T2 tanker
The T2 tanker, or T2, was a class of oil tanker constructed and produced in large quantities in the United States during World War II. Only the T3 tankers were larger "navy oilers" of the period. Some 533 T2s were built between 1940 and the end of 1945. They were used to transport fuel oil, diesel fuel, gasoline and sometimes black oil-crude oil. Post war many T2s remained in use; like other hastily built World War II ships pressed into peacetime service, there were safety concerns. As was found during the war, the United States Coast Guard  Marine Board of Investigation in 1952 stated that in cold weather the ships were prone to metal fatigue cracking, so were "belted" with steel straps. This occurred after two T2s, and , split in two off Cape Cod within hours of each other. "Pendleton"s sinking is memorialized in "The Finest Hours". Engineering inquiries into the problem suggested the cause was poor welding techniques. It was found the steel (that had been successfully used in riveted ship design) was not well suited for the new wartime welding construction. The high sulfur content made the steel brittle and prone to metal fatigue 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 1938–1939 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, Pennsylvania, 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 (steam) turbo-electric transmission system delivered , 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, and provide for the fuel needs of US forces in Europe and the Pacific, as well as to replace the tanker tonnage being lost at an alarming rate to German U-boats. 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 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, except with rather than 7,240. The A3 variation was essentially an A2 built as a naval 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 . Twenty-five of this design were ordered by the Maritime Commission, of which five became Navy oilers as the . T2-A-MC-K. T2-A-MC-K had a M.C. deadweight tonnage of 16,300 and a full load tonnage of 22,445. The dimensions were: Length: , Beam: and max. draft: . Powered by turbine engines rated at with a top speed of . The first Navy commissioning was in 1942. could hold 117,400 Bbls  of oil and 595,000 gal of gasoline. Crew of 23 officers and 329 enlisted men. Armament: one single 5'/38 cal dual purpose gun mount, four single 3"/50 cal dual purpose gun mounts, four twin 40 mm AA gun mounts and twelve single 20 mm AA gun mounts. Example was , a "Kennebec"-class oiler. Notable deployments. In 1966, the US Army reactivated 11 T2 tankers and converted them into floating electrical power generation plants and deployed them to Vietnam. The ships' propulsion systems' electrical turbines were used to generate electricity for on-shore use, drawing on fuel from the ships' 150,000-barrel  holds. This allowed the ships to produce electricity for two years without refueling for the Vietnam War. was the first to arrive in June 1966, then next was , both installed in Cam Ranh Bay.