Tapping Hitler's Generals

CSDIC (UK) decided against interrogating von Thoma and Crüwell, believing that the men were not in a frame of mind to divulge information. Instead, immediately after their arrival in England, they were brought to Trent Park in order that their conversations could be eavesdropped. Initially a German ‘stool pigeon’ was used ‘very successfully’ as a prompt[39] after which an even better strategy was found in having Lord Aberfeldy[40] live in the camp with the generals from December 1942. He acted as interpreter and his role was ostensibly to see to the comforts and wishes of the prisoners, accompanying them on long walks, making purchases on their behalf in London and always being on hand as a generally valued conversational partner. Very soon he had gained the trust of most prisoners, none of whom suspected that he might be anything other than a ‘welfare officer’. In reality, Aberfeldy worked for MI19, his job being to steer conversations along the lines desired by British Intelligence. A protocol (Document 147) of a conversation immediately after 20 July 1944 demonstrates that the German generals were not inhibited by his presence, a fact which enabled him to gather important information beyond the range of the microphones. A similar ‘trusted man’ had also inveigled himself with the Italians.[41]

Some of the generals captured in Tunisia were questioned before being brought to Trent Park. Confronting them with the usual system of intelligence gathering, it was hoped that they would discount the possibility of secret microphones at Trent Park–a hope fully realised. A number of generals did answer questions under direct interrogation, especially shortly before the war’s end. All generals captured from the summer of 1944 onwards were held for a few days at Wilton Park, or exceptionally Latimer House, before being transferred en bloc to Trent Park.

At Trent Park 12 rooms were bugged including the common room. Latimer House and Wilton Park each had 30 bugged rooms and six interrogation rooms equipped with microphones. At the earphones were mainly German and Austrian exiles.[42] As soon as something important was said a gramophone recording was started. A recording would last seven minutes. A long, interesting conversation would therefore be ‘apportioned’ over several records. Thus for example the first conversation between generals Crüwell and von Thoma on the evening of 20 November 1942 was documented in 27 parts.[43] From these records a protocol in German language was prepared. The average consolidated recording lasted 90 minutes although some were substantially longer. The most experienced member of the monitoring team would then read through the transcript and hear the record again where a part of the text was doubtful. Ambiguous words or passages of text would be indicated by editorial marks. Following the translation of the protocol into English the manuscript would be sent to MI19 at the War Office and the intelligence departments of the Admiralty and Air Ministry. After two months the records would be returned to the Post Office research unit for erasure but recordings of special interest, mainly in respect of war crimes, were kept.

The interrogation centre had begun with a modest staff of specially trained monitoring officers who worked in the so-called M-Room. When Trent Park began work in December 1939, a staff of six listened-in to conversations. With the increase to three camps, and these were occasionally bursting at the seams, the M-Room staffing levels expanded and by 1944 had risen to a complement of 100. It was no easy matter to find qualified operatives. British people, even those with very good German language skills, were unsuited to the work, and even many persons with German as their mother tongue failed to meet requirements. To resolve this problem it was decided at the end of 1942 to employ exclusively German and Austrian exiles for the task. A three-month training period was found necessary to familiarise candidates with military vernacular and to help them develop a feeling for conversations which ought to be recorded.[44] Only political and military matters were considered relevant. Talk about the weather and the food, or intimate matters personal to the speaker, were not wanted.

Life in Trent Park