Virginia Review of Asian Studies: 19 (2017) 1-27

Virginia Review of Asian Studies: 19 (2017) 1-27

ISSN: 2169-6306

Head: Vietnam Tunnels

“FERRETS” AND “RATS” TO THE RESCUE: A REEXAMINATION OF OPERATION CRIMP DURING THE VIETNAM WAR

William Head 78 ABW Office of History Robins AFB

During America’s Vietnam War, many combat events, such as the Tet Offensive, Rolling Thunder, and the Spring Offensive of 1972 became, and some remain to this day, iconic parts of the popular culture of the American people. However, many other aspects of that war have become obscured by the passage of time and are only remembered by a handful of veterans and analysts. One such operation was Operation Crimp or the Battle of the Ho Bo Woods. The designation referred to putting a crimp in Communist operations.[1]

Officially, Operation Crimp was recorded as a search and destroy action undertaken by U.S. and Australian forces in Binh Duong Province, in South Vietnam, between 8 and 14 January 1966. Major General Jonathan O. Seaman, commander 1st Infantry Division, acted as the overall commander of all Allied forces during the operation. The combat units included 8,000 soldiers from the 1st Infantry Division, comprised mainly of troops from the 173rd Airborne Brigade (173 AB) and the 3rd Infantry Brigade (3 IB). The 1st Royal Australian Regiment (1 RAR), operating as part of the 173rd AB, also played a significant role in the operation.[2]

As irrelevant as it seems today, at the time, it was the largest search and destroy operation undertaken. According to the After Action Report penned by Col. William D. Brodbeck, Commander, 3 IB and his Administrative Assistant, Second Lieutenant Leo J. Mercier, “On 8 January 1966, the 173rd Airborne Brigade terminated a successful Operation ‘MARAUDER’ along the Oriental River in Hau Nghia Province and moved directly into the largest U.S. operation thus far conducted in Vietnam.” He further reported that the operation was named “Crimp” and was:

A massive attack by air and land to strike at the very heart of the Viet Cong machine in Souther RVN. The notorious ‘HOBO WOODS’ Region in Binh Duong Province, just West of the fabled ‘IRON TRIANGLE’ was believed to hold the Politico-Military headquarters of the Viet Cong Military Region 4. The Objective of Operation ‘CRIMP’ was to find and destroy or capture all personnel, equipment, and intelligence material of this headquarters.[3]

The actual combat took place 12 miles north of what would become an infamous location for many Allied soldiers, Cu Chi. The primary reason for the raid was to locate and obliterate a vital Viet Cong (VC) headquarters (HQ) that intelligence operatives were certain was located in subterranean tunnels hidden by dense three-canopy jungle foliage. During this, the largest joint Allied military operation attempted in South Vietnam to that time, the American/Australian forces uncovered an extensive tunnel network which extended for more than 150miles. It was the first American engagement fought at the division level and, in spite of significant casualties, most Allied leaders believed the campaign was a success. In retrospect, it proved to be only a partial victory, and the tunnels in the region continued to be a key Communist transit and supply base throughout the war. The enemy’s resolve to sustain the tunnels allowed them to use them as a staging area for the attack on Saigon during the 1968Tet Offensive. It was not until 169-1970, when B-52s heavily bombed the tunnels, that they were destroyed.[4]

Tunnel Rats in Vietnam

During the battle, a group of specialized sappers, better known as “tunnel rats,” began to be used to crawl through the treacherous caverns to find and kill the VC in their hiding places. It was a dangerous job, but it allowed the allies to eliminate enemy combatants and destroy the tunnels. While Australian teams were originally referred to as “ferrets,” eventually, anyone brave or crazy enough, to perform such duties became a “tunnel rat.” The Communists had been building and renovating these caves for two decades when the American and Australian forces first discovered them. At first, sappers determined that the only way to root the enemy out of these underground facilities was to crawl in and kill them. The VC guerrillas had constructed this complex system of tunnels in order to hide from infantry sweeps and artillery attacks. They were intricate and perilous, replete with booby traps, and VC waiting to ambush anyone who tried to enter the tunnels.[5]

Standard procedure called for the “tunnel rats” to sneak in through the tight openings, creep carefully into the cave areas, and kill the ubiquitous enemy soldiers. Equipped with only a .45 caliber pistol, a grenade, and a flashlight, the “tunnel rats” were, out of necessity, smaller men with nerves of steel. Once inside the main passageways they often planted explosive charges that destroyed the tunnels. The soldiers assigned to this duty, especially in the Cu Chi tunnels, described the caverns as “eerie and dark.” They used the term “black echo” to describe their experience of being in the tunnels. While this group would become famous as the war progressed, it was during Operation Crimp they first burst onto the scene.[6]

