AN IMPROVED METHOD OF RAISING SCREW PROPELLERS
Year: 1864

page_text: LETTERS PATENT to William King Hall, of Sheerness, in the County of
Kent, Captain in the Royal Navy, Companion of the Bath, for the
Invention of "AN IMPROVED METHOD OF RAISING SCREW PROPELLERS."
Sealed the 5th May 1865, and dated the 8th November 1864.
PROVISIONAL SPECIFICATION left by the said William King Hall at
the Office of the Commissioners of Patents, with his Petition, on the
8th November 1864.
I, WILLIAM KING HALL, of Sheerness, in the County of Kent, Captain in
the Royal Navy, Companion of the Bath, do hereby declare the nature of the
said Invention for "AN IMPROVED METHOD OF RAISING SCREW PROPELLERS," to be
as follows:-
My Invention applies to those ships not provided with wells, through which
to raise the screw. It consists in raising the screw above the water line by
means of two threaded rods, the lower ends of which are attached to the
brasses in which the screw revolves, while the upper ends are carried through
the ship, and work in nuts toothed on the outside, both nuts being simul-

page_text: wise.
taneously acted on by a central toothed wheel driven by a capstan or other-
After the screw propeller has been raised above the water line or close
under the ship's counter I employ chains and davits. When the screw is
lifted a shackle is put on each of the screw blades, so that the screw may be
slung and disconnected from the threaded rods, the disconnection being
effected by knocking out the cotters which hold the parts together. The
davits are placed over the counter in the most convenient place, and should
it be necessary to alter the pitch or remove one of the blades, the screw need
not be brought on deck for such purpose; but if required to get the screw on
deck, the tackle from one davit can be lowered, while the tackle from the
other davit can be hauled on; the screw propeller will then find its perpen-
dicular position, and freed from the stern and rudder post can be hoisted
inboard.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William King Hall in the Great Seal Patent Office on the
8th May 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
KING HALL, of Sheerness, in the County of Kent, Captain in the Royal
Navy, Companion of the Bath, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of November, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William King Hall, Her special licence that I, the said William King
Hall, my executors, administrators, and assigns, or such others as I, the said
William King Hall, 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,
nexercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
METHOD OF RAISING SCREW PROPELLERS," upon the condition (amongst others)
that I, the said William King Hall, 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.

page_text: 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 King Hall, 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
thereof, reference being had to the Drawings hereunto annexed, that is to
say :-
My Invention applies to those ships not provided with wells, through which
to raise the screw. It consists in raising the screw above the water line by
means of two threaded rods, the lower ends of which are attached to the
brasses in which the screw revolves, while the upper ends are carried through
the ship, and work in nuts toothed on the outside, both nuts being simul-
taneously acted on by a central toothed wheel, driven by a capstan or other-
wise.
Figure 1 of the accompanying Drawings is a longitudinal section of a ship's
stern without a screw well, and fitted with my means of raising the screw
propeller; Figure 2 is a similar view, shewing the propeller raised.
A is the water line; a, a, are rods secured to the brasses in which the screw
revolves; they reach to the upper deck, and are screw threaded sufficiently
low down to enable the screw propeller to be raised up above the water line
by nuts fitted into the deck, and worked by a wheel c and piuions or teeth b
on the nuts through the intervention of a capstan d and bars, ratchet wheel,
or any other mechanical appliance. The T-head upon the screw must be
perpendicular when the screw is horizontal. After the screw propeller has
been raised above the water line or close under the ship's counter I employ
chains E and davits F, G. When the screw is lifted, a shackle is put on
each of the screw blades, so that the screw may be slung and disconnected
from the threaded rods, the disconnection being effected by knocking out the
cotters which hold the parts together. The davits are placed over the counter
in the most convenient place, and should it be necessary to alter the pitch or
remove one of the blades the screw need not be brought on deck for such
purpose, but if required to get the screw on deck, the tackle from one davit
say the davit H, can be lowered, while the tackle from the other davit G can
be hauled on; the screw propeller will then find its perpendicular position,
and freed from the stern and rudder post can be hoisted on board.
Figure 3 represents the screw suspended by the chains and davits.
And having now described the nature of my said Invention, and in what
manner the same is to be performel, I declare that I claim raising screw

page_text: propellers in manner and by the appliances herein-before described, and illus-
trated in the accompanying Drawings.
In witness whereof, I, the said William King Hall, have hereunto set
my hand and seal, this Fourth day of May, One thousand eight
hundred and sixty-five.
WILLIAM KING HALL. (L.s.)