EXAMPLES OF DOCK PLANS. 19 



The East and West Docks (Fig. 10) may be referred to 

 as affording a fair comparison between older and recent dock 

 construction, particularly with regard to the width of both 

 basins and entrances. The East Dock is 4300 feet long, 1000 

 feet of which is 300 feet wide, and 3300 feet 500 feet wide, with 

 a total area of 41 acres. The available wharfage, after allowing 

 for entrances, is equal to approximately 9000 feet with a depth 

 of water of 25 feet. 



On the west side, near the north end, there are two dry 

 docks 400 feet and 408 feet respectively, 48 feet width of 

 entrance, and with 17 feet depth of water over the blocks. 



The approach to the East Dock is through two locks and an 

 intermediate basin. The outer, or sea lock, is 220 feet long by 

 55 feet wide, with a depth of water at spring tides of 31 feet 8J 

 inches, and at neap tides 21 feet 8J inches. The intermediate 

 basin is 380 feet long by 250 feet wide, equal to an area of 

 21 acres, and the inner lock is 200 feet long by 49 feet wide. 



The West Dock is 4000 feet long by 200 feet wide for 1550 

 feet in length; the depth of water is 19 feet, and for the remain- 

 ing 2450 feet the depth is 13 feet only. This dock is approached 

 through an outer entrance, basin, and lock. The outer entrance 

 is 45 feet wide ; the basin is 300 feet long by 200 feet wide, and 

 the lock 152 feet long by 36 feet wide. The depth of water on 

 the outer sill is 28 feet 8 J inches at high water. There is means of 

 communication between the West Dock and the East Dock inter- 

 mediate basin by a junction dry dock; the entrances at both 

 ends, which are closed by caissons, are 50 feet wide with a depth 

 of water of 18 feet. Between the East Dock and the Roath 

 Basin there is also means of communication by a junction lock. 



Penarth Docks l (Fig. 11), constructed from the design of Sir 

 J. Hawkshaw, are situated on the south-west side of the river 

 Ely, near its junction with the Severn. The dock is 2900 feet 

 in length, with a greatest width of about 400 feet, and having 

 an area of about 23 acres. The available wharfage is about 

 6000 feet, with a depth of water of 35 feet at ordinary spring- 

 tide level, and 25 feet at neap tides. 



The dock is approached through an outer or sea entrance and 

 an inner lock, with a small basin intervening. The lock is 270 

 feet long by 60 feet wide, and the intermediate basin 400 feet 

 long by 330 feet wide, equal to an area of 3 acres. The sea 



1 Engineering, vol. sxxviii. p. H7. 



