30 NOTES ON DOCKS AND DOCK CONSTRUCTION. 



The chalk bank was given a width of 30 feet at the level of 

 the river bed; above low- water level, it was roughly formed 

 to a slope of 2 to 1 on the face, and it was intended to back 

 it with solid clay or other hard material. The western bank, 

 F G (Fig. 18), could not, however, be carried across the muddy 

 foreshore to join the outer embankment ; the advance made 

 by day was lost by night, and the mud of the foreshore rose 

 gradually until it overtopped the chalk bank. More chalk had 

 then to be added to prevent the mud from flowing into the 

 river, which increased the height of the bank without a corre- 

 sponding increase in strength. Endeavours were then made to 

 prevent the spreading of the bank, F G (Fig. 18), by sinking 

 several old barges filled with chalk in the line of the tip, but 

 the barges floated along in the mud, and, when the tip head 

 was 100 feet from the outer bank, a portion of the latter, which 

 had been 15 feet above low water, slipped forward. A solid 

 chalk bank was then put in 80 feet wide at the river bed, 



with a deep- dredged 

 Quay 'Level />gw _ trench 40 feet wide to 



Earth fillinsy, / ^Jfe~/^o~ TCCeive the toe, and 



backed with stiff clay 

 for 30 feet in average 



width - The seaward 

 face was pitched with 

 SCALE Bramley Fall stones, to 



protect the chalk from 

 disintegration (Fig. 19). 



The portion that slipped was secured by two rows of close sheet- 

 piling, the piles being 36 feet long, and the rows spaced 20 

 feet apart with strong walings; the two rows of piles were 

 firmly strutted and lashed together with chains. The connection 

 between the outer bank and the western tip head was also made 

 with rubble chalk. 



The middle bank, H I (Fig. 18), was continued in the same 

 manner to join the eastern side of the coffer-dam. The main 

 embankment and coffer-dam having been completed, the water 

 was excluded from the second reclamation. The inner embank- 

 ment, A B (Fig. 18), was then broken through, and the material 

 from the excavations within the reclaimed area were utilized 

 for forming the bank, D K (Fig. 18). The eastern portion of the 

 river embankment, I K (Fig. 18), was at the same time proceeded 



