Dr John Harold ‘Jack’ Plumb

Plumb was recruited directly to Bletchley Park from Christ’s College, Cambridge, in December 1940.
He was to be a key member of the Block B Naval Section and Head of a crypto/intelligence party dealing initially with German and Italian intelligence and later Japanese. He was appointed as Head of the Japanese Naval Traffic Analysis (TA) Sub-Section and subsequently the Head of Naval Section XI (the Crypto/Intelligence Section), from late 1943. He famously refused to fly to Washington on an official visit in January 1945. As a result he was then sent, with Gerald Godley, on the Queen Mary to New York to visit the BSC (British Security Coordination) in New York, OP-20-G in Washington and then on to Ottawa in February 1945.

In 1945 Plumb visited HMS Anderson in Colombo (Sri Lanka/Ceylon), before going on to Kandy and Delhi. On his return he replaced Harry Hinsley as the Naval Section ISO (Intelligence Staff Officer). He represented BP Naval Section on the TICOM Captured Documents Committee in June 1945. He was later appointed to the Committee in August 1945 tasked with the production of the official BP history. Plumb would write the section on Traffic Analysis with Major CHB Wills of SIXTA.

After the War Plumb returned to the familiar grounds of Christ’s College, Cambridge, where he became a Fellow in 1946. Plumb is remembered as the eminent historian and author that he was, who rose to the Professorship of Modern English at Cambridge. He was renowned for a ‘waspish tongue and taste for high living’ and was hugely popular with his students. He was knighted in 1982 and died on the 21st October 2001, aged 90.