T2 tanker The T2 tanker , or T2 , was an oil tanker constructed and produced in large quantities in the United States during World War II . The largest " navy oilers " of the period , after the T3 s , nearly 500 were built between 1940 and the end of 1945 . Many remained in service for decades after the war , and like other World War II ships pressed into peace time service were the subject of safety concerns . A United States Coast Guard Marine Board of Investigation in 1952 stated the ships were prone to splitting in two in cold weather and they were then " belted " with steel straps . This occurred after two T - 2s , and , split in two off Cape Cod within hours of each other . Engineering inquiries into the problems suggested at first the tendency of the tankers to split in two was due to poor welding techniques . Later , it was concluded the steel used in the war time construction had too high a sulfur content that turned the steel brittle at lower temperatures . Designs . T2 design . The T2 design was formalized by the United States Maritime Commission as its medium - sized " National Defense tanker , " a ship built for merchant service which could be militarized as a fleet auxiliary in time of war . MarCom subsidized the excess cost of naval features beyond normal commercial standards . The T2 was based on two ships built in 1938 - 39 by Bethlehem Steel for Socony - Vacuum Oil Company , " Mobilfuel " and " Mobilube " , differing from the Mobil ships principally in the installation of more powerful engines for higher speed . Standard T2s were in total length , with a beam of . Rated at 9 , 900 tons gross ( GRT ) , with , standard T2s displaced about 21 , 100 tons . Steam turbines driving a single propeller at delivered a top speed of . Six were built for commerce by Bethlehem - Sparrows Point Shipyard in Maryland , only to be taken over by the United States Navy following the attack on Pearl Harbor as the . T2 - A design . Keystone Tankships company ordered five tankers in 1940 from Sun Shipbuilding & Drydock of Chester , PA , based on the T2 but longer and with increased capacity ; Marcom would designate this design T2 - A . Bigger but faster , they were in total length , displaced about 22 , 445 tons , and were rated at 10 , 600 tons gross with — yet they attained a top speed approaching . All five were requisitioned by the Navy during the war and converted to fleet oilers as the " Mattaponi " class . T2 - SE - A1 . By far the most common variety of the T2 - type tanker was the T2 - SE - A1 , another commercial design already being built in 1940 by the Sun Shipbuilding Company for Standard Oil Company of New Jersey . They were long , abeam , with and . Their turbo - electric transmission system delivered 6 , 000 shaft horsepower , with maximum thrust of , which produced a top - rated speed of about with a cruising range of up to . After Pearl Harbor , the United States Maritime Commission ordered this model built " en masse " to supply U . S . warships already in accelerated production . 481 were built in extremely short production times by the Alabama Drydock and Shipbuilding Company of Mobile , Alabama , the Kaiser Company at their Swan Island Yard at Portland , Oregon , the Marinship Corp . of Sausalito , California and the Sun Shipbuilding and Drydock Company of Chester , Pennsylvania . During that period , average production time from laying of the keel to " fitting out " was 70 days . The record , however , was held by Marinship , which had the ready for sea trials in just 33 days . T2 - SE - A2 and - A3 . The T2 - SE - A2 variation , built only by Marinship of Sausalito , was nearly identical to the T2 - SE - A1 version , only with maximum thrust of rather than the former ’ s 7 , 240 . The A3 variation was essentially an A2 built as a Navy oiler from the start , rather than converted later as many A2s were . T3 - S - A1 . Despite the confusing T3 designation , the T3 - S - A1s built by Bethlehem Sparrows Point for Standard Oil of New Jersey were identical to the original T2s except for having less powerful engines of 7700 hp . 25 of this design were ordered by the Maritime Commission , of which five became Navy oilers as the " Chiwawa " class .