The Cu Chi Tunnels: The Technology and the Environmental Benefits (Fall 2012)

The district of Cu Chi is located in Saigon, Vietnam. The Cu Chi tunnels were constructed in the 1940’s during the Indochina War and expanded in the 1960’s during the Vietnam War. The tunnels provided a sneaky and faster way for the Viet Cong to accomplish their goals and confuse their opponents. The earth and environment gave Vietnam a better chance at victory because of the natural environment and the geography of Cu Chi. The soil and forest gave the Viet Cong a big advantage to stabilize the tunnels.

Cu Chi has a small population of peasants who relies on man power and agricultural produce for daily needs with no advanced technology or any major buildings. It was a very peaceful and beautiful land. “Cu Chi used to be a green area of intense agriculture, especially rice paddies, orchards, nut trees, and rubber plantations” (Mangold, 1985, 34). In 1940’s when France occupied Vietnam, tension rose when Ho Chi Minh wanted independence. As a result, France and Vietnam fought for eight long years known as the Indochina War. Vietnam was not a match to the French army whom was fully armed with aircrafts and more advance guns. Therefore, North Vietnam (the Viet Minh) engaged in guerilla warfare by fighting in small groups and conducting surprise attacks because of their lack in advanced military technology. Having limited military materials, the Viet Minh started digging tunnels in Cu Chi, now known as the Cu Chi tunnels. After the eight years of fighting, the French loss heavily and gave up due to the different military tactics and environment. As a result, Vietnam was divided into two parts: North Vietnam and South Vietnam.

When the French left, the Americans, afraid of the domino principle, got involved with Vietnam when United States’ ships were fired at on the Tonkin Gulf. President Johnson got permission from congress to pursue military actions to defend the United States and immediately started sending troops in the 1960’s. The Americans, similar to the French were well armed, but were not prepared for the guerilla warfare the North Vietnamese engaged in. The Viet Cong who sided with the North Vietnam gradually occupied South Vietnam as farmers. In the morning, they blended in as farmers, but when the night came, they attacked the Americans. The Americans found it hard to distinguish who were their friends (South Vietnam) or foes (Viet Minh and Viet Cong). As more and more American troops were deployed in Vietnam, the Viet Cong were busy expanding the tunnel systems in Cu Chi, located in what was known as South Vietnam. Cu Chi served as a base for the Americans, which made it easy for the Viet Cong to spy and follow through with their plans.

The Cu Chi tunnels was a systematic tunnel network created by the Viet Cong during the 1940’s when the French occupied Vietnam as a hiding place and expanded in the 1960’s when the Americans got involved for military purposes. The tunnels were dug by hand and stretched from Saigon to the border of Cambodia, a total of 250 kilometers. The tunnels and entrances were dug relatively small, made to be a maze and armed with booby traps to prevent the Americans from going in.

The tunnels made it possible for the Viet Cong to accomplish their goals. It strengthened the Viet Cong and provided a safe environment for soldiers and troops when the Americans dropped bombs. The tunnels became a secure place to discuss strategies and to organize traps in the tunnels as well as in the surrounding areas. “The primary role of the tunnels is stressed and restressed. ‘They are for the strengthening of combat vitality for our villages. They also provide more safety for our political and armed units, and for the masses as well. But their sheltering purpose is only significant when they serve for our soldiers in combat activities. As mere shelters, their great advantages are wasted’” (Mangold, 1985, 69).The tunnels were also a successful way to spy on the Americans. “Thanks to the tunnels, we remain with the Americans, see how their troops behaved and reacted, watched their mistakes. Our observations helped us decide what kinds of booby traps to set and where to set them” (Mangold, 1985, 51). It became a necessary military strategy as the war progressed. They achieved their main goal: to kill the Americans. The tunnels provided a sneaky way to accomplish military strategies, hunt the Americans, provide safety, and to communicate from North Vietnam to the Viet Cong in South Vietnam, especially during the Indochina War. “The tunnels were dug for the Viet Minh-for communication from one hamlet to another so that guerrillas could evade French army sweeps or spotter planes” (Mangold, 1985).

The complexity of the tunnels was confusing for the Americans; therefore, made it difficult to find the Viet Cong who are sneaky and quick. The Viet Cong set many tricks inside and outside of the tunnels. Inside the tunnels, they created false tunnel routes that lead the Americans to dead ends or booby traps. It was easy to get lost. There were also various traps outside of the tunnels. The tunnels had four levels for different purposes. The top level had traps, ventilation shafts, and firing posts. The second level had the kitchen and sleeping chamber. The third level had the Aid Station for wounded people, a storage room for weapons and food, and a route that is connected to the tunnel systems. Lastly, the fourth tunnel had a well for water. It was hard for the Americans to discover these areas because of all the false routes in the tunnels. The complex tunnels would not be possible without the natural environment in Cu Chi.

