B.1 – The initial production aircraft. First few with straight leading edge, later retrofitted with Phase 2 (kinked) wing. Early examples finished in silver, later changed to “anti-flash” white. Many converted to B.1A standard 1959–1963. Last few unmodified B.1s in RAF service with No. 230 OCU retired by 1966.Last flight by any B.1, an engine testbed XA903, March 1979.
B.1A – The B.1 with an ECM system in a new larger tail cone (as in B.2). Unlike the B.2, the B.1As did not undergo extensive wing strengthening for low-level flying and were withdrawn from service 1966–67.
B.2 – Developed version of the B.1. Larger, thinner wing than the B.1 (Phase 2C wing) and fitted with Olympus 201-202 engines, or Olympus 301 engines. Uprated electrics with AAPP and Ram Air Turbine (RAT). ECM similar to B.1A. TFR in nose thimble radome fitted to most aircraft in mid-60s. New Radar warning receiver aerials on tail fin giving it a square top from the mid-1970s.
B.2 (MRR) – Nine B.2s converted to Maritime Radar Reconnaissance (MRR). TFR deleted. Five aircraft further modified for Air Sampling Role. Distinctive gloss finish with light grey underside.
K.2 – Six B.2s converted for air-to-air refuelling with Mark 17 Hose Drum Unit (HDU) mounted semi-recessed in tail cone. TFR deleted. Fitted with three bomb-bay drum tanks, it was the only mark of Vulcan that could jettison fuel in an emergency.
B.3 – Proposed version intended as a long endurance missile carrier capable of carrying up to six Skybolt missiles on flights of up to 12 hours duration. Never built.