IMPROVEMENTS IN THE CONSTRUCTION OF DRY OR GRAVING DOCKS AND GRIDIRONS AND IN MEANS FOR FACILITATING THE EXAMINATION AND REPAIR OF THE KEELS, BOTTOMS AND SIDES OF VESSELS "
Year: 1883

page_text: LETTERS PATENT to Jeffery Walsh of Cardiff in the County of Glamorgan,
Ship Builder for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF DRY OR GRAVING DOCKS AND GRIDIRONS AND IN MEANS FOR FACILITATING
THE EXAMINATION AND REPAIR OF THE KEELS, BOTTOMS AND SIDES OF
VESSELS
"
PROVISIONAL SPECIFICATION left by the said Jeffery Walsh at the Office
of the Commissioners of Patents on the 9th May 1883.
JEFFERY WALSH of Cardiff in the County of Glamorgan, Ship Builder
"IMPROVEMENTS IN THE CONSTRUCTION OF DRY OR GRAVING DOCKS AND GRID
IRONS, AND IN MEANS FOR FACILITATING THE EXAMINATION AND REPAIR OF THE
KEELS, BOTTOMS, AND SIDES OF VESSELS.
"
Dry or graving docks as at present constructed are wider at the top than at the
bottom, the side walls being built up in steps so as to conform roughly to the
shape of a vessel and to facilitate the shoring up of the same in the dock. By this
mode of construction a much greater surface area than is absolutely necessary for
one vessel must be taken up, thus causing much valuable space to be wasted and
entailing considerable expense for shoring up the vessel.
Now the object of the present invention is so to construct dry or graving docks
that their cost will be greatly reduced, their accommodation will be increased, and
the expense of shoring up the vessels will be avoided.
In carrying out my invention I build the sides of the dock vertical from the
bottom to the top, and above the water or draught line of the class of vessels for
which the Dock is to be used, I form overhanging portions (overhanging say four
feet) properly supported by long lengths of cut stone, or wrought iron beams,
projecting from the wall and forming "dolphins "for the side of the vessel to rest
against.
The length of these overhanging portions or "dolphins" may vary from 30 to
35 feet, and the distance between them may range from 25 to 30 feet; and the
recesses thus formed will not only serve to admit air and light to the workmen
below, but may be provided with slides or lifts for passing materials up and
down.
The dock notes will be formed and fitted in the usual manner

page_text: The blocks which are used to support the keel may be of wood, but I prefer to
use two three or more wedge-shaped taper steel or iron blocks about 10 feet long
with a wood capping.
By the use of these taper blocks a set of blocks may be readily removed and
shifted, if they interfere with the repair of any particular part of the vessels keel,
or they may be replaced when the repairs are completed.
In constructing gridirons for ships according to iny invention, I employ a level
platform of wood in the usual way, and I adapt thereto a side frame or wall
constructed on the lines referred to above, namely, with overhanging portions
against which the vessels side can rest.
By the above described mode of constructing dry or graving docks and gridirons,
the whole of the ships bottom and sides above light water mark will be accessible
for repairs or for cleaning purposes, and the workmen will have plenty of room to
move about and work in beneath the overhanging portions. The necessity for
shoring up will also be obviated and the expense of material and labour entailed
by that operation will be avoided.
Docks thus constructed will also accommodate at one time double the tonnage
that a dock of the same area is now capable of receiving.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jeffery Walsh in the Great Seal Patent Office on the 8th November
1883.
JEFFERY WALSH of Cardiff in the County of Glamorgan, Ship Builder
"IMPROVEMENTS IN THE CONSTRUCTION OF DRY OR GRAVING DOCKS AND
GRIDIRONS"
Dry or Graving Docks as at present constructed are wider at the top than at the
bottom the side walls being built up in steps so as to conform roughly to the shape
of a vessel, and to facilitate the shoring up of the same in the dock. By this
mode of construction a much greater surface area than is absolutely necessary for
one vessel must be taken up, thus causing much valuable space to be wasted, and
entailing considerable expense for shoring up and unshoring vessels.
Now the object of the present invention is so to construct dry or graving docks,
that their cost will be greatly reduced, their accommodation will be increased and
the expense of shoring up the vessels will be avoided.
According to my Invention I build the sides of the dock vertical from the bottom
to about three feet above the light water or draught line of the class of vessels
for which the Dock is to be used, and thence upwards; I form overhanging
portions, properly supported by long lengths of cut stone or beams of wrought
iron or wood projecting from the wall and forming "dolphins" for the side of the
vessel to rest against.
In the accompanying Drawing Fig: 1 is a plan view of a Graving Dock
constructed according to my Invention. Fig: 2 is a cross section of the dock
on a larger scale, and Fig: 3 represents in cross section the same principle of
construction as applied to a Gridiron for repairing vessels and on about the
same scale as Fig: 2.
In these Figures the same letters of reference are employed to indicate like
or corresponding parts.
Referring now to Fig: 2 A A represent the vertical or nearly vertical portions.
of the side walls and B B represent the overhanging portions forming a part of the
said walls.
The height of the vertical portions from a to b. below. the overhanging
portions B B and the extent to which the said portions B B overhang will depend
on the size of Dock and the class of vessels it is intended to receive, but I have
found four feet to be a convenient amount of overhang.-The length of these over-
hanging portions or "dolphins " B B may vary from thirty to fifty feet, and the
distance between them may range from twenty-five to thirty feet, and the intervals
or recesses C. C. thus left or formed will not only serve to admit air and light to
the workmen below, but may be conveniently fitted with slides or lifts for passing
materials up and down.
In order to meet the requirements of ships of different sizes and enable them to
be repaired in the same dock, the overhanging portions B. B. may conveniently be
made some two feet lower at one side than the other.
The
The dock gates or caisson will be formed and fitted in the usual manner.
blocks which are used to support the vessels (which are marked V. V in the
Drawing) may be of wood but I prefer to use tapered steel or iron blocks D. D,
with wood capping; the lower block being fitted with lugs d. d for toggle bolts,
and movable on a ground block E E partly embedded in the bottom of the Dock.
These tapered blocks should be about eight feet long to suit a large number of
vessels of different breadths of bean, so as to prevent the cost of too frequent
djustments.

