Carrier capable bomber: you are in charge

[oldcrowcv63]

The IJN type 91 aerial torpedo was sufficiently lethal and advanced to keep it in service. It was far better than the US mark 13.

From Wiki

The Type 91 aerial torpedo rev.2 won the admiration of the world. This torpedo had two unique characteristics:

Wooden attachments (developed in 1936) on the tail fins, acting as aerodynamic stabilizers, which were to shed away on water entry.
An angular acceleration control system (PID controller) to control rolling movements, which was highly advanced and the biggest breakthrough in aerial torpedo development in 1941.
This system made it possible to release the Type 91 not only at a cruising speed of 180 knots (or 333 km/h, 207 mile/h) at an altitude of 20 m (66 ft) in a shallow water military port, but also in a power-glide torpedo-bombing run, at the Nakajima B5N2's maximum speed of 204 knots (or 378 km/h, 234 mile/h), into choppy waves of a rather heavy sea.

Two models of the Type 91 torpedo were used in late 1941-42. Both weighed about ~1850 lbs. with the lighter earlier version possessing a war head of 450 lbs while the later had one of about 530 lbs.

Both IJN models were capable of 41 knots speed sustained for 2 km. They could be launched from an airplane flying at about 160 kts and from

In contrast, the USN's Mark 13 Mod 0 1 aerial launched torpedo used in 1942, weighed about 1950 lbs, had a warhead of about 400 lbs, a speed of about 30 kts and a range of 5 km. It had to be launched from an aircraft flying at low altitude (~50 ft) and at just over 100 kts airspeed. It had a horrible record of success. The Mod 0 was apparently far more reliable and these may have been the versions that had some success in the early Pacific island carrier raids and at Coral Sea as supposedly some carriers may have had enough of the early ones in their magazines for two attacks. according to:

USA Torpedoes of World War II

 

[bowfin]

My bad. I was thinking of this torpedo, which was not the notorious original Long Lance of Guadalcanal fame.

The Type 94 aerial torpedo, was based on the highly successful Type 93 torpedo. The Type 93, called the "Long Lance" by the allied press, was a massive (2.8 tonnes fueled) weapon of superior performance, due largely to the use of compressed oxygen as a propellant instead of compressed air; pure oxygen has approximately five times the reactant capacity in regard to common fuels as the same mass of mixed gasses found in air. The Type 94 emerged from development somewhat smaller, similar to the Type 95 torpedo - a type also derived from the Type 93 and used successfully as a submarine weapon. It was nonetheless a heavy, unwieldy device and never deployed operationally.

Anyhow, if this torpedo was even somewhat close to the performance of the ship borne Long Lance, it would be worth designing an airframe around it. The anti-aircraft guns of the late wartime U.S. Navy would make some sort of stand off weapon almost mandatory, and a torpedo that lent itself to being dropped farther away from all those 40mm and 20mm guns would be make surviving a little more likely.

 

[oldcrowcv63]

Interesting thought... You don't want to create a weapon with any more range than absolutely necessary to save weight. To minimize your time inside the range of the terminal AA weapons (40 mm, 20 mm and 12.5 mm guns) suggests launching from about 5-10 km distance from your target. That's about 1/2 to 1/4 the range of the Long Lance. Even so, 5" RADAR directed guns could still score. A big drawback would be the distance the torpedo would have to travel to reach the target without terminal guidance. It would probaby work best at night for a Black Cat, ASV RADAR-assisted type of operation where the target may not be doing much manuevering or might be doing relatively predictable manuevering. I don't know how typical that was but would expect some manuevering in a war zone. But I am sure any success achieved would provoke some counter-manuever response from the enemy. The USN developed Air search RADAR and installed it on many ships before the war so RADAR detection would be exected to trigger a counter manuever. The Japanese had developed and installed air-search RADAR on their capital ships by the summer of 1942. So neither side has a clear theoretical advantage there. All this suggests to me some of the reasons why a long-range, aerial-launched torpedo wasn't more aggressively pursued during the war and why the use of anti-surface vessel torpedoes died out after the war.