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WW2 Military Radar Systems 1938 to 1945

 

Introduction

This covers the original metric floodlight radars with separate transmit and receive systems, for which Marconi designed and produced the arrays, and early combined systems for which Marconi designed and produced elements up to and during WW2, followed by the move to centimetric systems with the development of the magnetron. The CH and several other transmitters were designed and produced by Metropolitan Vickers. (The receiver came from Cossor).

 

When the Air Ministry's radar development team was established at Bawdsey Manor in the immediate pre-WWII period it was given the name Air Ministry Experimental Station or AMES for short and this acronym also became the basis for naming RAF radar systems through the war, hence the type names in the following list. The numbering continued postwar.

 

CH

  

AMES Type	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
1	CH	1Mw	5-45uS	12.5, 25, 50	22.7-29.7MHz	Figures for later modifications. Earlier systems had 200KW and 800KW outputs. Some systems designed for 42.5-50.5MHz. First experimental systems used NT46, then NT57 Then BTH Type 43 or 45 Demountable valves. Earlier stations had powers from 450-750Kw. T3026 reported as 450Kw, 5-40uS; T3026A 750Kw. May have used transmitters from MB series. Could do Height Finding from 1.5 to 16 Deg. Targets lower than 1 Deg are not detected.

 

     

 

CH description

This link is to a paper written by Bruce Neale and first published in the GEC Journal of Research

 

 CH description

This link is to a paper written by Mike Scanlan first published in the GEC Review

 

The CH Radiolocation transmitters - a paper written by Dr.J. M. Dodds and J. H. Ludlow.

 

Post Office Equipment for Radar

 

CH - Wikipedia

 

CH Tower at Baddow - this was originally one of those installed at Canewdon and a presentation about it is shown here courtesy of Andy Tyler.

 

This painting by Chris French G.Av.A. shows three steel towers with their transmitter antennas slung between. On the lower left, the "girl on the tube" interprets the "blips" of enemy aircraft on the screen. The information was then sent via the telephone (lower right) to filter and operations rooms where the table-map could be updated by a "plotter" (top right). The markers represented hostile and friendly aircraft and were used to plan and monitor air battles. 234 Squadron’s Spitfires (top left) peel of to intercept enemy bombers. The succession of functions became commonly known as "Read", "Report", "Filter", "Identify", "Tell" and "Plot". Click here for a larger version

 

1935/6/7  The success of the first five CH stations  promoted the ordering of twenty more, and for all of these Marconi provided the transmitter `curtain' arrays, and subsequently for the West Coast and other chains.

 

CHL and CHEL

 

AMES Type	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
2	CHL	150Kw	3	400	200MHz	PRF Variable around 400.  When on 200’ tower or on 200’ cliffs, range on target at 500’ is 110 miles. Aerial is a 5 bay, 4 stack of dipoles . Horizontal angle of beam about 20 Deg.
3	CH/CHL					Types 1 & 2 in close proximity operating as one unit.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Type 2 Tower and gantry mounts          Type 2 Transmitter station                                             Type 2 Receiver station with PPI and plotting board

 

Early CHL stations operated similar to their larger Chain Home counterparts, measuring the range and angle to the target. These were later upgraded with plan-position indicator displays (PPI) which provide a map-like 2-dimensional view of the airspace around the station. This eliminated the need to translate range and bearing measures into positions, instead the operators could simply plot the "blips" directly on a paper map, both for record keeping as well as determining the grid locations of the targets.

 

CHL Description

CHEL Description

Type 2 and Type 52 - 56

 

There are excellent descriptions of CH and CHL equipment in the book "RADAR How it all Began" by Jim Brown published by Janus in 1996. It is the story of Metro Vick's production of the Chain Home transmitter, the special tetrode valve designed by Dr. Dodds and subsequent work on other radars.

 

Naval Operations

1940/1  The Company was involved in the fitting of RDF for early warning against air attack to Navy capital ships. Modified Air-to-Surface metric equipment fitted to smaller ships. A crash programme to develop a small set also capable of detecting surfaced submarines was delivered in 1941. An improved form of aircraft warning system was the Type 281. 

