IMPROVED APPARATUS FOR FACILITATING THE FINDING AND RAISING OF VESSELS AND SUBMERGED ARTICLES
Year: 1856

page_text: LETTERS PATENT to Albert Demerit Bishop, of Woolwich, in the County
of Kent, Engineer, for the Invention of "IMPROVED APPARATUS FOR
FACILITATING THE FINDING AND RAISING OF VESSELS AND SUBMERGED
ARTICLES."
Sealed the 21st April 1857, and dated the 23rd October 1856.
PROVISIONAL SPECIFICATION left by the said Albert Demerit Bishop
at the Office of the Commissioners of Patents, with his Petition, on the
23rd October 1856.
I, ALBERT DEMERIT BISHOP, of Woolwich, in the County of Kent, Engineer,
do hereby declare the nature of the said Invention for "IMPROVED APPARATUS
FOR FACILITATING THE FINDING AND RAISING OF VESSELS AND SUBMERGED
ARTICLES," to be as follows:-
This Invention relates, firstly, to a mode of sweeping the waters to discover
the location of a submerged ship or other sunken property not visible on
inspection from above the water.
The great difficulty which submarine explorers have hitherto had to contend
with has arisen from the sweep chain catching against projecting substances of
various kinds lying on the bed of the sea or river. A diver had then to
descend either to inspect the ground or to release the chain, and this frequently
occurred before the property sought was discovered. To avoid this, I propose,
when sweeping the waters for, say, a sunken vessel, to use a floating rod, which

page_text: shall be kept to a given height from the bed of the sea or river, so as to
be clear of stones and other matters, but sufficiently low to come in contact
with, say, the mast of the ship, when drawn over the spot where it is located,
and thus indicate the presence of the ship sought for. Pendent from this rod
(which is kept up by suitable floats) are rods or chains, which are weighted to
the required degree to sink the rod to the desired level.
With this apparatus I propose to pursue the operation in the ordinary
When the ship or other property is discovered I sink chains at
opposite extremities thereof, and proceed to gather up the chains and draw
them taut, in order that they may grip the ship or other property which they
surround; but instead of using a sliding ring or other imperfect contrivance, as
heretofore, I employ for drawing the chains together a novel apparatus, which
forms the second head of my Invention. This apparatus may be described as
a weighted pawle frame, through which those ends of the drag chains are
passed that are connected with the capstans or other lifting apparatus. The
slot holes through which the chains are passed are each provided with a pawle
for gripping the chains and preventing them from sliding back, while they
leave the links of the chains free to move upwards. Each pawle is fitted with
an eye to receive a cord for lifting the pawles when required, and the frame
being weighted it will always have a tendency to run down the chains and take
a grip at the lowest point.
By the use of this apparatus-I am enabled to facilitate greatly the gathering
in of the chains, and to secure a grip or slacken hold of any chain at pleasure,
without the aid of a diver to assist the hauling operation from below.
SPECIFICATION in' pursuance of 'the 'conditions of the Letters Patent, filed
by the said Albert Demerit Bishop in the Great Seal Patent Office on the
23rd April 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALBERT
DEMERIT BISHOP, of Woolwich, in the County of Kent, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of October, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Albert Demerit Bishop, Her special license that I, the said Albert
Demerit Bishop, my executors, administrators, and assigns, or such others

