IMPROVEMENTS IN APPARATUS FOR AND IN THE MODE of CONSTRUCTING ARTIFICIAL BREAKWATERS, GROINS, PIERS, AND OTHER SUB- MARINE FOUNDATIONS
Year: 1878

page_text: LETTERS PATENT to Josiah Latimer Clark and John Standfield, both of No. 6,
Westminster Chambers, in the City of Westminster, Civil Engineers, for the
Invention of "IMPROVEMENTS IN APPARATUS FOR AND IN THE MODE of
CONSTRUCTING ARTIFICIAL BREAKWATERS, GROINS, PIERS, AND OTHER SUB-
MARINE FOUNDATIONS."
Sealed the 31st January 1879, and dated the 2nd December 1878.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark and
John Standfield at the Office of the Commissioners of Patents on the 2nd
December 1878.
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of No. 6, Westminster
Chambers, in the City of Westminster, Civil Engineers. "IMPROVEMENTS IN
APPARATUS FOR AND IN THE MODE OF CONSTRUCTING ARTIFICIAL BREAKWATERS,
GROINS, PIERS, AND OTHER SUBMARINE FOUNDATIONS."
To construct a breakwater, groin, or pier, we use a shield preferably of iron con-
structed in one or more pieces, and shaped internally so as to entirely enclose and
mould the breakwater or pier to the desired shape. The usual section of a sea wall
or breakwater is a quadrilateral figure with a considerable slope or inclination
towards the sea, and a nearly perpendicular face on the inner side, and such would
be the usual form of the inner side of the shield, which is intended to be filled with
concrete; the exterior form of the shield is similar, but the outward slope would bo
much greater so as to form a considerable angle, and to divert the direct blows of
the sea.
The shield has two skins, the interior skin forms the mould to give shape
to the faces of the pier or breakwater, and the exterior. skin is of great strength so
as to resist the impact of the waves; the two skins are united by internal decks
and bulkheads, and by iron stays which give strength and rigidity to the whole
structure, and divide the interior space into compartments, some of which are
watertight, and are provided with valves; the shield is also provided with engines
and pumping machinery, and when it has to be shifted or removed, the water is
Price 10d.1
.

page_text: pumped out of the interior compartments until it nearly begins to float. On the
other hand, when it requires to be fixed, water is pumped into the upper com-
partments above the level of the sea, so as to add weight to the structure and
prevent it from being moved by the sea. The shield is U shaped in plan, and
encloses in the interior a space of quiet water; when placed in position, concrete is
filled into the interior, and to prevent it from mixing with the water, it is poured
in behind a bag shaped apron or curtain of india rubber cloth, weighted at the
bottom, which is thrust forward by the concrete as fast as it is thrown in behind
it; to prevent adhesion to the shield, its inside is lined with woodwork or canvas,
and greased.
As soon as the interior space within the shield has been sufficiently filled with
concrete, and it has hardened, the shield is partially emptied of water until it
nearly floats, and it is then thrust forward a certain distance, and being adjusted to
its place, it is again allowed to sink, and is weighted in its new position and again
filled with concrete; and in this manner it is moved forward by degrees until the
whole length of the wall is completed.
If the interior space contains mud or sand, it is dredged out in the usual manner
before the concrete is poured in. The bottom chambers of the shield are also formed
into air tight chambers or compartments which are open at the bottom, and by
forcing air into them the water is expelled, and they can be used as diving bells,
suitable means of exit and entry being provided by double doors in the usual
manner. Men can enter into these chambers and remove mud or obstructions so as
to ensure a good foundation.
The inner ends of the shield have a connecting girder which is carried over the
wall already constructed and rests upon it, being guided by slides so that the whole
can be thrust forward by hydraulic pressure or other power. Where the accumu-
lation of mud is large, the front of the shield is made V shaped, like the head of a
snow plough, so as to throw off the mud on either side.
Where the bottom is rocky, sliding legs are provided which can be moved by
hydraulic pressure or other means so as to set and maintain the shield level.
