The withdrawal of the Valiant fleet because of metal fatigue in December 1964 meant that the RAF had no front line tanker aircraft, so the B.1/1A aircraft, now judged to be surplus in the strategic bomber role, were refitted for this duty. To get some tankers into service as quickly as possible, six B.1A aircraft were converted to "B(K).1A" standard (later redesignated "B.1A (K2P)"), receiving a two-point system with a hose and drogue carried under each wing, while the bomb bay remained available for weapons. Handley Page worked day and night to convert these six aircraft, with the first being delivered on 28 April 1965, and 55 Squadron becoming operational in the tanker role in August 1965.