IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS, FORESHORES, SEA WALLS. AND THE LIKE. AND ALSO OF ROADWAYS AND OTHER PAVEMENTS
Year: 1871

page_text: LETTERS PATENT to Arthur Auckland Cochrane, of the City of West-
minster, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS, FORESHORES, SEA
WALLS. AND THE LIKE. AND ALSO OF ROADWAYS AND OTHER PAVEMENTS."
Sealed the 2nd February 1872, and dated the 11th August 1871.
PROVISIONAL SPECIFICATION left by the said Arthur Auckland
Cochrane at the Office of the Commissioners of Patents, with
his Petition, on the 11th August 1871.
I, ARTHUR AUCKLAND COCHRANE, of the City of Westminster, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS,
FORESHORES, SEA WALLS, AND THE LIKE, AND ALSO OF ROADWAYS AND OTHER
PAVEMENTS," to be as follows :—
My improvements have reference to the better construction of marine
structures, as breakwaters, foreshores, sea walls, and the like, and also

page_text: to the formation Of 10adways, tramways, anu
consist,-
Firstly. In constructing breakwaters, foreshores, sea walls, and the
like structures of blocks or masses of bituminous concrete or other
suitable materials, such blocks to be of suitable form and weight of, say,
from four hundred to eight hundred tons each or upwards, that is to
say, of blocks of, say, several hundred per cent. greater than have
been heretofore employed for such purposes. And I propose so to con-
struct them that breakwaters and the like structures may be built
in a manner with a rapidity and at smallness of cost not heretofore
attained.
The plan which I propose to employ is to compound the materials of
which such blocks or masses are composed by means of suitably arranged
machinery erected near the spot where such structures as before named
arc to be erected, and to mould them to the desired form without
incurring the expense of transporting the prepared materials from the
machinery to the moulds, thereby superceding (in a great degree) the
necessity for hand labor in manipulating the materials. I further
propose to float out such blocks to their distination by means of one or
more caissons as may be found convenient, which can be attached
thereto and readily detached therefrom when the said blocks or masses
of concrete shall have been deposited in situ. This placing of the blocks
in situ I effect either by causing the blocks and caissons to subsido
gradually into place by admitting water into the caissons and allowing
the blocks to ground, or by lowering the blocks by means of suitable
machinery attached to the caisson or caissons, by which the same object
is effected without submerging the caissons. Great facility is thus
afforded for depositing immense quantites of material in a complete
form at one operation in deep water with accuracy and dispatch, and
entailing much less risk of disruption and displacement of the work by
gales which would probably occur during the building up (or subsequent
thcreto) of the structure if made of smaller masses or blocks, as in the
ordinary method of building such structures. The uniting of such
concrete blocks or masses can be readily effected (by means of divers) by
running up the joints or intervening spaces thereof with a suitable
bituminous cement or concrete, and additional security may be obtained
if desired by the employment of suitable cramps or ties for holding the
blocks together, or by the adoption of a system of bonding the courses.

page_text: I do not confine myself to the exclusive use of bituminous compounds
for the foregoing purposes, as the improved system and arrangement
of machinery is equally applicable as a whole or in part to concretes
made with hydraulic cements, ironstone, or other suitable materials
forming cemented masses (when such are found desirable), as they
may be prepared and deposited by the same appliances, the same object,
viz., the placing of large masses of material at a time being thereby
effected.
The object of employing the aforesaid improved machinery in the
preparation of ordinary hydraulic cement concretes is the heating of the
materials employed, conducing to their more perfect incorporation,
greatly accelerating the setting of such masses, and thereby advancing
the work more rapidly, and thus expediting the progress of building
such large structures. And by such process such works can be carried
on in winter as well as in summer, thus shortening the time required for
their completion.
And I further propose to construct breakwaters and the like in the
following manner, viz. :- Metallic or other shells of large and suitable
construction, base, and depth forming receptacles for the materials which
are to form the body of the structure. I propose to be lined on the
inside with block-in-course masonry, or with blocks of bituminous or
other concrete sct in cement with proper bonding blocks, so as to form
connecting ties with the internal mass of concrete, with which I propose
to fill up the body of the structure as hearting, and in addition thereto
courses of iron or other ties may be inserted extending from one side of
the structure to the other, so that in the event of the shell becoming
decayed in the course of time the structure would remain intact. The
several shells with their contents I float out to the spot where they are
intended to be deposited, and there submerge them or nearly so as the case
may be. After having deposited the shells in place I fill up the interior
with ironstone or other suitable materials, which are caused to agglome-
rate together and form with the stone or concrete lining of the shells
solid masses impermeable to water. The shells may be made to keep
line with each other by projecting flanges at their ends, which will also
serve as guides in lowering them into place. The operation of lowering
the compartments when they have been severally placed in position over
the spot where they are to be deposited is simply effected by admitting