In some cases it is preferable to make the head of the shield and one or both of
the sides in separate pieces, which can be bolted together so that the width or slope
can be varied at pleasure. As the water deepens we also bolt on one or more
additional segments either at the top or bottom of the shield so as to increase its
height. It is evident that the quiet water within the shield is well adapted for the
employment of diving bells, so that ordinary stone constructions can be expedi-
tiously constructed within the shelter.
Where the foundation to be constructed is of square or circular form, as is the
case of lighthouses and bridge piers, we construct the shield in a similar manner and
with similar compartments and pneumatic chambers, the outer and inner skins
being concentric, so that the whole forms an oblong or annular cylinder divided
into compartments, and so constructed in segments that it can be unbolted and
separated into two or three pieces, each of which can be floated away independently.
The annular shield would be usually considerably broader at the base than at the
top so as to withstand the action of the sea, and would be capable of being made
buoyant at any time by pumping the water out of some of the compartments.
In circular shields or caissons where it is intended to put in the foundations.in
the dry, the central cylinder is made very small so as only to afford convenient
room for ingress and egress to the pneumatic compartments, the rest of the space
being left filled with water except at the time when it is being floated, and the
bottom diameter of the cylinder being greatly enlarged and formed into diving bell
chambers so as to afford space forming broad foundations, or if preferred, access
may be obtained only by shafts in the annular space between the two skins, leaving
the centre open.
It is often preferable to leave the lower portion of the shield
permanently built into the foundations. In other cases we sink the shield into
position in the manner before described, and in its interior we sink an independent
iron cylinder or cone of the form of the pier to be constructed, and fill this cone

page_text: with concrete; or if desired, the space between the shield and the cone may be
puddled, and the water being pumped out of the interior cylinder, men can descend
and build their foundations within it, or the outer cylinder may itself be constructed
with a cutting edge which enters into the mud or clay, and converts it into a water-
tight caisson or cofferdam.
In some cases it is desirable to deposit piers and breakwaters in a single block or
in large hollow sections.
+
If the foundation to be laid be a square or circular base, such as the base of a
lighthouse, we construct it of concrete, or of concrete faced with stone or iron on
the shore between high and low water; and we place across the top of it or through
holes in it, a suitable number of wrought iron horizontal girders, and from these
girders we hang screw bolts with adjusting nuts, which bolts are attached to the
concrete base, or we make other suitable attachments; the girders projecting a
considerable distance on each side of the base. A little before high water we
bring two caissons or two fingers of a depositing dock, such as is described in the
Specification of a Patent granted to us, No. 514, of 1875, beneath the ends of the
girders, so that as the water rises the base is lifted by the dock; it is then towed
out to another bed prepared at a lower level and allowed to rest there while an
additional ring or layer of concrete or masonary is added; when the operation is
repeated, and finally when it has attained sufficient height, it is towed to its
position and deposited there.
In a similar way large square solid or hollow blocks of concrete weighing 500 or
1000 tons may be prepared and deposited like bricks so as to form piers or break-
waters. Instead of using a depositing dock with two fingers, we sometimes lift the
blocks by means of our patent gripping camels as described in our Patents, Nos.
170 and 985 of 1877, and No. 4527 of 1878, or we employ an annular pontoon of
square or circular form which is capable of being separated into two or more pieces,
or we employ two pontoons according to the form of the blocks to be deposited, so
that when they are deposited, the pontoons may be separated and floated away.
Where the depth is great or there is not sufficient rise and fall of tide, we
construct buoyant circular piers by means of wrought or cast iron cylinders which
support the concrete, and which may be placed either internally or externally. The
iron cylinder is first formed of suitable diameter, and we rivet upon it externally
(and also internally if desired) iron horizontal flanges or rings at distances of a few
feet apart, and upon these brackets or flanges we build brickwork or stone work so
as to surround the cylinder entirely, and completely envelop the iron work. While
this is done the ironwork can be either suspended from pontoons or be resting on the
ground at low water mark. As soon as the first section is completed the whole is
made buoyant by constructing a wrought iron dome over the top, leaving a hollow
airtight chamber within. A pipe and valve are fixed in the dome so as to admit
air or water when required, and we add further buoyancy if necessary by means of
pontoons. The whole is then floated at high water, and if of sufficient height is at
once deposited in its final position, but if not, the interior iron cylinder is lengthened
and more brickwork is added while it is still floating so as to increase its height to
any extent that may be required. As this process is carried on water is admitted
beneath the dome, and in addition to this either ballast or water is deposited in the
interior of the cylinder as it sinks so as to keep the bottom heaviest and ensure its
stability. Finally the whole is towed to its place and lowered into position by
allowing the water to enter. The bottom domed chamber is utilized as a diving
bell, being divided into compartments and provided with a small central cylinder or
cylinders for the entry of the men, who are thus enabled to cut away and form a
level foundation, and fill the interior space with brickwork or concrete.
