Shipowners decided to build slower vessels to save fuel: the average speed of newly delivered containerships dropped steadily from 25 knots in 1973 to 20 in 1984. Naval architects were no longer forced to design streamlined shapes to help achieve high speeds, and could concentrate instead on increasing pay-loads. Without getting much longer, vessels got much larger. The ships entering service by 1978 could hold up to 3,500 20-foot containers—more than had entered all U.S. ports combined during an average week in 1968.
