The papers consist of memoranda and letters relating to the reorganization of the Royal Naval Corps of Constructors, 1945 to 1947, appointment diaries, 1951 and 1952, and many programmes, invitations, photographs and details of honours relating to the latter part of Lillicrap's career.

Administrative / biographical background
Lillicrap became a shipwright apprentice at Devonport in 1902. After a time at Keyham and Greenwich he was appointed Assistant Constructor at Devonport in 1910. He then joined the Director of Naval Construction's department at the Admiralty, where he was made Acting Constructor in 1917. Lillicrap was appointed Lecturer in Naval Architecture to Probationary Assistant Constructors at the Royal Naval College, Greenwich, in 1921 and became Constructor, Director of Naval Construction Department, in 1922. He was Acting Assistant Director of Naval Construction, in charge of submarines from 1936, and Assistant Director of Naval Construction in charge of cruisers from 1938. In 1941 he was appointed Deputy Director, and in 1944, Director, of Naval Construction, a post he held until his retirement in 1951.