The River Weaver Navigation. 261

Papers.] SANDENAN ON THE RIVER WEAVER NAVIGATION. 261

(Paper No. 1718.)

" The River Weaver Navigation."' By JOHN WATTSANDEMAN, M. Inst. C.E. THEriver Weaver, which rises in the south-west of Cheshire, and flows through the towns of Nantwich, Winsford, and Northwich, ,joins the estuary of the Mersey at Weston Point. Its total length is 51 miles, 21 of whichare navigable. Alongwith its tribu- taries the Weaver drains about550 square miles of land, or nearly one-half of Cheshire. This river has been in existence as a navigation for a century and a half, and has played an important part in the commercial history of the county. Passingthrough the heart of thesalt district, it affords a convenient waterway for thecarriage and export of that article, of which 1,000,000 tons are annually con- veyed alongthe river. The tolls leviedupon thenavigation amount to ;E60,000 per annum. Thesalt is carried on the Weaver, and from thenceon the Mersey to Liverpool, in barges and sailing flats, from which it is transhippedinto sea-going vessels. At Winsford andNorth- wich about 100,000 tons of rock salt are mined annually, while ;1,250,000 tons of manufactured salt are obtainedfrom brine which overliesthe upper bed of rock salt,and naturally accumulates thereby the dissolving of thesalt. The brim is pumped to the surface, andthe salt obtained from it by evaporation. The removal of the brine is attended with considerable damage to land by the sinking which result.s, having extended to the depth of 70 feet within the memory of man. This causes the formation of lakes, connected with the rirer, which serve as storage reservoirs for the supplyof the locks. The first step taken towards the improvement of the river was in 1721, whenthree Cheshirelandowners obtained an Act of Parliament to make it navigable from the Mersey to Winsford. By 1807 several locks andweirs had been built. In 1829 ithe Weston canaland a tidal basin at its junctionwith the

Abstract by the Author of an Original Communication, which is accompanied by nine drawings, including a map and section of the river, details of the New Ship locks, the sluices, turbines employed to work the lock gates, &c.

Mersey had been constructed, and thenavigation wasdivided intoten reaches or ponds with a single lock at each pond. Between 1843 and 1850 the locks below Korthwich, and between 1850 and 1865, the locksabove Northwich, wereduplicated. Between 1865 and 1872 a system of river improvement, pro- jected by Mr. E. Leader Williams, M. Inst. C.E., for the purpose of enabling sea-going vessels to reach Northwich, and to afford facilitiesfor steam-towing, was commenced byhim, including the widening and deepening of the Westoncanal, and the construction of new locks at its upper and lower ends. Mr. Williams. also originatedthe hydraulic canal liftat Anderton,' for the purpose of establishing direct water communication between the river Weaver and the Trent and Mersey canal. Between 1872 and 1877 the Author carried out various improve- ments, including the hydraulic canallift at Anderton, the construction of large sluices for the relief of floods, a new weir, deep-wat.er- river quays, &C., and lastly, two sizes of new ship locks at Sal- tersford2 and Acton. The larger of these loclm is 229 feet long by 424 feet wide, and is capable of accommodating a vessel of 1,000 tons burden; the smaller is 220 feet long by 25 feet wide. The depth of water on the sills of both locks is 15 feet. Each lock has three pairs of gates, so as to enable only half the lock to be used when desired ; the gates of the larger locks are opened by means of' turbines,and those of thesmaller locks byhand capstans and quadrant wheels. Each lock has six cylindrical sluices, two inlet, two outlet, and two central, the latter to empty the upper and fill the lower compartments of the locks when the central gates are used; two intermediate sluices are also provided,affording communication between the locks. The locks arebuilt of Runcorn. red sandstone ashlar, backed with rubble. The hollow and square quoins, sills, fender courses, and coping are of Anglesey limestone. Portland cement concrete was employed for the stop walls in the trenches at the gatesills, and under the centralpiers of the locks. The lock gates areof greenheart and of English oak timber, the former being used for the heel- and mitre-posts, and the latter for the beams. The cleading is of American red pine. The gates are without rollers, but have caps of malleable cast iron upon their heel-posts, from which diagonaltie-bars extend upon both sides, and are secured to thelower ends of the mitre-posts, so as to sustainthe overhanging weight of the gates. The gate pivots and shoes aro also of malleable cast iron,turned to fit each other. The gate

Vide Minntes of Proceedings Inst. C.E., vol. xlv., p. 107. *Ibid.. vol. Iv., p. 147.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. Papers.] SANDEMAN ON THE RIVER WEAVER NAVIGATION. 263 anchor-straps are secured to cast-iron anchor-plates bolted to the masonry. The gate pivots and caps are eccentric to the hollow quoins to obviate frictionupon the masonry; this enables the small lock gates to be opened or closed by one man in about thirty seconds. By means of turbines, constructed upon Schiele’sl principle, the large lock gatesare easiIy opened or closed in abouttwenty seconds. The chief advantage. of the turbine over other motors is, that by its means the head of water at the locks, a power which costs nothing, cm be employed. The turbines are placed in circular wells, adjoining those of the chain capstans, and the shafting of both being vertical, the latter are driven without the intervention of bevelled gearing. The capstans are situate at the levels of thegate fastenings, and chains leadfrom them over carryingrollers to the gates. Themain supply and discharge pipes are 20 inches, and the branch pipes toeach turbine 16 inches, in internal diameter. The turbinewheels are 18 inches indiameter, with twenty double buckets 2 inches in depth; they have exit orifices 5 inch wide, giving a totalarea of 70 square inches, and are designed to work at one hundred and seventy-three re- volutionsper minute. There are sixteen ports inthe turbine

casing,having a totalarea of 60 square inches,capable of being 1 diminished to the extent of ,5,ths by five adjusting slides. The quantity of water consumed by each turbine is 270 cubic feet per minute. A form of equilibrium sluice, worked easily by hand, has been adopted for the locks, in preference to the ordinary sliding sluice, which would have necessitated the employment of steamor of hydraulic power. Sluicesupon a similarprinciple had been previously employed by Mr. Hawksley, Past-President Inst. C.E., at theLiverpool waterworks. The sluice, in the present instance, was designed by Mr. F. G. M. Stoney.2 It consists of a wrought- iron cylinder, open both at the top and at the bottom ; upon the bottom an annular casting is bolted, having a conical face turned to fit a cast-iron seat, which is also turned and is in two parts, the lower cemented into the masonry, and the upper removable for refacing, should such at any time be required. The top of the cylindrical sluice being above the upper water-level, the pressure due to the head acts only around its circumference, and in conse-

1 Vide “Mechanics of Engineering and of the construction of machines.” BY P. J. Weisbach, vol. ii., p. 516. New York, 1877. Vide Minutes of Proceedings Inst. C.E.. vol. Ix., p. Ss.

Downloaded by [ University of Liverpool] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 264 SANDEMAN ON THE RIVER WEAVER NAVIGATION. [Selectfd quence equilibrates itself,so that thesluice can be raised or lowered without heing affected by the water-pressure. The total weight to be raised is only that of the cylinder and fittings attached, and asthese are counterbalanced,and as the height of lift is only 165 inches, the sluice is easily raised or lowered by one man in aboutfour seconds. The sluicesfor thelarge locks are 5 feet 6 inches, and for the small locks 5 feet 3 inches, in diameter of opening. The new locks and cuttings were commenced in 1874; but for financial reasons their progress was delayed, so that they were not opened for traffic until 1878.

From the drawings accompanying this communication two have been selected for reproduction (Plate 11), namely, the map of the navigation, and the detailsof the New Ship Locks.