The Sun.
London, England, 1865-04-04 00:00:00

PRICE 4d.
STAMPED sd.

L square miles, forming the western suburb of Lon-
don, which is so low that its sewage has to be lifted
at Chelsea to a height of 17ift. into the upper end
of the Low Level Sewer. This sewer commences
at the Grosvenor Canal, Pimlico, and passes
. along Lupus-street and Bessborough-street, to and
along the river side from Vauxhall-bridge. From
Westminster-bridge to Blackfriars it is being formed
as part of the Thames Embankment ; and thence
it will pass under a portion of the new street to the
Mansion-house, and take the line of the Inner Circle
Railway to Tower-hill. From Tower-hill it is
being made mostly by tunnelling along Mint-street,
Cable-street, Back-road, Commercial-road, and
under the Limehouse-cut and Bow-common. It is
now being tunnelled under the river Lea, on its
route to the Abbey-mills pumping station, where its
contents will be raised no less than 36ft. by steam
power. It has two branches—one from Homerton,
and the other from the Isle of Dogs. All these sewers
meet in a great outfall sewer at Bow. This sewer
is a work of most peculiar construction, as, unlike
most other sewers, it is raised high above the level
of the surrounding country like a railway embank-
ment, which, indeed, just now it perfectly resembles,
as it has rags along the top of it for the con-
tractors' steam-engines and trucks, and is carried
by aqueducts over streams, railways, streets, and
roads. The outfall sewer at this point consists
of two huge main pipes, eaph Oft. by Oft., bedded
in concrete and earth, and fenced in by hedges,
as we have said, like a common railway embankment.
This outfall is continued to the Abbey-mills pump-
ing station, where low level sewage has to be raised
36ft. The Abbey-mills station is one of the largest
establishments of the kind on the Main. Drainage
works. It has a nominal engine power of 1,140
horses, for the purpose of lifting 15,000 cubic feet of
sewage per minute a height of 36ft. The engines are
all expansive and condensing, have a stroke of 9ft.,
with cylinders of 4ift. in diameter, and each works
two pumps. From this station the sewage is lifted
into the Barking reservoir, where it is in a great
measure disinfected, and where it is retained till
high water, and then discharged into the centre of
the river. The Barking reservoir is 16-Ift. average
depth, and is divided by partition walls into four
compartments, covering altogether an area of
412,384 superficial feet, or about 9Eacres. The ex-
ternal and partition walls are of brickwork, and the
entire area is covered by arches supported upon brick
piers, the floor being paved throughout with stone.
The reservoir is almost entirely above the general
surface of the ground, and is covered by an embank-
ment of earth, rising about 2ft. over the crown of
the arches. The ground on which it is built being
unfit to sustain the massive structure, the founda-
tions of the piers and walls had to be carried down
in concrete to a depth of nearly 20ft. So much for
the works on the north side of the Thames.
On the south the High Level Sewer and its southern
branch commence with the main line at Clapham and
a branch line at Dulwich, and they together drain
an area of about 20 square miles, including Tooting,
Streatham, Clapham, Brixton, Dulwich, Camber-
well, Peckham, Norwood, Sydenham, and part of
Greenwich. :Both lines are constructed of sufficient
capacity to carry off all the flood-waters, so that
they -may be entirely intercepted from the low dis-
trict, which is tidelocked and subjected to floods.
The storm-waters will be discharged into Deptford
Creek, while the sewage and alimited quantity of rain
will flow by four iron pipes, each 3ft. 6in. in diameter,
laid under its bed into the outfall sewer. The
length of this portion is only 4k miles, of which a
little over 300 yards was executed by tunnelling at
a depth varying from 30 to 35 feet below the surface.
The Low Level Sewer on the south does not follow
the course of the river, as on the north side, but,
commencing at Putney, it takes a more direct line
through low ground once forming the bed of a
second channel of the Thames, and drains Putney,
Battersea, Nine Elms, Lambeth, Newington,
Southwark, Bermondsey, Rotherhithe, and Dept-
ford, comprising an aroa, of 20 square miles. The
surface of this land is mostly below the level of high
water, and is, in many places, five or six feet below
it, having at one time been completely covered by
the Thames. The sewers throughout this district
had but little fall, and could never empty themselves
save at dead low water, and it was with reference to
the condition of this part of the metropolis that
some of our greatest engineers described the effects
of artificial drainage by pumping as equivalent to ,
raising the whole surface by more than 20ft. The
Low Level Sewer will in fact render this district as
healthy as the highest in the metropolis. Its length
is about 10 miles, and its size varies from 4ft. at the
commencement to the two main sewers, which are
7ft. by 7ft., at its termination. This line commu-
nicates with the pumping station at Deptford that
raises the low level sewage into the main southern
outfall. Four engines are used for this purpose,
each of 125-horse power nominal, and capable
together of lifting 10,000 cubic feet of sew-
age per minute to a height of 18 feet. From
this point the great tide of refuse passes off by
the southern outfall sewer, which, unlike that
on the northern side of the river, is constructed for
its whole length of nearly eight miles entirely under-
ground. This sewer, nearly 12ft. in diameter, was
taken under the town of Woolwich at a depth vary-
ing from 50ft. to 80ft. below the surface without
casualties or settlements of any kind. The Cross-
ness reservoir, into which this outfall flows at Erith-
marshes, is 61- acres in extent, and, like that at
Barking, is formed on the peaty soil by brick piers
ion brick arches, covered in with earth. The pump-
ing engines, by means of which the sewage is lifted
into this reservoir, are almost identical in power
and general arrangement with those at Deptford
Creek, From the reservoir at Crossness, as at
Barking, the sewage is discharged into the river at
high tide, the volume of water with which it mixes
and flows away being more than 100 times greater
than the bulk of that into which it was suffered to
flow under the old mismanagement which poisoned
the Thames.

The maximum quantity of sewage to be lifted by
these engines at Crossness Point will, as we have
said, ordinarily be about 10,000 cubic feet per
minute ; but during the night that quantity will be
considerably reduced, while, on the other hand, it
will be nearly double on occasions of heavy rain-fall.
The lift, also, will vary as much as fromlOft. to 30ft.,
according to the level of the water in the sewer and
the reservoir into which it has to be raised. These
very variable conditions of working led to some
difficulty in the arrangement of the engines and
pumps, which it has been endeavoured to meet by
the arrangement of pump plungers. The pumps,
which are single-acting, are placed equidistantly on
each side of the beam centre, the pumP cases being
each 12 feet in diameter, fitted with four plungers
4 feet 6 inches in diameter. These plungers are
placed in pairs, each pair being worked from a cross-
head on the main beam, which is in two flitches
with this object, and arrangements are made
pruni three,pas the inner
pair, smay be varied
for throwing either pair of plungers out of gear. By
thesein the means
proportionthe
capacityfone, of the
two,
o
outer pair, or both pairs are thrown into gear.
o
The sewage is discharged into a wrought-iron
trough, through hanging leather-faced valves,
which are suspended from iron shackles, and fitted
with wrought-iron back and front
plates. Each valve
is 12in. by 18in. It should be mentioned that sub-
stances which prevent the n propa.ac ion of the valves
are intercepted before reaching the pumps, by a
wrought-iron grating placed in front of the openings
to the pump well, the substances so stopped being
liftedfrom the face of the grating by an endless chain,
with scrapers and combs attached, working vertically
in front of and in close contact with the grating,
the teeth of the comb passing between the bars.
On the descent of the chain, the buckets aro over-
turned and discharge their contents into a trough,
from which they will be removed by manual labour.
The sewage, after being delivered from the pumps