Rainbow Code

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The Rainbow Codes were a series of code names used to disguise the nature of various British military research projects. They were mainly used by the Ministry of Supply from the end of the Second World War until 1958, when the ministry was broken up and its functions distributed among the forces. The codes were replaced by an alphanumeric code system.

History[]

During WWII, British intelligence was able to glean details of new German technologies simply by considering their code names. For instance, when they began hearing of a new system known as Wotan, Reginald Victor Jones asked around and found that Wotan was a one-eyed god. Based on this, he guessed it was a radio navigation system using a single radio beam. This proved correct, and the Royal Air Force was able to quickly render it useless through jamming.^[1]

Looking to avoid making this sort of mistake, Ministry of Supply (MoS) initiated a system that would be entirely random and deliberately unrelated to the program in any way,^[2] while still being easy to remember. Each rainbow code name was constructed from a randomly selected colour, plus an (often appropriate) noun taken from a list, for example:

• "Blue" + "Steel" = Blue Steel, a nuclear-armed stand-off missile
• "Green" + "Mace" = Green Mace, an anti-aircraft (AA) gun.

While most colour and noun combinations were meaningless, some were real names, although quite unrelated to the project they designated. For example, "Black Maria" is also a name for a police van and the "Red Duster" is a name for the Red Ensign, the flag flown by British merchant ships. Some code names were not assigned through the official system, but created to sound like it. An example is the Blue Yeoman radar, an unofficial name created by combining the names of two other projects, Blue Riband and Orange Yeoman.

The names were mostly dropped with the end of the Ministry in 1959. Its functions were split between the War Office, the Air Ministry, and the newly created Ministry of Aviation for civil aviation. After the reorganization, projects were mostly named with randomly selected codes comprising two letters and three digits, e.g. BL755, WE.177.^[3] Rainbow codes, or at least names that look like them without being official, have occasionally been used for some modern systems; current examples include the Orange Reaper Electronic Support Measures system and the Blue Vixen radar^[4]—the latter most likely so named because it was a replacement for the Blue Fox radar.

Projects[]

This list is incomplete; you can help by . (August 2008)

Black[]

• Black Arrow – a satellite launch vehicle derived from Blue Streak/Black Knight
• Black Knight – a launch vehicle used to test re-entry vehicles for Blue Streak
• Black Maria – fighter IFF interrogator
• Black Prince – proposed satellite launch vehicle based on Blue Streak/Black Knight — a.k.a. Blue Star
• – surface to surface guided missile

Blue[]

