Red Beard was the first British tactical nuclear weapon. It was carried by the English Electric Canberra and the V bombers of the Royal Air Force, and by the Blackburn Buccaneers, Sea Vixens and Supermarine Scimitars of the Royal Navy's Fleet Air Arm. Developed to Operational Requirement 1127 (OR.1127), it entered service in 1962 and was withdrawn in 1971.
Its measurements were 3.66 m (12 ft) in length, 0.71 m (28 in) in diameter and with a weight of approximately 1,750 lb (794 kg). Two versions were produced: the Mk 1, with a yield of 15 kilotons, and the Mk 2, with a yield of 25 kT. The Mk.2 was available in two variants, the No.1 used by high-altitude bombers, and the No.2 variant that was intended for low-level delivery by the Toss bombing method, and its "over-the-shoulder" variant referred to as the Low-Alititude-Bombing-System (LABS).
Red Beard's RAF and Royal Navy service designations were:
Weighing in at approximately 1,750 lb (794 kg), Red Beard was considerably lighter than the official service designation, which was based on the original technical requirement.
A significant improvement on Red Beard's predecessor, Blue Danube, was in the provision of electrical power for the bomb firing mechanism and the radar (altimeter) fuzing. Blue Danube had used 6 volt dc lead-acid accumulators that were unreliable and had to be installed at the last minute before take-off. There were also potential risks associated with "stray" electrical discharges to the firing mechanisms which might have led to accidental detonation. Red Beard used twin ram-air turbines located in the nose, from which there could be no stray discharges before bomb release. The air inlet can be seen in the extreme nose. They exhausted through "blow-out" patches in the nose sides. Until bomb release, the weapon drew electrical power from the aircraft for heating and pre-heating of the radar fuzes.
Like Blue Danube, the body diameter at 28 in (0.71 m) was greater than was desirable relative to the overall length of 12 ft (3.66 m). To compensate for this stubbiness, and quickly stabilize the bomb after release, Red Beard was equipped with flip-out fins that were activated pneumatically, triggered by a lanyard attached to the aircraft.
As with Blue Danube, the fuzing arrangements were composed of twin radar fuzes that were activated by a barometric "gate" after release. The barometric gate ensured that the radar fuzes were switched on in the last few seconds of free-fall to a computed burst height, and this technique minimised the possibility of radar countermeasures disabling the radar fuzes. There were back-up contact and graze fuzes to ensure bomb destruction in the event of a misfire.
None of the variants were capable of being armed in flight - "In Flight Insertion" (IFI) of the fissile core. The core was loaded while on the ground; inserted before take-off in a process referred to as Last Minute Loading (LML). For carrier-borne aircraft, landing with the armed weapon was forbidden and the aircraft would instead be diverted to a shore-base. Although the Royal Navy required its Sea Vixen aircraft to be type-approved for Red Beard carriage as "insurance" against delays in Buccaneer development, the Sea Vixen never needed to be deployed in the nuclear strike role. Early models were subject to severe environmental limitations, especially when loaded into Royal Navy Scimitars on exposed aircraft carrier decks in Northern waters. The Mk.2 variants were better engineered to withstand extreme conditions, and other than the yield difference, this was the main area of difference.
Not generally realised, is the fact that when delivered by low-level toss bombing, the aircraft was almost always at a lower altitude than the burst height; so in effect, the bomb was not really "dropped", but was released and "flew" upwards in a ballistic trajectory, to detonate when it reached the required altitude.
RAF stocks of Red Beard for the Canberra and V-bomber forces totalled 110. Of these, 48 were stockpiled in Cyprus to meet the UK's commitments to CENTO, 48 were stockpiled in Singapore to meet commitments to SEATO, and the remainder were located in the UK. Royal Navy stocks are believed, from archived declassified documents, to total 35 weapons to be shared between five aircraft carriers and shore-based supply and overhaul infrastructure. The carriers were thought (from similar sources) to each have an air-conditioned storage capacity for five Red Beard weapons.
Before the Red Beard codename was issued in 1952, it was frequently referred to in official documents as the "Javelin Bomb", because it was originally conceived as a weapon for the "thin-wing Javelin bomber", a projected derivative of the (thick wing) Gloster Javelin all-weather fighter. The designation "Target Marker Bomb" was a euphemism used to disguise the nature of the bomb, so that its dimensions and weights, etc could be circulated to aircraft, and aircraft equipment designers without compromising security.
It was replaced by WE.177 in the early 1970s.