AN IMPROVED GRID FOR DOCKING AND RAISING VESSELS
Year: 1878

page_text: LETTERS PATENT to Josiah Latimer Clark and John Standfield, both of 6,
Westminster Chambers, Victoria Street, in the City of Westminster, for the
Invention of "AN IMPROVED GRID FOR DOCKING AND RAISING VESSELS."
Sealed the 3rd Sontember 1878. and dated the 28th June 1878
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark and
John Standfield at the Office of the Commissioners of Patents on the 28th
June 1878.
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of 6, Westminster
Chambers, Victoria Street, in the City of Westminster. AN IMPROVED GRID for
DOCKING AND RAISING VESSELS."
"
Our improvement consists in so constructing the gridiron stage on which tho
vessel rests that it can be raised and lowered by hydraulic presses or other means,
the intention being that the vessel should be floated over the grid at high water,
and that the whole should then be raised by hydraulic presses or other means
to a suitable height above the level of high water, and there supported in a
convenient position for conducting repairs or painting.
In cases where there is no considerable rise or fall of tide we construct the grid
at a sufficiently low level to allow the vessel to be floated over it. To effect this we
prefer to construct the grid of wrought-iron plate, with hollow chambers, so that it
can be made buoyant to enable it to be easily floated away when required, and for
economy we prefer a skeleton form in which the backbone of the grid is a hollow
box girder, and the sides are in the form of short girders or ribs projecting at right
angles from the backbone at convenient distances, and on the top of these ribs
sliding bilges are constructed, and at their ends side-shoring frames may be erected,
the intermediate spaces between the ribs being planked over.
The hydraulic presses are placed directly under the grid, the prosses being
inserted in the ground.

page_text: The rams as they ascend carry up the grid with the vessel upon it, and when it
is at its highest level it is supported there on struts or pawl legs, which are by
preference jointed to the grid at the top, and which were at first suspended in a
horizontal position, but which are now allowed to fall vertically, so that their
bottoms rest upon the shoulders of the presses or upon convenient tables attached
thereto. As soon as the weight rests upon these struts the rams are lowered into
the presses to prevent them from rusting.
We prefer to divide the presses into three groups for maintaining the level of the
grid in the manner usual with hydraulic lift docks.
The grid is guided as it rises and falls by means of grooves and tongues or
rollers working in fixed vertical columns at the sides or ends.
In some cases we make the grid in the form of an ordinary pontoon.
Where a number of vessels have to be raised and stored they may be hauled or
slid off the grid when at its highest level on suitable ways.
We prefer to construct both the rams and presses of drawn steel tubes. The
tube used for the ram is closed at the lower end by an egg-ended plug, and the
interior entirely filled with Portland cement to give solidity.
The tube used for the press is closed at the bottom by a cap with a leather
washer to make it water tight. In fixing these rams wo first sink a hollow
cylinder or screw pile to the required depth and then lower the press into the
cylinder, and having adjusted it to a truc position we grout it in with cement
concrete.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Josiah Latimer Clark and John Standfield in the Great Seal Patent
Office on the 28th December 1878.
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of 6, Westminster
Chambers, Victoria Street, in the City of Westminster. "AN IMPROVED GRID
FOR DOCKING AND RAISING VESSELS."
Our improvemonts consist in constructing a gridiron stage on which the vessel
rests, and which can be raised and lowered by hydraulic presses placed directly
under the vessel, the intention being that the vessel should be floated over the grid
at high water, and that the whole should then be raised by hydraulic presses to a
suitable height above the level of high water, and there supported on struts in a
convenient position for conducting repairs or painting.
In those cases where there is no considerable rise or fall of tide we construct the
grid at a sufficiently low level to allow the vessel to be floated over it. To effect
this we prefer to construct the grid of wrought-iron plate with hollow chambers,
so that it can be made buoyant, to enable it to be easily floated away when required,
and for economy we prefer a skeleton form in which the backbone of the grid is a
hollow box girder, and the sides are in the form of short girders or ribs projecting
at right angles from the backbone at convenient distances, and on the top of these
ribs sliding bilge blocks are constructed, and at their ends side shoring frames may
be erected, the intermediate spaces between the ribs being planked over.
Figure 1 shows an end elevation of the grid with a vessel raised upon it.
A, A, are the presses; B, B, the rams; and C, C, the pontoon or grid. This grid is
further shown in Figures 2 and 3.
In Figure 2 the grid is shown in plan, with the skin plate removed to show the
construction, and with the outline of a vessel dotted upon it. The backbone is
there shown as consisting of two parallel wrought-iron girders the whole length of
the dock; there are also on each side an intermediate longitudinal girder and an.
outside girder. These are crossed at a right angle by a great number of transverse
girders or ribs. Five of these transverse girders are shown in pairs, and these are
placed over the bilge presses, which will be alluded to hereafter.
In Figure 1 sliding bilge blocks D, D, are shown, and at the ends of the girders
side shoring frames E, E, to keep the vessel upright.
The hydraulic presses are placed directly under the centre of the grid, these
presses being inserted in the ground. These presses are. shown in Figures 1 and 3,
and are marked A, A; they are also indicated by circles in Figure 2.
The rams as they ascend carry up the grid with the vessel upon it, and when it
is at its highest level it is supported there on struts or pawl legs, which are by.
preference jointed to the grid at the top, and which were at first suspended in a
horizontal position, but which are now allowed to fall vertically, so that their.
bottoms rest upon the shoulders of the pressos or upon convenient tables attached
thereto. These pawl legs or pillars are shown in their vertical position in Figure 1
resting upon the collars of the presses, and are marked F. There may be as many
legs as there are presses, or in some cases twice as many. As soon as the weight
rests upon these struts the rams are lowered into the presses to prevent them from
rusting.
We prefer to divide the presses into three groups for maintaining the level of the
grid in the manner usual with hydraulic lift docks, each group taking as nearly as
possible one-third of the weight.
The pipes leading from the three different groups are indicated by dotted lines
leading to the valve house, where they are concentrated into three sets, marked
H, I, K, Figure 2.
The grid is guided as it rises and falls by means of grooves and tongues or rollers
working in fixed vertical columns at the sides or ends. These columns also act as
fenders, and are marked L, L, in all three Figures. At the inner side of the dock
these grooves or tongues are secured to the wall as shown at M, M, Figures 1 and 2.