page_text: water into the interior with such velocity as will regulate the submersion
with the greatest nicety, the water being subsequently pumped out as
the work requires. I prefer to make the bottoms of the shells concave,
and I exhaust the enclosed spaces partially in order to seat them more
firmly in the soil.
Secondly. My improvements in the formation of roadways, tramways,
and other paved surfaces consist in the preparation and combination of
the materials employed therefor. I propose to use pavement for the
facing of such roadways of considerably less depth than usually applied
for such purposes, by which a saving of thirty to forty per cent. of the
material is effected, and with this reduction I obtain a stronger and
more durable roadway by reason of the combined strength of the super-
strata and substrata, such combination effecting a more uniform distri-
bution of the superincumbend load and traffic over a larger surface,
whereby local strain on pipes or other works beneath the surface of the
roadway (as at present arranged) will be in a great degree if not entirely
obviated. And as a means of promoting the contact and adherence of
stone pitching or other facing to the bituminous concrete upon which I
propose to place the superstrata the stones or other facing may be
coated with tar previous to bedding them. The substratum and facing
will thereby form one mass, and have much greater power to resist the
superincumbent weights passing over it than if such combination did not
exist.
I also propose to treat and employ iron ores, also certain roadmaking
materials made suitable for the superstrata and substrata of roadways
and other paved surfaces in a manner not heretofore practised, and in
some cases to admix therewith certain bituminous compounds. Such
roadways from the evenness of their surfaces and freedom from any
tendency to disturb the foundation will possess the advantages of
diminished traction and freedom from mud, mitigation of noise, and
increased durability and consequent economy resulting from the per-
manent character of its construction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Auckland Cochrane in the Great Seal
Patent Office on the 10th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
AUCKLAND COCHRANE, of the City of Westminster, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of August, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Arthur Auckland Cochrane, Her special
licence that I, the said Arthur Auckland Cochrane, my executors, ad-
ministrators, and assigns, or such others as I, the said Arthur Auckland
Cochrane, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times tlicrcafter
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 THE CONSTRUCTION OF BREAKWATERS, FORESHORES, SEA WALLS,
AND THE LIKE, AND ALSO OF ROADWAYS AND OTHER PAVEMENTS," upon the con-
dition (amongst others) that I, the said Arthur Auckland Cochrane, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and scals, 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 monthis next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur Auckland Cochrane, do
hercby declare the nature of my said Invention, and in what manner
O the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :—
In describing the particular nature of my improvements in reference
to marine structures and roadways I will state, firstly, my improved
method of preparing and incorporating the various materials which
5 I employ in forming the marine structures as hercin-after described and
referred to; secondly, the method by which I apply the same to the

page_text: of the same means to the preparation of the materials I use in the con-
struction of roadways and the like, together with the application of the
same with the view of obtaining a more durable, perfect, and economical
pavement.
And, firstly. The adaptations of my proposed plan of constructing
breakwaters, sea walls, and the like are numerous, viz., in the con-
struction of harbours of refuge, the projection of jetties, breakwaters,
piers, or sea walls into the sea or into rivers in sites which are exposed
to currents and tidal influences, or in the construction of viaducts
crossing rivers, estuaries, or arms of the sea, or for enclosure or boundary
walls for embanking out the sea, by which large tracts of land may be
reclaimed, thereby greatly facilitating the erection of such structures in
exposed waters. In such structures which require large quantities of
material to be manipulated and incorporated together for the purpose
of forming large masses it is desirable to effect the object with economy;
and for this purpose the machinery proposed to be used is arranged
in such manner as to constitute a consecutive serics of mechanical
operations, by which the materials employed may be advanced step by
step, so as to supersede in a great degree the necessity for manual labor,
and thus to induce great economy in their preparation. To effect this
object I propose to erect the machinery herein-after described con-
tiguous to the shore or spot where the proposed structure is to be built,
so as to make use as far as practicable of the materials locally available
for the purpose. As I propose to construct breakwaters and the like of
bituminous or other suitable concrete in larger masses than heretofore
employed it is desirable to economize the collection of the raw materials,
and I therefore propose to collect the shingle, ballast, or sand which
form the bulk of the blocks from the shore or as nearly so as may be,
which I convey by means of an elevator or inclined tramway or other
suitable device to the summit level of the machinery, and by means of a
circular or other conveniently formed tramway traverse the waggons
containing the materials, which I deposit in tanks placed at intervals
bencath such tramway. I use these tanks as feeders for a number of
rotating cylindrical (or other) heating vessels capable of being tilted by
suitable gear so as to receive a charge from the tanks above them, and
after being replaced over their furnaces of heating the materials to the