• – X-Band CW target illumination radar for Bristol Bloodhound – a.k.a. AMES Type 86
• – truck-mounted nuclear land mine – later renamed Violet Mist
• – portable 2.5 MW nuclear-powered electrical generator – previously Green Janet
• Blue Boar – TV-guided bomb^[5][6]
• – VHF speech scrambling
• Blue Bunny – ten-kiloton nuclear mine, see Blue Peacock
• – nuclear warhead a.k.a. Tony – UK version of US W44, a.k.a. Tsetse
• Blue Cedar – AA No. 3 Mk. 7 mobile anti-aircraft radar
• Blue Circle – Sarcastic nickname for concrete ballast fitted to early variants of the Panavia Tornado ADV in place of the AI.24 Foxhunter radar, after the concrete company Blue Circle Industries
• Blue Danube – the first British nuclear weapon in service
• Blue Devil – T4 optical bombsight – drift and ground speed from Green Satin
• – AA No. 7 anti-aircraft radar
• – ARI (Airborne Radio Installation) 18075 airborne low-band VHF jammer – against metric frequency radar such as Tall King – fitted to Victor & Vulcan
• Blue Dolphin – Blue Jay Mk V for Sea Vixen – see Hawker Siddeley Red Top
• Blue Duck – Anti-Submarine Warfare missile, entered service as Ikara
• Blue Envoy – surface-to-air missile to OR.1140, replaced Green Sparker as "Stage 2" SAM
• – kiloton range nuclear weapon, later renamed Indigo Hammer – not to be confused with the later Blue Fox radar
• Blue Fox – airborne radar
• – ARI (Airborne Radio Installation) 5880 airborne Doppler navigation radar fitted to Hawker-Siddeley Buccaneer aircraft.
• Blue Jay – air-to-air missile – entered service as de Havilland Firestreak
• Blue Joker – balloon-borne Early Warning radar – a.k.a. AMES Type 87
• Blue Kestrel – search radar
• Blue Label – AMES Type 84 radar
• Blue Lagoon – Infra-red air-to-air detector
• Blue Mercury – Centurion Crocodile flamethrower tank.
• Blue Moon – nuclear-armed cruise missile project, replaced by Blue Streak
• Blue Oak – AWRE Atlas 2 super-computer used for simulation of nuclear explosions
• Blue Orchid – Marconi doppler navigation equipment for helicopters
• Blue Parrot – ARI 5930 I band automatic contour-following radar for Buccaneer – also known as AIRPASS II (AIRPASS=Airborne Interception Radar & Pilot's Attack Sight System)
• Blue Peacock – ten-kiloton nuclear land mine – also known as Blue Bunny and Brown Bunny; it used the Blue Danube physics package.
• Blue Perseus – flamethrower kit for the Centurion Crocodile tank
• Blue Ranger – Delivery of Blue Steel to Australia
• Blue Rapier – Red Rapier – missiles – see UB.109T
• Blue Riband – large jamming-resistant radar. Cancelled 1958 and replaced by a smaller version as Blue Yeoman.
• – short-case nuclear weapon bomb casing for reconnaissance bomber to spec R156T, including the Avro 730, Handley Page HP.100, , and others.
• – ARI 18105 airborne radar warning receiver (RWR) – fitted to Victor & Vulcan
• – astro-navigation system – see also Orange Tartan
• Blue Shadow – navigation equipment for Canberra B.16, developed as Yellow Aster.
• Blue Shield – see Armstrong Whitworth Sea Slug
• Blue Silk – airborne Doppler navigation radar unit with lower speed range than Green Satin
• Blue Sky – see Fairey Fireflash
• – heavy ship-to-ship missile using Sea Slug launcher, nuclear or conventional
• Blue Star – satellite launcher – see Black Prince
• Blue Steel – an air-launched rocket propelled nuclear stand-off missile
• Blue Stone – Unit 386D ENI (Electronic Neutron Initiator) – nuclear weapon component
• Blue Streak – a medium-range ballistic missile
• – automatic blind bombing system for V-bombers
• – air-droppable target marking radio beacon developed by TRE.^[7]
• Blue Vesta – a later version of the Blue Jay air-to-air missile
• Blue Vixen – Pulse-Doppler radar for Sea Harrier FA2
• countermeasure to use of Radar AA Shells
• Blue Water – Nuclear-armed tactical surface-to-surface missile intended for Royal Artillery in West Germany. Also see Red Rose
• Blue Yeoman – Early Warning radar, also known as AMES Type 85, a component Linesman. Name created from the "Blue" of Blue Riband and the Yeoman of Orange Yeoman. Potentially non-official name.

Brown[]

• Brown Bunny – original, unofficial name for Blue Peacock

Green[]

• Green Apple – related to Window for measuring drift at sea
• Green Archer – mortar-locating radar
• Green Bacon – experimental anti-aircraft radar for Bofors units
• Green Bamboo – "hybrid" nuclear weapon design similar to Soviet RDS-6s^[8]
• Green Bottle – 1944 device for homing on U-boat radio signals (ARI.5574)
• Green Cheese – nuclear anti-ship missile^[9]
• – Green Cheese’s replacement
• – Surface-to-Air Guided Weapon (SAGW) or surface-to-air missile (SAM); see Yellow Temple
• – infrared proximity fuze for Red Top
• Green Garlic – Early Warning radar, also known as the AMES Type 80
• – surveillance radars – combined installation of AMES Type 88 and AMES Type 89
• – thermonuclear warheads: Green Granite (small), and Green Granite (large), both tested at Operation Grapple
• Green Grass – nuclear warhead for Violet Club and Yellow Sun Mark 1 bombs
• – low-altitude bomber, Doppler navigation
• – portable, nuclear power plant; see Blue Bishop
• Green Light – SAGW or SAM – see Short Sea Cat^[10]
• – tube-launched SAM with variable geometry wings
• Green Mace – 5-inch rapid firing anti-aircraft gun^[11]
• Green Minnow – Radiometer imager
• – ARI 18074 airborne VHF voice channel jammer with four pre-set channels, replaced in the Vulcan B2 by the I band jammer
• Green Salad – ARI 18044 wide-band VHF Homing equipment for the Avro Shackleton.
• Green Satin – ARI 5851 airborne Doppler navigation radar unit
• Green Sparkler – advanced SAM for the "Stage 2" program, became Blue Envoy
• – Infra-red homing system based on the German wartime Kielgerät
• – blind bombing equipment
• – pilotless interceptor/SAGW
• Green Willow – EKCO AI Mk. 20 Fire Control radar, backup to ARI 5897 AI Mk. 23 Airborne Interception radar for the English Electric P.1 fighter
• – instrument for calibrating anti-aircraft guns by measuring their muzzle velocity

