Immortalised by the largely fictionalised 1963 Hollywood film starring Steve McQueen and Richard Attenborough, ‘the great escape’ of RAF airmen from the German PoW camp has become the stuff of legend.

But how did 76 men escape via a 100m-long tunnel from a camp built on a site chosen especially to thwart an escape by such means?

Hugh was among a team of experts, archaeologists, veterans and modern-day RAF personnel taken back to the site near Zagan in Poland to excavate for the first time the remains of ‘George’, a tunnel that was in progress when the war ended, and the famous ‘Harry’ tunnel from which the Allied airmen escaped on the moonless night of March 24, 1944.

The results can be seen in ‘Digging the Great Escape’, shown on Channel 4 on Monday evening (November 28) at 9pm. The programme follows last year’s successful attempt by Dr Hunt to recreate 617 Squadron’s Dambusters raid.

Hugh, from Cambridge University’s Engineering Department, said: “Although only a handful of men worked on the tunnel directly, the escape plan involved hundreds of prisoners who never really knew what the plan actually was. It was some people’s job to move bin lids or wear their hat a certain way if a German guard was coming – but they never knew why.

“It took a year to dig the tunnel but for more than 70 years since then, ‘Harry’ and ‘George’ have remained undisturbed – and with them the final secrets of a remarkable story and history.

“We all came away with an appreciation of just how difficult – and dangerous – digging the tunnel must have been. Working with the particular type of sand you find there is very tricky. It’s like making sandcastles on the beach; it’s fine if it’s a bit damp, but it dries out very quickly and then the walls cave in. They also had to dispose of a ton of sand for every metre they tunnelled.”

To make their great escape, the prisoners led by Squadron Leader Roger Bushell, made use of (or stole) 4,000 bed boards, 90 double bunk beds, 635 mattresses, 3,424 towels, thousands of knives, forks and spoons and around 1,400 Klim powdered milk cans – used to engineer an ingenious ventilation system. Some of the original Klim cans used were uncovered in the excavation of the site.

They also forged documents and befriended, bribed or coerced German guards to provide them with the civilian uniforms and train timetables so essential once they reached the other side of the fence.

However, all but three of the escapees were recaptured. Fifty of the 73 recaptured were executed by the Gestapo, including Roger Bushell.

For the return to Stalag Luft III, Dr Hunt was among a team of experts including engineer Lt Col Philip Westwood RE; war historian Dr Howard Tuck, archaeologist Dr Tony Pollard and Hilary Costello, one of his own engineering PhD students from Cambridge..

Among a host of responsibilities, Hugh and Hilary designed the 10m tunnel dug by modern-day RAF pilots, evaluated shoring methods, built the railway track and crafted digging tools and saws fashioned from bits of gramophone players, bunk beds and kit bags.

Interweaving the historical narrative with first-hand testimonies and the unfolding story of the excavations and experiments, the film offers a new insight into the Great Escape, and is a celebration of the courage and ingenuity of a remarkable group of men. The recreation also assembles a remarkable cast of surviving veterans of the escape, including Stanley ‘Gordie’ King, the man who operated the tunnel ventilation system on the night of March 24.

Added Dr Hunt: “What I think we learned from attempting to do something similar ourselves is the magnitude of the task; it’s simply amazing what they achieved given how difficult it was. But talking to some of the people who were involved, we also got a sense of the bravery, camaraderie and fun of it all - despite the fact that the Germans knew they were tunnelling and were looking everywhere for them. In comparison, we had it easy.

“What is astounding is the range of skills that the prisoners had to build the tunnels, ventilate and light them, as well as making compasses, radios, forging documents, heat treating metals, you name it. A lot of these skills have direct links back to engineering and that can hopefully get young people thinking about university studies in engineering – rather than getting an economics degree and going to work in the city.”