IMPROVEMENTS IN GROYNES FOR RAISING OR PROTECTING FORESHORESAL
Year: 1883

page_text: LETTERS PATENT to Alfred Dowson of 3 Great Queen. Street, Westminster,
'
Middlesex Civil Engineer for an Invention of IMPROVEMENTS IN GROYNES
FOR RAISING OR PROTECTING FORESHORES
PROVISIONAL SPECIFICATION left by the said Alfred Dowson at the
Office of the Commissioners of Patents on the 20th January 1883.
ALFRED DOWSON of 3 Great Queen Street, Westminster Middlesex, Civil
IMPROVEMENTS IN
Engineer
OR
GROYNES FOR RAISING
SHORES
PROTECTING FORE-
This invention has for its object the gathering or retention of shingle or other
detritus washed up along the foreshore of the coast by the action of the sea.
The method usually adopted in seeking to attain this end is the construction of
solid groynes or walls at intervals along the foreshore. A serious drawback to
such a system is that the solid groynes or walls obstruct the waves as well as the
detritus, and the water is made to return in such a way as to cause a backwash.
The effect of this backwash is often to carry away the detritus previously
deposited.
To prevent the backwash before referred to and the consequent removal of
detritus I dispense with solid groynes or walls and build groynes of open con-
struction which allow the water to pass through freely, after having deposited any
shingle or detritus it may have brought up.
My mode of constructing these open groynes is to fix uprights of iron, timber or
other suitable material to the foreshore, and to attach to these uprights gratings of
iron, wood, concrete, pottery, wattling or other suitable materials or a combination
of two or more of them-The openings in the gratings may be vertical, horizontal,
or of any other form desirable, and the size of the openings in the gratings should
be regulated in each case by the size of the shingle or detritus to be retained. The
uprights may be made of the full height of the groyne required, but I prefer not

page_text: to fix the gratings to their full height at first, but to raise them or build them
up gradually as the deposit increases. In cases where the uprights are hollow
the portions of them to be buried in the ground or detritus may be perforated,
and liquid cement or other suitable adhesive substance may be forced down the
interior of the uprights and through the perforations so as to solidify the surrounding
soil or deposit.
The precise details of construction may bo varied to suit the particular materials
used in the formation of the groynes, but it is an essential part of my invention
that sufficient openings should always be left in them for the water to pass
through them freely after having deposited the shingle or detritus it may have
brought up.
.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent & of
an Order of the Lord Chancellor filed by the said Alfred Dowson in the
Great Seal Patent Office on the 23rd July 1883.
ALFRED DOWSON of 3 Great Queen Street in the City of Westminster Civil
Engineer IMPROVEMENTS IN GROYNES FOR RAISING OR PROTECTING FORE-
SHORES
"
This invention relates to improvements in groynes for raising or protecting
foreshores and has for its object the gathering or retention of shingle or other
detritus washed up along the foreshore of the coast by the action of the sea.
The method usually adopted in seeking to attain this end is the construction
of solid groynes or walls at intervals along the foreshore. A serious drawback
to such a system is that the solid groynes or walls obstruct the waves as well as
the detritus, and the water is made to return in such a way as to cause a back-
wash. The effect of this back wash is often to carry away the detritus previously
deposited.
J.
To prevent the backwash before referred to and the consequent removal of
detritus I dispense with solid groynes or walls and build groynes of open con-
struction which allow the water to pass through freely, after having deposited any
shingle or detritus it may have brought up:
My mode of constructing these open groynes is to fix uprights of iron, timber or
other suitable material to the foreshore, and to attach to these uprights gratings,
rails or screens of iron, wood, concrete, pottery, wattling or other suitable materials,
or a combination of two or more of them. The openings in the gratings, rails or
screens may be vertical, horizontal, or of any other form desirable, and the size of
the open spaces in or between the gratings, rails or screens should be regulated in
each case by the size of the shingle or detritus to be retained. The uprights may
be made of the full height of the groyne required, but I prefer not to fix the
gratings, rails or screens to their full height at first, but to raise them or build
them up gradually as the deposit increases. In cases where the uprights are
hollow the portions of them to be buried in the ground or detritus may be
perforated, and liquid cement or other suitable adhesive substance may be forced
down, the interior of the uprights and through the perforations so as to solidify the
surrounding soil or deposit.
The precise details of construction may be varied to suit the particular materials
used in the formation of the groynes, but it is an essential part of this invention
that sufficient openings should always be left in them for the water to pass
through them freely after having deposited the shingle or detritus it may have
brought up.
The accompanying drawing is intended to form part of this specification and to
illustrate practical modes of carrying the invention into effect; but I do not limit
myself to the precise forms and details shewn, as they may be varied without
departing from the nature of my invention.
Figs: 1. and 2. représent examples of the said groynes, and Fig: 3. represents a
hollow upright with perforations near the end embedded in the ground or detritus
to allow liquid cement to pass through them.
Fig: 1. is a side elevation of a groyne consisting of vertical uprights a. a. with
intermediate vertical rails b. b. connected together on the top by a horizontal rail c.
secured to the uprights a. a. thus forming a series of gratings or screens between
each pair of uprights. The uprights a. a. can be made of any suitable height and
the distances apart of the vertical rails b. b. should be regulated by the size of the

page_text: shingle or detritus to be retained. The uprights a. a. may be made of greater
height than the vertical rails b. b. and the borizontal rail c. may be secured to the
said uprights a. a. in such a way that when a deposit of shingle or detritus has
been formed round or against one of the gratings or screens, such grating or screen.
may be raised vertically and fixed above the deposit as shown in dotted lines in
Fig: 1. so that a second deposit may be produced above the first one.
Fig: 2. is a side elevation of a groyne consisting of vertical uprights d. d. to which
are attached screens of wattling with the openinga e, e. so arranged that the water
may pass through them freely while the shingle or detritus is stopped.
:
Fig: 3. shews one form of upright a., such as may be used in the arrangement
shown in Figs 1 and 2. and consists of a hollow tube with perforations f. f.-
Liquid cement or other suitable adhesive substance may be forced down the interior
of the upright and through the perforations f. f. so as to solidify the surrounding
soil or deposit.
Having now described the nature of my said Invention and the manner in
which the same is or may be used or carried into effect I would observe in
conclusion that what I consider novel and original and therefore claim as the
invention secured to mo by the hereinbefore recited Letters Patent is :-
1. The raising or protection of foreshores by means of groynes of open construction
which admit of the passage of water through them after all or part of the shingle
or detritus brought up by the water has been deposited near the groyne.
2. The construction of open groynes, for the purposes aforesaid, in one of the
modes described in Figs: 1, 2, and 3.
3. The construction of open grøynes, for the purposes aforesaid, of uprights of
iron, timber, or other suitable material fixed to the foreshore with gratings, rails or
screens attached thereto, such gratings, rails or screens being made of iron, wood,
concrete, pottery, wattling or other suitable materials or a combination of two or
more of them, the openings in the gratings, rails or screens being vertical, horizontal,
or of any other forin desirable.
In witness whereof I the said Alfred Dowson have hereunto set my hand and
seal this twentieth day of July One thousand eight hundred and eighty-three.
Signed and sealed in the
presence of
FRED ADAMSON
St Anne's on the Sea
Lancashire,
AUTRE
DOWSON