In other cases we construct a wrought or cast iron floating cylinder of the
required form and diameter, closed at the bottom by a dome shaped diaphragm.
The bottom portion is formed into a set of chambers of cast iron, which are to be
used as diving chambers, and of sufficient strength to support the pier when it is
rested on the bottom, and it may be provided with a cutting edge to enter into the

page_text: ground. Within the cylinder .we build the pier of brickwork or stonework and
concrete, leaving the centre portion hollow, and if necessary we add pontoons so
that the whole may float. As it sinks by the additional weight put on the top
additional concrete or ballast is added at the bottom so as to maintain the whole
stable. Finally, it is sunk in its position, and the foundations are made good by
means of the diving chambers. In some cases we build the interior masonry or
concrete ou the bottom of the cylinder, and we make the outer iron casing quite
detached from the pier, and we further give it a double skin with air chambers
between the two skins so as to give it buoyancy. When the pier or block has
been completed and deposited we separate the outer casing into two or more
sections, which being buoyant are floated away, leaving the pier resting on the
ground on its artificial base, which is left fixed as part of the pier. Additional
concrete is then thrown into the interior so as to make the whole base solid.
In forming breakwaters on this system we float an iron caisson of the required
form and dimensions, and gradually fill it with concrete at the bottom and sides,
leaving large hollow spaces in the centre temporarily strutted with wood or iron
girders so as to keep the whole as buoyant as possible. When it has acquired the
full dimensions we tow it to its position by the assistance of pontoons, and sink it
by admitting water. The interior is afterwards filled with concrete or ballast, and
the struts removed. The caissons are best formed by making the bottom and one
of the sides of an L shaped form similar to our depositing dock, as described in our
Patent No. 514 of 1875, and the remaining three sides of chambered iron work with
sufficient buoyancy to support the block. When these two parts are placed together
they form a square or oblong box, open at top, within which the block is moulded.
When complete the block is suspended or supported from girders, which are placed
across the three sided portion of the dock by means of screw or toggle bolts, and
these bolts may with great advantage be suspended from hydraulic cylinders to
enable the block to be lowered quickly. The bottom and the one side are now
floated away by admitting water into the compartments, leaving the block sus-
pended only from the three sides, and with one end free and ready to be placed
against the work already completed. The block is then deposited in its final
position, and the three sides floated away. It is obvious that the bottom and sides
may be quite detached and in separate pieces if preferred. Such blocks may be
made of any form, and of upwards of a thousand tons in weight, and the sections
should be high enough to reach above low water mark, cement concrete being grouted
in between them and poured into the holes so as to flow underneath them; the top
may be finished in masonry. These floating concrete blocks, either with or without
exterior iron casing, may also be constructed between high and low water mark,
pontoons being attached if necessary, and open valves being provided so that the
water can flow in and out at each tide. When the valves are finally closed and
the tide rises the whole mass floats away. These blocks may also with great con-
venience be constructed in a dry dock or on a floating dock or depositing dock, such
⚫ as those described in our Patents above mentioned. The dock is lowered until the
block floats when it is towed to its position and sunk. Such blocks may with
great advantage be faced with blue Staffordshire bricks set in Portland cement, and
braced by layers of hoop iron. The ends or sides of adjacent blocks which have to
be filled in with concrete after they are deposited should have angular notches or
recesses for receiving the concrete, and should be provided with projecting loops
of hoop iron. In some cases we insert air bags in the recesses of the blocks and
also externally, which are inflated so as to make them buoyant during the operation
of floating them out into their position.

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 31st May 1879.