Indigo[]

• – S-band radar jamming system
• – continuous wave radar, used with the Bristol Bloodhound and English Electric Thunderbird SAMs
• , formerly Blue Fox – nuclear weapon

Jade[]

• – continuous wave radar, developed from Indigo Corkscrew

Orange[]

• Orange Blossom – Probably a deliberate mis-identification of the Orange Crop pods fitted to 1312 Flight Hercules aircraft, (Pod-mounted electronic support measures used on the Hercules – maybe).^{[citation needed]}
• Orange Cocktail – Experimental homing radar weapon from 1950s
• – Racal MIR 2 ESM system for Royal Navy Lynx and Royal Navy Sea King (HAS.5 onwards but not Mk 4 "Junglies", who had the Racal Prophet lightweight RWR fitted to some, or to the Royal Navy SAR) helicopters and some Royal Air Force Hercules aircraft.
• Orange Harvest – S and X band warning receiver fitted to Shackletons
• Orange Herald – large boosted fission nuclear warhead, tested at Operation Grapple in 1957.
• – SAGW – surface-to-air missile
• – Ferranti, anti-aircraft, fire-control radar
• Orange Poodle – low altitude, OTHR (Over-the-Horizon) early-warning radar – abandoned
• – ARI 5800 airborne passive radar warning receiver tuned to Soviet AI radars and fitted to Canberra and Valiant.
• – Racal "Kestrel" ESM system for Royal Navy Merlin helicopters
• – 'Auto-Astro' automated star navigation system (day) – see also Blue Sapphire (night).^[12]
• Orange Toffee – radar for Blue Envoy
• Orange William – Swingfire, anti-tank missile
• Orange Yeoman – Early Warning radar & guidance for Bristol Bloodhound SAGW – a.k.a. AMES Type 82

Pink[]

• – early name for Fairey Fireflash missile. As this was a "watered down" version of the Red Hawk, and thus pink, it is an example of Rainbow Codes having some implied meaning, rather than their usual purely deliberately meaningless choice.

Purple[]

• – nuclear weapon – see Green Granite
• – Sub-kiloton demolition mine project related to Violet Mist.
• Purple Possum – VX Nerve Agent.

Red[]

• Red Achilles – flamethrower kit for the CT 25 armoured carrier
• Red Angel – air-launched anti-ship weapon or "special bomb"^[13]
• Red Bacchus – mobile mixing plant for Red Vulcan flamethrower fuel
• Red Beard – nuclear weapon
• Red Biddy – Infantry platoon anti-tank missile, cancelled 1953
• Red Brick – Experimental continuous-wave target illuminating radar
• – Naval radar^[14]
• – X-band radar jammer^[14]
• – Air-launched nuclear stand-off missile cancelled 11/54.^[14]
• – inertially guided bomb^[14] based on the work of Tubby Vielle
• Red Cyclops – flamethrower kit for the FV201 tank
• Red Dean – large air-to-air missile
• Red Devil – experimental blind bombing system using Green Satin and Red Setter radars together
• – airborne radar – see Avro 730
• Red Duster – Bristol Bloodhound surface-to-air missile
• Red Elsie – AP No. 8 anti-personnel mine, developed jointly with Canada.
• Red Eye – An American general-purpose infra-red homing missile^{[citation needed]}
• Red Flag – free-fall nuclear bomb – 'Improved Kiloton Bomb' – WE.177
• – experimental Q band H2S
• Red Garter – Cossor ARI 5818 airborne tail warning radar for the Vulcan, did not enter service
• – large missile "downrated" to give Pink Hawk which became Blue Sky
• Red Heathen – early SAM project, became Red Shoes and Red Duster^[15]
• Red Hebe – air-to-air missile, a replacement for Red Dean
• Red Hermes – FV3702 armoured fuel trailer for flamethrower tanks
• Red Indian – analogue anti-aircraft fire control computer for Bofors L/70 gun.
• Red King – two-barrel revolver cannon, developed alongside Red Queen. The name is likely not random, but instead a reference to its Oerlikon factory designation, RK, for Revolver Kanone.
• – X band jammer for V Bombers, entered service as ARI 18146
• – airborne side-looking radar (SLAR), tested on the Victor a 40 foot long aerial under each wing. Flexing in flight corrupted the resolution. Cancelled 1962.^[16]
• Red Planet – infantry platoon anti-tank missile
• Red Queen – rapid fire 42 mm revolver cannon anti-aircraft gun^[17][18]

