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Title:THE BRITISH DIRECTIONAL SONOBUOY [Main Title]
Film Number:AMY 563
Summary: Detailed information film focusing on the British Directional Sonobuoy.
Description: Reel 1: Description of the Sonobuoy and brief explanation of it's operation (360º non-directional type). Cavitation noise is main source of noise from submarines. Method of locating submarine by dropping several sonobuoys. “The Directional Sonobuoy” - this type uses a rotating hydrophone with a narrow beam to locate a target. Footage of British Directional Sonobuoys being loaded into bomb bay – soluble plugs ensure the devices sink after 4 hours to prevent them falling into enemy hands. On practice missions the sonobuoys have to be recovered before the plugs dissolve. Smoke markers are also loaded to be dropped at the same time. Shackleton aircraft taking off and dropping sononbuoy/smoke marker with underwater footage of the deployment of the hydrophone. Explanation of how Directional Sonobuoy works. Description of the hydrophone and rotating mechanism, stabilising paddles, compass unit, main transmitter unit.
Reel 2: Information transmitted by sonobuoy is presented to the operators in the aircraft described. Constituent parts consists of receiver, power unit, control unit, indicator unit and pre-amplifier which altogether make up the ARI. 5487 airborne equipment used for the omnidirectional sonobuoy T1945 or directional sonobuoy T1946. Processing of signal from sonobuoy described. “Tactical Method of using British Directional Sonobuoy” - explanation of method of detecting and attacking a submarine. Sonobuoy Tactical Team consists of two operators passing information to Tactical Co-Ordinator and Tactical Navigator. Also Bomb Aimer guides Pilot and calculates wind velocity for Navigator. Process of commencing tactical search for submarine explained and roles of team during dropping of Sonobuoys.
Reel 3: Taking readings of responses from sonobuoy and interpreting the data to predict course of submarine and calculate an interception point. (WB856 Avro Shackleton MR1A) taxis in. In training exercises a smoke marker and launch would be used.
Reel 4: All elements of the process of tracking and attacking submarine using sonobuoys shown as a “realtime” example from start to dropping bomb.
Production Country: GB
Production Details: AIR MINISTRY (Production sponsor)
Science Films (Production company)
Personalities, Units and Organisations:
Physical Characteristics: Colour format: B&W
Technical Details: Format: 35mm
Number of items/reels/tapes: 4
Footage: 2960 ft; Running time: 33 mins