The "killers of giants" and "wooden marvels" were known by many names during WW2, but the official and generic "PT-Boat", meaning "Patrol, Torpedo, Boat". They were an unknown type for the USN in WW1, as there was no needd for such "naval dust" when a large battlefleet as available. Therefore, it's the only the conditions of war that urged the need for these small vessels. Especially their main theater of operations: The confines of Pacific atolls, islands and islets. A well placed PT-boat base could seriously disrupt enemy traffic, thanks to their torpedoes. But PT-Boats played so much roles that is difficult to realy appreciate their contribution to the allied victory in WW2.
Essential players, although modest and relatively inexpensive, the fame of PT-Boats was largely earned in the battles fought in the Pacific, in fact, they forged a true legend. They immediately found their usefulness within the shoals of the innumerable networks of islands, lagoons and archipelagos of the Southeast Pacific, operating in close collaboration with the US Marines and serving as "jacks of all trades", ranging from support on the ground, troop transports, supplies, anti-aircraft cover, ASM patrol boats, and of course torpedo boats, threats for the light units aligned by the Japanese, ranging from their own speedboats to destroyers or even cruisers , passing through the landing craft.
One of the finest successes achieved in operation is undoubtedly the successful attack by a Japanese "super-destroyer" of the Akitsuki class, the Terutsuki, which was sent to the bottom at Guadalcanal. But for the almost 800 units built up to 1945, which made thousands of sorties, the list of losses was quite considerable, with hundreds of units sunk and a thousand more or less seriously damaged. The PT boats also recorded losses, especially in merciless duels against heavier units. They were generally "stars" much heavier and slower than those deployed by the allies, the small MTBs from Thornycroft, the MAS from Baglietto or the G5s from Tupolev. They had more to do with British Fairmiles, Italian MSs or Russian D3s.
Their generous dimensions and flexibility meant it was possible to adapt a fairly considerable variety of "a la carte" armaments, which the unit commanders (including John F. Kennedy the famous PT109), modified according to the possibilities and missions to be carried out. One of the striking elements of their flexibility of use was the large number of more or less improvised bases which were scattered over the theater of operations, sometimes a few nautical miles from garrisons or Japanese bases. Each was regularly supplied with fuel and equipment, managed administratively, could carry out the necessary installations and repairs and implement from 5 to 40 PT-Boats depending on its importance.
⚠ Note: This post is in writing. Completion expected in 2023.
Development
PT-9 off Washington DC (1940)
(To come)
General conception & construction
These PT-Boats were built en masse by four main firms: Elco, Higgins, Vosper and Huckins. Although the first two remain in the majority, the Vosper were of British origin, built and transferred in “resverse lend-lease” as it is true that the British expertise in the matter was recognized worldwide. 768 units will be built in total. The traditional doctrine of the US Navy, inherited from Mahan and ignoring the "naval dust", however used launches in large numbers during prohibition, patrolling against the traffic of Rum on the great lakes from Canada. . Thornycroft launches had been purchased on a trial basis at the end of the Great War, and in 1939, when hostilities broke out, several prototypes were ordered, including one built in Britain, from Hall-Scott, which became retrospectively the 9th of these prototypes (PT9) and the direct ancestor of the PT-Boats.
Quickly the PT10 to 19, of the "70 foot" model and armed with two torpedoes, were delivered by Elco (Electric Boat Company, founded by the father of modern American submarines, John Holland), then lengthened to 77 feet to place four torpedoes. 12 ASM models (PTC1-12), built in parallel, were sent to the Royal Navy on lease. The firm Elco then produced the series PT20 to 68, of 80 feet, which would become its standard. The PT109 was part of the third series, PT103 to 196, and there were 6 others, the PT314 to 367 and 372-383, and up to 790, or 400 copies in total until 1945. They were built in wood, in order to combine lightness with ease of construction and to contribute to the preservation of strategic materials.
Hull
ONI, know your boat, upper deck showing differences between Elco and Higgins boats, July 1945
Powerplant
Equipments
Armament
Their initial armament included 4 torpedo tubes, later phased out. We preferred the lighter aerial torpedoes with gyroscope launching from the side cradles, and 4 heavy machine guns 50 caliber (12.7 mm) in double positions. This armament was relieved with a 40 and a 37 mm AA gun, sometimes even 1 or 2 of 20 mm Oerlikon, whose stopping power was much higher. These guns were also often used for ground support, by strafing the vegetation on the bank. In this sense, many saw themselves adding 2 rocket launchers of 12 tubes of 114 mm, then 127 mm in 1944, with sometimes four sets of this type, which were added to 20 mm guns instead of the double positions of 12.7 mm, and a mortar of 60 mm which one could unload if necessary. Finally, all had one or two ASM compartments at the stern containing a total of 10 grenades and sometimes two mortars without reloads, or more often 2 to 4 side grenades in cradles.
