COST OF DREDGING. 371 



South Africa. Taken over a period of twelve months, a 

 Priestman's machine, with a 30-cwt. grab, lifted on an average 

 250 tons of sand daily. The cost for lifting, depositing in 

 a barge alongside, and subsequently conveying ashore, was 11 \d. 

 per ton. 



Calais and Boulogne. 1 Dredging in sand and conveying 

 about two miles out to sea, by a suction-pump hopper-dredger, 

 has been estimated to cost, including all charges except interest, 

 depreciation, and profit on plant, at Calais, 35 centimes per 

 cubic metre = 2*50 pence per cubic yard; at Boulogne, 46 

 centimes per cubic metre = 3'34 pence per cubic yard. 



This rate may be apportioned as follows : 



Pence per 



cubic yard. Per cent. 



Wages 0-920 = 2754 



Coal 0-930 = 27-84 



Stores 0-290 = 8'64 



Repairs and maintenance 1-200 = 35*93 



Total 3-34 99'99 



Dredging by bucket-dredger in materials consisting of mud, 

 and sand mixed with stones, hard soil, hard compact clay with 

 boulders and beds of rock, measured in the solid, removed to 

 sea a distance of two miles by hopper-barges and tugs, cost 3 '38 

 francs per cubic metre = 2s. OJd per cubic yard. 2 



Ceylon. 3 At Colombo, dredging and conveying the material 

 to sea has averaged 13d. per ton, including interest and 

 depreciation, the rate varying with the character of the material 

 raised. 



Holland. 4 At the Maas, pump-dredging and depositing at sea 

 has cost from Sd. to lOcZ. per cubic metre, equal to from 6 '07 to 

 7'64 per cubic yard. 



At the Amsterdam Ship Canal, dredging sand in the 

 harbour, and transporting a distance of two miles to sea, cost, 

 including 10 per cent, on first cost of plant, to cover interest and 

 depreciation 



By ordinary tucket-dredger ... 4'628 ^ = 8'338 pence per cubic 



Transport 3-700 / yard dredged. 



By sand-pumps 3'646 | = 7'234 pence per cubic 



Transport 3'588 / yard dredged. 5 



1 M.P.I.C.R, vol. Ixxx. pp. 261, 262. Ibid., p. 265. 



* Ibid., voL Ixxxix. p. 99. 4 



5 Ibid., vol. Ixii. p. 55. 



