The Type 291 radar was designed as a

search radar This is a list of different types of radar. Detection and search radars Search radars scan great volumes of space with pulses of short radio waves. They typically scan the volume two to four times a minute. The waves are usually less than a meter ...

for ships

destroyer In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...

-sized and smaller in 1942. By the end of the Second World War it had been installed in almost every British and Commonwealth destroyer and

escort ship Ocean escort was a type of United States Navy warship. They were an evolution of the World War II destroyer escort types. The ocean escorts were intended as convoy escorts and were designed for mobilization production in wartime or low-cost mass ...

as well as many submarines,

naval trawler Naval trawlers are vessels built along the lines of a fishing trawler but fitted out for naval purposes; they were widely used during the First and Second World Wars. Some—known in the Royal Navy as "Admiralty trawlers"— were purpose-built to ...

s, and motor torpedo boats. Some sets were furnished to the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

for their destroyers as a part of

Lend-Lease Lend-Lease, formally the Lend-Lease Act and introduced as An Act to Promote the Defense of the United States (), was a policy under which the United States supplied the United Kingdom, the Soviet Union and other Allied nations with food, oil, ...

. The initial model of the radar had separate transmitting and receiving antennas, but they were soon combined.Friedman, p. 196 The original Type 291 had a hand-steered antenna and it was replaced by Types 291M, P, and Q with power training and a

plan position indicator A plan position indicator (PPI) is a type of radar display that represents the radar antenna in the center of the display, with the distance from it and height above ground drawn as concentric circles. As the radar antenna rotates, a radial tra ...

. U and W variants with different antennas were produced for coastal craft and submarines respectively.

Notes

Bibliography

* *{{cite book, last=Watson, first=Raymond C. Jr., title=Radar Origins Worldwide: History of Its Evolution in 13 Nations Through World War II, publisher=Trafford, year=2009, isbn=978-1-4269-2111-7

External links

The RN Radar and Communications Museum
World War II British electronics Naval radars Royal Navy Radar World War II radars