IMPROVEMENTS IN-DAMS. LOCKS. AND LOCK GATES
Year: 1852

page_text: LETTERS PATENT to Peter Evans Donaldson, of Shrewsbury, in the
County of Salop, Engineer, for the Invention of "IMPROVEMENTS
IN-DAMS. LOCKS. AND LOCK GATES."
Sealed the 2nd April 1858, and dated the 20th October 1852.
PROVISIONAL SPECIFICATION left by the said Peter Evans
Donaldson at the Offico of the Commissioners of Patents, with his
Petition, on the 20th October 1852.
I, PETER EVANS DONALDSON, of Shrewsbury, in the County of Salop,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN DAMS. LOCKS, AND LOCK GATES," to be as follows:-
I construct my dams, locks, and lock gates chiefly of wrought iron.
I make the dam hollow, and capable of rising or falling between
upright guides or towers secured by suitable foundations in the bed of
the watercourse in which it is desired to place the dam. In addition
to the arrangements for enabling the dam to rise and fall 1 have
certain means for fixing it in any desired position. I intend to claim
the construction of dams, locks, and lock gates entirely of wrought
iron. I construct my locks with hollow sides and bottom, and fill
them up. I make them with recesses at right angles to the sides of

page_text: the lock, for the purpose of enabling the lock gate to be drawn or slid
back into them when necessary to open a passage through the lock. I
construct my gates with an air chamber at bottom, whereby I make
them sufficiently buoyant to be easily moved into and out of the
recesses.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Evans Donaldson in the Great Seal Patent
Office on the 20th April 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
PETER EVANS DONALDSON, of Shrewsbury, in the County of Salop,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of October, in the year
of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself. Her heirs and suc-
cessors, give and grant unto me, the said Peter Evans Donaldson, Her
special licence that I, the said Peter Evans Donaldson, iny executors,
administrators, and assigns, or such others as 1, the said Peter
Evans Donaldson, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise,, and vend, within the United Kingdoin of
Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN DAMS, LOCKS, AND LOCK GATES,"
upon the condition (amongst others) that I, the said Peter Evans
Donaldson, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Peter Evans Donaldson, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say:
The nature of my said Invention having been set forth in my
Provisional Specification, I will first repeat the same here, and then
proceed, by reference to the Drawings annexed, to describe the manner
in which the said Invention may be most advantageously carried into
effect.
+
PROVISIONAL. SPECIFICATION.
"I construct my dams, locks, and lock gates chiefly of wrought-
iron. make the dam hollow, and capable of rising or falling between
upright guides or towers secured by suitable foundations in the bed
of 'the watercourse in which it is desired to place the dam. In
addition to the arrangements for enabling the dam to rise and fall I
have certain means of fixing it in any desired position. 1 intend to
claim the construction of dams, locks, and lock gates entirely of wrought
iron. I construct my locks with hollow sides and bottom; and fill them
up. I make them with recesses at right angles to the sides of the lock,
for the purpose of enabling the lock gate to be drawn or slid back into
them when necessary to open a passage through the lock. I construct
my gates with an air chamber at bottom, whereby I make them suffi-
ciently buoyant to be easily moved into and out of the recesses."
my
Such being the nature and object of the several heads of said
Invention, now proceed to describe the best means with which I am
i
acquainted for carrying the same into effect, and in so doing refer to
the Drawings hereunto innexed.
Figures 1, to 10, inclusive. are different representations of a dami, and
the parts in connection therewith, constructed according to the first
part of my Invention.
:
"
Figure 1. is a general plan, taken partly at the level of the top of the
dam A, A, A, and partly at the level of the tops of guide towers B, B, B.
The dam may be constructed across a river in one or more lengths,
according to the circumstances. It is secured in its position by the
guide towers, through which it passes, and which are sufficiently high
to allow of its being raised to any convenient height.

page_text: gate
endways into the recess O; the water previously contained in the
recess passing partly through the openings X, in the ends of the
(colored brown, Figure XIV.), and partly through the openings Z,
Figure XIII. left in the walls and floor for that purpose; these open-
ings are connected with valves for turning the water to or from either
side of the gate; the motion of the water is reversed in closing the
gate, which is "supported by the lock walls and cills in either of the
two directions in which the pressure of the water may act.
"
Figure 14, is a section through recess walls on line a, a.
Figure 15, is a section through lock gate on line b, b.
;
The advantages of the dam arc, that it may be raised at any time'so
as to give nearly the whole area of the river for the discharge of extra-
ordinary land floods, or for the purpose of scouring the bed of the river;
that it will prevent the lands above it being overflowed by the tide,
thereby enabling them to be better drained and cultivated; and that by
its einployment rivers may be converted into most extensive docks at a
small cost.
The advantages possessed by the lock are, that it may, by connecting
it with the dam, be placed in the direct channel of the river, thereby
affording much greater facility and safety in the locking of vessels than
the usual locks, which are mostly placed at considerable angles with
the channel, and require vessels to be swung round before entering them;
that being made of the material before mentioned it will not be endan-
gered by the filtration of water through its walls, as is sometimes the
case with locks constructed of masonry; and that it may be placed in
situations where, from the badness of the ground, it would be difficult
to build a lock with masonry.
The advantages of the gate are, that one only is required at either
end of the lock instead of two; that there is no outward thrust on the
side walls as with pointed gates; that it is more easily and rapidly opened
or closed in consequence of its buoyancy and of its moving in a straight
line; that it will act equally well as a gate, notwithstanding the tide
may rise sometimes higher than the water in the pond, and vessels inay
be locked into the pond in such state of the tide quite as casily as in its
ordinary state; and that it may be fitted to locks already constructed.

page_text: And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,-
First, the hollow dam constructed as herein-before described, to-
gether with the means of raising, lowering, regulating, and fixing the
same;
And second, the combined construction of locks and lock gates as
herein-before described.
In witness whereof, I, the said Peter Evans Donaldson, have
hereunto set my hand and seal, this Ninth day of April, One
thousand eight hundred and fifty-three.
PETER EVANS DONALDSON. (Ls.)