Encapsulated in gas masks, 35-pound self-contained breathing apparatus tanks and leak-proof suits, Chemical, Biological, Radiological and Nuclear specialists descended into a tunnel complex behind Fort Leonard Wood's Lt. Joseph Terry CBRN First Responder Training Facility Nov. 4 to prepare for emergency rescue situations. In just five weeks of total instruction, service members in the Technical Escort Course must learn the ins and outs of chemical and biological agents and how to protect against them while saving lives. Service members in their second week of training are introduced to confined spaces and taught proper protective equipment, mechanical advantage -- how to lower and raise someone out of a hole -- and patient care procedures. "Our whole job is to make sure that these guys get a good foundation for confined space, chemistry (and) biology so that when they go on to their own chemical response teams, they have baseline knowledge of how they're supposed to conduct (themselves)," said Staff Sgt. Ryan Fowler, Technical Escort Course instructor. The extremely dark and close-quarters environment is meant to improve CBRN specialists' confidence in responding to real-world emergencies, said Charles Dashiell, HAZMAT/Dismounted Reconnaissance Department chief. "Say a casualty or somebody is down in a tunnel, they've passed out because of lack of air," he said. "(The Soldiers) can then put their SCBA tanks on, go down in the tunnel, and then rescue that person -- either providing air to them, or ... put them on a skid and hoist them out of that area." The course is interservice, hosting Airmen, Marines, Sailors, Soldiers and civilians. Dashiell added that it's challenging, with a student pass rate of about 85 percent. Spc. Dylan Crafton, a CBRN specialist with the 48th Chemical Brigade out of Fort Hood, Texas, participated in the confined-space training. He said the hardest part is keeping a level head. "It gets pretty tight," he said. "There's one spot where it's maybe about a foot and a half wide, and (you're) trying to slide your whole body through, plus your oxygen tank. There's a lot of parts where you can't see at all." Crafton said that despite feeling anxious prior to the training, it instilled confidence in him. "Before, the anticipation was nuts. I was scared -- not really good with confined spaces or anything like that," he said. "Once you're down there, it's not that bad, especially when you have people ahead of you, people behind you, because you're not so much working for yourself, it's (for) the team." After the tunnel training, a final exam awaits to prove their knowledge in all-encompassing, highly challenging, graded series of tasks -- the Situational Training Exercise. "STX is like a culminating event," Fowler said. "Everything they learn over the four weeks, they have to use all that stuff and put it all into practice during STX." He said that nothing substitutes for hands-on experiences. "There are some things that students won't understand until they're actually presented with it in front of their face," he said.