379 



The amendment is written assuming damage conditions for both collision and 

 stranding situations. These values represent the severe assumed injuries in such 

 accidents and are to be used to determine, by trial at all conceivable locations, 

 the worst combination of compartments which would be breached by such an 

 accident. The consequence of these injuries should not exceed the hypothetical 

 outflow limits mentioned earlier, therefore, providing criteria for vessel design, 

 encouraging use of double bottoms, double sides, void spaces and segregated 

 ballast. 



Economics Analysis 



Using IMCO's casualty "worst case" criteria, the following economic analysis 

 was made. 



For all types of ships, the economic impact of oil outflow limitations increases 

 with a decrease in the hypothetical oil outflow as the result of collision (Oc) or 

 stranding (Os). Similarly, increases in ship size with a fixed hypothetical oil 

 outflow value will cause an increase in the economic impact. 



Increases in the cost of building and operating vessels corresponding to reduce 

 tions in the volume of individual tanks was evaluated by means of the parameter 

 RFR (Required Freight Rate to carry one ton of cargo without profit), the value 

 of which is given by : 



IiFR=SB+K.I 



T. 



where *£= operating cost per year 

 /=investment cost 

 K= Kl+i")" amortization coefficient at interest rate i for an amortization time length of n years 



(1+0--1 

 To = tons of cargo carried per year 



The choice of the parameter RFR offers the following advantages : 



(1) Factors like taxes and net profit, which vary from country to country 

 and from time to time, need not be considered. 



(2) The evaluation of the increase of cost of building and operating vessels, 

 consequent from a retluction in the tank volume, if given in percent of RFR, 

 would minimize the effect of inaccurate assumptions made in the investment 

 cost. 



(3) The calculation of percent increases of RFR provides at the same tim^ 

 all elements to evaluate the absolute value of increases in the transportation 

 cost of one ton of crude oil as a function of the reduction of tank volume. 



The following analysis for tankers of 300.000 and 500,000 deadweight tonnage 

 (tdw) was made using the RFR parameter. The requirements of this amendment 

 do not significantly increase the transportation costs for vessels under 300,000 

 Idw and are not considered in this analysis. For example, a vessel of 227,000 tdw 

 would only incur an increase of 0.5% ; for vessels of 140,000 tdw or under, there 

 is no increase. An analysis for tankers over 500,000 tdw was not made because of 

 the lack of adequate information concerning ships of this size. 



TABLE '4.— EFFECTS UPON ECONOMICS OF 0, or 0, VALUES WITH TANK SIZE LIMITATIONS RANGING FROM 



20,000 to 40,000 CUBIC METERS 



i Estimated. 



Oc = hypothetical oil outflow as a result of collision. 

 o, = hypothetiCcl oil outflow as a resLit of stranding. 

 Tank across = breadth of tank. 



26-282 0—74 26 



NOTES 



