: First. A canal boat or other vessel with a screw propeller arranged
to work in a cavity or channel of the peculiar form herein specified
in the centre of the bow of the said boat or vessel for the purposes set
forth.
Second. The grating in front of the said cavity for the purpose set
forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and scal, this Eighth day of August, in
the year of our Lord One thousand eight hundred and seventy-
onc.
Witness,
E. C. JACKSON.
WILLIAM ROBERT LAKE. (L.S.)