A Platform with Supports and Appliances for Facilitating Erection of Structures in Deep Water.
Year: 1892

page_text: Date of Application, 26th Feb., 1892
Complete Specification Left, 25th Nov., 1892-Accepted, 31st Dec., 1892
[Communicated from abroad by THE CHANNEL BRIDGE AND RAILWAY
COMPANY LIMITED, of 69, Rue de la Victoire, Paris, France.]
A Platform with Supports and Appliances for Facilitating Erection
of Structures in Deep Water.
I, JOHN IMRAY of No. 28 Southampton Buildings in the County of London,
Consulting Engineer and Chartered Patent Agent, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the construction of a platform for carrying cranes,
machinery, shops or workmen's lodgings over the place where a structure such as a
bridge pier has to be made in deep water, to means of supporting, erecting and
fixing the platform firmly in position and of guiding down from it blocks or other
materials to form the subaqueous structure. For this purpose, there is prepared
on land or on lighters near the shore a strong rectangular framing the sides of
which are hollow girders made watertight so that they can float. Each angle is
formed as a socket to embrace loosely a hollow cylindrical column which is made in
separate lengths or sections also watertight. There are also provided, when the
water is of considerable depth cross ties made with sockets to embrace the columns.
The frame being constructed with suitable longitudinal and cross ties, is carried on
lighters along with the sections of columns to the place where it has to be erected,
where the lighters are moored. Through the sockets at the angles of the platform
the successive lengths of the columns are passed and fixed together, sufficient.
water being admitted to sink them, and when cross ties are required, these, having
previously been placed under the sides of the platform so that the lengths of
columns pass through their sockets, are fixed to the appropriate lengths of column
and descend with them as length after length is added above. When lengths of
columns have been added in sufficient numbers for the ends of the column to reach
the bottom, or nearly so, water ballast is admitted into the lighters, allowing the
platform to descend, and the ends of the columns to imbed themselves in the
bottom. In order to avoid damage to the lower ends of the columns by the heaving
of the lighters caused by waves when the columns have nearly reached the bottom,
it is preferred to provide each of the lowest column lengths with a spring plunger
to operate as a buffer when it meets the bottom. After the columns have taken
their bearing on the bottom, the platform is raised and levelled on them by
hydraulic jacks or otherwise and the lighters are floated away. In places where
the platform may be exposed to heavy seas it may be moored by anchors and
chains. On the platform are provided suitable rails for travelling cranes by which
building blocks or other parts of the subaqueous structure can be lowered. In
order to guide such parts truly down to their desired positions, rectangular columns
of iron or steel lattice work descend from the platform and the blocks or other
parts are lowered down them to their places on the structure below.
Dated this 26th day of February 1892.
ABEL & IMRAY,
Agents for the Applicant

