The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1840-09-25 00:00:00

THAMES TUNNEL-ITS NEAR COMPLETION

Those who are in the habit of passing up and down the
river must have observed, that a little below the tunnel pier
a portion of what is called Wapping Wall has lately been
cleared of its wharfs and warehouses ; and that an embank-
ment has been carried out for some thirty feet into the river
beyond the point to which the wharfs before extended. This
clearing has been effected for the purpose of making room to
sink a shaft at the Middlesex end of the Thames Tunnel,
which is now rapidly approaching towards completion ; every
obstacle and difficulty, by the perseverance and scientific skill
of Mr. Brunel, having been at length overcome.
All that remain now to be done to open this great under-
taking to the public, is plain and straight-forward work, pre-
senting neither difficulty nor danger. But a few details of
the process of completing the work may not prove uninterest-
ing to the public, who have always manifested a lively inte-
rest in the completion of the arduous task which it is the
glory of Mr. Brunel, not only to have undertaken, but to
have accomplished. As soon, then, as the river portion of
the tunnel had been brought to within thirty feet of the per-
pendicular of the old frontage of Wapping Wall, or to the
line of the new embankment, the works were then stopped
for the purpose of commencing the shaft ; it not being deemed
prudent to carry the tunnel too near the site of the intended
shaft, as cavities might thereby he formed, and a sinking of
earth the result.
The first step was to get permission from the Navigation
Committee to form an embankment, which having been given,
piles were driven, and the whole " puddled in" from a depth
of three feet below low-water mark to the level of the street
in Wapping. This has been nearly completed, and the sink-
ing of the shaft will commence almost immediately. An iron
" curb," 55 feet in diameter, and about four and a half in
height, has been prepared t'or this purpose. It consists of a
circular apparatus, like a large tank without a bottom, and
comprises forty-eight segments of iron, strongly bolted to-
gether. From the interior sides of this " curb," or circle
of iron, at about one-third of its height from the bottom,
project strong iron brackets, 'upon which are laid 'some
timbers of American elm (remarkable for their strength
and durability), extending three feet five inches towards the
centre, the timbers being attached by strong iron bolts to the
brackets below. These timbers form a platform or founda-
tion upon which the wall of the shaft will be built ; and the
breadth of this platform will be the thickness of the wall.
As the building proceeds, this apparatus, termed " the
curb," will descend by its own weight (and the weight of the
brick-work, which will rest upon it), as the earth is gradually
dug from under it, and brought to the surface. This process
of simultaneously building and undermining, and the con-
sequent sinking of the " curb," with its superincumbent
mass of brickwork, contiues until the whole depth of shaft
required is obtained, and the work is thus accomplished.
In shaft sinking the " curb" is sometimes so tightly
gripped by the surrounding earth that it is found necessary to
load it with many tons weight, in addition to the shaft walls,
in order to force it downwards.
In the centre of this shaft will be a second or temporary
shaft sunk simultaneoesly or a little in advance of the other,
by means of a " curb," twenty feet in diameter, for the pur-
poses of drainage ; and from it the water will be pumped up
to the surface by a steam-engine, to be erected at the shaft's
mouth, and passing up through a flexible tube, will run off
into the river.
The shaft above lalluded to is intended for the use of foot
passengers, and wi 1 be ascended and descended by an easy
spiral staircase. This is expected to be completed and
opened to the public by the beginning of March. The car-
riage entrance to the tunnel will be nearly four times the
dimensions of that already described, namely, 200 feet in
diameter, and will be made to the north of Wapping, and
near the London docks, at the point where now stands a

large granary.
The carriage-way of the tunnel will aiso be spiral, and not
an inclined plane, as was by some supposed. The gradients
of this road-way will be about 1 in 25, forming an inclination
which will not be found by any means inconveniently steep,
indeed less so than many of our London streets.
The premises removed to make way for the shaft were
formerly in the occupation of Sir William Curtis. Much
more ground will ultimately be cleared, to make room for
the approaches to the tunnel's mouth, on both sides of the
river.

An American ship now at Cowes, built of spruce and white
oak sixteen years ago, has all her original timbers and planks
in the most perfect state of preservation and soundness, ow-
ing to her having been, while on the stocks, tilled up between
the timbers with salt, and whenever she has been opened for
examination, filled up again.