Blue Steel missile

From Wikipedia, the free encyclopedia

Blue Steel
History

Type	Nuclear stand-off missile
Nationality	UK
Era	Cold War
Launch platform	Aircraft
Target
Builder	Avro
Date of design
Production period
Service duration	1963-1970
Operators	UK RAF
Variants	One/mod for low-level delivery
Number built	53 operational live rounds
Specifications
Type
Diameter	1.22 m (48 in) minimum
Wing span	4 m (13 ft)
Length	10.7 m (35 ft)
Weight	7,270 kg (16,000 lb)
Propulsion	Liquid fuel rocket
Steering
Guidance	Inertial
Speed	Mach 2.3
Range	240 km (150 miles)
Ceiling	21,500 m (70,500 ft)
Payload
Warhead	Red Snow (W-28) thermonuclear (1.1 MT)
Trigger	{{{fuze}}}

Blue Steel was a United Kingdom air-launched, rocket-propelled nuclear stand-off missile, built to arm the V bomber force.

1 Development
2 Specifications
3 Related content
4 External links

[edit] Development

Blue Steel was the result of a Ministry of Supply memorandum from 5 November 1954 that predicted that by 1960 Soviet air defenses would make it prohibitively dangerous for V bombers to attack with nuclear gravity bombs. The answer was for a rocket-powered, supersonic missile capable of carrying a large nuclear (or projected thermonuclear) warhead with a range of at least 50 miles (90 km). This would keep the bombers out of range of Soviet ground-based defenses installed around the target area, allowing the warhead to "dash" in at high speed.

The weapon (officially termed a Stand-off bomb) was developed primarily by Avro, with guidance electronics by Elliots. Its design period was protracted, with various development problems exacerbated by the fact that designers were handicapped by a dearth of information about the actual size and weight of the proposed boosted-fission warhead Green Bamboo, or its likely thermonuclear successor derived from the Granite series. The large girth of Blue Steel was determined by the 45 inches implosion sphere diameter of Green Bamboo. As it turned out, neither of these warheads were actually fitted, being superseded by Red Snow, an anglicised variant of the U.S. W-28 thermonuclear warhead of 1.1 Mt yield. Red Snow was smaller and lighter than the earlier warhead proposals. The missile was fitted with a, at the time, state-of-the-art inertial navigation unit. This inertial nav system allowed the missile to strike within 100 metres of its designated target. In addition, the pilots of the carrying Avro Vulcan or Handley Page Victor bombers could tie their systems into those of the missile and make use of the guidance system to help plot their own flight plan, since the unit in the missile was more advanced than that in the aircraft.

Blue Steel emerged as a pilotless, winged aircraft roughly the size of the experimental Saunders-Roe SR.53 interceptor, with clipped delta wings and small canard foreplanes. It was powered by a two-chamber Armstrong Siddeley Stentor Mark 101 rocket engine, burning a combination of hydrogen peroxide and kerosene. This was a considerable operational problem, because fueling the missile before launch took nearly half an hour, and was quite hazardous.

On launch the rocket engine's first chamber would power the missile along a predetermined course to the target at around Mach 1.5. Once close to the target, the second chamber of the engine would accelerate the missile to Mach 3. Over the target the engine would cut out and the missile would free-fall before detonating its warhead as an airburst.

Blue Steel finally entered service in February 1963, being carried by Vulcans and Victors, although its limitations were already apparent. The short range of the missile meant that the V bombers were still vulnerable to enemy SAMs. A replacement for Blue Steel, the Mark 2, was planned with increased range and a ramjet engine but this was cancelled in 1960 to minimise delays to the Mk.1. The UK sought to acquire the much longer-ranged United States Air Force AGM-48 Skybolt air-launched ballistic missile, and was greatly frustrated when that weapon was cancelled in late 1962. With no effective long-range weapon the original Blue Steel served on after a crash programme of minor modifications to permit a low-level launch at 1'000 ft, even though its usefulness in a hot war was likely limited. A stop-gap weapon (WE.177B) was quickly produced to extend the life of the V-bomber force in the strategic role until the Polaris missile was deployed. This WE.177 laydown weapon supplemented the remaining modified Blue Steel missiles using a low-level penetration followed by a pop-up manoeuvre to release the weapon at 1'000 ft. Forty-eight live operational rounds were deployed on 48 Vulcan and Victor bombers plus a further five live rounds as operational spares. An additional four non-nuclear rounds were produced for various RAF requirements, and there were 16 other unspecified training rounds.

Blue Steel officially retired 31 December 1970, with the United Kingdom's strategic nuclear capacity passing to the submarine fleet.