Cu Chi’s natural environment gave the Viet Cong a great advantage. The land being foreign to the Americans was already useful for the Viet Cong. The environment made it difficult for the Americans to thoroughly discover the land for military tactics and gave them a hard time to navigate around. In addition, the Viet Cong engaged in guerilla warfare, which the Americans were not familiar with. The Viet Cong seized most of their military weapons from the Americans when they launched surprise attacks. The elevation of the land made it possible for the Viet Cong to create trapdoors and ventilations that can resist fire and chemicals. “The entrances also had to be able to resist fire, flood, and chemical warfare: ‘for this reason, we must locate the entrances to the tunnels in dry, elevated, and well-ventilated areas’” (Mangold, 1985, 72).

Above the tunnels, it was surrounded by bamboos and various trees, making it possible to camouflage tunnel entrances to prevent intruders. False entrances were also created to trick the Americans. The relative location of the Saigon River to the Cu Chi tunnels gave them an advantage to water especially to treat the wounded and for cooking. The tunnels were an easy way to attack the Americans. “We may attack the enemy right in the center of his formations or keep on fighting from different places” (Mangold, 1985, 70). The tunnels will not exist if not for the unique environment of Cu Chi. The presence of the river created soil that is similar to clay known as laterite clay, found in areas between the Tropics of Cancer and the Tropics of Capricorn.

The laterite clay was a significant component for the success of the tunnels. In the rainy season the soil is was very soft and mushy, and during the dry season, it becomes very hard. Tunneling and shaping the tunnels was easier during the rainy season. The dry and hard clay made it possible to stabilize the tunnels. Laterite clay allows air to pass through the soil which provided a strong and stable structure when the workers were constructing the tunnel. The clay enabled the Viet Cong to create many tricks in the tunnels. The location of the Saigon River allowed the Viet Cong to mislead the Americans by digging a route that lead to a smelly pit hole. The tunnels being located in the forest also gave the Viet Cong an advantage to camouflage the entrances to the tunnels. They also camouflaged the traps set along the trails above the tunnels and inside it as well.

The Cu Chi tunnels were surrounded by many kinds of tress specifically bamboo trees. Bamboo trees were used in booby traps as well as being made into various tools for cooking. Their roots were very important in the construction of the tunnels. “…hard soil at the root of the bamboo tree or where there was a termite nest. Such soil could stand the weight of a tank” (Mangold, 1985, 75). The roots made the tunnels more durable and stronger. The trees made it hard for the Americans to identify where the traps and entrances were. In addition, it was hard for the Americans to see where the Viet Cong were aboveground; therefore, they used Agent Orange, a chemical to defoliate forest areas to make it easier to look for them. The effects of the chemical were devastating. Regardless, the forest gave the Viet Cong a better chance to win the war.

The Americans were aware of the tunnels existence and tried to destroy the network. The American trained people to be able to engage in combat with the Viet Cong in the tunnels and to explore anything helpful so they can end the tunnel systems. The result was a failure because the relative size of the entrance did not fit most Americans and the complex tunnels led most of the tunnel rats into dead ends or traps. The Americans also tried to flood the tunnels, but did not succeed because there were water drainage holes in the tunnels. “Every twenty or thirty meters the tunnelers dug a water drainage hole to prevent flooding” (Mangold, 1985, 76). “Because of the proximity of the Saigon River to many of the tunnels systems, flooding was thought to be an easy and convenient method of tunnels destruction. In fact, it turned out to be an expensive, time-consuming failure” (Mangold, 1985, 207). The Americans also tried bombing and throwing chemicals into the tunnels, but since the tunnels were deep into the ground and there were ventilations holes in the tunnels, it did not create much damage. All in all, the Americans could not get rid of the Viet Cong or the tunnel systems.

As a result, the earth and environment made the tunnel constructions possible which became a powerful source of technology for the Viet Cong. The tunnels assisted the Viet Cong in pursuing their goals to defeat the Americans by confusing them with the complex structure. The Viet Cong appeared and disappeared within a second. With the creation of the tunnels, continuing life underground became possible. They maintained their life and survived. The earth and environment of Vietnam was foreign to the Americans which meant they had a hard time navigating in the area because it was mainly trees, and they did not have many advantages besides the weapons they had. The hard and dry soil created a stable tunnel for the Viet Cong and the surrounding forest areas made it possible to conduct surprise attacks as well as camouflaging the entrances to the tunnels. With the hard work of the Viet Cong to construct these tunnels, it became a success in their victory against the Americans in the Vietnam War. The two history forces depended on each other in order to construct the tunnels and to make it effective. The two forces also worked together in a country that was not highly developed, yet succeeded in defeating their opponents because of their land, the most important thing to them. The Viet Cong established a useful strategy out of their environment to create the successful tunnel system: The Cu Chi Tunnels.


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