Mark 24 mine
| Mark 24 | |
|---|---|
| Mark 24 acoustic torpedo | |
| Type | Acoustic torpedo | 
| Place of origin | United States, Canada, United Kingdom | 
| Service history | |
| In service | 1942–1948 | 
| Used by | |
| Wars | World War II | 
| Production history | |
| Designer | Western Electric Company Bell Telephone Laboratories Harvard University Underwater Sound Laboratory | 
| Designed | 1942 | 
| Manufacturer | General Electric Company Western Electric Company | 
| No. built | 4000 | 
| Specifications | |
| Mass | 680 pounds (310 kg) | 
| Length | 84 inches (2.1 m) | 
| Diameter | 19 inches (48 cm) | 
| Effective firing range | 4,000 yards (3.7 km) (10 minutes search duration) | 
| Warhead | HBX | 
| Warhead weight | 92 pounds (42 kg) | 
| Detonation mechanism | Mk 142 fuze, contact exploder | 
| Engine | Electric, secondary battery | 
| Maximum speed | 12 knots (22 km/h) | 
| Guidance system | preset circle search, passive acoustic | 
| Launch platform | Aircraft | 
The Mark 24 mine (also known as FIDO or Fido) is an air-dropped anti-submarine (ASW) acoustic torpedo developed by the United States during World War II; it was called a mine to conceal its capabilities. The torpedo entered service with the Allies in March 1943; the United States Navy (USN) used it until 1948. Approximately 4,000 were produced. Of the 340 deployed during the war, 204 were fired, sinking 37 and damaging 18 Axis submarines.