ESQUIMALT DOCK. 



Thro 



Coping Level t|j 



JLWJ1<LS.-L- . i-Jlb 



ss 



Stiff Blue Clay 



FIG. 204. 



of rock which occurred near the head of the dock, and under the 

 caisson-chamber and engine-house. 



A 9-inch layer of 5-to-l fine concrete was laid over the 

 whole surface of the foundations, and against the backs of all 

 the walls; it was also introduced behind the brickwork and 

 stone facing generally throughout the work. 



The whole of the foundations of the entrance are brickwork 

 in 3-to-l Portland-cement , 



mortar, laid on a bed of 7-to-l 

 concrete. 



The dock side walls and 

 entrance walls are constructed 

 of rubble faced with ashlar 

 stones in 2-feet courses. At 

 the back the side walls are 

 vertical, with arched recesses, 

 the object being principally 

 the economy of material. 



The floor of the dock is 

 constructed of 7-to-l concrete 

 with rubble stones embedded in it. The paving for 10 feet in 

 the centre consists of two courses of stone, 2 feet in depth and 

 1 foot 9 inches in width, filled in between with five courses, 

 18 inches in depth. The remaining portion of the dock floor is 

 paved with two courses, 2 feet in depth and 18 inches wide, and 

 the remainder with stone 15 inches deep; the whole being 

 bedded and jointed with Portland-cement mortar. 



The inverts of the entrance are 112 feet radius, the outer 

 being 15 feet wide and the inner 20 feet wide; both are faced 

 with sandstone, with a hearting of brickwork and 7-to-l 

 concrete. 



The caisson-stops, or rubbing faces, are granite, with a 

 polished surface 12 inches wide, projecting f of an inch. 



The walls of the caisson chamber are constructed with 

 arched recesses on each side 6 feet wide. This arrangement 

 gives more room for effecting repairs when the chamber is used 

 as a dock for the caisson. 



For clearing away any mud that may accumulate upon the 

 roller-paths or floor of the chamber, a sluicing culvert is 

 provided at the far end of the chamber (Fig. 203). 



To relieve the bottom of upward hydraulic pressure when 