page_text: The lowermost tapered block is intended to be toggled to the ground block E to
prevent slipping.
I am aware that Dry or Graving Docks have been designed with a series of
piers or buttresses at intervals along each side and with steps or sloping walls
between the said buttresses but these piers or buttresses have vertical flush faces
and do not serve the purpose which I have in view.-In such Docks as these
shoring is still required in order to support the vessel in such a position as will
enable workmen to have free access to all portions of the hull below light water or
draught line; whereas in Docks constructed according to my invention as above
described the dock workmen have a free range along the entire length of the
vessels' side, and can repair any part to and above light water line with facility
without the necessity for shoring up the vessel.
In constructing gridirons for ships according to my Invention, I employ a level
platform of wood F in the usual way (see Fig: 3) and I adapt thereto a side frame
or wall A. B. constructed on the lines referred to above, namely with overhanging
portions or "dolphins " B against which the vessel's side can rest. The wall A B
may be formed by driving piles close to a gridiron and attaching suitable beams
to form the overhanging parts B B, or it may be constructed of masonry or of any
other suitable material.
By the above described mode of constructing dry or graving docks and gridirons
the whole of the ships bottom and sides to and above light water mark will be
accessible for repairs or for cleaning purposes, and the workmen will have plenty of
room to move about and work in beneath the overhanging portions. The necessity
for shoring up and unshoring will also be obviated, and the expense of material and
labour entailed by that operation will be avoided.
Docks thus constructed will also accommodate at one time double the tonnage
that a Dock of the same surface area is now capable of receiving.
Having now described the nature of my said Invention of "Improvements in
the construction of Dry or Graving Docks and Gridirons" and explained in what
manner the same may be carried into practical effect I wish it to be understood
that I claim :-
"
First Constructing Dry or Graving Docks with side walls having overhanging
portions or 'dolphins," whereby vessels may be supported without shoring;
increased accommodation is afforded, and access to the bottoms and sides of the
vessels for inspection and repair is facilitated, substantially as described with
reference to Figures 1. and 2 of the Drawing.
Secondly The adaptation to Gridirons for ships, of my improved construction of
side wall or supporting frame having overhanging portions or "dolphins" along its
upper part, in the manner and for the purpose above setforth.
In witness whereof I the said Jeffery Walsh have hereunto set my hand and
seal the second day of November in the year of our Lord One thousand eight
hundred and eighty three.
TERREDV
T&T C