IMPROVED MEANS FOR OBTAINING EQUILIBRIUM AND STEADINESS IN FLOATING STRUCTURES, AND IMPROVEMENTS IN THE MODE OF BUILDING SUCH STRUCTURES SO AS TO ATTAIN THE AFORESAID OBIECT.”
Year: 1874

page_text: LETTERS PATENT to Charles Hodgson, of 166, Fleet Street, in the
City of London, Civil Engineer, for the Invention of "IMPROVED
MEANS FOR OBTAINING EQUILIBRIUM AND STEADINESS IN FLOATING STRUCTURES,
AND IMPROVEMENTS IN THE MODE OF BUILDING SUCH STRUCTURES SO AS TO
ATTAIN THE AFORESAID OBIECT.”
PROVISIONAL SPECIFICATION left by the said Charles Hodgson at the
Office of the Commissioners of Patents, with his Petition, on the
29th October 1874.
I, CHARLES HODGSON, of 166, Fleet Street, in the City of London,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVED MEANS FOR OBTAINING EQUILIBRIUM AND STEADINESS IN FLOATING
STRUCTURES, AND IMPROVEMENTS IN THE MODE OF BUILDING SUCH STRUCTURES SO
AS TO ATTAIN THE AFORESAID OBJECT," to be as follows:-
The first object of my Invention is to impart to structures used for
landing stages, loading stages, bridge pontoons, discharging hulks, light
ships, bell and signal buoys, floating breakwaters, or other moored

page_text: floating vessels, a greater amount of steadiness than is obtainable under
the modes of construction hitherto adopted.
The second object of my Invention is so to construct ships, barges,
pontoons, or vessels which are to move or be moved from place to place
that a greater amount of stability than is at present obtained may be
secured during the time such vesssls are in motion.
In carrying the first part of my Invention into effect I construct the
required stages, pontoons, or hulks in two parts, one of which contains
floatative power in excess of that required to float the entire fabric, and
the other consists of the deck or platform with its framework. I fix the
latter portion of the stage, pontoon, or hulk at a considerable elevation
over the former, uniting and combining them by columns or framework
of several feet in height, adjusting such height to the necessitics of each
case. I then proceed to moor the combined structure by chains or ropes
to anchors, weights, or other moorings, leading the chains or ropes
through hawse holes near the extremitics of lower or flotative portion
of the stage or pontoon, and passing upwards to winches or other means
of hauling attached to the upper or platform portion of the structure.
By tightening these chains or ropes I now submerge the flotative portion
till it is drawn down partially or altogether below the action of any
waves likely to effect it in the position in which it is placed. At the
same timo I attain a tension between the effort of the pontoon to risc
and the resistance of the moorings, which tension to a great extent or
altogether neutralizes the effect of passing waves on the columns or
framework, uniting what may be called the pontoon and platform
portions of the structure. I give to the platform portion such height
over the water as may be convenient for the purpose to which the
arrangement is to be applied. I provide cocks to admit water into the
pontoons whilst being submerged or when submerged, and pumps to
withdraw such water, so that by regulating the quantity of water con-
tained in the pontoon portion, I can control its power of floatation and
regulate the strain on the moorings.
The second part of my Invention consists in constructing vessels in
two parts as before described, and uniting them by columns or frame.
work, but instead of maintaining their position in the water (with the
pontoon portion submerged and the platform portion elevated) by means
of mooring down, I do so by ballasting with water or otherwise, relying

