The Aldermaston IBM Stretch, of comparable power to the Ferranti Atlas, arrived in September 1962. It turned out not to be as fast as originally predicted and this was exacerbated by the lack of a Fortran compiler. Alick Glennie wrote the Fortran compiler, S1, by the end of the year. This allowed storage allocation at load time which was necessary for the large simulations being run. Even so, by the end of 1962 Stretch was not performing at full capacity.
Meanwhile, the IBM 7090 moved to Risley to greatly increase the power available to the rest of the AEA.
In December 1962, the Manchester Atlas was commissioned. This was run as a joint service, half available to Ferranti and half to the university. It was a smaller machine than the Chilton Atlas and eventually contributed about 0.4 of an Atlas Unit to the academic community.