Slitherine

quote:

On 14 May a Catalina of the US Navy attacked and destroyed a U-boat; this was either U-657[3] or U-640.[4] On 13 May Liberator B/86 had attacked a U-boat with a FIDO, but this vessel, U-456,[5] was only damaged, sinking the following day from damage received. One of these vessels was the first U-boat sinking achieved using FIDO. During its career, the torpedo sank a total of 37 submarines, achieving an effectiveness of about 22%, compared with about 9% for depth charges.

from US Navy OEG Study No. 289, 12 August 1946 provides the following data related to Mark 24 effectiveness:
Number of attacks in which Mark 24s were launched 264
Total number of Mark 24 torpedoes launched - all targets 340
Number of Mark 24s launched against submarines 204
Number of Mark 24 attacks on submarines by US aircraft 142
Number of Mark 24 attacks by Allied (primarily British) aircraft 62
Number of German U-boats sunk by FIDO 31
Number of German U-boats damaged by FIDO 15
Number of Japanese submarines sunk by FIDO 6
Number of Japanese submarines damaged by FIDO 3
Total number of submarines sunk by FIDO (German & Japanese) 37
Total number of submarines damaged 18
General characteristics

Diameter: 19 inches (46 cm).
Length: 84 inches (2.13 m).
Weight: 680 lb (308 kg).
Warhead: 92 lb (41.7 kg) HBX high explosive.
Propulsion: 5 hp (3.7 kW) electric motor driving a single propeller, powered by a 48 volt lead acid battery.
Speed and endurance: 12 knots for 10 minutes, giving a range of about 4,000 yards (3,700 m)
Homing system: 4 piezoelectric hydrophones operating at 24 kHz and vacuum tube signal processing system with proportional steering.
Maximum drop altitude: 200 to 300 ft (60 m to 90 m)
Maximum aircraft launch speed: 120 knots (220 km/h).

quote:

ORIGINAL: spence
That way the Japanese can park their subs 1 hex away from your airbases and almost never worry about air attack. German experience to the contrary doesn't count.

quote:

ORIGINAL: spence

quote:

On 14 May a Catalina of the US Navy attacked and destroyed a U-boat; this was either U-657[3] or U-640.[4] On 13 May Liberator B/86 had attacked a U-boat with a FIDO, but this vessel, U-456,[5] was only damaged, sinking the following day from damage received. One of these vessels was the first U-boat sinking achieved using FIDO. During its career, the torpedo sank a total of 37 submarines, achieving an effectiveness of about 22%, compared with about 9% for depth charges.

from US Navy OEG Study No. 289, 12 August 1946 provides the following data related to Mark 24 effectiveness:
Number of attacks in which Mark 24s were launched 264
Total number of Mark 24 torpedoes launched - all targets 340
Number of Mark 24s launched against submarines 204
Number of Mark 24 attacks on submarines by US aircraft 142
Number of Mark 24 attacks by Allied (primarily British) aircraft 62
Number of German U-boats sunk by FIDO 31
Number of German U-boats damaged by FIDO 15
Number of Japanese submarines sunk by FIDO 6
Number of Japanese submarines damaged by FIDO 3
Total number of submarines sunk by FIDO (German & Japanese) 37
Total number of submarines damaged 18
General characteristics

Diameter: 19 inches (46 cm).
Length: 84 inches (2.13 m).
Weight: 680 lb (308 kg).
Warhead: 92 lb (41.7 kg) HBX high explosive.
Propulsion: 5 hp (3.7 kW) electric motor driving a single propeller, powered by a 48 volt lead acid battery.
Speed and endurance: 12 knots for 10 minutes, giving a range of about 4,000 yards (3,700 m)
Homing system: 4 piezoelectric hydrophones operating at 24 kHz and vacuum tube signal processing system with proportional steering.
Maximum drop altitude: 200 to 300 ft (60 m to 90 m)
Maximum aircraft launch speed: 120 knots (220 km/h).

So 9 Japanese subs were destroyed by FIDO's. Although that seems like a small number in the Pacific the ratio of aircraft attributed kills to surface ship attributed kills much much less (probably because of the size and geography of the Pacific compared to the Atlantic).

Technically it was called a mine but it behaved like a torpedo. It is not included in the game even though on average it was 2 and 1/2 times as effective as depth charges.

Always remember that this is only a game and we MUST MUST MUST give the Japanese Player a chance to change history (improved ASW) even if it means discounting Allied tactical counter-developments (Mark 26 anti-escort torpedo) and their own improvements in ASW. That way the Japanese can park their subs 1 hex away from your airbases and almost never worry about air attack. German experience to the contrary doesn't count.