Obituary: Ailsa Maxwell, war-time codebreaker at Bletchley Park

Died: February 10, 2020.

AILSA Maxwell, who has died aged 97, was reading economics at Edinburgh University in the summer of 1943 when, out of the blue, she received a letter from the Foreign Office asking her to contact them about a possible job.

At the interview there was no indication what the job was or, as she related to the Bletchley Park Trust in 2013, “its location. Just that it was important and that they thought I might be suitable. I went south for the interview. They asked for references and I gave my next-door neighbour.”

She was told to take the train to Bletchley Park and that someone would meet her on the platform. After two weeks’ training, she was posted to Hut 6. She served in Block D, Machine Room, compiling menus from information acquired in other huts and using an electro-mechanical device known as the Bombe, which deciphered the Germans’ top-secret Enigma code. All the work had to be checked meticulously before the information was passed on to the authorities in London.

The deciphering machinery created at Bletchley meant that Churchill and the War Cabinet often knew of planned German troop movements before the German High Command did. General Eisenhower, Supreme Allied Commander, said after the war that the intelligence at Bletchley “has saved thousands of British and American lives and, in no small way, contributed to the speed with which the enemy was routed and eventually forced to surrender.”

Maxwell and her colleagues’ work in Hut 6 played a vital part in the intelligence gathering and analysis that made the Allies’ victory possible.

Ailsa Maxwell (née Macdonald) was born in Gourock, the daughter of Douglas, a railway manager, and Grace, a teacher. Her father was transferred to Euston, in London, and she was initially educated in London, completing her schooling at Dumfries Academy. Her mother died when she was 14 and Maxwell lived with her aunts in Moniaive, Dumfries and Galloway. She had planned to join the Wrens until the letter from the Foreign Office changed her life.

Her work at Bletchley was intricate and demanding. Alan Turing had developed the Bombe to decrypt Enigma’s secret settings, and Maxwell’s role was to compile Bombe menus from “cribs” and interpret the significance of the settings.

The gathering of clues was a complex and time-consuming business, and the pressure to interpret the signals with absolute accuracy was immense.

In the Bletchley records she explained: “Our main job was, when a stop from the Bombes satisfied the way it had been set up, we then set this up on the Enigma machines to see whether it was right. We didn’t know German, but it was obvious whether what came out was nonsense or made sense.”

They were never told the result of their decoding as they passed the information on to specialists. Maxwell added:“We were told we were breaking codes; people on the Watch were very happy when something was broken.”

One of her closest colleagues was Asa (later Lord) Briggs. They were on overnight duty when the unconditional surrender message from Hitler’s successor, Grand Admiral Dönitz, came through on May 7, 1945.

Her work at Bletchley finished on VE Day and she was not allowed to speak of her war service until 1974. Many former codebreakers at Bletchley were interviewed but Maxwell preferred not to talk. She simply said, “It took a bit longer for me to talk about it.”

She returned to Scotland and completed her degree at Edinburgh. She met her future husband, Stuart Maxwell, on a students’ reading weekend and they married in 1953.

She was attached to the Economic History Department at Edinburgh University and worked on Michael Flinn’s Scottish Population History from the 17th Century to The 1930s.

Maxwell also carried out research with her husband into one of his lifelong interests, the history of Scottish silversmiths and goldsmiths. She also qualified as one of the earliest Samaritans in Scotland.

Her husband, who died in 2012, was deputy keeper at the National Museum of Antiquities of Scotland. Maxwell is survived by their two sons; Ian, the national manager of the charity Shared Parenting Scotland, and Sandy, who works for the John Muir Trust. Sandy told The Herald, “I did not become aware of my mother’s role at Bletchley until relatively recently, following the publication of The Amber Shadows [a 2016 novel] when the author, Lucy Ribchester, talked with Ailsa while doing her research.

“My mother was always very modest about her work during the war. The laborious and painstaking approach to unravelling the coded messages stayed with her during her working career.

"Judith Gillespie, who worked with her on Scotland's Population History, commented that she brought that careful method to her work on Scottish records.”