The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1855-10-16 00:00:00

NEW WORKS AT BIRKENHEAD.

The following report, which was furnished to the special
committee of the council, as to the new works at Birkenhead,
and which was re-referred by the council, to the dock com-
mittee, was read :

Ig TO THE tItAIRMAS OE THE DOCK COMMITTEE.
" Sir,—ln accordance with the resolution of the Dock Com-
mittee, of the 16th of August last, ' That the surveyor do
prepare plans for such works upon the Birkenhead dock estate
as may be necessary to make that estate most useful for the
accomodation of trade and shipping, in connection with the
Liverpool docks ;' and the carrying out of this resolution
having, by thy instructions of the works committee, devolved
upon me, I have now the honour of submitting two plans for
your consideration, marked No. 1 and No. 2 respectively.
" In laying these plans before you, I would respectfully beg
to be permitted to make a few observations in elucidation
thereof. In considering the question involved in your resolu-
tion, I have felt that the main end to be arrived at has been to
obtain the greatest amount of most efficient accommodation at
the least cost ; and, inasmuch as the large area of Wallasey
Pool, with the great extent of land held in connection with
its south side, may be most readily made available, the side
walls having been constructed, and the principal part of the
land abutting thereon having been formed and rendered useful
for commercial purposes, it has appeared to me that the works
which ought to be first carried into execution should be the
formation of a proper communication between this pool and
the river.
"The description of communication to be thus formed is a
question of the greatest importance, as upon its efficiency must
in a great measure depend the extent of usefulness of the
large property to which it will form the key ; and to this point
I have consequently given the greatest consideration in my
endeavour to prepare such a design as should afford the most
convenient and easy access that the situation is capable of
allowing.
" It is a matter of considerable consequence in very many
respects, that the level of the water in the pool should be sub-
ject to as little fluctuation as may be ; and it is, I believe,
required by the Acts of Parliament sanctioning these works,
that the level of the pool should never under ordinary circum-
stances be reduced below that of a thirteen-feet tide, as given
by the published tide tables. This being so, it follows neces-
sarily that during all tides not rising to thirteen feet on the
tables, vessels must be locked up in the pool; and as this is
an operation requiring somewhat more time than under ordi-
nary circumstances, numerous entrances and deep sills are
of time necessary,
duringm or eweisi
ipcehc
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In Plan
No. 1, I have endeavoured to arrange the main entrance to the
pool in such a manner as will meet these requirements, and
afford the greatest convenience to the general class of shipping
frequenting the port.
" It will be seen that I propose to construct, in the first in-
stance, an open basin of about four and three-quarter acres
area ; and opening from this in the line of its direction, three
locks, of the various widths of 50 feet, 28 feet, and 80 feet—
the former being adapted for the reception of the general class
of sailing vessels, the middle one for the use of coasters and
river craft, and the larger lock for the convenience of steamers
and the largest class of shipping. This latter I have provided
with a pair of intermediate gates, that the lock may be used
for passing vessels of a medium size or for the general trade,
without the loss of water which would otherwise occur.
" The depths of the sills of these various entrances I pro-
pose to make as follows :—The sill of the 50-feet lock to be
laid 12 feet below old dock sill ; the sill of the 28-feet lock to
be laid 5 feet below old dock sill ; that of the 80-feet lock to
be laid 10 feet below old dock sill. -
" The level of the old dock sill being the datum from which
the heights of the tides in the published tables are calculated,
the depth of water on these sills at the lowest neap tides—
say on a tide rising but nine feet by the tables—would con-
sequently be 21 feet on the first, 14 feet on the second, and 19
feet on the last; and it must be borne in mind that this is
taking an extreme view of the case, as there have only been
about six days in the whole of the present year during which
the tides did not rise to 10 feet above the datum.
"The entrance locks thus described are intended to open
into an intermediate dock of about 8i acres area, which, it is
proposed, shall be excavated to the depth of 18 feet below the
old dock sill. Between this dock and the pool there will be a
50 feet and a 28 feet lock of similar size to those opening
from the river, and a passage 80 feet in width. By means of
these second locks we shall be enabled, during any great push
of business, such as frequently occurs after a prevalence of
earterly winds or bad weather, to work the intermediate dock
as a half-tide basin, with but the minimum loss of water from
the pool. The inner sills of the large inner locks, and those
of the passage, I propose to lay at the depth of 8 feet below
the old dock sill; the inner sill of the small lock at the depth
of 1 foot below that datum.
" The outer or open basin next to the river, I contemplate
having excavated and provided with a flooring of masonry at
th&depth of seventeen feet below the datum ; it will be sur-
rounded on its three walled sides with sewers and sluices,
communicating with the pool so as to obtain both a direct and
cross scouring power, and by these means, and keeping this
basin of the smallest efficient dimensions, I am in hopes of
being able to maintain the depth of water proposed to be
made. The principal practical difficulty will, I expect, arise
in keeping the platforms of the gates clear of sand sufficiently
to prevent its circumference with their working. To obviate
this difficulty as much as possible, I intend to lay those plat-
forms at a much lower level relative to the sill than has been
usually the practice, and by excavating the dock deeper, keep-
ing the working parts of the gates higher than the platforms,
and introducing a system of sluices in connection with the
sills, in addition to those we have hitherto adopted. I am in-
duced to believe that with care on the part of those having
the charge of them, these deep-water entrances may be worked
with safety, and the difficulty feared be overcome. It will,
however, be necessary to be prepared to lay all these locks and
passages dry whenever such may be needed, in order to secure
the efficiency and safety of the gates ; and I therefore propose
to construct at both the inner and outward locks a capacious
well, furnished in each case with a powerful steam engine.
These wells will have a separate connection with each lock and
possage, so that any one of them at any time may be pumped