«
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of No. 6, Westminster
Chambers, in the City of Westminster, Civil Engineers. "IMPROVEMENTS IN
APPARATUS FOR AND IN THE MODE OF CONSTRUCTING ARTIFICIAL BREAKWATERS,
GROINS, PIERS, AND OTHER SUBMARINE FOUNDATIONS."
Our apparatus consists in the first place of a shield, preferably of iron, constructed
in one or more pieces, and shaped internally so as to entirely enclose and mould the
breakwater or pier to the desired shape. The usual section of a sea-wall or break-
water is a quadrilateral figure with a considerable slope or inclination towards the
sea, and a nearly perpendicular face on the inner side, and such would be the usual
form of the inner side of the shield, which is intended to be filled with concrete.
The exterior form of the shield is similar, but the outward slope would be much
greater so as to form a considerable angle and to divert the direct blows of the sea.
The shield has two skins, the interior skin forms_the_mould_to_give-shape-to-the-
faces of the pier or breakwater, and the exterior skin is of great strength so as to
resist the impact of the waves. The two skins are united by internal decks and
bulkheads, and by iron stays which give strength and rigidity to the whole structure,
and divide the interior space into compartments, some of which are watertight and
are provided with valves. The shield is also provided with engines and pumping.
machinery, and when it has to be shifted or removed the water is pumped out of
the interior compartments until it nearly begins to float. On the other hand, when
it requires to be fixed, water is pumped into the upper compartments above the
level of the sea so as to add weight to the structure and prevent it from being
moved by the sea. The shield is U shaped in plan and encloses in the interior a
space of quiet water.
When placed in position concrete is filled into the interior,
and to prevent it from mixing with the water it is poured in behind a bag shaped
apron or curtain of india rubber cloth weighted at the bottom, which is thrust
forward by the concrete as fast as it is thrown in behind it; to prevent adhesion to
the shield its inside is lined with woodwork or canvas, and greased.
As soon as the interior space within the shield has been sufficiently filled with
concrete and it has hardened, the shield is partially emptied of water until it nearly
floats, and it is then thrust forward a certain distance, and being adjusted to its
place it is again allowed to sink and is weighted in its new position and again filled
with concrete, and in this manner it is moved forward by degrees until the whole
length of the wall is completed.
If the interior space contains mud or sand it is dredged out in the usual manner
before the concrete is poured in. The bottom chambers of the shield are also formed
into airtight chambers or compartiments which are open at the bottom, and by forcing
air into them the water is expelled and they can be used as diving bells, suitable
means of exit and entry being provided by double doors in the usual manner. Men
can enter into these chambers and remove mud or obstructions so as to ensure a
good foundation.
The inner ends of the shield have a connecting girder which is carried over the
wall already constructed, and rests upon it, being guided by slides so that the whole
can be thrust forward by hydraulic pressure or other power. Where the accumula-
tion of mud is large, the front of the shield is made V shaped like the head of a
snow plough, so as to throw off the mud on either side.
Figures 1, 2, and 3 represent the shield, Figure 1 being a sectional side elevation ;
Figure 2, a plan; and Figure 3, a transverse section of the same.
A, A, represent the portions of the pier already completed; B, B, and B', B¹, the
sides of the shield; and C, C, the head; the interior is divided into chambers in
the manner usual with floating docks and similar structures. .B', B', in Figures 2

page_text: and 3 shows the adjustable portion of the side which can be bolted to the head C, C,
in any position so as to form a pier of the desired width. The two sides B and B'
are further connected by transverse girders D, D, which are bolted to them and hold
them apart at any desired width. These girders rest on the finished portion of the
pier and may if required be carried on rollers so as to facilitate the thrusting forward
of the whole shield, which is effected by screws or hydraulic presses applied at any
convenient point. When this operation is effected the shield is temporarily lightened
by pumping water out of some of the compartments so as to render the whole nearly
buoyant. In order to render the Drawing clearer, the pumps and presses, which are
of the usual character, are not shown.
It is evident that the head of the shield may be either straight, circular, or
V shaped, as may be preferred. The india rubber or canvas curtain which protects
the cement from the wash is shewn at E, E, in Figure 1.
Where the bottom is rocky, sliding legs are provided which can be moved by
hydraulic pressure or other means so as to set and maintain the shield level. The
.construction of these will be obvious.
