IMPROVEMENTS IN FLOATING DOCKS AND PONTOONS
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Josiah Latimer Clark and John
Standfield at the Office of the Commissioners of Patents, with their
Petition, on the 8th January 1874.
We, JOSIAH LATIMER CLARK, and JOHN STANDFIELD, both of 5,
Westminster Chambers, Victoria Street, Westminster, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN FLOATING DOCKS
AND PONTOONS," to be as follows:-
Our Invention consists in an improved form of floating dock or
pontoon.
The improvement consists in constructing the dock or pontoon of a
series of circular or nearly circular tubes placed parallel to each other,
either longitudinally or transversely connected with similar vertical
tubes at their ends or sides. This circular form is peculiarly calculated to
withstand the pressure to which such structures are subjected in use.
These tubes are divided into water-tight compartments, and are provided
with suitable connections and pumps, by means of which after their sub-
mersion the water may be pumped out of them in the ordinary manner.
Each tube when complete is in the form of the letter U, and when the
pontoon is floating with a vessel upon it the horizontal portion supports

page_text: the weight of the vessel, and the vertical portion stands upright out of
the water. A series of these U shaped tubes placed side by side and
connected by angle or channel irons or timber forms the complete
pontoon. When it is submerged the horizontal tubes are partially filled
with water, and the floatation is maintained by vertical tubes.
the weight of the vessel, and the vertical portion stands upright out of
the water. A series of these U shaped tubes placed side by side and
connected by angle or channel irons or timber forms the complete
pontoon. When it is submerged the horizontal tubes are partially filled
with water, and the floatation is maintained by vertical tubes.
In some cases we prefer to make the horizontal tubes and vertical
tubes separate and distinct from each other, or to use horizontal tubes
only.
The several segments may be so grouped together that the dock or
pontoon may be divided into two or more portions which may be used:
separately, and which can at any time be bolted together again so as to
form one large dock or pontoon.
In some cases, instead of pumping water out of the top of the tubes we
prefer to keep the top of some of the tubes closed and to pump air into
them, the bottom of the tubes being left partially open below for the
escape
of the water. The air expands within them, expelling the water.
They are submerged by simply allowing the air to escape at top through
a suitable tap, and the compression of the air within as the pontoon
sinks and the pressure increases is again compensated by its expansion
when the pontoon is again raised to its surface, so that only a portion of a
the power is wasted when raising and lowering the dock or pontoon.
It is preferable to connect the series of tubes into three groups of
equal buoyancy, viz., the first group to consist of one-third of the whole
number at one end; the second group to consist of the right-hand half
of the remainder; and the third group to consist of the left-hand half of a
the remainder. By the suitable manipulation of these groups the whole
dock may be levelled and kept level either longitudinally or trans-
versely.