PT 109 was one of the hundreds of motor torpedo boats (PT) of the PT 103 class completed between 1942 and 1945 by Elco Naval Division of Electric Boat Company at Bayonne, New Jersey. The Elco boats were the largest in size of the three types of PT boats built for U.S. use during World War II. Wooden-hulled, 80 feet long with a 20-foot, 8-inch beam, the Elco PT boats had three 12-cylinder Packard gasoline engines generating a total of 4,500 horsepower for a designed speed of 41 knots. With accommodations for 3 officers and 14 men, the crew varied from 12 to 14. Its full-load displacement was 56 tons. Early Elco boats had two 20mm guns, four .50-caliber machine guns, and two or four 21-inch torpedo tubes. Some of them carried depth charges or mine racks. Later boats mounted one 40mm gun and four torpedo launching racks. Many boats received ad-hoc refits at advanced bases, mounting such light guns as Army Air Forces 37mm aircraft guns and even Japanese 23mm guns. Some PTs later received rocket launchers.
Originally conceived as antiship weapons, PTs were publicly, but erroneously, credited with sinking Japanese warships during the early months after Pearl Harbor. During the long Solomons campaign, they operated usefully at night and times of low visibility against Japanese barge traffic in the "Slot." Throughout World War II, PTs operated in the southern, western, and northern Pacific, as well as in the Mediterranean and the English Channel. Some served off Normandy during that invasion. Though their primary mission continued to be seen as attack of surface ships and craft, PTs were also used effectively to lay mines and smoke screens, to rescue downed aviators, and to carry out intelligence or raider operations. Almost all surviving Elco PTs were disposed of shortly after V-J Day. One Elco boat, PT 617, survives at Battleship Cove, Fall River, Massachusetts.
Although more 80-foot Elco boats were built than any other type of motor torpedo boat, other types were built by the U. S. The British-designed 70-foot Vosper boats which were built for Lend Lease fired 18-inch torpedoes. Since the U.S. produced the heavier and longer 21-inch torpedoes, the U.S. Navy wanted a larger PT boat. After experimentation, the first PT boat built in any quantity was the 77-foot type built by Elco. These boats were used early in World War II. In 1943 in the Solomons, three of these 77-foot PT boats, PT 59, PT 60 and PT 61, were even converted into gunboats by stripping the boat of all original armament except for the two twin .50 caliber gun mounts, and then adding two 40mm guns and four more twin .50 caliber machine guns. LTJG John F. Kennedy was the first commanding officer of PT 59 after the conversion.
Although the Huckins Yacht Company of Jacksonville, Florida, built a few 78 foot boats of the PT 95 class, the 80-foot Elco boats and the 78-foot Higgins boats became the standard motor torpedo boats of World War II. The Higgins boats which were built by Higgins Industries in New Orleans, Louisiana, were 78-foot boats of the PT 71 class. The Higgins boats had the same beam, full load displacement, engine, generators, shaft horsepower, trial speed, armament, and crew accommodations as the 80-foot Elco boats.
For more information on PT boats, you may want to consult these titles:
Bulkley, Robert J., Jr. At Close Quarters: PT Boats in the United States Navy. Washington: Naval Historical Division, 1962. OCLC 4444071
Chun, Victor. American PT Boats in World War II: A Pictorial History. Atglen PA: Schiffer Publishing Ltd., 1997.
Fahey, James C. The Ships and Aircraft of the U. S. Fleet. Victory Edition. New York: Ships and Aircraft, 1945. OCLC 830202. For the Naval Institute reprints see OCLC 10036394, OCLC 10036390, OCLC 10036385 and OCLC 11099658.
Friedman, Norman. U. S. Small Combatants, Including PT Boats, Subchasers, and the Brown Water Navy: An Illustrated Design History. Annapolis, MD: Naval Institute Press, 1987. OCLC 16093618.
Hoagland, Edward D. The Sea Hawks: With the PT Boats at War. Navato, CA: Presidio Press, 1999.
Johnson, Frank D. United States PT Boats of World War II in Action. Poole, UK: Blandford Press, 1980. OCLC 6697444.
Nelson, Curtis L. Hunters in the Shallows: A History of the PT Boat. Washington: Brassey's, 1998. OCLC 38853885.
Polmar, Norman and Samuel Loring Morison. PT Boats at War: World War II to Vietnam. Osceola WI: MBI Publishing Co., 1999. [Includes useful appendixes. In particular see Appendix C, "PT Boat Order of Battle," which includes hull numbers, designer/builder, completion date and disposition when known.]