16 NOTES ON DOCKS AND DOCK CONSTRUCTION. 



docks off the main dock. The tidal basin, which is irregular on 

 plan, has an area of 21 acres, with wharfage accommodation for 

 large ships amounting to 1500 feet, in addition to a jetty about 

 150 feet long, for discharging coal. The depth of water in this 

 basin at low-water spring tides is 26 feet, and at high water of 

 ordinary spring tides 45 feet. 



The main dock has an average length of 1800 feet by a width 

 of 600 feet square, to an area of 25 acres. The three branch 



. . E R T H A 



'ater Area 75 Acres (ORAVESEND REACH) 

 ength of Quay 4 Miles 



FIG. 9. 



docks are parallel to each other and at right angles to the main 

 dock into which they open on the side opposite to the lock. 

 The length of each is 1600 feet. The centre dock has a width 

 of 300 feet, whilst the two side docks have an average width of 

 250 feet, and having a collective area of about 29J acres. The 

 jetties between the three branch docks are 350 feet wide, affording 

 room for a double row of storehouses, railways, etc. The depth 

 of water in the main and branch docks is 38 feet below Trinity 



