Elco produced 326 of these patrol-torpedo boats, giving the United States a numerous coastal striking force. A recurring length-to-beam ratio of roughly four or five to one provided a useful foundation for a fast planing hull. PT-109 combined a 57-ton boat and an official speed near 41 knots with four torpedoes, automatic weapons, and an added 37 mm gun. The amount of armament on so small a platform shows how attack boats concentrated immediate striking power rather than endurance or protection. Official specifications still described only the starting condition of an operational PT boat.
Chapter · 23:40-24:56
Elco PT boats, PT-109, and field modification
PT-109 illustrates the Elco patrol-torpedo boat's production scale, fast hull proportions, torpedo battery, and crowded short-range weapon fit.