In 1937 the Astronomer Royal, H. Spencer Jones (later Sir Harold), once again became responsible for overseeing the work of the Office. The Admiralty took this decision, I have been lead to believe, due to the sudden departure of Comrie and the appointment of a very young Sadler.
At the start of the war, in 1939, the office was evacuated to Bath, to Laggan, College Road, and then in 1941 to Ensleigh Hutments, Lansdowne. The Hydrographic Office compilers were also moved here.
HMNAO was one of the first departments of the renamed Royal Greenwich Observatory (from Royal Observatory) to move to Herstmonceux Castle in Sussex. In October 1949 the staff moved into the temporary huts that stood on the South Courtyard. Shortly afterward the office acquired its own punch-card machines, whereas previously it had used machines at other establishments; at that time the rest of the Observatory was still using Crelle's Tables and other such aids for data rseductions.
In 1959 the Office obtained its own electronic computer, making it the first part of the Royal Greenwich Observatory to use this emerging technology.