IMPROVEMENTS IN FLOATING DOCKS AND PONTOONS
Year: 1874

page_text: LETTERS PATENT to Josiah Latimer Clark and John Standfield,
both of 5, Westminster Chambers, Victoria Strect, in the City of
Westminster, for the Invention of "IMPROVEMENTS IN FLOATING DOCKS
AND PONTOONS."
Sealed the 7th July 1874, and dated the 15th January 1874.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark
and John Standfield at the Office of the Commissioners of Patents,
with their Petition, on the 15th January 1874.
We, JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of 5, West-
minster Chambers, Victoria Street, in the City of 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 of iron or other material placed

page_text: parallel to each other either longitudinally or transversely, the tubular
form being peculiarly calculated to withstand the pressures to which
such structures are subjected.
We generally prefer to make the horizontal platform on which the
vessel rests of a series of tubes ranging longitudinally or transversely.
Each horizontal tube is connected at either end with a vertical tube, so
that the three tubes combined represent somewhat the form of the
letter U. A series of these U shaped tubes placed side by side and
braced or connected together forms the complete pontoon or dock.
When floating with a vessel upon it the horizontal tubes support the
weight, and the vertical tubes stand upright out of the water. When it
is submerged the horizontal tubes and vertical tubes are partly filled
with water, and the flotation is maintained by the vertical tubes.
The tubes are divided into a suitable number of compartments by
bulkheads. When the tubes range longitudinally with vertical tubes at
the ends the vessel is docked sideways, but when the tubes range trans-
versely (which is the more usual form) the vessel is brought in end on
between the two side rows of vertical tubes in the usual manner.
Sometimes we use the vertical or horizontal tubes independently of
each other, or use vertical or horizontal tubes only, or wo make the
horizontal platform one large square chambered pontoon of the usual
character, with vertical tubes at the sides or ends as the caso
may be.
The tubes are provided with valves for admitting water for partially
submerging the pontoon, and are fitted with pumps or other gear for
emptying them in the usual manner, but we prefer to use the following
arrangement: The tubes or chambers of the horizontal platform or
some of them are filled with air when the pontoon is floating at its highest
level. This may be done either by forcing air into them or pumping the
water out of them.
These chambers are provided with valves at the top, which can be
closed, and with other valves beneath which may be opened so as to
admit the water below.
.
The valves being in this condition (that is to say, with the upper
valves closed and the bottom ones opened), if it be desired to submergo
the pontoon we pump water into the vertical tubes until they are suffi-

page_text: pontoon descends the water enters the open valves at the bottom and
gradually compresses the air within the chambers more and more,
according to the depth of submersion, and thus assists in sinking the
pontoon; and when it is subsequently raised this air expands again and
expels the water, so that when it is at its highest level the chambers are
again empty.
As the pontoon with its empty chambers and open valves would not
sink of itself, it is necessary to pump a sufficient weight of water into
the vertical tubes to cause its submersion, the extra load necessary to
effect this being pumped up above the water level, the tubes standing up
out of the water sufficiently high to contain this quantity. The pontoon.
being now at its lowest level, and the bottom chambers being partly filled
with water and partly with compressed air, the vessel is brought over it
and secured in the usual manner.
If it be now desired to raise the vessel it is only necessary to allow
the water to escape out of the vertical tubes by suitable valves provided
for that purpose. As the water flows out the pontoons rises (being
further assisted in its flotation by the air expanding in the bottom
chambers and expelling the water), and by the time the whole of the
water has run out of the side chambers the vessel is raised and docked,
this operation only occupying a few minutes.
The dock may be so constructed as to be capable of being divided into
two or more separate portions, each forming a smaller dock, which can
when desired be recombined into one larger one.
When it is required to dock more than one vessel at a time we con-
struct pontoons or grids without vertical sides, consisting of a number
of circular horizontal tubes provided with bulkheads and braced together
so as to form a flat pontoon or grid of sufficient capacity to support the
vessel. These flat pontoons are brought over and within the floating
dock or pontoon previously described, and sufficient water is admitted
into them to allow them to descend within the larger dock. The vessel
is then brought over this pontoon and secured, the whole is raised to the
surface in the manner described, the water is allowed to flow out, the
valves are closed, and the large dock being again partially submerged the
pontoon with the vessel upon it is left floating, and may be towed away