• Red Rapier , Blue Rapier missiles – see UB.109T
• Red Rose – short-range, battlefield nuclear missile for the British Army – English Electric – later known as Blue Water; cancelled 1962
• – the AA predictor designed for use with the Green Mace automatic AA gun^[19]
• – experimental side-looking radar for V bombers
• Red Shoes – see English Electric Thunderbird
• Red Shrimp – ARI 18076 airborne high-band jammer fitted to Victor & Vulcan
• Red Snow – nuclear weapon physics package – fitted to Yellow Sun Mk2 and Blue Steel
• Red Steer – EKCO ARI 5919/ARI 5952 airborne tail warning radar – development of AI 20 Green Willow – fitted to Victor & Vulcan. The name likely refers to Jerry Steer at the RRE.
• – associated with AI 17 radar
• Red Top – air-to-air missile developed from the Firestreak Mk 4
• – phase coherent radar Moving Target Indicator (MTI)
• Red Vulcan – flamethrower fuel mixture

Violet[]

• – infrared seeker for Red Top
• Violet Club – nuclear weapon
• Violet Friend – simple ABM system ordered under AST.1135.
• – truck-mounted nuclear land mine – formerly Blue Badger. Used the Red Beard physics package.
• – UHF Homer, built by Plessey – Fitted to many RAF aircraft.^[20]
• – nuclear warhead for Corporal missile – based on Red Beard

Yellow[]

• – nuclear artillery shell warhead
• – H2S Mk 9A bombing radar, fitted to V bombers
• – radar warning receiver
• Yellow Duckling – infra-red submarine detector
• – missile seeker
• Yellow Fever – fire control system for the Bofors L/70 anti-aircraft gun, comprising a Blue Diamond radar and a Red Indian analogue computer
• – Loral ESM for E-3D Sentry and Nimrod MR.2
• – Orange Pippin's radar component
• – Doppler-navigation system for naval aircraft. Valve-based precursor to the transistorised Blue Jacket.^[21]
• – mobile tactical control radar for Bristol Bloodhound – a.k.a. AMES Type 83
• – anti-ship missile, possibly a precursor to Green Cheese
• Yellow Sun – nuclear weapon casing
• – nuclear-armed SAGW development of Red Shoes
• – Target illuminating radar used with the Thunderbird missile.
• Yellow Veil – ALQ-167 pod for Royal Navy Lynx.

Non-Rainbow codes[]

Several British military related terms have a similar "colour" format to Rainbow Codes, but are not since they do not refer to classified research projects, and some names have been used unofficially. These include:

• Black Banana – unofficial nickname for the Blackburn Buccaneer, originally named the Blackburn ANA (Blackburn Advanced Naval Aircraft).
• Black Beacon – The Orfordness Rotating Wireless Beacon, known simply as the Orfordness Beacon or sometimes the Black Beacon, was an early radio navigation system
• Blue Circle – sardonic name for concrete ballast for Buccaneer while awaiting Blue Parrot radar. Also used for Sea Harrier ballast in place of Blue Fox radar, and Tornado F.2 ballast. From the Blue Circle cement company.
• Blue Eric – improvised I band ECM jammer against the Fledermaus gun control radar during the Falklands War. Installed in the Harrier GR.3's starboard 30mm gun pod.^[22][23]
• Blue Yeoman – unofficial name for an experimental radar made from components of the Blue Riband and Orange Yeoman
• Green Goddess – colloquial name for Civil Defence fire pump
• – a 'spoof' SAM programme reported in the 1976 ^[24]
• Green Parrot – unconfirmed low yield nuclear weapon mentioned in a 1981 New Statesman article by Duncan Campbell^[25] who later claimed that it was "probably" a copy of the US B57 nuclear bomb.^[26] The WE.177 has incorrectly been referred to as the Green Parrot by some authors. However Green Parrot was a NATO codename for the Soviet PFM-1 anti-infantry mine. Green Parrot was also the term for an admiral's barge, traditionally with a green-painted hull.
• – RAF aircrew nickname for green-tinted H2S bombing radar display PPI image in Valiant, Victor & Vulcan
• Red Arrows – RAF display team
• Red Devils – Parachute Regiment display team
• Red Slab – joke name for a large ballast weight replacing the nose radar in Avro Vulcan XH558 in its return to flight as a civil display aircraft.
• – Ultraviolet light fire detection system for Concorde engine bays.^[27]

See also[]

• British military aircraft designation systems
• Nuclear weapons and the United Kingdom
• Rainbow Herbicides

References[]

Notes

Bibliography

• Public Record Office, London. TNA AIR 2/17322 E51B (a)
• Vulcan's Hammer: V-Force Aircraft and Weapons Projects Since 1945 – Chris Gibson – 2011 – ISBN 978-1-902109-17-6

External links[]

• British nuclear weapon history