As the water deepens we bolt on one or more additional segments either at the
top or bottom of the shield so as to increase its height. It is evident that the quiet
water within the shield is well adapted for the employment of diving bells so that
ordinary stone constructions can be expeditiously constructed within the shelter.
Where the foundation to be constructed is detached, and of square, circular, or
polygonal form as in the case of light houses and bridge piers we construct the shield
of a circular form and with similar compartments and pneumatic chambers, but the
outer and inner skins are concentric so that the whole forms an oblong or annular
cylinder divided into compartments, and so constructed in segments that it can be
unbolted and separated into two or three pieces, each of which can be floated away
independently. The annular shield would be usually considerably broader at the
base than at the top so as to withstand the action of the sea and would be capable
of being made buoyant at any time by pumping the water out of some of the
compartments.
Figures 4 and 5 shew such an annular shield; F, F, shew the annular compart-
ments into which the shield is divided; and G, G, shew the pneumatic chambers at
the bottom which are provided with entrances leading down to them from the upper
chambers. One of these entrance tubes is shewn at I leading from the upper
pneumatic chambers H to the lower chambers G; they are also shewn in Figure 5.
The annular space G may be divided in any convenient number of chambers by
diaphragms with separate entrances.
In circular shields or caissons where it is intended to put in the foundations in
the dry, the central cylinder is made very small so as only to afford convenient
room for ingress and egress to the pneumatic compartments, the rest of the space
being left filled with water except at the time when it is being floated, and the
bottom diameter of the cylinder is greatly enlarged and formed into diving bell
chambers so as to afford space for forming broad foundations; or if preferred access
may be obtained by shafts in the annular space between the two skins as shewn in
Figures 4 and 5, leaving the centre open. It is often preferable to leave the lower
portion of the shield permanently built into the foundations. In other cases we
sink the shield into positon in the manner before described, and in its interior we
sink an independent iron cylinder or cone of the form of the pier to be constructed
as shewn at J, J, in Figures 4 and 5, and we fill this cone with concrete so that the
outer cylinder is only used as a temporary coffer dam, the iron. cone with its
concrete interior being left in position. If desired the space between the shield
and the cone may be puddled, and the water being pumped out of the interior
cylinder men can descend and build their foundations within it. The outer
cylinder may also be constructed with a cutting edge which enters into the mud or
clay and converts it into a watertight caisson or coffer dam.
Where the depth is great or there is not sufficient rise and fall of tide, we
construct buoyant circular piers by means of wrought or cast iron cylinders which

page_text: support the concrete, and which may be placed internally. The iron cylinder is
first formed of suitable diameter, and provided with a domed top as in Figure 8,
and we rivet upon it externally (and also internally if desired) iron horizontal
flanges or rings at distances of, a few feet apart, and upon these brackets or flanges
which are shown in Figures 8 and 9 in various forms, we build brickwork or stone
work so as to surround the cylinder entirely and completely envelope the iron
work; while this is done the ironwork can be either suspended from pontoons or
be resting on the ground at low water mark; as soon as the first section is completed
the whole is made buoyant by injecting air into the iron domed cylinder, a pipe
and valve being fixed in the dome so as to admit air for this purpose, and we add
further buoyancy if necessary by means of exterior pontoons; the whole is then
floated at high water and if of sufficient height is at once deposited in its final
position, but if not the interior iron cylinder is lengthened at the top as shewn at
K, K, in Figure 8, and more brick work or concrete is added either while it is still
floating, or while resting on the bottom, so as to increase its height to any extent
that may be required; as this process is carried on water is admitted beneath the
dome end; in addition to this either ballast or water is deposited in the interior of
the cylinder as it sinks, so as to keep the bottom heaviest and ensure its stability;
finally, the whole -is- towed-to-its-place, and lowered into-position-by allowing the
water to enter; the dome chamber may if preferred. be utilized as a diving hell,
being divided into compartments, and provided with a small central cylinder or
cylinders for the entry of the men, who are thus enabled to cut away and form a
level foundation and fill the interior space with brickwork or concrète.