Cu Chi Tunnels

From the very beginning of the Southern insurrection, led by the National Liberation Front (NLF) and their guerilla forces, better known as the VC, the rebels had to find low tech means to combat the better supplied Army of the Republic of Vietnam (ARVN) troops. They hollowed out hundreds of miles of tunnels throughout South Vietnam. The ones in the Cu Chi district, northwest of Saigon, consisted of a widespread network which the VC had dug, little bits at a time, often by hand. The U.S. made several efforts to destroy these subterranean outposts including Operation Crimp. Allied engineers used a geological and soil survey approach to eventually detect the enemy network of underground defenses. This was followed, in January 1967, by an assault on Cu Chi and the Iron Triangle Areas, known as Operation Cedar Falls. Finally, in 1969-1970, B-52 bombing destroyed most of the tunnels.[7]

The tunnels were built into Old Alluvium terraces and were highly resilient to most explosives because the soil contained large levels of clay and iron. The iron percolated from the ground level and gathered in the lower layers creating a cement-like binding agent. When the soil layers dried, they were like concrete, seldom becoming moist again especially around the tunnel walls. Young “volunteers” dug the tunnels in the monsoon season when the upper layers of soil were soft. As it dried, the soil remained stable, without supports, and could withstand adjacent explosions.[8]

Communist soldiers used these underground caves and transport routes to house troops, transport supplies, plant booby traps, and initiate surprise attacks on opposing forces. After each assault, they would disappear into their underground sanctuaries. It was because of these tunnels that Allied leaders directed that some troops be trained to be the aforementioned “tunnel rats.” They navigated the tunnels in order to detect booby traps and the presence of enemy guerillas.[9]

The southern supporters of the Viet Minh Communist had begun digging the tunnels under the jungle terrain of South Vietnam in the late 1940s. During this time, Socialist forces, led by Ho Chi Minh, were fighting for their independence from the French. They employed a myriad of tools and methods; in some cases, tunnels were dug with sticks and rifle butts on hands and knees, frequently only a few yards at a time.[10]

Once the Americans joined the conflict in the early 1960s, they gradually escalated their military presence in Vietnam to prop up various non-Communist governments in South Vietnam. In response, North Vietnamese Army (NVA) and VC troops not only expanded the infiltration routes from the North through Cambodia, known as the Ho Chi Minh Trail but, also, expanded their tunnel complexes. Northern leaders in Hanoi dedicated dozens of non-combat units to keeping the logistics and transport routes open. At the high point of the war, tunnels in Cu Chi linked Communist support bases which covered more than 150 miles and went from the outskirts of Saigon all the way to the Cambodian border.[11]

A Map of the Ho Bo Woods, Iron Triangle, and Cu Chi Base Camp

In areas which experienced heavy artillery shelling, enemy troops spent most of their time underground. In some cases, the Cu Chi tunnels grew to the point where they could house entire villages underground. These included “living quarters, kitchens, ordnance factories, hospitals and bomb shelters. In some areas there were even large theaters and music halls to provide diversion for the troops and their families.”[12]

The tunnel complex near Cu Chi not only played a critical role in providing the VC with a safe haven but also facilitated Communist attacks against nearby Saigon. To protect these vital caverns, they placed trip wires to detonate grenades or dumped boxes of scorpions or poisonous snakes onto Allied troops. As mentioned, in an effort to thwart these tactics, Australian, ARVN, and American soldiers were trained to avoid the booby traps. It proved to be a hazardous job since they had to traverse the cramped, dark tunnels to scout for enemy troops.[13]

Tunnel complex at Cu Chi and how they were used

While the first Allied attacks against the Cu Chi complex involved the 8,000 U.S. and Australian troops of Operation Crimp, it was not the last. Numbers of B-52 bombers assaulted this same area with good results and, a year later, around 30,000 American troops launched Operation Cedar Falls, sweeping across the Iron Triangle region of Binh Duong province north of Saigon near the Cambodian border. This was followed by more bombing raids and defoliation of rice fields and contiguous jungle areas with herbicides. Once exposed, U.S. tanks and bulldozers sealed some tunnels either suffocating the inhabitants or causing survivors to flee.

This proved to be only a temporary setback since, within only a few months, Communist forces returned. In January 1968, they used the restored complex as a base from which to launch their attacks against Saigon during the Tet Offensive of 1968. Perhaps the cruelest irony is that today, the tunnels near Cu Chi have become a tourist attraction. In the years following the victory by the North in 1975, the new government in Hanoi preserved the tunnels and made them part of a network of national war memorial parks. Today, visitors to Saigon can explore the passages where 45,000 VC and NVA died defending the Cu Chi tunnels.[14]

The tunnels in recent times

The Enclave Strategy

In retrospect, one of the more significant aspects of Operation Crimp was that it was, simultaneously, the last Allied military engagement to operate under the “Enclave Strategy” and one of the first search and destroy operations of the War. Soon after, General William C. Westmoreland, Commander, Military Assistance Command, Vietnam (MACV) convinced President Lyndon B. Johnson to change from a defensive policy to one of attrition. In early 1965, before the President began dispatching large number of U.S. troops to Vietnam, he made it clear he intended to implement a plan originally conceived by the American Ambassador to Vietnam, General Maxwell Taylor, known as “The Enclave Strategy.” Taylor opposed involving large numbers of U.S. forces in Vietnam. His strategy advocated that the Americans establish control only in areas of Vietnam already controlled by the Saigon government. This meant that the Republic of Vietnam (RVN) had to win the war, and the U.S. military acted only as support for ARVN troops by controlling the densely populate coast.[15]

