The Tunnels of Cu Chi (15 page)

   The Tunnel Rats

Tunnels for having babies in, for hospitals, for hiding, for fighting—the American commanders arriving in Vietnam had never come across anything like them before. After initial bruising experiences, it became clear that they would need to develop a new military skill in tunnel warfare, and develop it fast.

In Operation Crimp in January 1966 the U.S. Army's commanders were astonished by the scale and extent of the Viet Cong tunnel systems, but they should have been prepared. As long ago as 1963, the ARVN, then fighting a losing war against burgeoning Viet Cong forces, had warned its American advisers of the tunnels' existence. There was, for instance, an ARVN briefing at the presidential palace in Saigon on 20 September 1963 by officers from the III Corps Tactical Zone. This was translated into English and transcribed at the specific request of the intelligence chief at the U.S. Military Assistance Command (MACV). The briefing described a two-month ARVN operation in the Iron Triangle, and other actions in the Ho Bo woods. The ARVN briefing officer was gloomy:

“Tunnels provide the enemy with an extensive means of resistance and are established in Viet Cong controlled areas.
To completely destroy a VC tunnel system, we must conduct a long-range operation and pay a dear price.”

In the two-month operation, twenty ARVN soldiers had been killed, and sixty wounded, by mines and snipers; eight vehicles had been damaged by mines. The ARVN claimed ten Viet Cong killed. It had indeed been costly.

The briefing officer glumly continued: “We must admit that it is very difficult for us to discover Viet Cong concealed trenches and tunnels, because of their skillful and delicate organization. Short-range mop-ups in VC base areas conducted by units which have no knowledge of the terrain and accurate information rarely bring about desired results.” The ARVN officer went on to describe the tunnels' structure and defenses with some accuracy, even pointing out that “it is useless to toss tear-gas grenades into trenches because they are provided with partitions which hold back smoke.” ARVN “war dogs,” he said, dared not enter the tunnels. He gave various bits of advice on tunnel detection, such as looking for freshly dug earth or cultivation in unlikely places. He went on: “It is necessary to probe separate graves located far from villages with a pointed stick. If the stick fails to strike the lid of a coffin, we are sure that the grave is a camouflaged VC trench.”

One thing that emerged from the briefing with startling clarity was that no ARVN soldier ever ventured down into a tunnel to explore it or to engage the Viet Cong. The officers evidently never considered sending a man on such a mission. This was confirmed by former Viet Cong Captain Nguyen Thanh Linh, who said that the ARVN not only never entered tunnels, but even occasionally shouted greetings to Viet Cong inside, such as “Sleep well, you guys, so that you can go to work tonight!” The ARVN troops would even conceal tunnel entrances from their superiors, or fail to report their discovery, for fear of being asked to do the logical thing and investigate. In the 1963 briefing there was mention of “combating this system of VC warfare,” without any real suggestion of how to do it, short of bemoaning the difficulties. The only tactic proposed was to surround a Viet Cong tunnel entrance and wait for the guerrillas to come out. It is hardly surprising that by the time the American army arrived in 1965 the Viet Cong were, literally, so well entrenched, their bunkers so extensive and so permanent.

The briefing found its way into MACV's bulging files, and references to it crop up in documents written years later. Brigadier General Richard Knowles, who in 1966 took command of the 196th Light Infantry Brigade, recalled debriefing Special Forces officers with Vietnam experience before he left the continental United States. “We used to listen to them by the hour,” he said. “In the process I heard about the tunnels in considerable detail; apparently the South Vietnamese just left them alone. I was aware of the tunnels, but not of their significance to the Viet Cong effort in South Vietnam. We didn't appreciate the full extent of that till much later.”

Brigadier General Ellis W. Williamson led the 173rd Airborne Brigade into the Iron Triangle in October 1965, and wrote afterward: “The Iron Triangle was thoroughly searched and investigated, and all enemy troops and installations were destroyed.” Admittedly, his troops had entered the area and destroyed a number of dwellings and killed some of the inhabitants. But one of his company commanders, Captain Henry B. Tucker, made a more realistic assessment: “We burned the buildings, but we could not do anything to the fortifications; they were dug too damn deep.” The proof that General Williamson was wrong lies in the massive operation that had to be conducted a year later over exactly the same ground, Operation Cedar Falls. And even after the devastation and depopulation of that great search-and-destroy exercise in 1967, the major thrust against Saigon during the Tet offensive of 1968 came out of the Iron Triangle.