page_text: required temperature for amalgamation with the bituminous or other
matters to be mixed with them a rotary or other motion may be com-
municated to the vessels from a prime mover conveniently placed.
From these heating vessels the materials may be discharged into one or
more mixing mills heated by fire or superheated steam, as found most
convenient, and admitting of the temperature being controlled so as to
prevent overheating of the materials. In these mills the materials may
be thoroughly incorporated by means of revolving stirrers, and after-
wards discharged through suitable apertures into shoots connected with
the moulds beneath, which it is desirable should be placed as near to the
mills as convenient, so that the materials should be delivered into the
mould in a sufficiently heated state to insure their coherence. In these
several operations the labour of moving the materials should, as far as
practicable, be performed by mechanical power with only such manual
labor as may be requisite to direct the charging and discharging of the
several machines, such as opening and closing apertures and arranging
the quantities of the respective ingredients. The moulds into which the
mixed materials are ultimately discharged may be made of iron or other
suitable material, and of such form and dimensions as the nature of the
work requires, and so constructed as to be readily detachable from
the cast block when it has sufficiently set. And in order to facilitate
the setting the sides of the mould may be made hollow to admit water,
having a diaphragm extending nearly its entire height to promote the
circulation of the water, and the casting with its mould may be trans-
ferred from the spot where it was cast by means of a slip or tramway
and placed in the water. And when the mass or block is sufficiently
cooled and set (which may be accelerated by openings in or through tho
mass) the shell mould may be removed. Having thus arranged the
casting of the blocks it is proposed to float them out to their destination
by means of one or more caissons attached to each block, and to deposit
them in succession. These caissons may be attached to the blocks at
low water, so that the rise of the tide may float them. The form and
dimensions of the caissons may be such as convenience may suggest,
care being taken that the attachments are of sufficient strength to
support the weight of the block. Where one caisson is used it may be
brought over the block at high water, and by means of suitable
machinery the block may be weighed and remain suspended from the
caisson, and when floated over the spot where it is required to be

page_text: deposited it may be lowered into place without submerging the caisson.
Or two caissons may be employed, that is, one on each side of the block,
to which they may be attached by any suitable device. When floated
and towed over the spot where the block is to be deposited water may be
admitted into the interior of the caissons, and they may be gradually
submerged together with the block, which having been allowed to
ground the caissons may be detached therefrom, and the surplus water
being pumped out they may be re-floated. Care will be necessary to
avoid collision between the submerging and deposited blocks and to
place them in their intended position. If deemed necessary the blocks 1
may be connected by ties, which could be attached by divers. Such
blocks being of several hundred tons weight will render them capable of
resisting the displacing action of the sea after being deposited in place,
whereas if smaller blocks were employed the contrary would most
probably ensue, and the continual disruption of the fabric would be the ]
consequence.
Although I prefer to make the blocks of bituminous concrete from
its superior binding qualities in the proportion of about 6 to 10 per
cent. of Trinidad or other similar bitumen with 3 to 5 per cent. of
gas tar or other similar tar to 75 to 90 per cent. of ballast or shingle
(by preference broken) with the addition of about 12 to 15 per cent.
of sand, I do not confine myself exclusively to the use of bitu-
minous concrete, as hydraulic or Portland cement concrete of good
quality may be employed, and when made into blocks by means of the
previously described improved machinery the setting qualities of the
cement may be proved and the consolidation of the work greatly
accelerated. By such process also the works may be carried on in
winter as well as in summer, thus shortening the time for their com-
pletion.
I further propose to construct breakwaters and the like structures {
by encasing the concrete or other materials in shells or cases of iron or
other suitable material in the following manner :-Metallic or other
shells of large and suitable form and dimensions constituting receptacles
for the concrete or other materials which are to form the body of the
work I prefer to be lined on the inside with block-in-course masonry or a
with blocks or masses of bituminous or other concrete set in cement
11
1

