The two national authorities had overall responsibility for R&D, and Vickers Ltd was the co-ordinating design authority. They were also the design authority for the carriage and Rheinmetall GmbH was the authority for the elevating mass, including the sights, and for the APU. There was a further breakdown at a more detailed level and production worksharing. The UK Royal Armament Research and Development Establishment (RARDE) was responsible for designing the HE projectile and the charge system. Germany was responsible for Smoke, Illuminating, Minelet and extended range HE, although the development of the last two was not completed in the program.