page_text: as I; the said Albert Demerit Bishop, 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
"IMPROVED APPARATUS FOR FACILITATING THE FINDING AND RAISING OF VESSELS
AND SUBMERGED ARTICLES," upon the condition (amongst others) that I, the
said Albert Demerit Bishop, by an instrument in writing under my hand and.
seal, 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 Albert Demerit Bishop, 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, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
This Invention relates, firstly, to a mode of sweeping the waters to discover
the location of a submerged ship or other sunken property not visible on
inspection from above the water. The great difficulty which submarine
explorers have hitherto had to contend with has arisen from the sweep chain
catching against projecting angles of rocks or detached masses of stone
and other substances lying on the bed of the sea or river. When this occurred
a diver was required to descend to inspect the ground or to release the chain,
and thus frequent descents were made before the property sought for was
discovered. To avoid this tardy process of ascertaining the location of sunken
property, and also to prevent the liability of breaking the drag chains, I
propose, when sweeping the waters for, say, a sunken vessel, to use a floating
rod or wire, which shall be kept to a given height from the bed of the sea or
river, so as to be clear of stones and other matters, but sufficiently low to come
in contact with, say, the mast of a ship, when drawn over the spot where it is
located, and thus indicato the presence of the ship sought for.
. In the accompanying Drawing, Fig. 1 illustrates the manner in which I
proceed to sweep the waters, a sunken steamer being represented as the
property desired to be recovered. a, a, is a rod or wire, threaded through and
sustained in a horizontal position or nearly so by floats b, b. This wire is let
down into the water by draft chains or cords c, c, from the drag boats, and it is
sunk to any required level by pendent rods or wires d, d, which are weighted
sufficiently to ensure their touching the bottom. 1 find it convenient to make

page_text: these wires d about fifty feet in length, and I thus secure a good elevation for
the horizontal rod or wire a. The distance apart of the rods d I prefer to be
somewhat greater than their length, say, sixty feet; but these dimensions may
be changed, to suit different circumstances, the nature of the property sought
to be recovered determining the level of floatation of the horizontal wire.
With this apparatus I propose to pursue the operation of sweeping waters in
the ordinary manner. It will now be understood that if the men in the drag
boats perceive a sudden draft upon the apparatus it must be due to an
obstruction standing up above fifty feet from the bed of the sea, and therefore
it will be an indication that the vessel sought for is discovered. When
the location of the ship is thus made known I sink chains at opposite
extremities thereof, and proceed to gather up the chains and draw them taut,
in order that they may grip the ship which they surround; but instead of
using a sliding ring or other imperfect contrivance, as heretofore, for drawing
the chains together, I employ a novel apparatus, which forms the second head
of my Invention.
This apparatus is shewn in side elevation at Fig. 2, in sectional elevation at
Fig. 3, in plan view at Fig. 4, and as applied to the raising of a ship in Fig. 5.
It may be described as a weighted pawle frame, through which the chains that
are passed round the vessel to be raised are conducted before they are returned
to the capstans or other lifting apparatus employed in raising the sunken
vessel. e, e, is the pawle frame, made of wrought iron, and in it are formed
slot holes through which the lifting chains are passed. Fitting into these slots
are pawles f.f, for gripping the chains and preventing them from sliding back,
while they leave the links of the chains free to move upwards. The pawles
are jointed by cross pins to the frame e, and they are each fitted with an eye
to receive a cord for raising them and discharging them from the chains when
required. The under side of the frame is provided with a weighted projecting
piece g, which will give it a tendency to run down the lifting chains and take
a grip at the lowest point. By the use of this apparatus (which may, if
desired, be constructed to receive and grip two, three, or more chains abreast
of each other,) I am enabled to facilitate greatly the gathering in of the chains
(as shewn at Fig. 5), and to secure a grip or slacken hold of any chain
at pleasure, without the aid of a diver to assist the hauling operation from
below.
Having now set forth the nature of my Invention of "Improved Apparatus
for Facilitating the Finding and Raising of Vessels and Submerged Articles," I
wish it to be understood that under the above in part recited Letters Patent
I claim,-

page_text: First, the floating drag apparatus, as described, for sweeping inland and
other waters at any desired elevation from the bed or bottom thereof.
And, secondly, the novel construction of apparatus for drawing together and
securing the lifting chains, as explained.
In witness whereof, I, the said Albert Demerit Bishop, have hereunto
set my hand and seal, the Twenty-third day of April, in the year of
our Lord One thousand eight hundred and fifty-seven.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. D. BISHOP. (L.S.)