IMPROVEMENTS IN THE CONSTRUCTION OF SUBAQUEOUS WORKS AND FOUNDATIONS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by John Smith Burke and Benjamin
Burleigh at the Office of the Commissioners of Patents, with their
Petition, on the 11th July 1867.
We, JOHN SMITH BURкB and BENJAMIN BURLEIGH, both of 4, Queen's
Square, Westminster, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF SUBAQUEOUS WORKS AND FOUNDATIONS,"
to be as follows:-
This Invention has for its object the improvement of the construction of
foundations and all kinds of works beneath the surface of the water.
The plan of operation is as follows:-We propose to construct a pontoon
or floating vessel of steel, iron, wood, or other suitable material having a flat
bottom, or bottom of any required form, the pontoon to be worked by steam
power or otherwise, and to be provided with screw propellers and apparatus
for guiding and fixing in position, and with pumps for air and water pressure,
and all other necessary apparatus. We then construct in a dry dock or other
suitable situation a casing of wood or metal of such form as may be required
for a section of the work or foundation of the work to be erected; the said
casing is then filled with brickwork, masonry, concrete, or other suitable
material. The water is then let into the dock or other receptacle, and the
pontoon is floated immediately over the casing, to which it is lowered by the
admission of water, or by the action of the tide, and then securely fastened
either by bolts, chains, slings, or other suitable apparatus, the pontoon being
so constructed that when emptied of the water which has been let in for the

page_text: purpose of lowering it it shall have sufficient floating power to lift the casing
and its contents together and float them into their permanent position; when
they are lowered into place and fixed in position, either by the action of the
tide, or by readmission of water into the pontoon, which is then detached in
order to repeat the operation. By this means very large masses of material
may be dealt with, thus affording much greater stability in a work than can
be attained by any ordinary method now in use. The blocks of masonry or
other material may also be removed in the same manner independently of the
casing.
We also sometimes float the casing itself into place over the bed of the
foundation, and partly fill the same with masonry or other material, and then
by the admission of water or by the action of the tide sink it to its place, the
remaining portion of the casing being filled up solid, either by means of
diving or by tipping material in from above.
We also sometimes vary the construction of the pontoon, making the whole
or any required portion of it into an air vessel, and thus by pumping in or
exhausting the air when required we facilitate the process of raising or
lowering the casing and its contents.
We also sometimes construct the pontoon with vertical shafts rising from the
bottom, the bottom of the pontoon being provided with an inverted open case
large enough to cover the mass intended to be lowered; or it may be con-
structed with side flaps or wings to be lowered in such manner as to enable
workmen to descend and make good or level any inequalities in the portion of
the work already lowered. The vertical shafts are also sometimes used as
pneumatic shafts for the purpose of blowing out the water to enable workmen
to level off and adjust the masonry or other material used.