364 NOTES ON DOCKS AND DOCK CONSTRUCTION. 



Allowing, therefore, interest on the above sum at the rate of 

 7 per cent, per annum, the cost for plant per cubic yard of block- 

 work set was 3 20 pence. 



The cost of masonry blocks, including the platform or carriage on which 

 the blocks were built, labour, and material of all kinds was 



Launching 



Lifting, transporting, and sotting in place 



Total cost of block-work 

 Add for interest on plant 



Total 



Per 

 cubic yd. 



1580 

 1-78 



6-96 



16 4-54 

 3-20 



10 7-74 



Or, 16'8 per cubic yard. 



Assuming, however, that the block-work should bear the 

 whole cost of the special plant required, with the addition of 5 per 

 cent, interest on the first cost, then the charge for plant, spread 

 over a series of years, and the total cost, would be as follows : 



6 years. 10 years. IB years. 



Charge for plant and interest 9'14 5'71 420 



Cost of blocks in place ... 16 4'73 16 4*73 16473 



Portsmouth Dockyard. 1 



17 1.87 



16 10 44 



16 8-93 



Carlingford Lock and Grecnore. 2 The cost of the quay walls 

 (Figs. 72, 73), averaging 45 feet in height, including foundations 

 (except dredging the sites), staging, and fenders, per foot lineal, 

 27 8s. 



1 M.P.I.C.E, vol. Ixiv. pp. 233, 234, 235. 2 Ibid., vol. xliv. p. 141. 



