comparing a system of superior operational capabilities with one of more 

 restricted capabilities, since choosing the superior system can be justified 

 only if the improvements in performance are commensurate with the increase 

 in cost. Any error in cost estimates can, therefore, be misleading and lead to 

 a false engineering decision. 



There is no guideline available for estimating the construction cost of 

 a platform, primarily because there have been few platforms constructed. 

 For ships, it has been found that the cost per ton is a minimum of about 

 $1 ,600 for a cargo vessel and a maximum of $3,000 for special research 

 ships. The cost of a platform is probably comparable to that of a new ship. 

 It is estimated that a cost of $2,400 per ton for the platform is realistic, and 

 the cost for a new ship would be about the same. Converting an old ship for 

 heavy lift would cost roughly $500 per ton, although a price of as much as 

 $1,000 per ton could result if extensive reworking is needed. 



Table A-1 presents the approximate dimensions of the ships under 

 consideration. Also included are order-of-magnitude total cost figures 

 which require some explanation. 



T-2. The T-2 tanker is discussed in detail in Appendix B in the 

 section on ship motions. The total cost is based on extensive modifications, 

 including a new center section. Assuming no initial cost to purchase the 

 ship, the cost breakdown is as follows: 



Shipyard modifications $3,300,000 



Preparing and approving plans 300,000 



Positioning and sensing equipment 120,000 



Electronics 350,000 



Steering screws 400,000 



Power equipment 200,000 



Total $4,670,000 



C-2. The C-2 is a general cargo ship which would require only minor 

 modifications for strengthening. The cost breakdown is as follows: 



Shipyard modifications $1,800,000 



Preparing and approving plans 250,000 



Positioning and sensing equipment 120,000 



Electronics 350,000 



Steering screws 400,000 



Power equipment 700,000 



Total $3,620,000 



94 



