Cu Chi Tunnels - U.S. Campaigns Against The Tunnels

U.S. Campaigns Against The Tunnels

The tunnels of Củ Chi did not go completely unnoticed by U.S. officials. They recognized the advantages that the Viet Cong held with the tunnels, and accordingly launched several major campaigns to search out and destroy the tunnel system. Among the most important of these were Operation Crimp and Operation Cedar Falls.

Operation Crimp began on January 7, 1966, with B-52 bombers dropping 30-ton loads of high explosive onto the region of Củ Chi, effectively turning the once lush jungle into a pockmarked moonscape. Eight thousand troops from the U.S. 1st Infantry Division, 173rd Airborne Brigade, and the 1st Battalion, Royal Australian Regiment combed the region looking for any clues of PLAF activity.

The operation was, for the most part, unsuccessful. On the occasion when troops found a tunnel, they would often underestimate its size. Rarely would anyone be sent in to search the tunnels, as it was so hazardous. The tunnels were often rigged with explosive booby traps or punji stake pits. The two main responses in dealing with a tunnel opening were to flush the entrance with gas,water or hot tar to force the guerrillas into the open, or to toss a few grenades down the hole and “crimp” off the opening. The clever design of the tunnels along with the strategic use of trap doors and air filtration systems rendered American technology largely ineffective.

However, an Australian specialist engineering troop, 3 Field Troop, under the command of Captain Sandy MacGregor did venture into the tunnels which they searched exhaustively for four days, finding ammunition, radio equipment, medical supplies and food as well as signs of considerable Viet Cong presence. One of their number, Corporal Bob Bowtell died when he became trapped in a tunnel that turned out to be a dead end. However the Australians pressed on and revealed, for the first time, the immense military significance of the tunnels. At an International Press Conference in Saigon shortly after Operation Crimp, MacGregor referred to his men as Tunnel Ferrets. An American journalist, having never heard of ferrets, used the term Tunnel Rats and it stuck. Following his troop's discoveries in Cu Chi, Sandy MacGregor was awarded a Military Cross.

From its mistakes, and the Australians' discoveries, U.S. command realized that they needed a new way to approach the dilemma of the tunnels. A general order was issued by General Williamson, the Allied Forces Commander in South Vietnam, to all Allied forces that tunnels had to be properly searched whenever they were discovered. They began training an elite group of volunteers in the art of tunnel warfare, armed only with a gun, a knife, a flashlight and a piece of string. These specialists, commonly known as “tunnel rats”, would enter a tunnel by themselves and travel inch-by-inch cautiously looking ahead for booby traps or cornered PLAF. There was no real doctrine for this approach and despite some very hard work in some sectors of the Army and MACV (Military Assistance Command, Vietnam) to provide some sort of training and resources, this was primarily a new approach that the units trained, equipped and planned for themselves.

Despite this revamped effort at fighting the enemy on its own terms, U.S. operations remained largely unsuccessful at eliminating the tunnels. In 1967, General William Westmoreland tried launching a larger assault on Củ Chi and the Iron Triangle. Called Operation Cedar Falls, it was, in principle, exactly the same as Operation Crimp, but with 30,000 troops instead of the 8,000.

On January 18, tunnel rats from the 1st BN 5th Infantry Regiment, of the 25th Infantry Division, uncovered the Viet Cong district headquarters of Củ Chi containing half a million documents concerning all types of military strategy. Among the documents were maps of U.S. bases, detailed accounts of PLAF movement from Cambodia into Vietnam, lists of political sympathizers, and even plans for a failed assassination attempt on Robert McNamara. With this one exception, Operation Cedar Falls failed to achieve its objective of destroying the communist stronghold in the region.

By 1969, B-52s were freed from bombing North Vietnam and started "carpet bombing" Củ Chi and the rest of the Iron Triangle. Ultimately it proved successful but futile. Towards the end of the war, the tunnels were so heavily bombed that some portions actually caved in and other sections were exposed. But by that time, they had succeeded in protecting the local guerrilla units in "surviving to fight another day".

Throughout the course of the war, the tunnels in and around Củ Chi proved to be a source of frustration for the U.S. military in Saigon. The Viet Cong had been so well entrenched in the area by 1965 that they were in the unique position of locally being able to control where and when battles would take place. By helping to covertly move supplies and house troops, the tunnels of Củ Chi allowed guerrilla fighters in their area of South Vietnam to survive, help prolong the war and increase American costs and casualties until their eventual withdrawal in 1972, and the final defeat of the Republic of Vietnam in 1975.