In the U.S. Army, after each operation the commander must append to his after-action report (AAR) a list entitled “Lessons Learned.” Operation Crimp in Cu Chi district in early 1966 proved to be a genuine and sobering education. Despite the upbeat and optimistic (if not self-deluding) tone of these army documents, and repeated claims of successes that often proved illusory, the references to the tunnels show how serious and how unforeseen a headache they presented. From the AAR of Williamson's 173rd Airborne Brigade:

With some urgency, just two months after Operation Crimp, MACV published a confidential report entitled “Operations Against Tunnel Complexes,” which was distributed to all U.S. commands in Vietnam. It drew on the experience of American and Australian units in recent operations in the III Corps Tactical Zone. It emphasized the problems of detecting and exploring “fighting” tunnel complexes in “war zones” and “VC base areas.” This confidential report shows that the intractable nature of the war was beginning to dawn on the military analysts after one year in Vietnam. This is what they wrote:

In Operation Crimp, tunnel exploration and destruction was entirely ad hoc. There was apparently no body of knowledge or experience upon which to draw. Soldiers improvised crawling and measuring techniques; some suffocated underground when smoke grenades had been used; others died from Viet Cong booby traps and mines. The MACV report listed the inherent dangers of underground exploration. As well as bad air and booby traps, it included, somewhat superfluously, “VC still in the tunnel.” But its main recommendation was the creation of a specialist soldier, with a new military skill unique to the Vietnam War:

The creation of those teams would prove one of the more extraordinary phenomena in the history of American arms: the birth of an infantryman who rejoiced in the undignified but menacing title of Tunnel Rat.

If Sergeant Stewart Green was the first reluctant tunnel explorer in Vietnam, Captain Herbert Thornton was the first of the new tunnel rats. Although the 25th Infantry Division originally called them tunnel runners and the Australian army called them ferrets, “tunnel rats” eventually became the accepted official term among the armed forces of the West. Far from derogatory, the name was a source of pride and esprit. Thornton had been the Big Red One's chemical officer when it arrived in Vietnam in 1965 and was based at Di An, just south of the Iron Triangle, east of the Saigon River. Herbert Thornton was forty in 1966, a round-faced, balding Southerner. He is lucky to be alive today. He was once crawling in a tunnel behind a soldier from the 25th Infantry who set off a booby-trap
mine. Thornton was blown physically out of the tunnel and into the open air above, uninjured but deafened in one ear. His companion was buried and never found.

Thornton's chemical platoon was given special responsibility for tunnel destruction, and participated in Operation Crimp in that role. The infantry decided that the chemical CS gas—along with explosives—was the best way to deny the use of the tunnels to the enemy. When powder grenades were exploded, CS crystals lodged in tunnel walls, and the resulting gas would painfully irritate the skin and lungs of anyone passing through. The crystals were effective for about a week, though natural moisture would wash them away. Another tunnel-denial tactic was pumping acetylene gas into the tunnels with a Sears Roebuck orchard blower, an air compressor used at home for spraying pesticide onto trees. It was imported in large numbers into Vietnam and nicknamed the “mighty mite.” The acetylene was then ignited and burned up the oxygen in the tunnel. In addition, demolition charges were used to blow up tunnel sections.

The policy of tunnel destruction was recognized as shortsighted when intelligence officers began evaluating items found in tunnels—documents such as Viet Cong tax records and personnel lists, as well as maps of U.S. bases, including Bien Hoa air base and Cu Chi. (North Vietnam's Premier Pham Van Dong once said, “The Americans like captured documents; we made sure they got plenty.”) Consequently, Captain Thornton and his men were ordered to explore the tunnels before destroying them.

This task demanded not only special skills, but also—it was recognized—a special type of temperament and courage. The tunnel rats were obliged to perform the most unnatural and stressful tasks: to crawl through pitch-dark, narrow, low, earthen tunnels for hundreds of yards, facing the threat of sudden death at any moment. Heavily armed Viet Cong units hid in their underground refuges for most of the daylight hours. In addition, every tunnel was sown with mines and booby traps. There were fire ants, rats (real ones), and other creatures. In damp black holes dug for the slim and slight Vietnamese, most Americans found claustrophobic panic barely controllable. General Bernard Rogers, then an assistant commander of the Big Red One, described the rat's task: “Hot, dirty, and gasping for breath, he
squeezed his body through narrow and shallow openings on all fours, never knowing whether the tunnel might collapse behind him or what he might find ahead around the next turn, and sensing the jolt of adrenaline at every sound. Surely this modern combat spelunker [cave explorer] is a special breed.”

General Fred Weyand, who commanded the 25th Infantry Division in 1966, said of these men: “There's nothing more curious than an American soldier, particularly if he thinks there's an enemy down there somewhere. I found in each company, when it went out into an area of tunnels, the tunnel rat became a sort of oddball hero. You had guys who took great pride in showing their buddies they were unique in terms of courage; it's amazing what human beings will do in that sort of situation.” Herbert Thornton himself: “It just takes a special kind of being. He's got to have an inquisitive mind, a lot of guts, and a lot of real moxie into knowing what to touch and what not to touch to stay alive. Because you could blow yourself out of there in a heartbeat if you didn't really keep your eyes open all the time. There were no bad days. They were all good days if you got through them.”