A cable from OSS Headquarters in Washington in mid-April 1944 stimulated the establishment of the SUSSEX Plan under the direction of three men, British SIS Commander Kenneth Cohen, American OSS Colonel Francis Pickens-Miller and the Frenchman BCRA operator Gilbert Renault. This was an intelligence operation to drop covert teams into France, North of the Loire Valley between January and September 1944 to spearhead the approach to the OVERLORD plan. It was to become the biggest Intelligence operation of the entire Second World War.
Their mission was succinctly put by Pickens-Miller ‘to secure strategic and tactical intelligence from rear areas.’ At its outset this tripartite venture took some time to cement ‘The British were exceedingly reluctant to enter into such an arrangement. Eventually the British agreed, but it was quite clear that they desired to narrow the scope of such tripartite meetings.’
There were 2 main reasons for it to be established:
1. The fear that gathering of Allied forces for the invasion of Europe, would rapidly increase German security measures in occupied France, where the existing ‘reseaux’ would become immobile, cut off from their communications, or penetrated and dismantled. The Plan would be a form of re-insurance to cover this possibility.
2. It was desirable to organise a chain of agents in certain areas as directed by the intelligence branch of the Combined General Staff, who would be capable of obtaining information of direct interest and value. This would be operational intelligence from the enemy rear areas which could not easily be obtained through normal Army sources.
There were to be a total of 56 SUSSEX teams deployed, involving over 120 volunteers who would receive specialist training by SIS and OSS instructors at Praewood House in St Albans, and a week-long parachute training course at the Ringway school. The RAF dropped 58 of the SUSSEX agents into France during 1944, and the USAF ‘Carpetbaggers’ infiltrated some 48 SUSSEX agents. Many of the Carpetbaggers operations quirkily had names of car manufacturers such as BENTLEY, ELLIS, LINCOLN and PLYMOUTH. The SUSSEX teams would fly out of RAF Harrington or Tempsford airfields after a period at the holding station of Farm Hall, on West Street in Godmanchester.
It was extremely dangerous work. Seven of the teams were caught during their operations and executed. The individuals selected for such an assignment had to be cherry picked for the roles.
The W/T operators for the SUSSEX teams were each supplied with the British Mark 7 or the American TR-1 radio sets and the cipher book, containing a double-transposition cipher with flash code. A flash code acts as a group of numbers which relay to a distinct phrase or word which carries significance. Some of the operators had come from Section VIII of SIS, based out of Whaddon in Buckinghamshire. They were to form up as Special Communications Unit (SCU) 9 and be dropped with the SUSSEX teams.
The Berkshire town of Hurley became integral to the SUSSEX Plan communications. The OSS established a secret communications centre in the town to transmit and receive messages carrying vital intelligence on German military strengths and dispositions, particularly the Panzer divisions. Codenamed Station VICTOR, this acted as the communications hub for the deployed SUSSEX teams.
One of the most famous SUSSEX operations, due to the intelligence they provided to Allied forces, was undertaken by team VITRAIL, which was deployed into Chartres on the 10 April 1944. It was the first deployed SUSSEX team to send messages back to Station VICTOR. Soon after deploying they discovered the location of the Lehr Panzer division in Chartres. SHAEF HQ later commented that this message alone was worth the cost of the whole SUSSEX operational plan.
Another plan conceived by General Colin Gubbins in his role as Head of SOE was to run in parallel with SUSSEX. Operation JEDBURGH would consist of around 70 highly trained special forces soldiers who would be parachuted into France to support the resistance around D-Day in June 1944. They were to be controlled via the JEDBURGH Section in Special Forces Headquarters (SFHQ) in Montagu Mansions, London.