page_text: to any desired place, and may be again lowered by a similar dock in the
same manner as is done by ordinary hydraulic lift docks.
to
any
desired place, and may be again lowered by a similar dock in the
same manner as is done by ordinary hydraulic lift docks.
By these pontoons vessels may be readily raised and floated over
shallow bars or through canals and again lowered into the water.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Josiah Latimer Clark and John Standfield in tho
Great Seal Patent Office on the 14th July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOSIAH
LATIMER CLARK and JOHN STANDFIELD, both of 5, Westminster
Chambers, Victoria Street, in the City of Westminster, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing dato the Fifteenth day of January, in the
year of our Lord One thousand cight hundred and seventy-four, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Josiah Latimer Clark and :
John Standfield, Her special license that we, the said Josiah Latimer
Clark and John Standfield, our executors, administrators, and assigns,
or such others as we, the said Josiah Latimer Clark and John Stand-
field, our 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
"IMPROVEMENTS IN FLOATING DOCKS AND PONTOONS," upon the condition
(amongst others) that we, the said Josiah Latimer Clark and John
Standfield, our executors or administrators, by an instrument in writing
under our or their hands and seals, or under the hand and seal of one of
us or them, should particularly describe and ascertain the nature of the
said Invention, 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 we, the said Josiah Latimer Clark and
John Standfield, do hereby declare the nature of the said Invention,

page_text: 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-
Our Invention consists in an improved form of floating dock or
pontoon.
The improvement consists in constructing the horizontal platform of
the dock or pontoon of a scries of circular or nearly circular tubes of
iron or other material placed parallel to each other, either longitudinally
or transversely in combination with vertical tubes at the sides or ends,
so that the structure represents somewhat the form of the letter U.
When the dock is floating with a vessel upon it the horizontal tubes
support the weight and the vertical tubes stand upright out of the water.
When it is submerged the horizontal tubes, and in some cases also the
vertical tubes, are partly filled with water and the flotation is maintained
by the vertical tubes. The tubes are divided into a suitable number of
compartments by bulkheads. When the tubes range longitudinally with
vertical tubes at the ends the vessel is docked sideways, but when
the vertical tubes are ranged along the sides of the dock (which is the
more usual form) the vessel is brought in end on between the two side
rows of vertical tubes in the usual manner. Sometimes we make the
horizontal platform one large square chambered pontoon of the usual
character and combine with it vertical tubes at the sides or ends, as the
case may be.
The tubes are provided with valves for admitting water for partially
submerging the pontoon and pumps, or other gear is provided for
emptying them. We prefer to use the following arrangement:-The
tubes or chambers of the horizontal platform are filled with air when
the pontoon is floating at its highest level; this may be done either by
forcing air into them or pumping the water out of them.
These chambers are provided with valves at the top which can be
closed, and with other valves beneath which may be opened so as to
admit the water below.
If it be desired to submerge the pontoon the valves at the bottom are
opened and water allowed to flow into the bottom tubes and to assist the
submersion of the pontoon; water may be at the same time admitted or
pumped into the vertical tubes or some of them until they are sufficiently
filled to submerge the pontoon to the desired level.

