The design limitations of the three "Centaur"-class carriers completed in 1953-4 meant that a rebuild to the standard adopted for the other carriers would be difficult, if not impossible. A particular problem was the lack of hangar deck strength, which when the ships were ordered in 1943, was specified to handle aircraft. A fully loaded Sea Vixen FAW1 could weigh up to and the Scimitar up to . This would mean that in operation these aircraft would have to be armed and fuelled on the flight deck. Nonetheless, no other hulls were available, and given the potential "gap", a quick solution was needed. It was therefore decided that one "Centaur"-class would be given a limited modernisation, to give her the minimum capability to operate these aircraft. "Centaur" herself was selected for this purpose in May 1956.