Thanks to the Hollywood film, most of us are well aware of the Great Escape - the daring attempt by allied prisoners of war to flee Stalag Luft III.

To mark the 70th anniversary of the breakout, here are some facts about the bid for freedom that might have escaped your attention.

The scarred skier

Squadron Leader Roger Bushell (right) pictured with Wing Commander Bob Tuck

The main architect of the escape plan was Squadron Leader Roger Bushell, upon whom the film character of Bartlett, played in the film by by Richard Attenborough, was based. 

Although he was Cambridge-educated and had British parents, Bushell (picture above, on right) was actually born and brought up in South Africa.

An excellent skier, he once had a black run in St Moritz named after him in recognition of his alpine feats. Indeed, the facial scar Attenborough sports in the film was based upon Bushell’s own, which was caused by a skiing accident in Canada.

Bushell was shot down in his squadron’s first engagement with enemy aircraft in May 1940. He was one of the first out of the tunnel on the night of March 24-25, 1944, but he was recaptured just hours later and executed by the Gestapo.

Don't mention the tunnels

The three escape tunnels dug were named Tom, Dick, and Harry for the sake of secrecy.

Bushell was so strict about this that he threatened to court-martial anyone who uttered the word ‘tunnel’ aloud.

Remarkable feats of construction under the circumstances, each was dug down 30 feet underground to avoid the seismograph equipment set up by the Germans to detect tunnelling.

The tunnels were just two-feet square for the most part, although larger ‘staging post’ chambers were built along their length in order to prevent large amounts of dug earth having to be moved too far.

The deployment of 'penguins'

Stalag Luft III - Imperial War Museum

The film accurately depicts the dispersal of the dug-up sand and earth using a method invented by Lieutenant Commander Peter Fanshawe.

POWs nicknamed ‘penguins’ would carry the dirt into the prison compound in sacks down each trouser leg, then release it using drawstrings in their pockets, while other POWs followed them to mix the earth into the compound’s top soil.

According to Pilot Officer Jimmy James, 130 tons of sand were dispersed in this way in the summer of 1943 by around 200 ‘penguins’ making over 25,000 trips.

Tom peeped

With news that the camp's  American POWs were to be moved to another compound, work on Tom was intensified so that they would have a chance to take part in the escape.

The heightened activity aroused German suspicions, and Tom was discovered in September 1943.

Dynamite was used to blow up the tunnel - but the show of force backfired on the Nazis. A nearby guard tower sank into the hole created by the blast, giving the prisoners some comfort in that so much of the guards’ time had to be taken up in repairing it.

Over the wire

The film’s depiction of the death of one of the prisoners, who cracked and tried to leap over the prison fence after Tom was discovered, is based on fact.

A POW named Jimmy Kiddel announced, as he had on previous occasions, that he was going over the wire.

This time, however, he meant it. He attempted to climb the perimeter fence, ignoring warnings from the guards, and was shot to death.

According to other prisoners, a near-riot ensued when the prisoners were not allowed near the body after it was cut down from the wire.

A staged breakout

The ‘penguin’ system ran into difficulty due to the fact that the winter of 1943/44 was the coldest in 30 years, and the ice and snow meant that an alternative system of earth dispersal had to be established.

Remarkably, the Germans had allowed the construction of a “very fine” theatre in the camp, with a proper stage and auditorium that held around 300 people.

It was realised that there was a large area under the auditorium that could be accessed in secret after dark - the dug-up sand and earth was transferred here.

Wrong pick

By February 1944, with Harry close to completion, the Germans running the camp became suspicious that an escape attempt was in the offing.

They duly selected 19 men believed to be ring-leaders and moved them on to another camp.

Roger Bushell, despite his record, was not among them, and according to those who took part no more than six of those selected were major participants in the escape plan.

It is estimated that of the 1,500 men in the camp’s north compound, only 600 were involved with the escape.

The chosen ones

Former prisoners of Stalag Luft III visit the site in 2009

Of those 600, there were only resources enough for around 200 to escape (not the 250 claimed by the film). 

A group of around 30 prisoners were specially selected as having a stronger chance of getting to neutral territory by dint of their language skills or other abilities.

Another 70 were next in line after consideration was given to how much work they had put into the plan.

The rest of the would-be escapees, who were thought unlikely to succeed, had to draw lots.

Contrary to the film’s depiction, no American POWs took part as they had already been moved to another compound.

Last-minute hitches

Four factors held up the escape on 24-25 March 1944.

Firstly, the exit ‘trap’ at the far end of the tunnel had iced over in the cold, and it took an hour and a half to free.

Second, the exit was discovered to be some 20-to-30 feet short of the woods, meaning that a warning system (as seen in the film) had to be set up to prevent detection.

Thirdly, a tunnel support was knocked out and had to be shored up.

Finally, an air raid on Berlin meant all power was cut, leaving the tunnel in darkness until lamps were lit. As a result the main escape did not commence until well after 1am on March 25.

War crimes

A total of 76 men escaped from the tunnel before it was discovered at 4.55am.

Due to bad luck and poor weather, most were unable to get far and 73 were recaptured, mostly within days.

Hitler furiously decreed that they should all be shot, but some of his high-ranking officers protested that this would be against the Geneva Convention and clearly seen as murder.

Hitler therefore ordered Himmler to execute "more than half" of the escapees in ones and twos, on the pretext of “resisting recapture”. He reasoned that this way it could not simply be seen as a mass slaughter of the prisoners involved.

A bloody cost

Stone marking the spot where the 'Harry' tunnel emerged beyond the wire.

Eventually, 50 of the escapees were executed - 22 Britons (including Bushell), six Canadians, six Poles, four Australians, three South Africans, two Norwegians, two New Zealanders, and a man each from Belgium, Czechoslovakia, France, Greece, and Lithuania.

All but seven were airmen of the RAF. 

After the war, the Special Investigation branch of the RAF Police identified 72 Nazis that they deemed guilty of the killings - 38 of these were eventually tried, 17 sentenced to imprisonment, and 21 were executed, including Wilhelm Keitel, Supreme Command of the Armed Forces of Nazi Germany and Hitler's de facto war minister.