page_text: 1
As the pontoon descends and the water enters the open valves at the
bottom it gradually compresses the air within the chambers more and
more, according to the depth of submersion, and when it is subse-
quently raised this air expands again and expels the water so that when
it is at at its highest level the chambers are again empty. The dock or
pontoon being now at its lowest level the vessel is brought over it and
secured in the usual manner.
If it be now desired to raise the vessel it is only necessary to expel the
water from the bottom tubes, either by allowing the water to escape out
of the vertical tubes by suitable valves provided for that purpose, or by
admitting air under pressure into the bottom tubes. As the water flows
out and the dock or pontoon rises the air in the bottom chamber expands
and expels the water, and by the time the whole of the water has run
out the vessel is raised and docked. This operation only occupying a
few minutes.
In some cases we employ the vertical tubes or some of them as
reservoirs into which air may be compressed by pumping engines, and
the compressed air contained in such reservoirs may be used for expelling
water from the bottom tubes when the dock or pontoon is to be raised.
The dock may be so constructed as to be capable of being divided
into two or more separate portions, cach forming a smaller dock which
can, when desired, be recombined into one larger one.
When it is required to dock more than one vessel at a time we con-
struct pontoons or grids without vertical sides consisting of a number of
circular horizontal tubes, provided with bulkheads and braced together
so as to form a flat pontoon or grid of sufficient capacity to support the
vessel. These flat pontoons are brought over and within the floating
dock or pontoon previously described, and sufficient water is admitted into
them to allow them to descend within the larger dock, the vessel is then
brought over this pontoon and secured, the whole is raised to the surface
in the manner described, the water is allowed to flow out, the valves are
closed, and the large dock being again partially submerged the pontoon
with the vessel upon it is left floating and may be towed away to any
desired place, and may be again lowered by a similar dock in the same
manner as is done by ordinary hydraulic lift docks.
If the vessel and pontoon be of greater weight than the dock is
capable of lifting the water in the pontoon may be pumped out or

page_text: expelled by the admission of compressed air, so that the pontoon and dock
combined have greater lifting power than either of them would have
separately.
By these pontoons vessels may be readily raised and floated over
shallow bars or through canals and again lowered into the water.
In the Drawings hereunto annexed we have shewn examples of docks
and pontoons constructed according to our Invention.
Figures 1, 2, and 3 shew one of these docks with a vessel upon it.
In Figure 1 a dock is shewn submerged in the act of raising a vessel.
In Figures 2 and 3 water has been pumped or forced out of the tubes
and the dock is shewn at its full elevation with the vessel out of the
water. In Figure 2 the dock is shewn in longitudinal section. It
consists of 30 circular U shaped tubes, which are shewn in elevation in
Figures 1 and 3.
The general construction of the dock is clearly shown by the Drawings,
so that it is unnecessary to give any detailed description of it.
Figure 4 shews an end elevation of a similar dock submerged, with a
tubular pontoon within it, and a vessel upon the pontoon ready for
being lifted. The pontoon consists of 5 tubes, and when raised by the
dock to the surface with the vessel upon it the water flows out of it, tho
valves are closed, and the pontoon and vessel are left floating in the
same manner as is usual with hydraulic lift docks. One of the
advantages of this system is, that suppose the dock itself to be capable
of lifting a vessel of 3,000 tons, and the pontoon to be capable of floating
a vessel of 2,000 tons, the two combined will be capable of floating a
vessel of 5,000 tons, and therefore they can either be employed in their
combined form so as to dock a vessel of 5,000 tons, or in their separate
form so as to dock a vessel of 3,000 tons and 2,000 tons respectively.
The arrangements for pumping or forcing the water out of these docks
will be explained hereafter.
Figure 5 shews a dock in which the tubes are arranged longitudinally
instead of transversely; and Figure 6 shews a sectional elevation of the
same dock in the act of lifting a vessel. The vessel in this case has to
be hauled on to the dock sideways instead of endways. In other