page_text: concrete or hearting with which it is proposed to fill up the interior of
the structure; or the concrete may be built in as bêton en pisè, the
opposite sides being connected by transverse ties, so that in the event of
the subsequent decay of the case or shell the body of the work may
remain intact. These shelves I cause to be filled in a manner similar
to the moulds previously described or in such manner as may be found
convenient, and when so far loaded as to be capable of being floated out
to sea and navigated I tow them to their destination, and there submerge
them, or nearly so (as the case may be) by the admission of water into
interior compartments in such manner as to regulate the submersion
with precision. A portion of the shells or caissons may be left above
water, so that they may subsequently be filled up with concrete, iron-
stone, metallic slay, or other cheap powerable material, as hearting, so
as to bring the work up to high water mark or above it, as may be
determined. To insure the correct placing of the successive blocks
in line with each other projecting flanges may be provided at the
ends of the shells or caissons, which will serve as guides in lowering
them into place. As the hearting is tipped into the shell the water
employed for submerging it may be pumped out, and to facilitate
this the shell is proposed to be divided into compartments with a
view to seating the blocks firmly on their bed. The bottoms are made
concave, so that by exhausting the air and water therefrom through
pipes provided for the purpose the edges of the shells will penetrate
into the soil, giving them increased lateral stability. For the further
strengthening of the shell tubes may be inserted either longitudinally
or transversely, which will reduce the bulk and weight of the fitting-in
materials. This tube may be used, if desired, to graduate the draught
or immersion of the block by the admission of water into it, which can
be pumped out when requisite after the shell with its load is deposited
in lace
The foregoing arrangements for the preparation and employment of
the materials apply to all kinds of sea walls, viaducts, embankments for
the reclamation of land, and the like, either in shallow or deep water, as
structures herein described can be placed in situation without incurring
the cost of cofferdams, and in very deep water works the magnitude and
weight of the blocks may be advantageously extended to many thou-
sands of tons.

page_text: My improvements in relation to roadways and other pavements consist
in the proportion and treatment of the materials employed, that is to
say, for roadways superstrata I propose to use a composition of from
7 to 9 per cent. of pounded bitumen mixed with about 8 to 10 per cent.
of Stockholm or other tar having similar properties combined with about
80 to 84 per cent. of finely pounded Portland or other suitable stone,
and these ingredients I incorporate together, having previously heated
the stone on a large kiln floor or suitable heating surface. The stone
after it has been heated to a temperature of about 200° Fahrenheit may
be transferred with advantage to other heated surfaces, and the tar and
bitumen added to it, the tar having been well mixed with the stone
before the bitumen is added thereto. This mixed is best compounded
at a temperature of about 190°, which temperature will admit of its
being transported to a distance in casks or covered carts without sus-
taining any notable loss of heat, and in a condition to be laid down in
the state of powder as a roadway material in the ordinary manner by
punning, &c. When it is desired to send the material to a considerable
distance from the place of its manufacture I propose to admix the tar
and bitumen with the stone, as before described, at a temperature of
about 130° Fahrenheit, and after the mixture has been allowed to cool
it should be reduced to a state of granulation, and may then be packed
in casks, and when required for use should be re-heated to about a tem-
perature of 190°, and when so heating to be well stirred; it will then
be in a condition to be laid down, as before described, for footways,
floorings, and the like.
I propose to employ a material composed of shale tar gas pitch and
furnace slag, or calcarious substances reduced to powder (sand and chalk
may also be combined with the bituminous mixture with great advantage
in the proportion of 67 per cent. of the former to 17 per cent. of the
latter to 16 per cent. of the bituminous composition herein-after named),
and treated in the following manner:-I take shale tar and gas pitch
in equal proportions (should the tar contain acid it is desirablo to
neutralize or remove it by any of the well-known processes). The tar
boiled for several hours until it has lost about 25 per cent. of its
weight, when the gas pitch is to be added to it. I boil them together
until they are well incorporated, and then to about 16 per cent. of this
composition I add and admix therewith about 84 per cent. of the slag or