The best recount of the Enclave Strategy can be found in Section III – Strategies for Ground Force Employment, Part B – Enclave Strategy of the Pentagon Papers. It states that:

The President decided during NSC meetings on 1 and 2 April 1965 to get U.S. ground combat units involved in the war against the insurgents. He did this in the sober awareness that Rolling Thunder was unlikely to produce immediate results, but also with the caveat that U.S. troops might not do too well in an Asian insurgency environment. The enclave strategy, which had been presented by Ambassador Taylor as a way to get U.S. troops engaged at relatively low risk, was implicitly endorsed by the President. The strategy proposed that U.S. troops occupy coastal enclaves, accept full responsibility for enclave security, and be prepared to go to the rescue of the RVNAF as far as 50 miles outside the enclave. Initially, the U.S. was to experiment with four Marine battalions in two coastal enclaves to see if the concept and the rules for operating with the RVNAF (which were to be worked out with the GVN) were feasible.

Without the benefit of any experimentation the number of battalions was increased at Honolulu in mid-April to 17 and the number of enclaves to 5. The enclave strategy as formalized at Honolulu was designed to frustrate the Viet Cong in the South while Rolling Thunder continued to hammer the North. The intent was not to take the war to the enemy but rather to deny to him certain critical areas while simultaneously providing ready assistance to the RVNAF if they should run into difficulty. The RVNAF were expected to continue aggressively prosecuting the war against the enemy's main forces, thereby bearing the brunt of the casualties.

The enclave strategy was controversial and expectations for it ran the gamut from extreme optimism to deep pessimism. The Ambassador expected it to buy some time for the Vietnamese to eventually save themselves. General Westmoreland and other military men expected it to guarantee defeat for the U.S. and the RVNAF, who were already demonstrating that they were incapable of defeating the enemy.

A masterpiece of ambiguity, the enclave strategy implied a greater commitment to the war on the part of the U.S., but simultaneously demonstrated in the placing of the troops with their backs to the sea a desire for rapid and early exit. While purporting to provide the basis for experimentation with U.S. soldiers in an unfamiliar environment, it mitigated against the success of the experiments by placing those troops in close proximity to the Vietnamese people, where the greatest difficulty would be encountered. In order to prove the viability of its reserve reaction foundation, it required testing; but the rules for commitment were not worked out until the strategy was already overtaken by events. As a consequence of this delay, several opportunities were passed up when the RVNAF really needed help and U.S. troops were available. The whole enclave concept implied that the RVNAF would ultimately prevail, but in any case the Viet Cong could never win as long as certain areas were denied to them. The enclave strategy tacitly yielded the initiative to the enemy, but the initiative was not seen as the vital factor. The key was to be able to outlast the enemy at lowest cost to the United States.[16]

A Different Kind of Strategy – Attrition

While the focus of this article is not the evolution of U.S. strategy from early 1965 to early 1966, it is important to understand how this evolution manifested itself in the nature and tactical realities of Operation Crimp. Once Gen. Westmorland took over the prosecution of the Vietnamese civil war, he made it clear he did not believe in the Enclave Strategy and pressed the Johnson to deploy larger numbers of U.S. troops to Vietnam in order to “take the battle to enemy.” The General argued the overall performance of the ARVN, in battles like Ap Bac in January 1963, and the increase in the number of VC attacks beginning in June 1965 made the Enclave Strategy useless and made the RVN’s position untenable. While Johnson inched closer to supporting Westmoreland, he remained hesitant for the moment. Finally, in the late summer of 1965, he concluded that the only way to make Ho Chi Minh seek a negotiated peace and force the NVA to depart South Vietnam was to adapt Westmoreland’s strategy. This led to the Gulf of Tokin Resolution and Americanization of the War in Vietnam.[17]

As the number of troops increased, Westmoreland implemented a strategy called “The War of Attrition.” This was not a normal tactic for U.S. ground forces. For generations, they had been trained to capture and hold ground not “search and destroy.” Operation Crimp became the transitional reality of this new strategy. The tactical manifestation of this policy involved sending ground forces into the field to search and kill as many VC and NVA troops as U.S. weapons’ superiority would allow. It also expected U.S. air forces, to cause as many casualties as possible and destroy North Vietnam’s limited economy and industrial base in order to assure it could not resupply its men in the field and prolong the war. The problem with these notions was that destroying the Northern infrastructure was not only difficult but unimportant since, eventually, most of the weapons and resupplies necessary to continue the conflict came from the Soviet Union and China which were off limits to U.S. air or ground attacks.[18]