page_text: respects its construction is the same as that of the docks previously
described.
Figure 7 shews the plan of a dock in which the horizontal tubes are
arranged longitudinally. It consists of 6 tubes, and it has at each.
corner 7 vertical tubes which support the weight and ensure stability
when the dock is submerged. Figure 8 is the side elevation of the
same dock, and Figure 9 an end elevation. 4 engines and pumps are
indicated as being placed one in each corner group for the purpose of
pumping out the water or forcing it out by compressed air. Figure 10
is an end elevation of the same dock with a flat pontoon and vessel
within it. The pontoon is raised and the vessel floated in the manner
already explained in referring to Figure 4.
Figure 11 is a side elevation of a similar dock, but in this case a
larger number of tubes are brought up above the surface along the sides
of the dock, the inner tubes being each shorter than its neighbour, as
shewn in the Drawing. By this system increased stability is obtained
during flotation at the time when the vessel is nearly raised out of the
water.
Figure 12 shews a construction for the pontoon in which the two
outer tubes are strapped or hinged on to the three inner ones in such a
manner that they are capable of raising and supporting the bilges of
the vessel so as to grip it with greater firmness, the object being to ensuro
the more perfect action of the side shoring frames and bilge blocks, and
to give a more uniform pressure under the vessel while on the pontoon.
Figures 13, 14, 15, 16, and 17 shew various forms of multiple com-
partments in which the tubular form is introduced and which may be
useful in certain cases.
In Figure 18 the top and bottom curves A, A, and B, B, are intended
to represent buckle plates and girders connecting 2 semi-circular tubes
which form the outside.
In Figure 19 a series of circular tubes are shewn in section joined by
segments of circles so as to give great flotation within a given space.
In most cases we prefer to use the plain circular tubes, as shewn in
section in Figure 20, with egg shaped, conical, or spherical shaped
ends and bulkheads. These tubes are braced together with suitable
angle I or channel irons in a manner which will be familiar to all

page_text: engineers. They are protected from injury by wooden fenders or balks
of timber, as shown in Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.
These docks are submerged by allowing water to flow into the tubes
when the sink by their own weight in the usual manner, or this may
be assisted by pumping water into the vertical tubes. In raising them
out of the water again with the vessel upon them 3 different methods
may be employed.
1st. We close the valves in the bottom, and pump water out of
them in the ordinary manner.
2nd. We expel the water by forcing air into the upper part of the
tubes, suitable valves being arranged at the bottoms of the tubes, which
can be opened and closed at pleasure. When these valves are opened,
and the air is forced in by an air pump or from reservoirs of compressed.
air, the water is expelled through the bottom valves, and the whole dock
rises to the surface. The valves at the bottom are then closed, and the
dock is left floating.
3rd. If in order to submerge the dock water has been pumped into
the vertical tubes in sufficient quantity to cause the dock to sink to the
required level, then when it is desired to raise the dock this water is
allowed to flow out again, and the dock rises by the floating power of
the horizontal tubes.
In each case we prefer to divide the dock into 4 or more portions, for
example, the horizontal tubes may be separated in their centre by
diaphragms or bulk heads; and if we suppose the dock to consist of 30
tubes, as shewn in Figure 21, each quarter of the dock would consist of
15 half tubes, viz., a, a, a, b, b, b, c, c, c, and d, d, d. By pumping or
forcing the water out of these respective divisions in suitable proportions
the dock can be always kept in a level position, both transversely and
longitudinally, or can be canted on one side or one end at pleasure.
When raising the dock by the second system we connect all the half
tubes a, a, a, together by suitable pipes, and also the remaining
halves b, b, b, c, c, c, and d, d, d; and the 4 pipes which connect these.
groups are led into one spot on the top of the dock, and provided with
suitable valves or taps.
When raising the dock the bottom valves V. V. Figure 22. are onened.

