design considerations for aluminum hull structures - Ship Structure ...

-108-7)is,zg~ gg~5e mzz~E’4E!~K2j,— — — — —NOTE: Gmrves based on single shipPrucuremont,P@duced .Wui -sition Price for AluninumACONCLUSIONS)2 —$ I01 231J 5678 91011 12 13 1ARoUiTC VOYAGEDISTANCE- 1000 MILESFIG, 23 Required Freight Rate Versus RoundYoyage ~ 3 Legs Weight Sensitive CargoThe following conclusions may be drawn from this study:oFor the realistic cases examined, an aluminwm dry bulk carriersimilar to CHALLENGER always produced,a higher RFR than thatof a steel ship with the same life.This unfavorable economic potential of the aluminum ship resultedeven though factors favorable to the higher priceddaluminum ship wereconsidered including:oAluminum ship cargo deadweight capacity was increased becauseof reduced structure weightoAluminum ship life was extended from 20 toincrease in scantlings30 years with noo Aluminum ship salvage value was $1,089,500of the steel shipmore than thato After tax return on investment of IO per cent and 7 per centinterest on borrowed capital, both relatively low at present,were assumed.The foregoing sensitivity studies indicate that there are severalareas in which the acquisition cost of an aluminum bulk carrier mightbe reduced. However, these studies also clearly indicate that at thistime even with these reductions, it is unlikely that an aluminum b~kcarrier will be directly competitive with an equivalent steel vessel onthe basis of Required Freight Rate.