- Mark 24 FIDO Torpedo
The Mark 24 FIDO Torpedo was a US air-dropped passive acoustic homing anti-
submarine torpedoused during the Second World Waragainst German and Japanese submarines. It entered service in March 1943 and continued in service with the US Navy until 1948. Approximately 4,000 torpedoes were produced, sinking 37 and damaging a further 18 submarines out of a total of 204 fired. The torpedo was also supplied to the British and Canadian forces.
The US Navy began studies into an air dropped anti-submarine torpedo in the autumn of 1941. Based on a formal set of requirements, Harvard Underwater Sound Lab (HUSL) and Bell Telephone Labs began development in December 1941. These later projects later became Office of Scientific Research and Development project 61 (FIDO).
Both Bell Labs and HUSL proceeded with parallel development of torpedoes, with a complete exchange of information between both projects.
Western Electricwere to develop a lightweight, shock resistant, 48 volt Lead-acid batterycapable of providing 110 amps for 15 minutes. General Electricwere to design and fabricate propulsion and steering motors and to investigate an active acoustic homing system. David Taylor Model Basinwas to assist with hydrodynamics and propulsion.
The guidance system consisted of four underwater microphones or
Hydrophonesplaced around the mid-section of the torpedo connected to a vacuum tubebased sound processing array. A Bell Labs proportional and HUSL non-proportional steering system had been demonstrated by July 1942.
An existing Mark 13 torpedo provided the body of the torpedo, it was modified by shortening the hull, reducing the diameter, reducing the weight, and designing a hemispherical nose section to carry the explosive charge, and a conical tail section with four stabilizing fins and rudders and a single propeller. The effect of these modifications was to produce a relatively short "fat" torpedo.
In June 1942 the US Navy decided to take the torpedo into production even though there was still major testing work remaining on the project, including air-drop testing. The Bell Labs version of the guidance system was selected for production with proportional homing. Testing of the pre-production prototypes continued on into December 1942 and the US Navy received the first production models in March 1943.
Initially 10,000 torpedoes were ordered, but FIDO proved so effective that the order was reduced to 4,000. The torpedoes ended up costing $1,800 each.
Upon water entry, FIDO performed a circular search pattern at a predetermined depth controlled by a bellows and pendulum system. This continued until the potential target's 24 kHz acoustic signal detected by the hydrophones exceeded a predetermined threshold level, at which point control was then shifted to the passive acoustic proportional homing system. Initially the torpedoes were set to search for a target at a depth of 50 feet (15 m), this was later changed to 150 feet (45 m). To prevent the Torpedo accidentally attacking surface ships, the Torpedo resumed its circling search pattern if it rose above a depth of 40 feet (12 m).
The torpedo's relatively low speed was kept secret since, while U-Boats could not outrun the torpedo underwater, they could outrun it on the surface.
The first sinking with FIDO occurred in May 1943 and was possibly U-640 or U-657. During its career the torpedo sunk 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 1946provides 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 submarines sunk by FIDO 31 Number of submarines damaged by FIDO 15 Number of Mark 24 attacks on subs by Allies (primarily British) 62 Number of submarines sunk by FIDO 6 Number of submarines damaged by FIDO 3 Total number of submarines sunk by FIDO (German & Japanese) 37 Total number of submarines damaged 18
*Diameter: 19 inches (0.48 m).
*Length: 84 inches (2.13 m).
*Weight: 680 lb (308 kg).
* Warhead: 92 lb (41.7 kg)
Torpex 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
piezoelectrichydrophones operating at 24 kHz and a " 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).
* Mark 27 "Cutie" was developed for submarine use against surface vessels. It saw service in the Pacific war from the summer of 1944.
* "Hitler's U-Boat War: The Hunters, 1939-1942" , Clay Blair, ISBN 0-679-64032-0
Wikimedia Foundation. 2010.
Look at other dictionaries:
Fido — may mean: * Fido is a common name for a pet dog, from the Latin fidelis , faithful. * Fido (band), a punk/rock band from Melbourne, Australia * Fido (film), a 2006 Canadian zombie comedy film * Fido (software), a software scheduled media… … Wikipedia
Torpedo — in einem U Boot vor dem Einführen in das Torpedorohr Der moderne Torpedo ist eine Unterwasserwaffe mit eigenem Antrieb und einer Sprengladung. Er zündet bei Kontakt oder bei Annäherung an ein Ziel. Der Torpedo ist vor allem als Hauptwaffe von U… … Deutsch Wikipedia
Mark 27 (торпеда) — Mark 27 Торпеда Mk 27 Основная информация Назначение противокорабельная (Mod 0) … Википедия
Torpedo — The modern torpedo (historically called an automotive, automobile, locomotive, or fish torpedo) is a self propelled explosive projectile weapon, launched above or below the water surface, propelled underwater toward a target, and designed to… … Wikipedia
Mark 34 torpedo — A Mark 34 Torpedo at Kanoya Museum, Japan. The Mark 34 torpedo (initially Mine Mk 44, technically Mk 34 mod 1) was a U.S. torpedo developed that entered service in 1948. It was an improved version of the Mark 24 FIDO passive acoustic homing… … Wikipedia
Mark 24 Mine — The Mark 24 Mine (also known as FIDO or Fido) was a US air dropped passive acoustic homing anti submarine torpedo used during the Second World War against German and Japanese submarines. It entered service in March 1943 and continued in service… … Wikipedia
G7e torpedo — The G7e or more appropriately the G7e/T2, G7e/T3, and G7e/T4 Falke torpedoes were, with the exception of the T4 model, the standard torpedoes for Germany during World War II (WWII). All of the G7e models shared standardized dimensions for all… … Wikipedia
List of World War II topics (M) — # M 1941 Field Jacket # M 24 (Japanese midget submarine) # M B Etheredge # M class Minesweeper (Germany) # M class minesweeper # M Special Unit # M. A. Yegorov # M. R. D. Foot # M. Z. Kiani # Maori Battalion # Möbelwagen # Möhne Reservoir #… … Wikipedia
German submarine U-402 — Unterseeboot 402 ( U 402 ) was a German type VII C U Boat of World War Two. U 402 commanded by Kapitänleutnant Siegfried von Forstner carried out eight combat patrols sinking 14 merchantmen and one warship during the Second World War. U 402 also… … Wikipedia
Siegfried von Forstner — Infobox Military Person name= Siegfried von Forstner born=birth date|1910|9|19|df=y died=dda|1943|10|13|1910|9|19|df=y placeofbirth=Hannover placeofdeath= KIA Atlantic Ocean nickname= allegiance=flagicon|Germany Weimar Republic (to 1933)… … Wikipedia