PT boat
[2][page needed] Primary anti-ship armament on the standard PT boat was four 21-inch Mark 8 torpedoes, each of which had a 466-pound (211 kg) TNT warhead and a range of 16,000 yards (15,000 m) at 36 knots (67 km/h).
At the outbreak of war in August 1914, W. Albert Hickman devised the first procedures and tactics for employing fast maneuverable seaworthy torpedo motorboats against capital ships, and he presented his proposal to Rear Admiral David W. Taylor, the chief of the US Navy's Bureau of Construction and Repair.
The Admiralty found it interesting but thought that "no fast boat of 50' to 60' length would be sufficiently seaworthy", so Hickman built and launched his own privately financed 41-foot (12 m) sea sled capable of carrying a single 18-inch Whitehead Mark 5 torpedo.
When it was delivered and tested in the summer of 1917, it was not deemed a success, so a second boat (C-378) of the sea sled design was ordered from Hickman in either late 1917 or early 1918 (conflicting dates).
In 1938, the US Navy renewed their investigation into the concept by requesting competitive bids for several different types of motor torpedo boats but excluded Hickman's sea sled.
[7] In March 1941, during a heavy weather run from Key West to New York by Motor Torpedo Boat Squadron 2 (MTBRON 2), Elco 70-footers pounded heavily in 8-to-10-foot (2.4 to 3.0 m) waves even at moderate speeds, and seas continuously broke high over the bows.
All boats suffered from some sort of structural failure: forward chine guards ripped away, bottom framing under bows broken, side planking cracked [indicating lack of longitudinal strength], and other weaknesses were reported.
In early 1941 the U.S. Navy Bureau of Ships lent Packard engines to both Huckins and Higgins, which wanted to build competitive boats at their own expense.
Five Elco boats were manufactured in knock-down kit form and sent to Long Beach Boatworks for assembly on the West Coast as part of an experiment and as a proof of concept.
They were assigned to specific outposts in the Panama Canal Zone, Miami, Florida, the Hawaiian Sea Frontier at Pearl Harbor and Midway, and a Melville Motor Torpedo Boat Squadrons Training Center.
Most probably due to the lateness in joining the PT boat program and unlike Elco and Higgins, the Huckins yard was not provided government support to construct a larger facility prior to the war.
The success and ruggedness of the Huckins' 78-foot seagoing design is demonstrated by Squadron 26's constant ready-boat operations and fleet torpedo boat training in the oceans around Midway and Hawaii during the last two years of the war.
Vospers of Great Britain arranged for several boatyards in the United States to build British-designed 70 ft (21 m) motor torpedo boats under license to help the war effort.
146 boats, armed with 18 in (460 mm) torpedoes, were built for Lend Lease, and exported to Allied powers such as Canada, Britain, Norway, and the Soviet Union.
According to Robert McFarlane, the US Navy built the hulls of some PT boats partially from 3,000-year-old white cedar logs recovered from sphagnum bogs in New Jersey.
[10][11] As a testament to the strength of this type of construction and watertight bulkheads, several PT boats withstood catastrophic battle damage and still remained afloat.
Occasionally, some front line PT boats received ad hoc up-fits, where they mounted such weapons as 37 mm aircraft cannons, rocket launchers, or mortars.
One such field modification was made to Kennedy's PT-109, which was equipped with a single-shot Army M3 37 mm anti-tank gun that her crew had commandeered; they removed the wheels and lashed it to 2x8 timbers placed on the bow only one night before she was lost.
Their answer was found in the 37 mm Oldsmobile M4 aircraft automatic cannon cannibalized from crashed P-39 Airacobra fighter planes on Henderson Field on Guadalcanal.
These features made it highly desirable because of the PT boat's ever-increasing requirement for increased firepower to deal effectively with the Japanese Daihatsu-class barges, which were largely immune to torpedoes because of their shallow draft.
On 2 November 1943, PT-59 participated in the rescue of 40 to 50 Marines during the raid on Choiseul and a foundering Landing Craft, Personnel (Ramp) (LCP(R)) which was under fire from Japanese soldiers on the beach.
Originally conceived as anti-ship weapons, PT boats were publicly credited with sinking several Japanese warships during the period between December 1941 and the fall of the Philippines in May 1942[24][page needed]—even though the Navy knew the claims were all false.
[citation needed] Crews feared attack by Japanese seaplanes, which were difficult to detect even with radar, but which could easily spot the phosphorescent wake left by PT propellers.
[24][page needed] During some of these nighttime attacks, PT boat positions may have been given away by a flash of light caused by grease inside the black powder-actuated Mark 8 torpedo tubes catching fire during the launching sequence.
This eliminated the telltale flash of light from burning grease, did not use any form of explosive to launch the torpedo, and weighed about 1,000 lb (450 kg) less than the previous tubes.
The effectiveness of PT boats in the Solomon Islands campaign, and countering "Tokyo Express" Japanese resupply in New Georgia Sound, was substantially undermined by defective Mark 8 torpedoes.
The Japanese were cautious when operating their capital ships in areas known to have PT boats, knowing how dangerous their own Type 93 torpedoes were and assuming the Americans had equally lethal weapons.
PT-309 was named in honor of Frank Sinatra, who the boat's commanding officer met at a nightclub shortly before MTBRON 22 left New York for the Mediterranean Theatre.
Shortly after her retirement from service, the PT-796 was used as a float during President John F. Kennedy's inaugural parade to represent PT-109, with the PT-109 hull number painted on the bow, and several of PT-109's surviving crew members manning the boat.
Today, PT-796 is located at the Battleship Cove Naval Museum in Fall River, Massachusetts, in a Quonset hut-style building, protected from the weather and up on blocks.