 

Type 281

Type	Aerial outfit	Peak power (kW)	Frequency (MHz)	Wavelength (mm)	In service
281	AQB	350	85	3,500	1940

 

Metric air warning set with separate Tx / Rx antennas. Type 281B had combined Tx / Rx antenna. First fitted to HMS Dido then HMS Prince of Wales^[2] This set also had a secondary surface search and gunnery capability  and used a Precision Ranging Panel. The Type 281 ranging system allowed the user to select either a 2000yd to 14000yd or a 2000yd to 25000yd range display with range accuracies of 50 or 75yds RMS, respectively.

 

Type 7

 

AMES Type	Function	Power (Peak	Pulse Width	PRF	Freq	Notes
7	GCI	80-100Kw	3,5 or  8uS	300-540	192-209MHz	Final static GCI radar known as Happidrome. Effective Range 90 miles. Aerial 30’ x 25’ comprising three separate aerials at 7.5’, 12.5’, & 25’.Can combine these or use separate. Rotates at up to 8 RPM. Can detect a target at 1000’ at 30 Miles. Transmitter is a CHL type. Height finding between 2.5 and 20 Deg.

 

                

 

Type 7 on The Web:

Radars Type 7 and 8 at RAF Sopley

Radar Type 7 in detail.

Radar Type 7 at RAF Holmpton

Radar Type 7 but focuses mainly on the ROTOR program

Early air defence radar

 

Type 8 - there were various marks of this GCI radar, mobile and semi-static, replaced by the Type 7

 

Type 9

Mobile Chain Home Radar deployed in the field. The aerials were supported on the two 105-ft collapsible towers.

 

 

Type 11

 

AMES TYPE	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
11Mk1   goes to MK8	CHL/GCI	50Kw?	4	500	565MHz	Mk1 was mobile. Output Device is NT99. Mobile sets as standby if the 200MHz band was jammed. 600MHz was used by Germany.. Later versions from Mk5 Were coherent. First versions had rotary spark gap modulator. Horizontal beam 4 Deg, Vertical 11 Deg.

 

 

Description

 

Magnetron Development

1940/1  The Vacuum Laboratories at Baddow take over magnetron development and production.

 

1942  Following improvements to the magnetron the Chelmsford factory produced amplifier units for a new naval radar Type 271 which went on to become the initial radars used for CHEL operation. The Admiralty continued development of the Type 271 radar and the improved model, known as the Type 277 entered R.A.F service as the Type 14.

 

Centimetric radar

This link is to a paper written by Mike Scanlan first published in the GEC Review

 

Type 13

 

AMES Type	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
13Mk1     goes to Mk5 with new aerial	Height Finder CMH Mk1	500Kw	0.6 or 1.9uS	500	3GHz	Only  13 made. Used twin parabolic dishes. Based on 277. Also known as CMH.  Nodding Height finder. First versions were not very successful and were initially used for low angle detection fixed at 2.5 degrees. Aerial was twin parabolic cheese 20’ x 18”. Beam widths 1.75 x 6.5 Deg. Could nod between -1 and +20 Deg. Range 60 miles, at which it was accurate to 500’.

 

Description

 

Simulation

 

A number of Type 13 radars were manufactured by Scanners Limited in Gateshead. Many passed through MWT at Rivenhall in both static and mobile versions. The mobile versions were mounted on hydraulic jacks and could be raised and lowered onto a  heavy vehicle chassis. The transmitter/receiver and turning gear were mounted in a cabin behind the waveguide fed antenna and the whole assembly rotated as a single unit.

 

In most cases the mobile Type 13's formed part of a radar convoy comprising a search radar (usually a Type 14); an operations vehicle containing the display and communications facility and one or two diesel generator vehicles. These systems were assembled and tested at Rivenhall prior to shipment to a customer. The writer recalls that a number of "convoys" were supplied to India and Pakistan in the late 50's and early sixties.

