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232 Annual Report of the London County Council, 1913.
The sludge is taken to sea by the Council's sludge vessels, which are six in number, viz., the
"Barking," "Barrow," "Bazalgette," "Belvedere," "Binnie," and "Burns" and each is manned
by a staff of officers and crew numbering 24. Each vessel carries a load of about 1,000 tons. During
the year under review the vessels made 2,629 trips to and from the deposit area in the Black
Deep ; the distance travelled being about 289,190 miles. The vessels are insured for £108,000.
The series of experiments which were undertaken during the summer months of 1911 and
1912 at the Northern outfall with regard to the precipitation of sewage were continued, and in this
case the experiments were conducted during the four months beginning on 1st December, 1913. A
special examination was made of the water of the river Thames between Charing Cross and Grays
during the summer months, when the aeration of the water is low, with a view of ascertaining, if
possible, the causes which lead to this condition.
On 5th December, 1899, the Council approved in principle a scheme of main drainage extension
works necessitated by the increasing strain imposed upon the existing system owing to the growth of
the population. This scheme was estimated to cost roughly £3,772,550.
During the year under review, the two outstanding works comprised in the scheme were completed.
The southern low-level sewer No. 2 (Battersea to Deptford) was finished and came into use
on 9th January, 1913. The total amount of the tender of Griffiths and Company, Contractors, Limited,
for the construction of this sewer, was £481,553 9s. 11d. There are certain matters outstanding in
connection with the accounts and the final cost cannot, therefore, be stated. The new sewer is constructed
partly of brickwork 5 ft. 6 in. and 6 ft. 6 in. in diameter, and partly of cast-iron lined with
concrete 7 ft. 6 in. and 8 ft. in diameter, and including connections, is nearly eight miles long.
The extension of Abbey Mills pumping station, the other work referred to,was opened by Mr. Cyril
Cobb, M.V.O., Chairman of the Council, on Thursday, 29th May, 1913. This extension was designed
to relieve the pressure on the existing plant during times of storm, and it can be used in cases of breakdown,
or stoppage for any other reason, of the steam pumps. The new engine-house is 180 feet long
by 42 feet wide and contains seven centrifugal pumps with suction and delivery pipes 38 inches in
diameter, capable of dealing with 700 tons a minute. Each pump is driven by a vertical gas engine
capable of developing 475 b.h.p. at about 160 revolutions a minute.
There are certain works which, while not specifically provided for in the scheme, are so closely
connected therewith as practically to form part of it, and although their cost was not included when
the rough estimate of £3,772,550 was prepared, it is anticipated that their inclusion in the scheme will
not cause this estimate to be exceeded. They are (i.) the enlargement of the Crossness pumping station;
(ii.) the extension of the southern high-level sewer No. 2 from Catford to Nunhead ; and (iii.) the
enlargement of North Woolwich pumping station.
The necessity for increasing the pumping power at Crossness arises from the fact that in connection
with the main drainage extension scheme, the discharging capacity of the outfall sewers has
been doubled, and when, in times of storm, these sewers are full, the pumping power at the outfall
is quite inadequate. A new engine-house is being erected, and the tender, amounting to £63,690, submitted
by Dick, Kerr and Co., Ltd., has been accepted for the work. The new engine-house will be
constructed to accommodate eight main driving steam engines and centrifugal pumps, but, in the first
instance, only one half of the machinery, estimated to cost £30,000, will be installed. Owing to labour
strikes, which occurred last year, the contractors for the erection of the buildings are much behindhand
with their work. Contracts have been let for the supply of boilers, engines, pumps, etc., and
during the year the undermentioned tenders for the supply and erection of machinery, etc., have been
accepted—John Spencer, Ltd., steam piping, etc., £5,570 ; Walton and Clough, Ltd., coal conveyors
and elevators, £625 ; Joseph Booth and Bros., Ltd., overhead traveller, £600 ; Arthur Lowcock, Ltd.,
fuel economiser, £571 ; and other tenders have also been accepted for smaller items.
The southern high-level sewer No. 2, which was constructed as part of the extension scheme
above mentioned, extends from Catford to Crossness, and its gradient is such that the contents of the
sewer do not have to be pumped. The extension of this sewer from Catford to Nunhead has been
completed by Messrs. Wm. Underwood and Bros., whose contract price amounted to £88,398 14s. 9d.
The final figures of the cost of the work are not yet available.
Owing to the large increase in the amount of sewage pumped at North Woolwich pumping station
the Council on 17th December, 1913, authorised the preparation of plans, etc., for the enlargement of
this station, and work upon the plans is in hand.
Besides the beam engine-house and the new engine-house above referred to there is at Abbey Mills
pumping station another house known as the Worthington engine-house, which deals with the flow of
sewage from the Isle of Dogs and a portion of that in the Hackney Wick relief sewer. The engines
in this house have not proved satisfactory, and their present condition renders it necessary to remove
them. It is proposed to substitute centrifugal pumps driven by small high speed compound vertical
engines and it will be possible by this means to provide in the existing building four sets of engines
and pumps of more than double the present capacity. The hydraulic machinery for the station will,
owing to recent extensions, be increased, and it is proposed to remove it from this house to an annexe
to be erected. The total estimated cost of the work proposed amounts to £34,000, and preliminary
work, including the preparation of plans, is in hand. Tenders have been obtained for the supply, delivery
and erection of a hydraulic engine and accumulator and that of the Leeds Engineering and Hydraulic
Company, Limited, amounting to £1,090 has been accepted.
There is no separate system of sewers in London for dealing with the surface water apart from
the sewage, but large storm-water sewers have been constructed to relieve the main and intercepting
Precipitation
operations.
Main
drainage
additional
works.
Storm relief