dry independent of the others, and by having caissons pre-
pared to suit a fifty-feet and an eighty-feet opening, which
can be moved about and applied as circumstances require, the
whole of the inner gates may also at any time be laid dry, to
be overhauled .or repaired, without running the dock or the
pool dry.
" The works I have now described, and the construction of
the wall at the east end of the pool, are those which, in my
opinion, shosila first be carried into execution ; but it will
be necessary that the whole of the pool should be excavated
to the full depth intended at the same time ; and the same
opportunity should be taken advantage of to complete the
walls upon its nothern margin, to accomplish which full
powers are, I understand, given by the present acts of parlia-
ment. It will also be advisable to construct the 70-feet lock
which I have shown between what is now the Egerton Dock
and the pool, so as to render the large area of the latter safe
should any accident happen to the outer gates of the Alorpeth
Dock.

" At this stage of my description it may be well that I call
your attention to the difference that exists between plans No.
1 and No. 2, as it applies entirely to those features of the
design I have been hitherto explaining.
"The principal of the two designs is the same, with this
exception, that inasmuch as great stress has been laid upon
the desirability of making preparation, in any works that
might be contemplated at Birkenhead, for the reception of the
very largest steam vessels yet built, I have made a design
embracing that proposition, in which it will be seen that in
place of the 80-feet lock, as shown upon plan No. 1, I have
laid down a passage 120 feet in width, furnished with .double
gates to retain the water, and a reserve gate to shut it out when
necessary. The inner passage is in every respect, except in
width, the same as in No. 1 plan. The double outer
retaining gates are not proposed to act in any manner
for lockage purposes, but merely as a safeguard against
accidents, and to relieve each other from the full
pressure. Whenever it may be necessary to lock a
steamer of the largest class up into the pool, the intermediate
dock must be used as a half-tide basin or lock, the opera-
tion being that this dock would be opened to the tide of the
day whatever it might be, and upon the steamer entering and
the outer gates being closed, the water in the dock, if lower
than that in the pool, would be raised to the same level, and the
steamer passed through. Ido not offer any opinion as to the
policy of providing such accommodation, as that is a question
entirely for the dock committee to decide ; but should it be
their opinion that such is desirable, the plan I have the honour
of submitting will, I think, meet the end in view, in the least
objectionable form and in the most economical manner, but at
the loss of some of the convenience to general trade that would
be afforded by plan No. 1. In the depths of the sills and other
like details there will not be any difference between the two
designs.
" The remaining features of the two plans are the same, and
require but little explanation.
" Whenever additional dock accommodation may be found
necessary at Birkenhead, I should propose to provide it, in the
first instance, upon the south reserve, and in connection with
the existing docks, as shown upon the plans, but having en-
trances from the river distinct in every respect from those
already described. The design before you provides a double
river entrance, having openings 70 feet and 60 feet in width,
giving access to a half-tide basin 52 acres in area : from this
open two docks of a long and narrow character, of the respec-
tive areas of 62 and 74 acres; the former, or north dock, being
distinct in itself, the latter joining to and forming an enlarge-
ment of the present Egerton Dock. In connection with this
half-tide basin I have laid down the design for four graving
docks of different capacities, which will, I imagine, be found an
indispensable adjunct to any increase of trade at Birkenhead.
" It will be seen, on reference to the plans, that these docks,
as designed, will be most conveniently situated so far as regards
the means of connecting their quays with the existing railways
in that locality.
"There only remains for me now to lay before you the esti-
mated cost of the works I have described, which is as follow :