Corgi AA39401 RAF Vickers Valiant B Mk1 Strategic Bomber - XD818, Operation Grapple, Christmas Island, 1957 (1:144 Scale)
"In the future, war will be waged essentially against the unarmed populations of the cities and great industrial centers."
- Italian General Giulio Douhet
The Vickers-Armstrongs Valiant was a British four-jet bomber, once part of the Royal Air Force's V bomber force. The Valiant was originally developed for use as high-level strategic bomber. When the other V-bombers came into use it was also used as a tanker. However, when the RAF moved to low-level attacks, low-level flying in the Valiant, along with the choice of an inappropriate type of aluminum alloy used for the manufacture of the wing spar attachment castings, caused premature fatiguing with inter-crystalline corrosion. Rather than repair or rebuild the fleet, it was grounded and the Handley Page Victor took over the tanker role.
The Valiant was a conservative design, with a shoulder-mounted wing and four Avon RA.3 turbojets, each of 6,500 lbf (29 kN) thrust, two in each wing root. The design gave an overall impression of a plain and clean aircraft with simple aerodynamics. George Edwards described it appropriately as an "unfunny" aircraft.
The root chord thickness ratio (ratio of wing thickness to length at the root) was 12% and allowed the Avon engines to be within the wing rather than on pods as in the contemporary Boeing B-47. This "buried engine" fit contributed to the aircraft's aerodynamic cleanliness. However, it made engine access for maintenance and repair difficult and increased the risk that the failure of one engine would contribute to the failure of its pair due to flying debris such as turbine blades. It also increased the complexity of the design of the main spar which had to be routed round the engines. For these reasons the buried engine layout is not used nowadays and the podded layout pioneered by the Boeing B-47 is often employed. This also has the advantage of reducing wing root bending moment in flight because the podded engines can be mounted more outboard than in the "buried engine" layout (or engines mounted on the fuselage, for that matter).
The Valiant wing had a "compound sweep" configuration, devised by Vickers aerodynamicist Elfyn Richards. It had a 45 angle of sweep back in the inner third of the wing, reducing to an angle of about 24 at the tips. This was because the thickness/chord ratio could be reduced closer to the tips, balancing this against the sweep reduction in postponement of Mach effects such as buffeting and drag rise. Limiting in-service speed was Mach 0.82 and a typical cruise of Mach 0.76 at heights up to 55,000 ft when light. A "clean" Valiant (one without underwing tanks) could climb straight to 50,000 ft after takeoff unless it had heavy stores in the large bomb bay.
The engine inlets were long rectangular slots in the first prototype, but later Valiants featured oval or "spectacle" shaped inlets to permit greater airflow for more powerful Avon engine variants. The jet exhausts emerged from fairings above the trailing edge of the wings. Water injection was fitted to some Valiants, for instance those in the tanker role, and increased takeoff thrust by about 1,000 lb (450 kg) per engine. The tail surfaces were swept back, and the horizontal tailplane was mounted well up the vertical fin to keep it clear of the engines' exhaust.
The wing loading was low by modern standards and the Valiant was fitted with double-slotted flaps for takeoff (20 flap) and landing (40 or full flap, about 60). The aircraft featured tricycle landing gear, with twin-wheel nose gear and tandem-wheel main gear retracting outward into the wing. Most of the aircraft's systems were electric including flaps and undercarriage.
Pictured here is a 1:144 scale replica of a RAF Vickers Valiant B Mk1 strategic bomber that participated in Operation Grapple over Christmas Island during 1957.
Wingspan: 9-1/2 inches
Length: 9 inches
Release Date: July 2011
Historical Account: "Operation Grapple" - Operation Grapple, and operations Grapple X, Grapple Y and Grapple Z, were the names of British nuclear tests of the hydrogen bomb. They were held 1956-1958 at Malden Island and Christmas Island in the central Pacific Ocean. Nine nuclear detonations took place during the trials, resulting in Britain becoming a thermonuclear power. All of the bombs were exploded in the air, rather than on the surface, to reduce the effects of fallout.
Untested and unproven thermonuclear designs being developed at Britain's nuclear weapons research establishment, the AWRE, required proof testing, so Grapple was conducted as a massive tri-service operation, the largest of its kind since World War II. Initial preparation for the operation, including establishing necessary infrastructure on Christmas Island, began at the end of May 1956. About 1,200 civilian and military personnel were stationed on Christmas Island during that year.
Initial landings were from the Bibby Line troopship Devonshire which had sailed from the Far East and embarked servicemen at Suva, Fiji, who had been flown from the United Kingdom by commercial airlines. From early October, following the rebuilding of the island's main runway, the majority of arrivals were directly from the United Kingdom, via Hawaii, using Qantas chartered Super Constellation aircraft. Departures of the first arrivals started in early June 1957, using the same Qantas arrangement to Hawaii.
While Christmas was the main base, three other locations featured as key elements of the operation. Malden Island, about 200 miles south of Christmas Island was the site for the air-dropped tests, and Penrhyn Island, a further 200 miles south was used as a monitoring site and weather station. Air support for the operation was generally routed through Hickam Air Base on the Hawaiian Islands to the north, where a support group was located.
Supplies for the island were shipped primarily from the southern hemisphere - Australia and New Zealand, by freighters of the Royal Fleet Auxiliary (RFA). The Royal Navy established a water processing plant early in the operation, which provided adequate supplies of drinking water and semi-salt water for showering.