the prisoners had given their word not to misuse the materials; the parole system was regarded as inviolate. Internal "legal advice" was taken and the SBOs (Senior British Officers) decided that the completed building did not fall under the parole system. A seat in the back row was hinged and the sand-dispersal problem was solved. German prison camps began to receive larger numbers of American prisoners. The Germans decided that new camps would be built specifically for US airmen. To allow as many people to escape as possible, including the Americans, efforts on the remaining two tunnels increased. This drew attention from guards and in September 1943 the entrance to "Tom" became the 98th tunnel to be discovered in the camp; guards in the woods had seen sand being removed from the hut where it was located. Work on "Harry" ceased and did not resume until January 1944. Tunnel "Harry" completed "Harry" was finally ready in March 1944. By then the Americans, some of whom had worked on "Tom", had been moved away; despite the portrayal of three in the Hollywood film, only one American, Major Johnnie Dodge, participated in the "Great Escape", and he had become a British citizen. Previously, the attempt had been planned for the summer for its good weather, but in early 1944 the Gestapo visited the camp and ordered increased effort to detect escapes. Rather than risk waiting and having their tunnel discovered, Bushell ordered the attempt be made as soon as it was ready. Many Germans willingly helped in the escape itself. The film suggests that the forgers were able to make near-exact replicas of just about any pass that was used in Nazi Germany. In reality, the forgers received a great deal of assistance from Germans who lived many hundreds of miles away on the other side of the country. Several German guards, who were openly anti-Nazi, also willingly gave the prisoners items and assistance of any kind to aid their escape. In their plan, of the 600 who had worked on the tunnels only 200 would be able to escape. The prisoners were separated into two groups. The first group of 100, called "serial offenders," were guaranteed a place and included 30 who spoke German well or had a history of escapes, and an additional 70 considered to have put in the most work on the tunnels. The second group, considered to