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"Pom-Pom" director was a
The Pom-Pom Director, Mark IV
in ''The Gunnery Pocket Book'', B.R. 224/45, 1945 placed online courtesy of Historic Naval Ships Association
Illustration of the Pom-Pom Director, Mark IV in ''The Gunnery Pocket Book'', B.R. 224/45, 1945
placed online courtesy of Historic Naval Ships Association Artillery operation Naval guns of the United Kingdom Military computers Fire-control computers of World War II de:Ordnance QF 2-Pfünder-Marinegeschütz it:2 libbre navale ja:ポンポン砲 pl:Armata przeciwlotnicza 40 mm Mark VIII
"Pom-Pom" director was a director
Director may refer to:
Literature
* ''Director'' (magazine), a British magazine
* ''The Director'' (novel), a 1971 novel by Henry Denker
* ''The Director'' (play), a 2000 play by Nancy Hasty
Music
* Director (band), an Irish rock band
* ''D ...
for British anti-aircraft guns on British warships of the 1930s into the Second World War.
Development
The Vickers 40 mm QF 2 pounder "Pom-Pom" gun anti-aircraft mounting was introduced to the Royal Navy in the early 1930s. The multi-barrel mounting was capable of a tremendous volume of fire but the crew had great difficulty in aiming the mounting due to the smoke and vibration created by the guns. It was, therefore, essential to aim the mount from a remote location, using adirector
Director may refer to:
Literature
* ''Director'' (magazine), a British magazine
* ''The Director'' (novel), a 1971 novel by Henry Denker
* ''The Director'' (play), a 2000 play by Nancy Hasty
Music
* Director (band), an Irish rock band
* ''D ...
that had a clear view, free from smoke and vibration. The director crew would aim at the target aircraft and, in the early versions of the director, cause the layer (altitude) and trainer (azimuth
An azimuth (; from ) is the horizontal angle from a cardinal direction, most commonly north, in a local or observer-centric spherical coordinate system.
Mathematically, the relative position vector from an observer ( origin) to a point ...
) pointers to rotate on the gun mount. The gun crew would then move the mount to match the pointers rather than having to try and aim at the target aircraft.
Mark I - III directors
Directors I to III controlled the gun mounting through "follow the pointer" control and aimed at aircraft using eye shooting techniques through a simple ring sight. These directors began to appear on Royal Navy cruisers, battleships and aircraft carriers in 1930. They were universally fitted, one per pom-pom gun mounting, by the late 1930s. Most destroyers and smaller ships that carried 2-pounder guns continued to rely on aiming the guns with the on-mount gunsights due to the lack of space on these ships to site a director.Director Mark IV
The Mk IV director was a considerable improvement and usedgyroscopes
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining Orientation (geometry), orientation and angular velocity. It is a spinning wheel or disc in ...
in a gyro rate unit coupled to an optical rangefinder
A rangefinder (also rangefinding telemeter, depending on the context) is a device used to Length measurement, measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, suc ...
and Type 282 radar to determine the range, speed and direction of enemy aircraft and then used an on-director computer to produce an accurate fire control solution to hit the target. Later versions of the Mk IV director introduced remote power control
Remote may refer to:
Arts, entertainment, and media
* ''Remote'' (1993 film), a 1993 movie
* ''Remote'' (2004 film), a Tamil-language action drama film
* ''Remote'' (album), a 1988 album by Hue & Cry
* Remote (band), ambient chillout band
* ...
(RPC) and could control the gun mounting by remote control from the director. The Mk IV director was fully tachymetric A tachymetric anti-aircraft fire control system generates target position, speed, direction, and rate of target range change, by computing these parameters directly from measured data.
The target's range, height and observed bearing data are fed in ...
, but performance suffered as the director was not stabilized against the movement of the ship. It consequently required a carefully trained crew (a total of eight including the radar operator in the radar office) to achieve good results. Even so, the Mk IV director was highly advanced and placed the Royal Navy in the forefront of naval anti-aircraft fire control when it was introduced to the Royal Navy on in 1940. Later versions were upgraded with Type 282 radar and RPC beginning in 1941, with HMS ''Prince of Wales'' being one of the first ships to receive the radar upgrade, which she first used in action during Operation Halberd
Operation Halberd was a British naval operation that took place on 27 September 1941, during the Second World War. The British were attempting to deliver a convoy from Gibraltar to Malta. The convoy was escorted by several battleships and an ai ...
.Tarrant, ''King George V class Battleships'', p88
See also
*List of anti-aircraft guns
Anti-aircraft guns are weapons designed to attack aircraft. Such weapons commonly have a high rate of fire and are able to fire shells designed to damage aircraft. They also are capable of firing at high angles, but are also usually able to hit ...
Notes and references
*External links
{{Commonscat-inline, QF 2 pounder pom-pomThe Pom-Pom Director, Mark IV
in ''The Gunnery Pocket Book'', B.R. 224/45, 1945 placed online courtesy of Historic Naval Ships Association
Illustration of the Pom-Pom Director, Mark IV in ''The Gunnery Pocket Book'', B.R. 224/45, 1945
placed online courtesy of Historic Naval Ships Association Artillery operation Naval guns of the United Kingdom Military computers Fire-control computers of World War II de:Ordnance QF 2-Pfünder-Marinegeschütz it:2 libbre navale ja:ポンポン砲 pl:Armata przeciwlotnicza 40 mm Mark VIII