WEST KENT DRAINAGE SCHEME.
The members of the West Kent Main Sewerage Board on Thursday invited the parochial authorities of Bromley, Beckenham, Bexley, Crayford, Chislehurst, Dartford, and the parishes in the valley of the Cray to an official inspection of the works now in progress at Halfway-street, Eltham. The parishes named have long suffered from want of effective drainage and the means of disposing of their sewerage.
The West Kent Main Drainage Scheme was designed by Sir Joseph Bazalgette, and consists of a sewer 9 miles in length from Beckenham to an outfall in Dartford Marshes, Long Reach, 7 miles below the northern and southern outfalls. It is proposed by Sir J. Bazalgette that the main sewer should be continued from Beckenham westward by Croydon, Mitcham, Merton and Kingston and it will form the out fall for all the towns in the Thames valley. The contract drawings were prepared by Mr Alfred Williams and entreated to Messes John Neave and Son, the contractors. The cost is estimated at £150,000, the time allowed for the completion of the work being two years and a half.
There were on Thursday 8 shafts at work, 4 others being in the course of sinking to the level of the sewer, which is from 40 to 50 feet deep. An important feature of the work is that the sewer is constructed in Portland cement concrete, consisting of ballast 5 parts, sand 1 part, and Portland cement 1, which is one third less cost than brickwork. Nine hundred feet of tunnelling is completed out of 28,100 feet. The length of the Cray Valley Branch Sewer is 34,736 and the total length of the Main Sewer is 58,528 feet. The sewer is egg-shaped, 6 feet by 4, and in one portion is a circular 6ft. sewer, and towards the outfall 5 feet 6. At the outfall the sewage can be discharged at all times. Five hundred men are employed on the work, which is progressing at the rate of 350 feet a week, the actual length under operation by the 12 shafts being 6500 feet.
The Board and visitors had a cold collation at the Black Horse, Sidcup, the gentlemen present being Col. Lennard, J.P., in the chair, R. B. Berens. Esq., J.P., Messrs Beggs, Couchman, and Janson, members of the West Kent Main Sewerage Board. The officers present were Sir Joseph Bazalgette, consulting engineer; Mr May, solicitor; Mr Mullen, clerk of the Board; and Mr Williams, C.E., resident engineer. The visitors present from Croydon Local Board of Health were Messrs Saunders, Coldwell, and Peerless; from Bromley Local Board, Dr Ilott; and the Beckenham Committee, Messrs Cobben, Carpmael, HolifieId, Lovelock and Molyor. Messrs Neave & Son and Mr Fry were also present.
Colonel Lennard said the scheme originated with the Public Health Act, which threw the work on the Bromley Board of Guardians. The Education Act had also been thrown on Boards of Guardians. The willing horse had too much thrown upon it, and sooner or later it would break down. The Bromley Board of Guardians did not wish to be accused of incapacity or idleness, and accepted the drainage work cheerfully. The Guardians had no means to recoup themselves unless the Bill became law, and a number of gentlemen agreed to a guarantee fund, to defray the costs in the event of the Bill not passing. These gentlemen commenced the work with a rope hanging about their necks, and trusted to those employed on the Bill to make their charges small in the event of non-success. They met with opposition at Bromley and Dartford; but it was withdrawn when it became evident that their interests were identical. They were willing that the Dartford, Bromley, and Croydon parishes should join in the scheme upon the same terms as themselves, the Board not wishing to make a profit out of them. Caution and care were necessary in the formation of the scheme, it being essential to avoid pettifogging on the one hand, and of frightening the ratepayers by going on too large a scale on the other hand. He believed the works were being carried on with the goodwill of all parties.
The works had begun at the outfall; but the roads being impassable, the Board proposed shortly to visit it by water, embarking at Erith.
Sir Jos. Bazalgette recommended parishes to combine for drainage purposes instead of going to work single-handed. They had a successful example that day of the result of combination.
The Metropolitan Main Sewage cost 4 millions, and was incapable of performing more work. It therefore became necessary to have a supplemental system. The West Kent scheme presented several novelties, such as aqueducts and a syphon. At the reservoir at Long Reach, the sewage would be filtered.
The health of Colonel Lennard was then proposed, after which the visitors proceeded to inspect the works. Amongst the geological curiosities there had been found 17 ft. strata of decomposed sea shells. and several members of the Board carried away some perfect specimens of oyster and other shells. The boring showed the strata to be what is known as the Woolwich and Reading beds. In one portion of the work, several of the visitors donned some rough clothing, and descended in a truck down a cutting 38 feet deep, where they walked along the sewer right and left. At the open cuttings they descended by a ladder, and walked about half a mile through the sewer, which was lighted up with candles. The visitors also inspected the manufacture of the concrete blocks, the washing of the ballast in the river Bourne, and other interesting points in connection with the works. In the evening some 50 or 60 of the workmen were regaled with a substantial supper.
Mitcham History Notes 