Page 3 - Minutes of Proceedings of Civil Engineers Vol CXCV 1913-14 Part 1

f 'rrurodirrgs,l TIIE " WHITE STAR " DOCK AT SOUTIIAMPTON. 43 Itig, l, Plate 1, it will be seen that the dock-estate consists of a l,rinngular piece of land about 239 acies in area, bounded by the l,orvn and by the rivers Itchen and Test, The two estuaries 'Water, tttrrrt at the apex of the triangle to form Southampton rr, tidal channel 6 miles long and 1| nile wide leading direct l,o the deep water of the Solent. It may be recalled that South- 'Water rrtnpton is famous among English harbours for its sheltered lxrsition, its moderate range of tide (about 13 feet at springs), its rlopth (which has now been improved by dredging to a minimum of il5 feet at L.W.O.S.T.), and its long perigd of high waier (about 2 hours). It has also the advantag" oi U"lIrg fairly free from silt, rrs, although the channel is lined with large mud-banks, the amount of silt brought down from the upper rivers is insignificant. The rluantity of mud deposited in the docks is only about 9 to 12 inches l)er a,nnum and the mud being of a soft clayey nature, no demage is ; rlone to vessels if by chance they should touch bottom. These rr,dvantages have induced sone of the largest shipping-companies to use Southampton as a home port and as a port of call, in spite of the facts that it is 78 miles from London, and that there are nolarge manufacturing or commercial centres close to it, as is the case with rr,ll other first-class ports. The docks.have grown steadily since their commencement in 1834, in response to an unceasing demand for :rccommodation for nore and larger ships. Fig. 2, Plate l, shows the southern poition of the dock-estate on completion of the works described in this Paper. Gorrnlr, AnnnNcouuxr oF NEw Docr-W'onrs. The new dock-works consist of a tidal basin (the White Star tlock) and four adjoining quays. The dock is in shape a parallelo- gram, 1,700 feet long and 400 feet wide, with a water-area of 15| acres. The depth at low water of ordinary spring-tides is 40 feet, andat high water 53 feet. It opens direct on to the River Test, whore a curved basin with sufficient area to swing the largest ships has been dredged to a depth of 35 feet below L.W.O.S.T. This basin forms the head of a channel of the same depth, which leads straight down Southampton Water to the Solent. - The adjoining quays are numbered 41, 48,49, and 42 on the plan (Fig. 2). The berths in front of the first three quays are dredged to depths of 30 feet, 30 feet, and.25 feet respectively below L.W.O.S.T. The fourth (No. 42) is a jetty and forms a guiding stage to ships entering or leaving the dock. It can also be used as a lay-by berth. The depth in front of it is 35 feet at L.W.O.S.T.