page_text: COMPLETE SPECIFICATION:
A Platform with Supports and Appliances for Facilitating Erection
of Structures in Deep Water.
I, JOHN IMRAY, of No. 28 Southampton Buildings, in the County of London,
Consulting Engineer and Chartered Patent Agent, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to the construction of a platform for carrying cranes,
machinery, shops or workmen's lodgings over the place where a structure such as a
bridge pier has to be made in deep water, to means of supporting, erecting and
fixing the platform firmly in position and of guiding down from it blocks or other
materials to form the subaqueous structure. For this purpose, there is prepared
on land or on lighters near the shore a strong rectangular framing the sides of
which are hollow girders made watertight so that they can float. Each angle is
formed as a socket to embrace loosely a hollow cylindrical column which is made
in separate lengths or sections also watertight. There are also provided, when
the water is of considerable depth cross ties made with sockets to embrace the
columns.
The frame being constructed with suitable longitudinal and cross ties, is carried
on lighters along with the sections of columns to the place where it has to be
erected, where the lighters are moored. Through the sockets at the angles of the
platform the successive lengths of the columns are passed and fixed together,.
sufficient water being admitted to sink them, and when cross ties are required,
these, having previously been placed under the sides of the platform so that the
lengths of columns pass through their sockets, are fixed to the appropriate lengths
of column and descend with them as length after length is added above. When
lengths of columns have been added in sufficient numbers for the ends of the
column to reach the bottom, or nearly so, water ballast is admitted into the lighters,
allowing the platform to descend, and the ends of the columns to imbed themselves
in the bottom. In order to avoid damage to the lower ends of the columns by the
heaving of the lighters caused by waves when the columns have nearly reached
the bottom, it is preferred to provide each of the lowest column lengths with a
spring plunger to operate as a buffer when it meets the bottom. After the columns
have taken their bearing on the bottom, the platform is raised and levelled on
them by hydraulic jacks or otherwise and the lighters are floated away. In places
where the platform may be exposed to heavy seas it may be moored by anchors
and chains. On the platform are provided suitable rails for travelling cranes by
which building blocks or other parts of the subaqueous structure can be lowered.
In order to guide such parts truly down to their desired positions, rectangular
columns of iron or steel lattice work descend from the platforin, and the blocks or
other parts are lowered down them to their places on the structure below.
The accompanying drawing is a perspective view of a structure according to this
invention.
It is composed of a metal platform of rectangular shape, supported by four
tubular columns or piles A. A A A.
The platform is constructed of a series of iron beams the ends of which are made
to embrace the heads of the columns; they are made of sufficient depth to provide
between the top and bottom enclosure of the platform considerable space to
accommodate room for stores, for machinery and for workmen.
The structure is erected in the following manner :-
The platform, being put together on the ground at a river or seaport, is loaded
upon two barges of a tonnage corresponding to its weight. The columns for

page_text: supporting it are placed in suitable lengths upon the platform, the lengths being
made to fit together with suitable watertight joints. The outer diameters of all the
lengths are made so as to be able to pass through the sockets formed at the corners
of the platform.
After loading the latter on the barges, either before or after leaving the port,
the lowermost lengths of the columns are lowered through the corner sockets by
means of cranes or hydraulic apparatus on the platform; then, as the depth of
water increases after leaving port, other lengths of the columns are fixed to those
already lowered, and are lowered in their turn through the sockets, so that the
supports for the platform are in this way gradually extended downwards while the
structure is being conveyed to its place of destination, care being taken to keep
the lower ends some yards clear of the bottom.
The above described operation is greatly facilitated by the fact that the lengths
of hollow column, when they are sunk, are closed by a partition near the lower
end so that as their displacement is greater than their weight, the extent of sub-
mergence can be accurately regulated by admitting regulated quantities of water
ballast.
The structure having been brought to the place where the work is to be
executed, and being adjusted accurately in position by any suitable means, the
columns are sunk quite to the bottom and their upper ends are securely fixed in
the sockets by tightening up the sections of these so as to grip the columns firmly
making them integral with the platform. Although for this operation the calmest
weather should be selected, the columns will necessarily be raised and lowered
with the platform subject to the action of the waves, causing shocks to the lower
ends of the columns which might cause serious damage, unless the precaution was
taken to deaden such shocks by providing the foot of each column with a spring
piston or plunger of the following description.
In an internal cylinder a a connected to the wall of the column by wings b b
slides with moderate friction a plunger cc the lower end of which forms the
supporting point of the column, and this central support, of section less than that of
the column, ensures a sound bearing on the bottom. The head of the plunger c
works in a cylinder d which is closed at the top and connected to the wall of the
column by wings ee and contains a pile of spring discs to deaden shocks as for the
recoil of heavy guns. The shocks to be thus deadened exist however only for a
short time, for, when the columns reach the bottom, the admission of an abundant
charge of water causes the barges to sink several inches, and thus a firm bearing is
taken on the bottom.
In order to correct any defect in level resulting from wave motion when the
columns take their bearing, the heads of the columns may be adjusted in the
sockets by hydraulic jacks.
It need scarcely be said that the weight of the platform and the dimensions of
the columns are calculated so as to ensure, in the greatest storms, complete stability
and safety, that is to say
1. Complete equilibrium of the whole structure and absolute resistance to
overturning.
2. Strength of columns suited to their vertical load.
3. And strength to support transverse shocks resulting from waves or floating
bodies.
It is found by calculation that these conditions can be realised for depths
exceeding 25 fathoms.
The rigidity of the structure and stiffness of the columns are substantially
enhanced by cross stays B at about half the height. The placing of these stays
involves no difficulty, provided that they are placed under the platform at the
setting out of the barges, so that their eyes coincide with the sockets through which
the columns slide; and they can be fixed on the columns by setting screws around
their eyes, when it has been ascertained by soundings at what heights they should
be fixed so as to ensure their being level after submersion. For additional safety,
the structure, when placed, can have each of its corners anchored by a chain to a