page_text: other hard calcareous material in a pounded and heated state. It can
then be applied and spread on a concrete substratum or on the levelled
surface of the ground; in the latter case a thicker layer of the material
will be found necessary to insure its durability.
DESCIPTION OF THE DRAWING.
Figures 1 and 2 represent the general elevation and plan of an arrange-
ment of machinery by means of which the materials constituting the
concrete employed for the construction of breakwaters and other marine
structures, roadways, &c., in which A is a circular tramway of the
summit of the series upon which the waggons containing the ballast,
shingle, or sand are conveyed, and from which the materials are dis-
charged into the tanks or hoppers B beneath the tramway, and from
these into the heating vessels C below them, where the temperature
of the materials is raised to about 170 to 200° Fahrenheit, and then
discharged into the mixing mill D, where the other ingredients of the
mixture are thoroughly incorporated with them by rakes or stirrers
attached to the centre shaft. The mill should be heated by superheated
steam surrounding the sides and bottom of the pan by preference, or by
fire in flues beneath and around the pan. E, a shoot from the mixing
mills to convey the materals when mixed to the mould F. Where the
mould is of necessity at some distance from the mixing mill a travelling
chain of buckets or other convenient device may be employed for con-
veying the materials from the mill to the mould. When the mould has
been filled the cooling of the casting may be accelerated in the manner
herein-before described, or by any other more convenient method which
the locality may suggest.
Figures 3 and 4 are longitudinal and transverse sections of a block
forming a section or part of a breakwater, and Figure 5 plan of the
same. G is the block of concrete faced with stone or concrete blocks,
thus rendering the surface exposed to the action of the sea or the
collision of vessels more capable of resisting such contingencies; H, H,
arc caissons attached to the block as a means of floating it out to sca,
and to admit of its being navigated to its destination and deposited
in situ.
Figures 7, 8, 9, are longitudinal and transverse sections as well as plan
of a cased block forming a section or part of breakwater. I is a shell or

page_text: caisson of iron or other suitable material, and which is constructed of
sufficient strength to contain the material which is to be placed in it.
As much material as can be floated at low water, half tide, or high
water, as the case may be, is placed in it, and when floated out to its
destination as much water may be admitted into the water-tight com-
partments into which it is divided as will submerge it and allow it to
ground, after which the water may be pumped out and the residue of
the material filled in to complete the block. The bottom is made
concave, so that when the air and water is exhausted therefrom the
pressure of the superincumbent mass may cause it to scat itself in the
soil, whereby all tendency to lateral disturbance will be obviated.
Having now particularly described my said Invention, and the manner
in which the same is to be performed, I would have it understood that
I do not confine myself to the precise details and proportions herein
specified, so long as the main features of my Invention are retained, as
they may be advantageously varied to suit the special character of the
application; but that which I claim as my Invention, and which I
believe to be novel is,-
Firstly. The general arrangement of the machinery as herein described
for preparing and treating the materials herein mentioned for the pur-
pose of constructing marine and other structures, roadway and other
pavements, and their substrata herein referred to.
Secondly. The application of masses of bituminous or other concrete
and other material, as herein described, to be used in the construction of
marine and other structures, as herein referred to.
Thirdly. The construction of marine and other structures as hercin
referred to by the employment of metallic or other shells or caissons
containing suitable materials, as herein described, which may be deposited
in shallow or deep water to form breakwaters, sea walls, embankments,
piers, harbours of refuge, and the like structures, thus obviating the
employment of expensive cofferdams and the delays incident to the
ordinary mode of constructing such works.
Fourthly. The construction of roadway and footway superstrata,
floorings, and the like, prepared in the manner herein described.
Fifthly. The use and application of heated floors or kilns for heating
natural bituminous rock materials use for asphaltic pavements, or for

page_text: other asphaltic compounds use for roadway or footway pavements,
being a more expeditious and economical process than that in present
use for those purposes by means of rotating and other boilers,
In witness whereof, I, the said Arthur Auckland Cochrane, havo
hereunto set my hand and scal, this Tenth day of February, in the
year of our Lord One thousand eight hundred and seventy-two.
Witness to the signature of
A. A. Cochrane,
AMI. H. RENTON.
ARTHUR A. COCHRANE. (L.S.)