Ministry of Supply The Ministry of Supply ( MoS ) was a department of the UK Government formed in 1939 to co - ordinate the supply of equipment to all three British armed forces , headed by the Minister of Supply . There was , however , a separate ministry responsible for aircraft production and the Admiralty retained responsibilities for supplying the Royal Navy . During the war - years the MoS was based at Shell Mex House in The Strand , London . In 1946 the Ministry of Aircraft Production was abolished and the MoS took over its responsibilities for aircraft . In the same year it also took on increased responsibilities for atomic weapons , including the H - bomb development programme . The Ministry of Supply was abolished in 1959 and its responsibilities were devolved to three single - service ministries . Later , these ministries were to merge to form the Ministry of Defence . The Ministry of Supply instigated the Rainbow Codes designation system . This assigned projects a two - word codename , the first word being a colour and the second a noun . As a result , secret weapon projects — including numerous nuclear weapons — were given lighthearted names such as Green Cheese , Blue Slug or Red Duster . World War II . The Royal Ordnance Factories . The Ministry of Supply was responsible for building and running the Royal Ordnance Factories which produced explosives and propellants ; filled ammunition ; and constructed guns and rifles . However , the Ministry of Works and / or private building contractors acted as agents during their construction . The Ministry was also responsible for the supply of tanks and other armoured fighting vehicles ; however , these were mostly designed and built by private armaments companies , such as William Beardmore and Company and Vickers , as well as other engineering companies . Agency factories . The Ministry of Supply also arranged for the construction of a large number of Agency Factories which were run on its behalf by private companies , such as Nobel Industries . These were similar to the Royal Ordnance Factories , but were not part of the Royal Ordnance Factory organisation . Labour supply . The Ministry of Supply was also responsible for the labour force of these factories . Although the Ministry of Labour did the recruitment . From the middle of the war onwards the Ministry of Supply was in direct competition with the Ministry of Aircraft Production for labour and the two organisations had to reach agreement . Towards the end of the war the Ministry of Supply released labour so that they could transfer to the Ministry of Aircraft Production . Post - war Ministry of Supply . Expansion of scope . Following World War II , the post - war Ministry of Supply was created on 1 April 1946 as a result of the amalgamation of the former Ministry of Supply and the Ministry of Aircraft Production . The functions and responsibilities of the new department remained basically the same as its predecessors . Atomic weapons . Later in the same year , the MoS took over the responsibility for atomic weapons research . Lord Portal was appointed as Controller of Production ( Atomic Energy ) ; and the Atomic Weapons Research Establishment ( AWRE ) was set up , with William Penney as its first Director . The atomic energy research function was relinquished in 1954 when the UK Atomic Energy Authority was set up , although the Ministry of Supply retained responsibility for the control of atomic weapons . Reversion to single - service ministries . The Ministry of Supply was wound up in 1959 when the Ministry of Aviation was created , and other functions in respect of British Army and Royal Air Force supply reverted to the War Office and Air Ministry respectively .