THE FLEET-STREET SEWER.

The works in progress for deepening the Sewer of Fleet-street have attracted considerable attention, partially from the obstruction which they have presented to the public traffic. They are, however, of intrinsic interest; although the Sewer of Fleet-street cannot compete, in antiquity, with the ancient water-course known as the Fleet Ditch,- 
        The king of dykes, than whom no sluice of mud
        With deeper sable blots the sliver flood.
    It appears that although Sewers have been constructed in London for upwards of four centuries, it is only within the last ten or fifteen years that the drainage of the City has boon satisfactorily accomplished. Hitherto, it was very defective and imperfect; some of the smaller streets having a Sewer, while the larger thoroughfares, as Cheapside, Ludgate Hill, &c., had none. From time to time, however, this evil has been remedied; and the Sewerage is now nearly completed. 
    The Sewer of Fleet-street, the subject of our Engraving, having been found insufficient to carry off the water, for which it was intended, it became necessary to cut deeper, and construct a new sewer, the greatest requisite depth is 25 feet, which decreases to about 17 feet near Temple Bar; hence the Sewer runs easterly to Water Lane, where it is joined by another Sewer, which runs into Whitefriars Dock.
    One of our Engravings conveys an idea of the extraordinary labour requisite for excavating the ground to the requisite depth, and the numerous provisions against accidents in the dangerous operation. Such is the underground labour whilst the difficulty of keeping open the traffic, so as not to extinguish the "very animated appearance" of Fleet-street, is a work of much difficulty. The cost of the present undertaking, contracted for by Messrs. Ward and Son, of Aldersgate-street, is £2000.
    There do not appear to be published data from which the total extent of the metropolitan Sewers can be ascertained. The Holborn and Finsbury divisions contain eighty-three miles. In addition to these, there are sixteen miles of smaller Sewers, to carry off the surface-water from the streets and roads, and two hundred and fifty-four miles of drains leading from houses to the main Sewers.

from The Illustrated London News, 1845

see also Hector Gavin's Sanitary Ramblings - click here

THE SEWERAGE OF LONDON is under the control of the "Board of Works," and is intended to relieve the River Thames of the 31,650,000,000 gallons of refuse and animal matter poured into it annually by the sewers of London. The main sewers measure 166 miles. Including the branch sewers, from the great trunks, the London sewage is conveyed through about 1,000 miles of subterranean ducts.
    I. North of the Thames are:
    1. The High-level Sewer from Hampstead Heath, through Holloway, Stoke Newington, and Bow, to Barking Creek.
    2. The Middle-level Sewer from Oxford Street, through Clerkenwell, Bethnal Green, Old Ford, and Hackney, to the High-level Sewer.
    3. The Low-level Sewer from Millbank Prison runs nearly parallel with the Thames, and will follow the course of the Blackwall Railway, till it joins et Bow the high-level Sewer.
    II. South of the Thames are
    1. The High-level Sewer from Clapham, through Stockwell, Camberwell, and Peckham, to New Cross; thence under Greenwich, East Greenwich, and Woolwich, to Crossness Point. 3½ miles above Erith.
    The Low-level Sewer from Putney, through Wandsworrh, Battersea, Lambeth, Southwark, Bermondsey, and Deptford; and between Deptford and Greenwich to the High-level Sewer.

MAIN DRAINAGE WORKS.

    On April 4th, 1865. H.R.H. the Prince of Wales opened the works of the Southern Outfall, at Crossness Point, near Plumstead, Kent, which have been completed under the superintendence of Mr. Bazalgette, Engineer to the Metropolitan Board of Works. The Northern Outfall at Barking has been in operation since August, 1864.
    Northern Outfall- The reservoir has an average depth of l6¾ft., and is divided into four compartments, covering 412,384 superficial feet, or 9½ acres. The external and partition-walls are of brickwork, and the entire area is covered by brick arches, resting on brick piers, and the floor paved with York stone. The reservoir is covered by an embankment of earth, rising two feet above the crowy of the arches. The sewage is prevented rising above a certain level by a weir, or overflow, in the partition-walls,. which are built hollow, and communicate with the discharging culverts below the outfall sewers.
    Southern Outfall.-The reservoir, which covers 6½ out of the 34 acres bought for this outfall station, and into which the sewage will be pumped, gravitates down the 7¾ miles of main sewer from the Deptford Pumping Station. It will hold 6,250,000 gallons. The superincumbent and lateral pressure is provided for by 644 brick piers. It is divided into four compartments, and is 15 feet 6 inches high at one end, and 13 feet 6 inches at the other. This reservoir alone will cost 115,000l. The culverts lying below the reservoir have walls 2 feet 3 inches thick, and 12 feet 6 inches high. On the river side rise the boiler and engine houses. On the right is seen the tall, square smoke-shaft of brickwork 207 feet in height, and with an internal circular aperture of eight feet. The pumping power is supplied by twelve of Adamson's patent boilers to four engines, each of 125 horse power, and working two compound pumps, with four plunges each. The fly-wheel weighs 52 tons. The pumps lift 56,000 gallons per minute from the sewer into the reservoir ; and the contractors guarantee that the engines shall raise eighty millions of pounds, or more than 35,700 tons, a foot high with the expenditure of only one cwt. of Welsh coal.

Cruchley's London in 1865 : A Handbook for Strangers, 1865