IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS OR WAVE SCREENS, APPLICABLE' ALSO IN CONSTRUCTING BRIDGES, ROADWAYS, PIERS, JETTIES, LANDING STAGES, AND OTHER STRUCTURES
Year: 1858

page_text: LETTERS PATENT to Arthur Hyde Dendy, of 27, Fortess Terrace, Kentish
Town, in the County of Middlesex, Esquire, Master of Arts, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS OR
WAVE SCREENS, APPLICABLE' ALSO IN CONSTRUCTING BRIDGES, ROADWAYS,
PIERS, JETTIES, LANDING STAGES, AND OTHER STRUCTURES."
Sealed the 6th May 1859, and dated the 8th November 1858.
PROVISIONAL SPECIFICATION left by, the said Arthur Hyde Dendy
at the Office of the Commissioners of Patents, with his Petition, ou
the 8th November 1858.
I, ARTHUR HYDE DENDY, of 27, Fortess Terrace, Kentish Town,. in the
County of Middlesex, Esquire, Master of Arts, do hereby declare the nature
of the said Invelion for "IMPROVEMENTS IN THE CONSTRUCTION OF BREAKWATERS
OR WAVE SCREENS, APPLICABLE ALSO IN CONSTRUCTING BRIDGES, ROADWAYS, PIERS,
JETTIES, LANDING STAGES, AND OTHER STRUCTURES," to be as follows:-
1 construct my breakwater or wave screen by laying down in the required
position a series of tubes side by side, either with or without intervening
spaces, with another series of tubes superimposed thereon; and so on according
to the height required.
The several tubes may be similar or dissimilar in form and size, and
composed either wholly or in part of iron, or other suitable materials, always
observing that the lengths of the tubes should bear such a relative proportion
Price 8d:1

page_text: to their sectional areas or waterways as to thereby effectively counteract the
undulatory force of the waves in passing through them, my object being so to
construct my breakwater, and place it in such position that it shall present a
very inconsiderable facial resistance to the direct action of the waves as com-
pared with the mass of the structure, and shall at the same time counteract as
far as may be requisite, their undulatory motion and breaking force, by
causing them to pass through long tubes or tunnels. These tubes may be
secured, fitted, or fastened together by means of rings, bolts, pins. rivets,.
chains, or other contrivances, or they may be built up in cement or other
materials; and the tubes may be formed in stonework, brickwork, cement,
or other materials, or, by combining corrugated plates or pieces of metal, or
by any other method, so as to give the effect of open tubes or tunnels. And
I may observe, that the face or faces of this breakwater can be constructed at
right angles to the horizon, or at any other angle or angles less or greater
than a right angle.
This breakwater being carried up to the maximum height of the waves at
high-water springs, can have a road or gangway superimposed thereon, and
indeed a similar kind of structure will form a bridge, roadway, pier, jetty, or
landing stage, and will also form the substructure of lighthouses, beacons, and
other erections.
The above is a description of the nature of the Invention, which night
however be varied in its practical details.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Arthur Hyde Dendy in the Great Seal Patent Ollice on the
7th May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, ARTHUR
HYDE DENDY, of 27, Fortess Terrace, Kentish Town, in the County of
Middlesex, Esquire, Master of Arts, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Arthur Hyde Dendy, Her special. licence that I, the said Arthur Hyde
Dendy, my executors, administrators, and assigns, or such others as 1, the said
Arthur Hyde Dendy, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter

page_text: OTHER
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 OR WAVE SCREENS, APPLICABLE ALSO IN CON-
STRUCTING BRIDGES, ROADWAYS, PIERS, JETTIES, LANDING STAGES, AND
STRUCTURES," upon the condition (amongst others) that T, the said Arthur
Hyde Dendy, my executors, or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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 I, the said Arthur Пyde Dendy, do hereby
declare the nature of the said Invention, 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:
It is now generally admitted that waves are of two kinds, namely, waves of
oscillation or deep water waves having little or no horizontal percussive force.
and waves of translation or shoal water waves having often times an immense
horizontal percussive force.
Breakwaters as hitherto constructed are designed to oppose a direct facial
resistance to the oscillation and percussive force, however, violent, of every
description of wave.
The long slope principle has most frequently been adopted in the construc-
tion of the sea front of breakwaters, but it is now considered to be objection-
able from its forming an artificial shore, whereby simple waves of oscillation
become converted into waves of translation, and it is now being generally
abandoned in favor of the vertical or upright wall principle. The upright.
wall, however, as applied to ordinary breakwaters, is directly opposed to the
nimost accumulated horizontal percussive force of the waves, and is probably
the worst form that could be adopted in waters of moderate depth to resist
waves of translation, although it is well calculated to reflect waves of oscilla-
tion, and prevent their conversion into waves of translation.
Breakwaters of stone, although very costly, are continually liable to wreck-
age from extraordinary storms, and also from the explosive force of the air
contained in the vacant space between the stones, whenever, by reason of any
slight defect in the sea face, the water obtains admission to the interior of
the structure. They necessarily occupy very many years in construction,
invariably require a large annual outlay for repairs, and when applied to

page_text: close harbours, occasion a large deposit of silt, which in the case of the Dover
harbour, now constructing, it is calculated it will cost 20,000l. annually to
remove it.
Breakwaters partly formed of wood are far less costly, but they can only be
expected to withstand the action of the elements for a limited period. The
structures known as wave screens are comparatively inexpensive, but they are
only adapted to deep water, and their form of construction does not con-
veniently allow of their being used as piers, jetties, or landing stages. Their
object is merely to lessen the undulatory motion of the deep sea waves to the
extent of one-half, or thereabouts, and to prevent the deposit of sill. It being
generally acknowledged that all the existing modes of construction are
defective and capable of improvement, the object of my Invention is to con-
struct a breakwater which shall combine thorough efficiency and durability.
with comparative economy of cost, allowing also of facility and rapidity of
construction.
(I.) Now the nature of my Invention consists in constructing breakwaters
by means of a number or series of open tubes or tunnels of a length considerably
exceeding their diameter, or the height or breadth of their waterway, disposed
in layers and laid horizontally, or as nearly so as may be convenient or requisite,
and placed in such a position that they shall present a very inconsiderable
facial resistance to the direct action of the waves as compared with the mass
of the structure, and at the same time shall counteract to any required extent
as well the undulatory or oscillatory motion of the waves, as also their breaking
or percussive force, by causing them to pass through such tubes or tunnels;
always observing that the greater the diameter or height and breadth of the
waterways thus formed, the greater must be their length, all which may be
readily understood by reference to the accompanying Drawings and the
following statements.
(11.) Having thus described the nature of the said Invention, I now
proceed to describe in what manner the same is to be performed. I construct
my breakwater or wave screen by laying down in the required position a
number or series of such open tubes, side by side, either with or without
intervening spaces, with another series of open tubes superimposed thereon,
and so on, according to the height required. The several tubes may be
similar or dissimilar in form and size, and composed either wholly or in part
or iron or other suitable materials.
I prefer, for convenience of construction, to use straight iron tubes, all
similar in size and form, every tube having the sectional area of its waterway
of a square form or of any oblong form, and either with or without com-