 

In 1950 static Type 13 and 14 radars were installed at London Heathrow airport and were the forerunner of ATC surveillance radars in the UK.

 

                                                         

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static Type 13 and S264 (Believed to be at Heathrow)                            Mobile Type 13 (later aerial and earlier aerial)

(Picture: R. A. Webb)

 

 

Type 14

 

AMES Type	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
14Mk1 goes to MK9 ( with new aerial	CHEL	500Kw	0.6 or 1.9uS	500	3GHz	Based on 277. Became Type 51. Mk1 -5 had cheese aerial, 20’ x 3’  From 400’ cliff will spot all targets  above 0.01 Deg elevation.

 

Description

 

 

Mobile type 14 (earlier and later aerials)

 

 

1945  For D-Day Marconi designed, developed and manufactured from research carried out by TRE an airborne system, code named Bagful, TR3549, comprising R1624 and T1360, a self-recording L-band equipment for the interception of signals from the Wurzburg radar, recording the wavelength, time and duration of the received signal and approximate positions of enemy radar stations which was in large-scale operation prior to the invasion to build up a dossier. On June 6th a multiplicity of jamming stations, in an operation code named Carpet paralysed the Germans radar networks. Also for the invasion Marconi Marine provided servicing for all radio, echo sounding and radar equipments.

 

A rather quaint overview of wartime radar published in Flight magazine in June 1945

 

Immediate Post-war Military Radar Systems

This covers the radars re-engineered or produced by Marconi immediately post-war and up to 1950.

 

An individual record of a major radar site with multiple installations

 

MOD/RAF

 

Type 15

 

AMES Type	Function	Power (Peak)	Pulse Width	PRF	Freq	Notes
15Mk1 goes to Mk4 with higher power	GCI	80-100Kw	3,5 or  8uS	300-540	192-209MHz	Successor to Type 8. Interim GCI.

 

 

Description

 

Type 16/24

Fighter Direction installation, comprising a final Ground Control of Interception (GCI) structure and a Type 24 30ft parabolic array mounted on rotation gear.

 

 

Type 54

S band surveillance, low cover

 

Type 79

 

Type S233

 

Type S244/269

S band very long range height finding

 

                               

 

                                                       S244                                                                        S269

 

Type S247

S and L band back-to-back very long range surveillance

 

 

Type S255

 

Type S259 (Type 95)

L band medium range mobile

 

Type S266

 

Green Ginger Type 330 (Type 88) Type 404 (Type 89)

mobile surveillance - L and S bands            mobile height finding - C band 

 

New Military Radar Systems

This covers radars produced by Marconi after 1950 including those taken over from AEI.

 

Type 80

although not a Marconi design it did influence our development work so should be mentioned

 

 

Type 82 Orange Yeoman

S band surveillance with height finding

 

 

Type 83 Yellow River

S and X band precision tracking

 

Type 84

L band, very long range surveillance

 

 

Type 85 Blue Yeoman

S band long range 3D - led to Type 40T2

 

 

Type 86 Blue Anchor

X band tracker for Bloodhound

 

Blue Joker

S band low cover on balloons

 

Green Satin

Doppler navigation system 

 

Type S600 Series (Surveillance - Type 97, Heightfinder - Type 98)

 

 

S600 Series Radar Deployed (L-Band "Squintless Feed" antenna (TBC); Equipment Cabin; Operations Cabin and Heightfinder (Picture, R.A. Webb) (Deployed at RAF Cranfield and three other sites for Stansted Airport Traffic Survey - Third London Airport controversy!)

 

Type 711

 

 Martello

 

Type S713 (RAF Type 90)

 

Type S723 (RAF Type 91)

 

Type 743D 

 

 

HF Over the Horizon Radar (Sky Wave)

 

HF Over the Horizon Radar (Surface Wave)

 

Passive Detection

 

High-speed antenna

 

 

Later Systems

Post-MRSL

 

Radar Turning Gears

A discussion on the John Curran turning gear from the Radar Type 80 and 84 and the Marconi Pivot Mount S3322

 

 

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