While all of this activity was going on above ground many of about 600 officers taking various escape roles would of course be constructing the three tunnels, and then a fourth. And using the very primitive tools they also had to create by hand to get the job done.
As previously mentioned, very earlier in the planning stages it was decided to use the terms TOM, DICK and HARRY, and finally GEORGE, as names for the tunnels. They chose not to us the term tunnel to prevent the guards from catching on from any overheard conversations.
Each of the tunnels was rather long. The very idea of doing three was so that in the event of one being discovered, the enemy would hopefully be dumbfounded with the originality of all the work. The guards would probably not then expect that there was another... and yet a third (and even a fourth) also being constructed at the same time.

There were several compounds in the camp. This is the North one. TOM and DICK were to travel over 250 feet to the west, and end just inside the treeline. (Not shown at right in above sketch.) HARRY would travel northbound and also was planned to end inside the tree line (again not shown) but almost 340 feet away from its start point.
Most of the above ground escape crew did not know the whereabouts of the entry to the tunnels. TOM's was in hut #123 and in a dark corner below a secret trap door built within the four walls of the chimney base. Dick's was most creatively build UNDER a constant pool of water in the washroom area in hut #122. Here the water was constantly pooled from drippings from the shower area. And HARRY's, where the escape of this story took place, was below the stove in hut #104.

The sketch on the left shows the tree line outside the compound and to the left, bottom and right. At the bottom, or north end, the tree line was pushed back further northbound when HARRY was almost completed. So too at the right in this image, or west side when TOM was completed. The image on the right shows the entrance shaft of HARRY in hut #104, and its route northbound to front end of the camp and then beyond the barbed wire obstacles and into the woods beyond. At least that was the plan!
The right image also shows some workspace at the base of HARRY and the other tunnels. Forgers and manufactures worked in these spaces to make their tools etc. The fellow on the left is working the bellows they created to send air into the tunnels.
When the tunnels began they were not secured by being re-enforced on the sides and top, but as the tunnel got longer and longer shoring was needed. For these they "borrowed" bed boards that were all 2 feet long and used these at the sides and top. (They used over 4,000 of these boards and lots of other wood found in support rafters, wall studs, etc in this work.) As they were put in place the men would force loose sand behind them to make a tight and secure wall and ceiling before digging further along the way.
The tunnels were so narrow that only one man could fit into them. But they would be in two man teams. Feet to feet. The first facing the end of the tunnel being worked and the 2nd man facing the entry end. The first would do the digging and push most of the sand past his body and the second would scoop it up and put it into pails or whatever was available for tying up and being hauled out by ropes back at the base of the entry shaft. From there the dispersing teams would pack it for movement above ground and tossed about the camp. Much later a trolley system would be built to haul the sand along a set of runners to the face for unloading. By this means the men could advance about 3 feet a day in each tunnel, and at the same time move about a dozen tonnes of sand DAILY... by hand!
The men also had to work at first in the dark. But soon they would get the manufacturers to make candles out of fat from food supplies and wicks from pajama ropes, and use these to see what they were doing. Later the air became so bad that they had to create the bellows used to pump air along the route and also pull out stale air through another line of KLIM tins.

The security crew would be responsible to control who entered the tunnel and to remove the hidden trap door below the stove, and replace as needed.
They had this refined to such an art that upon notice of an approaching guard the POW's could put the stove back in place and clean up any fallen sand... and do this, remarkably in 20 seconds.
The above right image is of the entry trap door to TOM. Below this is the entry shaft that starts the 30 foot drop to the start of the tunnel. When the tunnel was discovered it was blown up and it is doubtful any of this exists today.

The image on the left is a re-creation of the tunnel done as part of the 50th anniversary of the 1944 escape. It is unknown if the other two are actual photo's, those made for the 1963 movie or yet other celebrations etc. But clearly all show what an incredible cramped space over 1/3rd of the 600 men worked in at some point or other during the construction of these tunnels.

Each tunnel had such a device. By so doing they either pumped air into the Klim can tubing, or pulled stale air out with the opposite stroke. Men would man these constantly when the digging was going on.
In the bottom photo you can see an actual candle holder... a bowl of sorts... that fat would be drained into, a homemade wick put in and lit for tunnel use.
Later, when the POW's and trades people came in to work on the new theatre, two of the POW's scooped over a thousand feet of wiring when the guards were not looking. This was ultimately hung in the tunnels and tapped into the camp power supply and thus, lighting came to the tunnels. Later when the Gestapo started investigating and finding those involved in the loss of the wiring, they learned the men did not report the loss for fear of retaliation. Indeed they had good fears. The Gestapo shot them!

The image on the right is believed to be the actual entrance into tunnel DICK. Not long ago this tunnel was excavated but very quickly closed up again because the sand was so shifting that the workers thought it just too dangerous to continue. These first two shots show the depth the men dug...just to get past the entrance shaft and then start the tunnel out to freedom. The fellow at the left is not a part of the working crew. His is one of the actual former POWs who worked on this tunnel and possible the others as well.
As the three tunnels were being pushed forward, more and more American airmen were being shot down and eventually ending up at Stalag Loft lll. It was only a matter of time before the Germans decided that they ought to open up another compound for the every increasing numbers, dedicate to the Americans, and move all Yanks out of the north compound and into the new facility. Rumors of this caused horror within the north compound were so many of the Americans had worked on TOM and played support roles for so many other escape duties above and below ground as well.
It was felt by many that with the relocation they would not be able to participate in the escape and so all work on DICK and HARRY was suspended and TOM became the hub of activity. This of course resulted in far more sand being brought to the surface from that area. And with this it was only a matter of time before one of the dispersing crew was discovered droping the sand at the surface. The guards then started a massive hunt for a tunnel.
With long metal probes many a guard would wonder about prodding the ground, of course not realizing that any probe led than 30 ft. would find nothing. But in one of the searches the guards were inside hut #123 when one stumbled and dropped his probe. It hit the corner of the false trap door to the tunnel and chipped off a piece. The guard snooped about and soon the tunnel was discovered.
Men were marched off to the cooler and the German high command were so interested in the workmanship that it sent experts to Stalag lll to witness first hand what the POW's were up to. Then they brought in a special crew to blow TOM up, and with it they took its roof.
Soon after this they rounded up many of those thought to be involved in the digging and sent them off to other camps miles away. Those transferred included many of the ringleaders.This could not have happened at a worse time. The tunnel was just about finished and the Allies were really just waiting for a moonless night to make the final break through of the last few feet and make their escape.
All work was then put on hold for several months to give everyone a chance to cool off and of course at the same time luring the Germans into a sense of false security.
But then it was decided to start up HARRY again and just use DICK as a storage place for all their tools and even some of the sand coming to the surface.
And then it happened! They got to the end of their tunnel and about to break surface outside the camp.
But 'll bring you that next Wednesday.
Bart