page_text: foundations, and the said Figures shew variations in the substratum of the
said construction. Fig. 2 is a ground plan of a breakwater constructed on
the principles herein claimed, shewing the mode of forming the said con-
struction in deep water or as a wave screen, so as to give it greater stability, and
also shewing its applicability to a close harbour. Figs. 3 and 4 shews the
rectangular tubes- so formed as to dovetail one into the other, and having
divisional compartments to ensure greater rigidity. the same may be con-
structed of tubes in short lengths, and the whole bolted or otherwise firmly
secured together, each tube having a flange at one end of the top bed, as
shewn in the Drawing.
Fig. 4 shews another method of laying square or oblong tubes with
intervening spaces. Upon each of these tubes there should be a continuous
lug or bracket, forming when in its place a crutch for the reception of the
other tubes. Fig. 5 shows a mode of laying hexagonal tubes. Figs. 6 & 7
in like manner represent the fastening of hexagonal tubes by means of pins.
claws, or dowels being cast on or otherwise affixed to the side or sides of the tube,
and dropping into holes suitably formed for their reception in the adjoining
tube, or other the said hexagonal tubes may be bolted together, as the case
may be.
The efficiency of my breakwater does not, however, depend on the form
or size of the tubes; they may be round, hexagonal, or any other form, or
oblong; or they may be bent, crooked, twisted, or taper as well as square;
neither is it necessary that they should all be placed parallel to one another.
It may be convenient in certain situations to construct the breakwater in
the form of a curve by the use of tubes of a taper form, as shewn at A, in
Fig. 2; and where the embaying winds do not always blow from the same
point or quarter of the compass, and for some of the purposes to which my
mode of construction is applicable, some of the tubes may be placed diagonally
obliquely to or across others.
The means of fastening the tubes together may, however, be varied; they
may be secured, fitted, cemented, or fastened together by means of rings, bolts.
pins, rivets, chains, or other means or appliances, or they may be built up in
cement, or in any other materials. And the tubes may be formed in stone-
work, brickwork, cement, glass, stoneware, or other materials, or by combining
corrugated or flat plates of iron, or iron girders, or angle iron, or pieces of
metal, or by any other method, so as to give the effect of open tubes or
tunnels.
Fig. 8 shews a mode of forming and giving the effect of tubes by means of
corrugated plates of iron or other suitable material or materials of sufficient

page_text: strength, laid horizontally or laid vertically, as in Fig. 9, commencing from
pieces of masonry or other convenient and suitable material to affix the
aforesaid corrugated plates thereto, which is done by means of bolts and nuts
of suitable strength and material, and the whole of the said corrugated materials
to be strongly rivetted together.
Figs. 10 and 11 shew a mode of fixing and giving the effect of tubes to
cast or wrought plates of iron or other suitable material, the same to be firmly
connected and anchored together by means of tie bars, angle pieces, or other
suitable means or appliances at convenient distances, all-parts necessary so
treated.
My mode of construction may be combined with any other mode at present in-
use in the formation of breakwaters or wave screens, and where several solid
stone piers or buttresses are used the intervening spaces may be filled with
tubes of any size or shape that may be convenient and adapted to the purpose
required, as shewn in Fig. 9. Also, in places where from the nature of the
ground all the tubes cannot conveniently be placed side by side in a line
horizontally or on the same level, a portion of them may be fitted or fastened
to piers or buttresses, or to foundations either natural or artificial, and the
tubes or pipes so placed as to form an opening over the intervening spaces,
us shewn at B, in Fig. 1. And I may observe that the face or faces of this
breakwater can be constructed at right angles to the horizon, or at any other
angle or angles less or greater than a right angle, but I prefer its being
constructed with a vertical face to a depth of about 15 feet below the surface
of low-water at neap tides, below which depth any form or species of
foundation or support for a breakwater constructed according to my Invention
may be adopted; it may be carried on screw piles, with or without iron
girders, or on arches, as shewn at C and D at Fig. 4. This breakwater being
carried up to the maximum height of the waves at high-water springs, can
have a road or gangway superimposed thereon, as shewn at E, in Fig. 1.
The same or a similar kind of structure will form a bridge, roadway, pier,
jetty, or landing stage, and will also form the substructure of lighthouses,
beacons, and other erections, & for all or some of these purposes it may be
convenient to place some of the tubes diagonally or obliquely to or across one
another, so as to allow of the passage of the water in different directions
through them.
(11.) Having now particularly described the nature of my Invention, and
in what manner the same is to be performed, I hereby declare that it is to be
understood that I do not confine myself to the precise details above referred

page_text: io, as these may be varied; but I claim the Invention the nature whereof is
set forth in the outset, marked (I.) of this my Specification thereof.
In witness whereof, I, the said Arthur Hyde Dendy, have hereunto set
my hand and seal, this Seventh day of May, in the year of our Lord
One thousand eight hundred and fifty-nine.
Signed & sealed in my presence,
F. W. CAMPIN, Patent Agent,
156, Strand.
ARTHUR HYDE DENDY. (L.S.)