In some cases the blocks are built hollow as in Figures 10, 11, and 12, and when
completed they are made temporarily buoyant by the insertion of an elastic bag M
provided with a pipe N, which is inflated with air until it floats or nearly floats;
the blocks can then be lifted by a floating derrick and placed side by side as shewn
in Figures 8 and 10, so as to form a pier or breakwater, the form of these buoyant
blocks may be varied indefinitely.
Another part of our Invention consists in constructing piers and breakwaters of
large square blocks, by means of special arrangements and appliances.
In building breakwaters on this system, we form a large square iron caisson or
floating mould of the required dimensions, and we gradually fill it with concrete at
the bottom and sides leaving large hollow spaces in the centre so as to keep the
whole as buoyant as possible; when it has acquired the full dimensions we tow it
to its position and deposit the block in the ground, the interior spaces are after-
wards filled with concrete or ballast. The mould or caisson is a hollow chambered
structure of boiler plate formed by making the bottom and one of the sides of an
shaped form similar to our depositing dock, as described in our Patent No. 514, of
1875, and the remaining three sides which are separate and detachable also of
chambered iron work with sufficient buoyancy to support the block, when these
two parts are placed together they form a square or oblong box, open at top, within
which the block is moulded.
Figure 13 shews a longitudinal section of this floating mould, of which Figure 6
is a transverse section; Figure 14 is a plan of the same. L, L, Figures 6, 13, and
14 represent the L portion of the mould, which forms the bottom upon which the
block is built. It is entirely removeable from the other half of the mould, which is
marked U, U, in Figures 6, 7, 13, 14, 15, and 16, and which we call the U shaped
portion of the mould in consequence of its resembling in plan the letter U; the
L shaped portion is provided with an outrigger Q, the construction and use of
which which will be fully understood by reference to our Patent No. 514 of 1875.
By means of this outrigger the L shaped portion may be raised or lowered at will
independently of the U. These two parts are first placed together and in this form
they constitute a square box or mould, open at the top, and the block is moulded
within them, as shewn in section in Figure 6. The sides of the U are connected
by a number of iron girders R, R, R, shewn in all the Figures. In Figure 14 the

page_text: U is partly shewn in section to shew its interior construction, and the ends of the
girders R are in this Figure broken off over the sectional portion. The block is
suspended from these girders R by tension rods or chains S, S, as shown in Figures 6
and 7, but these only come into action when the L shaped portion has been removed.
When the block is completed the L is lowered away, being guided by the outrigger,
leaving the block suspended on the rods with its bottom hanging a little below the
U, as shown in Figures 6, 7, and 16. It now hangs only on the U, and in this
condition it is floated to position, and by letting water into the U it is deposited on
the ground, as shown in transverse section in Figure 7, and in plan in Figure 15,
where it forms the outer end of a pier.
The screw or toggle bolts may with great advantage be suspended from hydraulic
cylinders, as indicated at T in Figure 15, to enable the block to be lowered more
quickly. Such blocks may be made of any form, and, if required, of a thousand or
several thousand tons in weight, and the sections should be high enough to reach
above low water mark, cement concrete being grouted in between them and poured
into the holes, which are marked O, O, in Figure 15, so as to flow underneath them
and consolidate the whole; the top may be finished in masonry. These floating
concrete blocks, either with or without exterior iron casing, may also be constructed
between high and low water mark, pontoons being attached if necessary, and open
valves being provided so that the water can flow in and out at each tide. When
the valves are finally closed and the tide rises the whole mass floats away. These
blocks may also with great convenience be constructed in a dry dock, or on a
floating dock or depositing dock, such as those described in our Patents above
mentioned. The dock is lowered until the block floats, when it is towed to its
position and sunk. Such blocks may with great advantage be faced with granite
or with blue Staffordshire bricks set in Portland cement and braced by layers of
hoop iron. The ends or sides of adjacent blocks which have to be filled in with
concrete after they are deposited should have square or angular notches or recesses
for receiving the concrete, as at P, P, Figure 15, and should be provided with pro-
jecting loops of hoop iron. In some cases we insert air bags in the recesses of the
blocks, and also externally, which are inflated so as to make them buoyant during
the operation of floating them out into their position.
