ESQUIMALT DOCK. 



213 



and sand to 1 part of Portland cement. The granolithic blocks 

 for the altars were composed of 3 parts of crushed granite to 

 1 of Portland cement, and for the granolithic-faced ashlar used 

 in the circular head of the dock, 5 parts of stone and sand to 

 1 of Portland cement, with a facing 6 inches thick composed of 

 the same ingredients and proportions as the altar blocks. 



The dock is closed by an iron caisson, rectangular in shape, 

 15 feet wide on the deck, 67 feet long at the top, and 57 feet 

 6 inches at the bottom, and capable of carrying a load of 20 

 tons. It is moved into the chamber by hydraulic power on 

 rollers fixed under it which run on broad iron rails laid on each 

 side of the chamber and berth. 



Esquimau Dock. 1 Figs. 201 to 204. This dock, constructed 

 from the plans of Mr. Kinipple, M.I.C.E., has the following 

 dimensions : 



Ft. in. 



Length from the inner face of the caisson to the circular head ... 451 



Ditto, with the caisson berthed in the outer stop ... 482 



Width of entrance 65 



dock at coping 90 



on the floor 41 



Depth of water over sill at H.W.O.S.T 26 6 



Total depth from coping to floor 36 6 



Depth from coping to invert 33 6 



the 



of this dock 



the 



Noticeable features in the design of this dock are, 

 arrangement of the entrance and the arched recesses 

 at the rear of the side walls. With legard to the I***, 

 entrance by the arrangement adopted, it is possible, 

 whilst having the advantages of straight sides to the 

 entrance, to remove the caisson from its normal berth 

 without difficulty. 



This is effected by making the width across the 

 outer invert greater than the inner invert, as at a, in 

 Fig. 201. The caisson being run a very short distance 

 into the chamber, and raised only sufficiently to clear 

 the invert, can then be readily removed from the 

 entrance. 



The strata in which this work was carried out 

 consisted chiefly of sand and shells for a depth of 6 

 feet. Below this level, very stiff blue clay was reached, and 

 extended over the whole area with the exception of an outcrop 



1 Engineering, vol. xliv. p. 390. 



FIG. 201. 



