Year: 1888

page_text: 1, WILLIAM MATHER SWANSON of 27 Prince Leopold Street; Roath, Cardiff
in the county of Glamorgan, Ship-yard manager, do hereby declare the nature of
this invention to be as follows:-
This invention consists in improvements in pontoons or floating docks whereby
they may themselves be more conveniently floated for docking, inspection, repairs,
painting or for other purpose.
According to this invention a main pontoon is combined with its superstructure as
a rigid structure, and at each end the superstructure extends outwards from the
body of the main pontoon. Below the extensions of the superstructure are two
smaller pontoons, that is to say one at each end. These smaller pontoons may be
attached to and detached from the main pontoon at will.
When it is required to raise the main pontoon for inspection, repairing, painting
or other purpose, the end pontoons are sunk to the required level by charging them
with water. The space then intervening between the bottom of the end extensions
of the superstructure of the main pontoon and the top of the smaller pontoons is
packed with blocks or other suitable appliances and the water is then pumped out of
the said smaller pontoons.
Thus the main pontoon is raised above the level of the water.
The smaller pontoons may be docked on the main pontoon, and this is accomplished
by first detaching them from the superstructure of the main pontoon, and then
sinking them so as to be clear of the main pontoon.
The main pontoon is then sunk to the required depth and the smaller pontoons
are floated on to it. The main pontoon is then raised and the smaller pontoons
are carried up with it and thus access may be had to any part of the smaller
pontoons.
2 A
1 1000

page_text: Improvements in Pontoons. or Floating Docks.
I, WILLIAM MATHER SWANSON, of 27 Prince Leopold Street, Roath, Cardiff,
in the county of Glamorgan, ship-yard manager, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention, which relates to pontoons or floating docks einployed for receiving ships
requiring repairs, cleaning painting or other attention, consists in the use, for the
said purpose, of a set of such structures, constructed and arranged as hereinafter
more particularly described.
By virtue of such construction and arrangement the pontoons are themselves more
conveniently floated for inspection, repairs or other purpose.
According to this invention, a main pontoon, which with its superstructure is
made one rigid structure, and two supplementary pontoons are employed.
The superstructure of the main pontoon is extended at each end beyond the deck
or body. Below the extensions of the superstructure are received two supplementary
pontoons which may be conveniently referred to as the small pontoons. They are
coupled to the main pontoon by any convenient connection and are easily detached.
The supplementary pontoons fill the space at each end between the outer ends of
the superstructure and the ends of the body of the main pontoon which, with the
supplementary pontoons, constitutes one floating dock for the reception of ships.
"
When it is required to raise the main pontoon for repairing or painting the same,
or for other purpose, the end pontoons are sunk to the required level by charging
them with water. The space then intervening betwen the bottom of the end
extensions of the superstructure of the main pontoon and the deck of the small
pontoons is packed with blocks, beams or other appliances, and the water is then
pumped out of the said small pontoons. The main pontoon is accordingly raised
clear of the water..
The small pontoons may be docked on the main pontoon and, when this is requisite,
the small pontoons are detached from the main which is then sunk to a required
level and when the small pontoons have been floated over its deck the main pontoon
is raised and carries the small pontoons up with it.
Referring to the accompanying sheet of drawings, Fig. 1 thereon represents a side
elevation of a set of three pontoons constructed and arranged in accordance with
this invention. The set consists of the main pontoon a and the supplementary
pontoons b. The superstructure a¹ of the main pontoon a is extended at each end
beyond the body or deck. The superstructure and the body are combined in one rigid
structure.
Below the extensions of the superstructure of the main pontoon a are received
the supplementary pontoons & connected in any convenient manner to the main.
When thus connected the set of pontoons constitute one floating dock for the
reception of ships, as seen at Fig. 1. The ship is raised on a rigid structure and

page_text: the strain is thus more equally distributed over the whole length of the ship
through the main pontoon.
The quantity of water which it is necessary to pump out is nearly equal to the
weight of the ship, a suitable margin being taken out for stability.
Should the ship rest on the main pontoon and one of the small pontoons only,
the quantity of water to be pumped out of the other small pontoon is only such as
is necessary to balance it with the superstructure so as to keep an even strain on
the latter.
The ship being raised clear of the water line the air circulates more freely around
it than in a graving dock.
At Fig. 2 is represented a side elevation of the pontoons the main pontoon a
being raised by the end pontoons b. To accomplish this the pontoons 6 are first
charged with water and thus made to sink to the required extent. The space then
intervening between the underside of the ond extensions of the superstructure a¹
and the top of each of the small pontoons is packed with beams or blocks c, or
otherwise, and the necessary quantity of water is pumped out of the pontoons b,
and the main pontoon a is thus raised out of the water for inspection, repairs or for
other purpose.
At Fig. 3 is represented a part plan and part horizontal section of the combined
pontoons.
In order to dock either of the pontoons 6 in the main pontoon a the pontoon to
be docked is detached from the main and the latter is sunk to the necessary extent.
The small pontoon is then turned partially round so as to bring its narrowest side
opposite the end of the main pontoon above the deck of which it is then floated.
The inain pontoon is then raised and carries up the small pontoon with it.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of the superstructure of a pontoon or floating dock with the
body as one rigid structure, substantially as described.
2. Extension of the superstructure of a pontoon or floating dock, at each end,
beyond the body, substantially as hereinbefore described.
more
3. The use in conjunction with a main pontoon such as a of two or
supplementary pontoons such as separable from the main pontoon, substantially
as hereinbefore described with reference to the accompanying sheet of drawings.
Dated this 27th day of December 1888.
NICHOLAS WATTS,
Applicant's Agent.