NOTES ON DOCKS AND DOCK CONSTRUCTION. 



ground level, the sides of the 

 clock have two altars 4 feet 1 

 inch wide, and, the face being 

 constructed with a batter of 

 1 in 5, makes the total width 

 at the ground level 89 feet 10 

 inches. 



Stairways are placed on the 

 sides at either end; and at the 

 centre of the rounded end there 

 is an additional flight of steps 

 with timber slides on each 

 side. 



For emptying the dock, cul- 

 verts 4 feet 1 inch wide by 8 

 feet 2 inches high are placed on 

 each side of the dock, and are 

 connected with a sump on the 

 centre line just inside the en- 

 trance. A small transverse drain 

 connects the side- floor channels 

 with the drainage culverts. The 

 culverts terminate in a sluice- 

 chamber, from which a series of 

 secondary culverts, controlled by 

 valves, lead to the main pump- 

 ing well which is constructed 

 independent of the dock. 



The pumping power consists 

 of three large centrifugal pumps, 

 which, when working together, 

 empty the dock from the highest 

 level in less than three hours. 

 Supplementary centrifugal 

 pumps are employed to keep the 

 dock dry when it is in use. 



Somerset Dock, Malta. 1 The 

 general plan and sections of this 

 dock are shown by Figs. 182 to 

 185, The leading dimensions 

 being as follows : 



1 M.F.I.C.E., vol. xxxiii. p. 352. 