page_text: on the submerged position of the bulk of the vessel and the slight
nature of the columns, tubes, or framework exposed to the action of the
waves for obtaining a platform more steady than in ordinary floating
vessels, and capable of serving some special purposes, such as a gun
platform or passenger traffic, under certain conditions.
I do not limit myself to the number or shape of the individual
pontoons to be used or combined in each or any such structure as above
described, nor do I limit myself as to the number of compartments into
which I may divide cach pontoon for the purpose of security, or for the
better regulation of the pneumatical state of the combination.
filed by the said Charles Hodgson in the Great Seal Patent Office on
the 29th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HODGSON, of 166, Fleet Street, in the City of London, Civil Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of October, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Charles Hodgson, Her special
licence that I, the said Charles Hodgson, my executors, administrators,
and assigns, or such others as I, the said Charles Hodgson, 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 MEANS
FOR OBTAINING EQUILIBRIUM AND STEADINESS IN FLOATING STRUCTURES, AND
IMPROVEMENTS IN THE MODE OF BUILDING SUCH STRUCTURES SO AS TO ATTAIN THE
AFORESAID OBJECT," upon the condition (amongst others) that I, the said
Charles Hodgson, 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

page_text: 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 Charles Hodgson, 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, that is to say:-
The first object of my Invention is to impart to structures used for
landing stages, loading stages, bridge pontoons, discharging hulks, light
ships, bell and signal buoys, floating breakwaters, or other moored
floating vessels, a greater amount of steadiness than is obtainable under
the modes of construction hitherto adopted.
The second object of my Invention is so to construct ships, barges,
pontoons, or vessels, which are to move or be moved from place to place
that a greater amount of stability than is at present obtained may be :
secured during the time such vessels are in motion.
In carrying the first part of my Invention into effect, I construct the
required stages, pontoons, or hulks in two parts, one of which contains
floatative power in excess of that required to float the entire fabric, and
the other consists of the deck or platform with its framework. I fix the
latter portion of the stage pontoon or hulk at a considerable elevation
over the former, uniting and combining them by columns or framework
of several feet in height, adjusting such height to the necessities of cach
casc. I then proceed to moor the combined structure by chains or ropes
to anchors, weights, or other moorings, leading the chains or ropes
through hawse holes near the extremities of lower or floatative portion
of the stage or pontoon, and passing upwards to winches or other means
of hauling attached to the upper or platform portion of the structure.
By tightening these chains or ropes I now submerge the floatative
portion till it is drawn down partially or altogether below the action of-
any waves likely to affect it in the position in which it is placed. At the
same time I attain a tension between the effort of the pontoon to risc
and the resistance of the moorings, which tension to a great extent or
altogether neutralizes the effect of passing waves on the columns or
framework, uniting what may be called the pontoon and platform
portions of the structure. I give to the platform portion such height
over the water as may be convenient for the purpose to which the

page_text: arrangement is to be applied. I provide cocks to admit water into the
pontoons whilst being submerged or when submerged, and pumps to
withdraw such water, so that by regulating the quantity of water con-
tained in the pontoon portion I can control its power of floatation an
regulate the strain on the moorings.
The second part of my Invention consists in constructing vessels in
two parts as before described, and uniting them by columns or frame-
work, but instead of maintaining their position in the water (with the
pontoon portion submerged and the platform portion elevated) by means
of mooring down, I do so by ballasting with water or otherwise, relying
on the submerged position of the bulk of the vessel and the slight
nature of the columns, tubes, or framework exposed to the action of the
waves, for obtaining a platform more steady than in ordinary floating
vessels, and capable of serving some special purposes, such as a gun
platform or passenger traffic under certain conditions.
I do not limit myself to the number or shape of the individual
pontoons to be used or combined in each or any such structure as above
described, nor do I limit myself as to the number of compartments into
which I may divide each pontoon for the purpose of security, or for the
better regulation of the pneumatical state of the combination.
Having thus described my Invention, I claim,-
First. The submerging by drawing downwards towards fixed points in
the bottom of the water pontoons or other floating bodies, for the
purpose of obtaining a comparatively steady base for any such super-
structure as described above and shown in the accompanying Drawings.
Secondly. I claim the use upon such structure of pumps and valves
to admit water, arranged in any convenient manner to regulate the
stability of such structures.
In witness whereof, I, the said Charles Hodgson, have hereunto.
set my hand and seal, this Twenty-ninth day of April, One
thousand eight hundred and seventy-five.