SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!1The Tunnels of Cu ChiRamon W. AlmodovarJ. David Rogers“No one has ever demonstrated more ability to hide his installations than the Viet Cong; they were human moles.”General William WestmorelandSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!2PurposeTo provide the class with an overview of the Cu Chi Tunnels and how they impacted the Vietnam War.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!3References• The Tunnels of Cu Chi by Tom Mangold and John Penycate• http://images.google.com• www.25thida.com/photos.html • www.users.qwest.net/~huffpapa/ CuChiMap.html• www.rjsmith.com/ cu-chi-taor-nf.html• cybersarges.tripod.com/ cuchi.html• www.pbs.org/wgbh/amex/vietnam/ refer/map1/indexjs.htmlSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!4Outline• Area of Operations• History of Cu Chi Tunnels• Tunnel Construction• Viet Cong Tunnel Fighting•Cu Chi Base Camp• Operation Cedar Falls• Tunnel Rats• Tunnel Destruction• Summary• ConclusionSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!5Vietnam is located in Southeast Asia, east of Cambodia and Laos, south of China and bordered on the east by the Gulf of Tonkin/South China Sea.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!6SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!7•The district of Cu Chi is located Northwest of Saigon (Ho Chi Min City) and served as a stronghold of the Viet Cong throughout the Vietnam War.•It was of strategic significance because it straddled the main land and the river routes used by the Viet Cong to infiltrate supplies into South Vietnam from the terminus of the Ho Chi Min Trail in Cambodia.•This was also the only sizable area in South Vietnam where troops and vehicles could move easily during the monsoon season (May to October).•As seen on the map, Cu Chi was located in the III Corps Tactical Zone. •Cu Chi became the most bombed, shelled, gassed, and defoliated area in the history of war (see photos).SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!8TUNNELES WERE CONCENTRATED IN THE IRON TRIANGLE AREASAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!9The Iron Triangle was a known Viet Cong stronghold. It was 40 square miles of jungle and briar with an intricate network of interconnecting tunnels and bunkers, extending over 200 km! The remained in oeration throughout the war.From the preceding map you can see the proximity of the Iron Triangle to Cu Chi base.The Iron Triangle, the HoBo Woods and the Boi Loi Woods were defoliated and their original populations relocated. The red Xs mark VC/NVA headquarters locations.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!10A LITTLE BACKGROUNDSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!11•The tunnels stretched from Saigon to the Cambodian border•By the end of the war approximately 200km of tunnels were constructed.•The tunnels were used to connect villages, districts, and provinces together so the guerrilla fighters could move between areas undetected.•They were originally dug as hiding places for the Viet Minh, nationalist guerillas who fought the Japanese during World War II and France afterwards (1946-54).•The tunnels were subsequently expanded in response to pressure brought on by conventional ARVN and US forces.•No central entity designed the tunnels or oversaw their construction. They evolved out of necessity.•Aircraft, bombs, artillery, and chemicals forced the Viet Cong to station themselves underground.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!12TYPICAL TUNNEL CONSTRUCTION(1 of 6)SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!13•The tunnels were excavated in laterite clay, a ferric soil with clay and iron oxide binder which allowed some air penetration.•The clay was not affected by seasonal changes in water content because of the iron cementation. It was further strengthened by tree roots.•The thickness of the useable clay layer varied between 10 to 20 meters, depending on the depth of the water table.•The tunnels were mostly excavated by hand methods with 2 people rotating digging and 2 to 3 people who removed the cuttings.•The normal rate of advance was about 1 cubic meter per person per day, but varied with the digger’s health, age, the climate and the soil.•The earth removed from the tunnels was used in the basements of local houses, furrows for potato growing, banks for communication or combat trenches, or poured into streams, to prevent US forces from discovering the tunnel entrances.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!14Camouflaged Tunnel EntriesSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!15•Most of the tunnel entrances were well concealed, covered by boards 1cm thick and 2 to 3 cms wide arranged in two frames, one horizontally, the other vertically.•A nylon sheet was then glued between the 2 frames.•The door was then covered with sponge rubber and wax, so that itwould feel like natural ground when walking across it.•The sides of the trapdoor were beveled downward at an angle so it could take considerable overpressure, even from vehicles.•Most of the tunnels were filled with camouflaged trap doors. These were also concealed by covering them with earth.•If a door led to the exposed ground surface, dead foliage was used to camouflage the door and was changed every three days.•Entrances had to resist fire, flood, and chemical warfare, so they were located in dry, elevated, and generally well-ventilated areas.•Some doors were even hidden in pig pens because the VC knew thatAmerican soldiers would not want to check such places thoroughly.SAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!16TUNNELS EXPOSED TO REVEAL LAYOUT CHARACTERISTICSSAPPERS EAGLE!SAPPERS EAGLE!AIR ASSAULT!AIR ASSAULT!17These are pictures of the tunnels with their earthen cover removed.Tunnels were usually excavated in a zig-zag pattern, at angles between 60 and 120 degrees. This was intended to prevent linear lines-of-fire and help deflect explosive blasts if the tunnel complex was invaded by enemy troops.Communications passages were constructed no wider than 1.2 meters, no narrower than 0.8 meters, at a height of 0.8 to 1.8 meters, with a minimum roof thickness of 1.5 meters. Big fellaswould have a difficult time negotiating such openings. These dimensions were strictly adhered to as a standard that ensured uniformity and sound construction.SAPPERS