Where the blocks have to be sunk into great depths circular hollow columns
such as those described in our Patent above mentioned are placed on the top of the
U portion, as shown in Figures 6, 7, 13, and 14, in order to give buoyancy and to
permit the mould and block to be lowered to the required depth, as in Figure 7.
Figure 15 shows the U portion provided with an outrigger Q, Q, in order to enable
1t to be lowered to an extra depth when required.
Where there is any current to be encountered it is preferable that the U portion
should be provided with a bow and stern, and should take the form of a short flat
bottomed steamer with a notch or slot cut more than half way through it in the
centre, and provided with engines, screws, and stearing gear. Such a vessel is
shown in plan at Figure 17, in side elevation at Figure 18, and in transverse
section at Figure 19.
The girders S, S, and hydraulic presses T are lettered in these Drawings the
same as in the preceding ones.
It is evident that the blocks may be built either upon a tidal foreshore or upon a
depositing dock, such as that described in the Patent 514 of 1875, or upon the
shaped part of the mould, as previously described, and the blocks when built and
hardened upon the dock are brought within the U shaped notch of the vessel, and
the tension bars being adjusted the weight is transferred to the steamer, the L piece
is removed, and the block hangs suspended from the vessel a few feet lower than
the bottom, and is ready to be deposited against the end of the pier already com-
pleted, as shown in Figures 17, 18, and 19, where W is the block hanging on the
.steamer, and X and Y the blocks already fixed in their position forming part of the
pier.

page_text: Having thus described the nature of our Invention, and the manner of performing
the same, we would have it understood that we claim,-
First. The modes, substantially as hereinbefore described, of constructing artificial
breakwaters, groins, and other submarine foundations.
Second. The construction and use of the U shaped shield formed with two skins,
the inner skin forming a mould to mould the breakwater or pier to form, and with
the space between the skins divided into compartments into or from which water
can be pumped to float or lift the shield.
Third. Making the bottom chambers of such shield air tight and open at bottom
in order that they may be used as diving bells.
Fourth. Connecting the inner ends of such shield at their top by a cross girder,
which may rest upon the top of the wall already constructed.
Fifth. Making such shield V shaped in front to push aside mud when shield is
moved forward.
Sixth. For forming lighthouses, bridge piers, and such like the use of a similar
shield of a tubular form, square, circular, oval, or polygonal in section, with double
sides, divided into compartments and pneumatic chambers, and formed in segments
that can be separately floated and removed.
Seventh. The use of a-similar double-sided -tubular guard, divided-into-compart-
ments and pneumatic chambers, and formed in segments that can be separately
floated and removed to form a shield for an inner cone or mould in which a light-.
house or pier is to be constructed.
Eighth. Building submarine structures or sections of structures upon internal
hollow cylinders or frames, so that when completed they may be made buoyant and
floated by forcing air. into internal cylinder or frame and be afterwards sunk in
position.
Ninth. Building submarine structures or sections of structures hollow and
rendering them buoyant by inflating an elastic bag within the hollow when it is
required to float them.
Tenth. Adapting the interior of the internal cylinder or frame of such structures
to be used as a diving bell.
Eleventh. Building or forming submarine structures or sections of structures upon
a caisson or floating pontoon composed of two parts, one part of an L shape forming
the bottom and one side, the other part, which is separate and detachable, of a
U shape, forming the three remaining sides, so that the structure whilst being built
may rest upon the bottom of the pontoon, and when finished be suspended to the
Ushaped portion and be by it floated into position and sunk, the shaped portion
having been first removed..
Twelfth. The construction of a caisson or floating pontoon in two detachable
parts in the above manner to allow of structures being built or formed upon them
and afterwards lowered into position by means of hydraulic cylinders, substantially
as described.
Thirteenth. The construction of a U shaped pontoon with a bow and stern, and
with engines and propelling mechanism, and steering gear, substantially.as described,
so that the pontoon resembles an ordinary broad steain vessel with a slot cut partly
through it at one of its sides, baving hydraulic suspending mechanism for suspending
blocks within the slot.
In witness whereof, I, the said John Standfield, have hereunto set my hand
and seal, this 30th day of May, in the year of our Lord One thousand
eight hundred and seventy nine.
JOHN STANDFIELD. (L.S.)