The Vickers "Valiant" was part of the ultra-critical "V-bomber" force for the Royal Air Force, Britain's airborne nuclear-capable deterrent operated during the Cold War (1947-1991) arranged from the Valiant, the Avro "Vulcan", and the Handley Page "Victor". The three originated from advanced design studies tracing their roots to the final years of World War 2 (1939-1945) when it was becoming clear that turbojet technology, coupled with swept-back wing mainplanes, were the future of aerial combat. In time, these qualities were transferred from smaller, compact fighter and interceptor types to larger, highly-capable bomber forms.
The nuclear-capable, subsonic-speed Valiant was produced in only 107 total examples from 1951 until 1957. Series introduction occurred in 1955 and the line remained an active component of the RAF into January of 1965 at which point the fleet was retired from frontline service as bombers.
Before its retirement, this same aircraft formed the basis of a proposed low-altitude bomber project in the Vickers Valiant "Low-Level Bomber" (LLB), the initiative attempting to add a low-level bombing capability to increase the aircraft's tactical viability over the battlefield. The large aircraft could now be expected to fly closer to the terrain into, and across, enemy territory with the hope that the bomber would "sneak" in beneath the search-and-tracking capabilities of Soviet ground-based radar systems - all the while retaining a useful conventional and nuclear war load capability.
The proposed Valiant Mk.2 production model was to have been a refined version of the original Mk.1 offering but, unlike the Vulcan and Victor, it was not accepted and furthered by the Air Ministry. Nevertheless, the Mk.2 was selected as the starting point for the proposed LLB, retaining much of its form-and-function including a four-engined configuration (these units buried in the wing roots), swept-back wing mainplanes, and an internal war load consisting of drop bombs. The mainplanes were slightly adjusted through additional sweepback (reducing span) for the high-speed, supersonic flying envelope while the fuselage was to receive a lengthening of about 10 feet to accommodate additional fuel stores which, in turn, were to help increase the bomber's inherent operational range. Rounding out the major structural changes was a revised, larger-area tail unit to better compensate for the higher speeds at play.
The main legs of the tricycle undercarriage were to recessed into conformal nacelles located at the trailing edges of the wing mainplanes. Under the wingtips would have been integrated fuel tanks to benefit range.
With the four-engined arrangement outputting between 36,000lb and 48,000lb of combined thrust, the bomber was estimated with a top speed reaching between 600 and 650 miles-per-hour. Due to its excessive take-off weight under full war loads, the bomber was to receive air-to-air refueling as soon as it reached altitude. Once topped off for the mission, the bomber could then range out to some 5,000 miles to deliver its pay load. The bomb load, held entirely internally, was estimated at 10,000lb and this to comprise multiple 1,000lb bombs or a single 10,000lb nuclear-tipped drop munition. Gross weight was to reach 306,000lb.
Other facets of the bomber, as penciled out, included an overall length of 124.5 feet with a wingspan of 81 feet.
Beyond some preliminary work in 1952, the Vickers LLB was not evolved. There were other attempts to make the Valiant something more than the original was but these too fell to naught. Similarly, the Vulcan and Victor both went through design studies of which little came from - resulting in many "paper" aircraft based around this trio of classic airplanes.