1945, the first supertanker,'^ 28,000 dwt, was 

 constructed. In 1950, the first U.S. tanker in 

 excess of 30,000 dwt was built; and by 1956, 11 

 U.S. tankers between 30,000 and 35,000 dwt were 

 in service. 



The average-size tanker in the world fleet 

 increased from 12,800 dwt in 1949 to 27,100 dwt 



The term "supertanker" changes meaning with each 

 new generation of vessels. 



1965 Commodity Distribution of Total U.S. Oceanborne and Great Laltes Commerce 



in 1965. During this same period, the typical U.S. 

 flag tanker increased from about 15,000 to 25,000 

 dwt. The trend toward larger-volume tankers 

 accelerated during the past decade. In 1966, over 

 one-third of the world tanker fleet was composed 

 of vessels 30,000 dwt or larger; further, these ships 

 comprised about 64 per cent of the world fleet 

 dwt capacity. While ships of 30,000 dwt have 

 become common, they are dwarfed by the largest 

 vessel now operating— a 312,000 dwt Japanese 

 built tanker— and will look smaller still compared 

 to the 760,000 dwt supercarriers under considera- 

 tion. 



B. Dry Bulk Carriers 



Dry bulk vessels, which transport commodities 

 ranging from iron ore to general cargo, have not 

 grown at the same rate as their tanker counter- 

 parts.'^ Nevertheless, the number of vessels 

 30,000 dwt and larger now in service comprise 

 about 16 per cent of the world's dry bulk carrier 

 fleet compared to less than 2 per cent in 1953. 

 Such vessels represent, at present, about 40 per 

 cent of the world's fleet dry bulk tonnage capa- 

 city. 



C. Vessel Size Projections 



1965 Distribution of Total U.S. Oceanborne and Great Lakes 

 Commerce By imports, Exports, and Domestic 



Table 4 is based on a recent study which 

 projected growth in the dead weight tonnage of 

 freighters, dry bulk carriers, and tankers. The table 

 summarizes anticipated vessel sizes and shows 

 expected physical characteristics. 



V. TRANSPORT COST IMPLICATIONS 



1965 Regional Distribution of Total U.S. Oceanborne and Great Lakes Commerce 

 (Ail figures represent tonnage distribution^ 



Figure 4. Distributions of U.S. marine com- 

 merce. (Source: U.S. Army Corps of Engineers) 



A. Tankers 



Although the shape of a 200,000-ton super- 

 tanker and a 17,000-ton T-2 tanker differs little, 

 there is a major difference in the cost of shipping. 

 The capital and operating cost per ton of vessel 

 dead weight reduces substantially as vessel size 



In some instances, petroleum tankers are used to haul 

 other goods, such as grain. Where this is done, the tankers 

 must be thoroughly cleansed of all petroleum residue to 

 avoid contamination of the grain. Cleansing is an expen- 

 sive operation and is practiced only where several consec- 

 utive grain cargoes can be secured. 



'^U.S. Maritime Administration, Merchant Ships of 

 100,000 Tons Deadweight and Over, April 1967. 



III-66 



