(19 



TYPE C 



Maintcnaiu-c and interest SO . 1800 



As maintenance and interest alone for this type are greater than the total cost of 

 Type A, it is at all times more expensive than the latter and its cost increases with 

 its life. 



TYPE D 



Maintenance and interest SO 11 1 



Annual payments, reserve funds .0458 



Re(iuired at end of life: 



Sinking fund 1 . 8500 



Depreciation reserve 2 . 1275 



Loss of re\'enue . 3000 



Total required S4.2775 



Life necessary to produce this sum at 5%, 35.6 years. 



TYPE E 



Maintenance and interest SO . 1350 



Annual payments, reserve funds 0.0218 



Ketiuired at end of life; 



Sinking fund 2 . 2500 



Depreciation reserve 2 . 5825 



Loss of revenue . 3000 



Total required S5 . 1375 



Life necessary to produce this sum at 5' i, 50.4 years. 



TYPE F 



Maintenance and interest SO . 1 1 20 



Annual payments, reserve funds .0448 



Required at end of life: 



Sinking fund 1 . 4000 



Depreciation reserve 1 .6100 



Loss of revenue . 3000 



Total required S3 . 3100 



Life necessary to produce tliis sum at 5'^( , 31.5 years. 



In the above calculations allowance was made for the cost of removal by increasing 

 the depreciation funds as follows: 



lO'^"^ of the first cost for T>pe A. 

 20%, of the first cost for Types B and C. 

 15% of the first cost for Types D, E and F. 

 Revenue per square foot was assumed at SO. 3000 per annum and one year was 

 allowed for reconstruction, an assumption fa^•orable to concrete structures. 



Maintenance charges were taken at 5 per cent for Type A, 1 per cent for Types B, 

 C, D, and E, and 3 per cent for Type F". The parts most subject to wear are fender 

 lines and deck pavements, and as the maintenance cost for these parts is the same for 

 all types, the maintenance percentages assumed are also favorable to concrete structures. 

 The calculations presuppose the use of the best construction methods with result- 

 ing structures not subject to failure on account of the lack of precautions on the part 

 of the builders. 