page_text: mentioned it is led into the respective compartments or groups a, a, a,
b, b, b, c, c, c, and d, d, d, Figure 21; and by partially opening or
closing these valves in a suitable manner the proper amount of water is
expelled from each compartment, and the dock is kept level, both trans-
versely and longitudinally.
When the dock is raised the valves V, V, V, are closed; and the whole
remains floating.
When it is desired to lower it again the valves V are opened, and the
air is allowed to escape gradually from the 4 compartments in such
manner that the water enters, and the whole descends uniformly.
E
1
Sometimes we prefer to insert bulkheads in the middle of the vertical
tubes or some of them, as shewn at N, Figure 22, so as to form upper
compartments or air chambers. The whole of these air chambers are
connected by an air tube, which is common to them all, and they are
used as a reservoir for compressed air. The air is forced into these.com- 1
partments under considerable pressure, and remains stored up ready"
for use.
-
When it is desired to lift a vessel quickly the compressed air is
allowed to force itself into the 4 groups of tubes a, a, a, b, b, b, c, c, c,
and d, d, d, Figure 21; and the water being expelled the dock is quickly, 2
raised to the surface. This system is very useful when it is desired to
lift a vessel quickly in rough water, as the compressed air forces the
water out very rapidly, and allows the ship to take its bearing'
quickly in the dock before it has time to do injury by bumping.
When the dock again descends the valves V, V, are opened, and the 2
air is allowed partially to escape as the docks descends, the pressure on the
air within it increases, and this pressure causes the valve M, Figure 22,.
to open, and the air enters the reservoir at this pressure.
The pressure
is afterwards increased by pumping to the necessary amount. It is
quite unnecessary to shew the valves and connections by which this is 3
arranged, as their construction would be perfectly understood by any
engineer.
Figure 23 shews the third system of floating the dock. The transverse
tubes F, F, Figure 23, and a portion of the vertical tubes G, G, arc
constructed airtight, and are separated from the vertical tubes by bulk- 3
heads. They are open to the water at the bottom by the valves V, V.

page_text: When it is desired to submerge the dock water is pumped into the
upper compartments H, H, in sufficient quantity to sink the dock to
the desired level for docking the ship. As the dock descends into the
water the pressure within the tubes F, F, is increased, and the air being
under compression diminishes in bulk so that a certain quantity of water
enters the tubes, and assists in submerging the dock. If, for example, the
vertical tubes descend to a depth of 30 feet the pressure on the air will
be equal to two atmospheres, and it will be contracted into half its bulk,
and a corresponding quantity of water will therefore enter within the
tubes.
When it is again required to raise the dock it is only necessary to
open the valves or taps at I, I, and allow the water to flow out, by
which means the dock will again rise, and the air expanding will expel
the water out of the horizontal tubes, and the dock will again float at
its highest level.
If necessary compressed air may be forced into the chambers F, F, to
expel the last remaining quantity of water, or the valves V, V, may be
closed, and the remaining quantity of water pumped out.
1st. We claim the forming the sides or ends of floating docks of a
series of vertical circular or nearly circular tubes.
2nd. We claim the forming of the horizontal platform of floating
docks or pontoons of a series of parallel circular tubes or of flat box-
shaped chambers in connection with vertical, circular, or nearly circular
tubes at the sides.
3rd. We claim the forming of floating docks of a series of trans-
verse, circular, or nearly circular tubes having at their ends vertical
tubes rising up from them to form sides to the dock, as herein
described.
4th. We claim the construction of floating docks or pontoons in such
manner that water may be expelled from the tubes or chambers
of which they are composed by introducing into them air under
pressure, and be then excluded by valves at the bottom, as herein
described.
5th. We claim the use of a reservoir of air under compression to
enable the dock to be rapidly lifted, as hercin described.

page_text: 6th. We claim the use of pontoons constructed of closed tubes, and
from which the water may be pumped out or expelled by means of air
under pressure in combination with floating docks or hydraulic lift
docks for lifting vessels of a weight greater than the dock or lift is
capable of raising by itself.
In witness whereof, we, the said Josiah Latimer Clark and John
Standfield, have hereunto set our hands and seals, this Thirteenth
day of July, in the year of our Lord One thousand eight
hundred and seventy-four.
JOSIAH LATIMER CLARK. (L.S.)
JOHN STANDFIELD.
(L.S.)