How & Why during WWII Motor Torpedo Boats(MTBs) became Motor Gun Boats(MGBs): Pacific Theatre

British and American torpedo-boat builders shared ideas through the civilian yachting market, while Hickman's sea sled offered a fast tunnel-hull approach.

An American sea-sled proposal helped inspire the British coastal motor boat, while the US Navy repeatedly delayed its own fast torpedo-boat development.

C-378 demonstrated speed in rough water, but the Armistice interrupted American torpedo-boat development and shifted surviving craft into support duties.

The US Navy sought fast boats with specified endurance and armament while excluding Hickman's sea-sled design.

Above roughly 100 to 120 tons, the classification becomes debatable, perhaps closer to a motor torpedo ship.

A criticism of the Ajax decision favors the mature CV90, accompanied by conflicting personal reports from Army contacts in 2023.

The 54-foot proposal paired transportability with alternative torpedo and gunboat configurations.

George Crouch's preference for Hickman's sea sled challenged the design restriction in the competition he had just won.

Competing builders produced and adapted early prototypes, while Elco imported a British Power Boat design that became PT-9.

None comes to mind, although that does not rule out a proposal or trial.

The so-called plywood derby compared competing PT boats under load, exposing differences in pounding, speed, machinery, and turning ability.

Elco built the best-known US PT boats in large numbers, while Higgins shifted toward landing craft and Huckins remained a small producer despite a strong trial result.

Claims that Elco built more motor torpedo boats than anyone else depend on how mixed-role Fairmile craft are classified.

Higgins PT boats fought from the Aleutians and Mediterranean to D-Day, while rugged Huckins boats supported training and readiness around Midway and Hawaii.

The anti-suicide-boat screen off Okinawa showed why a torpedo-focused PT boat could not cover every close-in defence task.

Japanese treaty-era small craft were burdened by an ambition to fight above their natural role.

The Type 14 combined torpedoes with a light gun, while the Type 38 offered another small design built in comparable numbers.

German drawings could not supply the manufacturing experience needed to reproduce a Schnellboot in Japanese yards.

Steady improvement and room for heavier weapons could matter more than outstanding performance in one category.

Japan built thousands of Shinyo and Maru-Ni special-attack boats, creating a serious potential threat to any home-island invasion force.

The German A32 was sunk during Operation Albion, raised by Estonia as Sulev, and absorbed into the Soviet Navy before fighting its original builders in the Second World War.

The Sh-4 combined extreme speed ambitions with a whaleback hull, stern torpedo cradles, and materials that proved difficult to maintain at sea.

They were built in several places and assigned across the Baltic, Black Sea, and Pacific, although the surviving built and commissioned totals do not agree.

The G-5 pushed Soviet fast-boat performance to more than 50 knots, but its alloy hull and stern-launch system imposed severe operational limits.

Duralumin gave Soviet fast boats a light structure, but aircraft-derived design choices imposed relentless corrosion control in salt water.

Yes. G-5 publicity claimed corrosion had been conquered, despite service evidence of severe continuing maintenance demands.

G-5 development increased speed and light gun armament through successive production series.

The large Soviet G-5 concentration in the Far East is interpreted as a defensive hedge against a Japanese attack.

G-5s made several torpedo attacks, but troop transport, personnel movement, and landing escort often made better use of the difficult whaleback design.

Soviet D-3 development sought a larger, better-armed boat, but prototype weaknesses and unreliable engines sharply reduced its intended performance.

Despite development failures, D-3-family boats fought across several Soviet theatres, including the sinking of German torpedo boat T31 and a decorated Arctic service record.

The P-4 combined a flush deck and Packard engines with a more useful weapons layout, though its alloy hull still demanded intensive corrosion protection.

P-4 boats served in Asian fleets after World War II, with a Taiwan Strait example and a tentative connection to the Gulf of Tonkin.

Wartime coastal fighting demanded gun armament and hulls capable of carrying it alongside or in place of torpedoes.

They came from a separate design tradition. Including them would require a wider comparison covering equivalent river gunboats, including the Royal Navy's Insect class.

The influence was substantial, helping inspire early Soviet interest, but it also left the Soviets tied to an approach that needed more revision.

Steel gun components close to the aluminium-copper hull in salt water would risk worsening corrosion.

No. In the world wars they were already viable as a massed, affordable defensive threat to larger ships.

British procurement incorporated the gunboat role into new boats while crews elsewhere adapted torpedo-focused designs.

The problem may not be universal, but weaker examples ignore how imperial planning and institutions were already changing.

A modern uncrewed small craft may look novel while reviving the older logic of cheap, fast boats carrying danger into defended waters.

The Gay class shared some similarities without being a straightforward successor. The other two class lineages remain unresolved.

No reliable size is given from memory. A viewer cites 400 kg and 800 kg for two unspecified designs, while most circulating figures are treated as estimates.

Soviet torpedoes began the war less reliably than British weapons, then improved quickly.