Torpedoes
Anti-aircraft
Depth Charges
Appearance
Many of these units were camouflaged to match the densely vegetated environment. Still on the “decorative” chapter, their crews liked to paint “shark mouths” on the stern, others were more inspired by pin-ups and cartoon characters taken from the habits of bomber crews. But these aesthetic escapades were often in contradiction with the official directives whose respect was ensured by more or less tolerant unit commanders...
They also had a draft allowing them river patrols, and many fought the Japanese troops inside the theaters of land operations. In many respects, these “PT-Boats” were a good school to then define the PBR in plastic of the Viet-Nâm war.
The Elco were the best known, the most widespread and also the best armed of these series of PT-Boats. In 1944, a prototype with great firepower was built, the “Thunderbolt” equipped with a post of 20 mm Oerlikon quadruple at the back, similar to that which equipped certain Half-Track servants with the DCA.
Huckins 78-foot (24 m) PT-259 underway near Midway c.1944
Trials by Fire: Tactics & Operations
USS PT-167 is holed by an enemy torpedo that failed to detonate, 5 November 1943. Painting by Gerard Richardson
(To Come)
An 80-foot (24 m) Elco PT boat with original Mark 18 torpedo tubes on patrol off the coast of New Guinea, 1943
JF Kennedy's PT 109 crew
PTs in the cold war
The Argentinian ARA Alakush in 1962
Drawing of a PTF Boat (Patrol (boat), Torpedo, Fast) in 1964
Src/Read More
PT 658 off Portland, still operational.
Books
Conway's All the World's Fighting Ships, 1922–1946
The PTs produced by Higgins, in New Orleans, were 215 units in all, from PT71 to PT808, but with many cancellations. These were shorter but also wide models. Also 1.60 m deep, their hull was habitable, wide and deep. They could travel 500 nautical miles at 20 knots. In 1944, Higgins produced the prototype "Hellcat" (PT564) lightened in aluminum, but it could not receive heavy armament and was not followed.
Specs
Displacement: 40 tons, Full load.
Dimensions 24.38 m long, 6.30 m wide, 1.60 m draft.
Machinery: 3 shafts gasoline engines 1050 hp. Top speed 39 knots.
Armament: 4 torpedoes 18-in (457 mm), 1 x 40mm, 1 x 37mm, 1 x 20m AA, 2x2 HMG 50 cal. (12.7 mm), 2 depth charges, 2×12 5-in 127 mm rocket launcher.
Crew: 17.
Higgins 78 footers (1942)
The PTs produced by Higgins, in New Orleans, were 215 units, from PT71 to PT808, but with many cancellations. These were shorter but also wide models. Also 1.60 m deep, their hull was habitable, wide and deep. They could travel 500 nautical miles at 20 knots. In 1944, Higgins produced the prototype "Hellcat" (PT564) lightened, aluminum, but it could not receive heavy armament and was not followed.
Specs
Displacement 52 t. Full Load
Dimensions 23.93 m long, 6.12 m wide, 1.60 m draft
Machines 3 propellers, 3 mot. ess. 1050 hp.
Maximum speed 39 knots
Armament: 4x 18in (457 mm) TTs, 1 gun of 40, 3 of 20 mm AA, 2 ASW grenades, 2×12 LR 127 mm
Crew 17
Huckins 78 footers (1943)
(To Come)
Specs
Displacement 52 t. Full Load
Dimensions 23.93 m long, 6.12 m wide, 1.60 m draft
Machines 3 propellers, 3 mot. ess. 1050 hp.
Maximum speed 39 knots
Armament: 4x 18in (457 mm) TTs, 1 gun of 40, 3 of 20 mm AA, 2 ASW grenades, 2×12 LR 127 mm
Crew 17
Vosper 72 footers (1945)
Specs
The PTs produced by Vosper in Great Britain, in 1944-45, were 137 examples, smaller, slower but with more autonomy on patrol (570 nautical miles at 20 knots). They had two torpedo tubes in order to revert more to an anti-ship role. Finally, the Huckins were smaller and wider and did not give satisfaction. Only 16 examples were built in 1942 (PT95 to 102 and PT255 to 264.).
Specs
Displacement 45 t. Full Load
Dimensions 22.10 m long, 5.87 m wide, 1.68 m draft
Machines 3 propellers, 3 mot. ess. 3375 hp.
Maximum speed 38.75 knots
Armament 2 x 533 mm TLT, 2 x 20 cannon, 2 x 12.7 mm AA, 4 ASM grenades
Crew 10-12