360 NOTES ON DOCKS AND DOCK CONSTRUCTION. 







Barry Docks. Per ncre of water area (including gates and caissons) (approx.) 8,300 

 Ditto, fully equipped (including all railway sidings round the dock, coal- 

 tipping machinery, hydraulic machinery, buoys and moorings, water 



supply, electric light, weighing-bridges, etc. 1 (approx.) 12,950 



Prince of Wales's Dock, Swansea. 29J (including lock entrance and com- 

 plete equipment) 2 (approx.) 18,GOO 



Cost of Docks and Locks. Approximate cost per cubic yard 

 internal capacity 



(This did not appear to include the whole of the excavation.) 



Portsmouth Docks. Cost per foot lineal : 



No. 12 dock. 6 Granite invert, Portland sub-invert. Port- 

 land lower altars ; upper altars Portland, capped with 

 granite; granite broad altar ; slides, slips and coping ; 

 brick and concrete backing ; beech and fir piles and 

 lir timber in foundation and excavation. Mean depth 

 of dock to floor 42 feet. Approximate cost 



No. 13 flock. Granite invert, Portland stone sub-invert. 

 Granite lower altars; upper altars Portland stone, 

 capped with granite ; granite broad altar ; slides, steps 

 and coping ; brick and concrete backing, beech piles 

 in the foundation, fir timbers, and excavation. Mean 

 depth of dock to floor, 42 feet 3 inches. Approximate 

 cost 



Deep dock. Granite invert, also lower and upper altars, 

 broad altar slides. Steps, sides and coping ; brickwork 

 and concrete backing. No timber or piles in the foun- 

 dation. Mean depth of dock to the floor 46 feet 8 

 inches. Approximate coat 



Per foot 

 run. 



. d. 



Per cubic 

 yd. internal 

 ' rapacity. 

 L s. d. 



259 00 1 19 



296 210 



280 1 19 



1 M.P.I.C.E., vol. ci. p. 169. 2 Hid,, vol. ciii. pp. 153-156. 



3 " Lectures on Marino Engineering, School of Military Engineering," 1875, 

 1876. J. B. Redman. 



4 Deduced from M.P.LC.R, vol. Iv. p. 21. ' Ibid., vol. xli., p. 113. 

 Hid., vol. Ixiv. p. 234. 