page_text: mass sufficiently distant and heavy, this being especially important in order to
protect the structure against the effects of shocks from large floating bodies.
Finally, in order to provide against accidents resulting from unforeseen causes;
the interior of the platform is divided into watertight compartments, so as to
ensure its buoyancy. All these arrangements contribute to render the platform
a workshop of absolute safety, suited, by reason of its great extent and its stability
for any operations to be conducted under it, for instance the preparation of the
bottom by drags or other apparatus, the lowering of foundation blocks, injection
of liquid mortar or cement, placing of tubes or caissons, and generally for all
operations requiring such exactness as can be obtained by the use of a stable
and stationary support. It is especially claimed as a direct application of this
invention, the construction of masses of masonry, foundations for bridges, forts,
batteries and other marine structures by means of artificial blocks placed in exact
positions by means of metal guides extending down from the platform. The
drawing shews three of these guides C suited for lowering large artificial stone
blocks weighing say 150 tons, an operation which could not be safely carried on
without such a stable support as this platform affords.
The construction with guided blocks is not necessarily connected to the use of
the metal platform, it is applicable to any work in moveable or excavable bottoms
and especially for erection of quays on a loose bottom. Such a quay can be made
by piles of independent blocks kept in line by metal guide piles which are driven
down to sound ground and are supported by land ties, being driven down separately
as the excavation proceeds at the base of the quay, without throwing the whole out
of shape, and requiring only to fill up by head blocks the space left over each pile
by its sinking.
In the drawing the guide columns are made of trellis work so as to offer great
resistance to waves with a height of more than 55 or 60 yards. This arrangement
may be varied to any extent to suit the depth, the agitation of the water and the
character of the works to be done.
It especially permits of the ulterior introduction, into the wells of the guides, of
submerged concrete to form a connection of all the blocks. In structures requiring
exceptional solidity the guides may be left in the masonry of which they will con-
stitute effectual ties. When it is desired to execute some important structure, the
lines of blocks which are to form it or its exterior may be firmly connected by ties
or struts attached to the guides and acting in any desired direction. If, for
instance, the foundation of a bridge pier has its exterior formed of blocks thus
placed and connected from one side of the foundation to the other by iron ties,
extending from one guide to another; if the interior is filled with materials which
are agglutinated by cement injected from above the platform, so as to envelope in
a. concrete mass all the ties connecting the walls, there will obviously be thus
formed a foundation of the greatest solidity capable of carrying the strongest and
heaviest superstructure.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. The use for subaqueous works at any depth of a metal platform carried on
four columns which rest on the bottom.
2. The method of erecting the platform by floating it off entire by barges and
gradually submerging the columns, taking advantage of their buoyancy.
3. The rapid fixing of the platform by clamping the columns in the sockets of
the platform through which they pass.
4. The deadening of shocks on submerging the columns by the spring apparatus
above described.
5. The settling of the platform by admitting water ballast into the barges.
6. The adjusting of the level of the platform by hydraulic jacks acting on the
heads of the columns.

page_text: 7. The application of the apparatus to all civil or military works under water in
rivers, canals, lakes or seas.
8. The use of stationary metal columns to guide blocks of masonry and ensure
their exact placing, and to connect them by the guides and ties attached to these
columns.
Dated this 25th day of November 1892
ABEL & IMRAY,
Agents for the Applicant.