page_text: In some cases we prefer to incline the presses at an angle, in which case the grid
rolls or slides up an inclined plane. The presses in Figure 1 are shown thus
inclined and leaning towards the inner wall.
Where a number of vessels have to be raised and stored they may be hauled or
slid off the grid when at its highest level on suitable slip ways in a manner well
understood.
We prefer to construct both the rams and presses of drawn steel tubos. The tube
used for the ram is closed at the lower end by an egg-ended plug, and the interior is
entirely filled with Portland cement to give solidity.
The exterior tube used for the press is closed at the bottom by a cap with a
leather washer to make it water tight. In fixing these rams we first sink a hollow
cylinder or screw pile to the required depth, as shown at N, Figures 1 and 3, and
then we lower the press into the cylinder, and having adjusted it to a true position
we grout it in with cement or concrete. Or the hollow pile may itself serve as the
cylinder of the press.
In place of the struts or legs F, F, wo sometimes employ a framing of trestle-
work with diagonal braces, and this may be constructed like a skeleton box with
four sides, in which case we construct it of timber, so that it can be conveniently
floated into its place when the vessel is raised.
Figure 4 shows an end elevation and Figure 5 a side elevation of one of the
skeleton trestles. The vessel is brought over the grid at high water, tho pumps are
set in action, and the grid and vessel are raised well above high-water mark,
the legs or trestles are placed in position, and the whole is lowered until the grid
rests on the legs. The rams are now lowered down into their presses, and allowed
to remain there while the vessel is being cleaned or repaired.
Having thus described the nature of our Invention and the manner of performing
the same, we wish it understood that we claim in respect to our improved gridiron
for docking and raising vessels,―
First. The rigid skeleton floating gridiron adapted to be raised and lowered by
hydraulic presses.
Second. In combination with the gridiron the supporting trestles, frames, or
pillars.
Third. The arrangement of the hydraulic presses in inclined position, so that the
gridiron may bear principally against one side.
.
Fourth. The arrangement of the rams in rows or groups directly beneath the
vessel to be raised.
Fifth. The construction of the presses with screw piles, forming or containing the
cylinders of the presses.
Sixth. The construction of the presses of two concentric tubes, with the space
between filled with cement.
Seventh. The construction of hydraulic gridiron docks, substantially as herein-
before described.
In witness whereof, I, the said John Standfield, have hereunto set my hand
and seal, this Twenty-eighth day of December, in the year of our Lord One
thousand eight hundred and seventy-eight.
TATT