PT boats (Patrol Torpedo boats) were deployed in all theaters of the Second World War. They were fast, maneuverable, and capable of operating on inland waterways and the open seas. Hundreds of them were built in the United States and provided to allied navies, including the fleet of the Soviet Union. Often referred to as built from plywood, the majority of them had hulls of either cedar or mahogany. The PT 103 class had hulls of layered mahogany, creating a hull which was two inches thick. Designed to plane on the water at the speed of 23 knots, the hull was capable of a top speed of over 40 knots. PT 109 was of this class.
Three Packard twelve-cylinder engines delivered a total of 4,500 horsepower, with each engine driving a separate propeller. The engines were muffled to allow the crew to hear aircraft overhead. Four torpedo tubes provided offensive punch against enemy shipping, and machine gun mounts offered defensive protection. Most were designed to accommodate a crew of 17 – three commissioned officers and 14 enlisted. PTs were popular among junior officers, since they afforded the opportunity for an independent command at relatively junior rank. All of the officers and crews were volunteers. The danger of the duty was evident from their motto during the war – They Were Expendable. Here is the story of two of them, PT 109 and PT 59
1. PT boat duty was extrahazardous for several reasons
PT boats were developed between the wars, and most of the testing and evaluating of the various designs took place in Atlantic waters near Long Island or the Chesapeake Bay. When they deployed to the South Pacific in World War II, several problems presented themselves. The boats could seldom make their top designed speeds after just a few weeks in the theater, due to the marine growth on their wooden hulls. Japanese destroyers could outrun them. The torpedo launching system was problematic, often failing to eject a torpedo after its motor had started. This led to the motor overheating and exploding in the tube.
Torpedoes which did launch properly often failed to detonate when reaching their target, a problem which also plagued American submarine commanders in the first two years of the war. PT boat commanders often added additional firepower to their boats, including 20 mm and larger anti-aircraft cannons. Many also added armor around the deckhouse and machine gun mounts as protection for their crews. The added weight further slowed the boats, a disadvantage because they were designed to use speed as their primary weapon against the enemy. The boats were designed to operate in small flotillas, with speed and maneuverability overcoming the defensive armament of the ships they encountered.