In the week that Enigma, the film version of events at Bletchley Park during World War Two, comes to Pembrokeshires cinemas, one Thornton resident has his own memories of the code-breaking effort. Jim Jarman served in the Special Wireless Service of the Royal Corp of Signals between 1942 and 1947.

Known as the wire service, the SWS was charged with intercepting enemy radio signals and passing on the radio traffic to code-breakers at Bletchley Park.

Jim, the son of a Metropolitan policeman, was born in Haverfordwest, but moved to London when he was two. He lived in London until 1940, when, at the age of 16, he was evacuated back to Haverfordwest. Two years later, he was called up for military service.

After special operations training on the Isle of Man, Jim was stationed at Bishops Waltham where he monitored transmissions from directly across the English Channel.

The Bishops Waltham field unit was one of several along the south-east coast of England.

The units operated in four-wheel-drive vehicles, each containing six wireless operators.

The men slept ten to a tent and worked eight hours on, eight hours off, with some small relief being provided by cups of tea in Bishops Waltham Town Hall.

Information passed from the field units to Bletchley Park formed the basis of the code-breaking attempts.

Even after the enigma code was broken, the field units had to listen for call-signs which would change at the start of every month.

The radio traffic monitored by Jim and his team included messages from three Panzer tank divisions around Paris.

Jim said: We had been intercepting radio messages 12 months before D-Day and by the time of the invasion, we knew where each section of enemy troops was.

Life in the field unit was not without its share of danger.

The first V1 missile (or doodlebug) Jim saw, on a June evening in 1944, was very nearly his last. Jim was on guard duty as orderly corporal, casting a watchful eye over soldiers returning to camp from the village, when the doodlebug came in.

Jim said: An anti-aircraft gun crew down the road were taken by surprise and opened fire after it had passed them. They must have hit it and it came down straight towards us, landing in the middle of the field.

Jim threw himself to the ground as the bomb exploded but was still showered in red-hot shrapnel. When he got up, he saw tents and bodies strewn around the camp. His battledress was burned by the shrapnel and his epaulet severed in two.

Jim accompanied the 17 wounded men to hospital before resuming his watch. When he looked at the crater the next day, he saw he had been just 25 yards away from where the bomb landed.After the war ended, Jim remained at Bishops Waltham for another two years before being stationed in Austria, where he spent most of his time keeping an eye on Tito.

Jim (centre back) with the rest of his team while stationed at Bishops Waltham.