Australia and the Vietnam War

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Combat

Viet Cong Tunnels

'Tunnel rat' Lance Corporal Ron Rockliffe 6RAR, of Campsie, NSW, prepares to drop into a Viet Cong tunnel during Operation Enoggera, June 1966. [AWM CUN/66/0525/VN]

'Tunnel rat' Lance Corporal Ron Rockliffe 6RAR, of Campsie, NSW, prepares to drop into a Viet Cong tunnel during Operation Enoggera, June 1966. [AWM CUN/66/0525/VN]

Just 40 kilometres from Saigon, around an area known as the Iron Triangle in the Cu Chi district, lay the most complex Viet Cong tunnel system in South Vietnam. The area, a Viet Cong stronghold, was heavily defended and used as a base for attacks on the South Vietnamese capital, Saigon. The most extensive of the tunnel systems, which covered some 400 kilometres, lay to the north of the village of Cu Chi.

The tunnels concealed living areas, storage depots, ordnance factories, hospitals, headquarters – a range of facilities than enabled people to live, and wage war from, underground for years at a time. When United States and Australian troops began sweeps into the area they had no idea of the tunnels’ existence. Known as Operation Crimp and involving some 8,000 troops from the United States 1st Infantry Division, the 173rd Airborne Brigade and troops of the 1st Battalion, Royal Australian Regiment (1RAR), the attempt to defeat the Viet Cong in the Cu Chi district was, to that date, the largest American operation in Vietnam.

  • The Cu Chi tunnel system was discovered during Operation Crimp, carried out by the US Army’s 173rd and 3rd Brigades together with 1RAR in Cu Chi, Binh Duong Province in January 1966. During the operation, engineers of 3 Field Troop, Royal Australian Engineers, used a turbo jet blower to produce and circulate diesel mist into a section of the tunnel system, when ignited it destroyed this part of the tunnel. [AWM P01595.007]
  • A US Army map showing the location of tunnels in the Cu Chi Area.
  • A diorama showing a typical village ‘cordon and search’ operation and the type of intricate tunnel systems often constructed by the Viet Cong. [Vietnam, their place in history; the Australian War Memorial remembers those who served in Vietnam, Australian War Memorial, 1992.]
  • Second Lieutenant John ‘Lofty’ Dwyer of 1RAR stands in front of a typical Viet Cong bunker in Ho Bo Woods during Operation Crimp. The bunker’s roof was constructed of hard packed, baked mud that set like concrete. January 1966. [AWM KEL/66/0020/VN]
  • Second Lieutenant John Burrows of WA (left), Defence and Employment Platoon Commander, uses a field radio to call in helicopters during searches of an enemy bunker system in the Xuyen Moc region of Phuoc Tuy Province. On the right is Private Greg Tulloch of Vic. February 1971. [AWM PJE/71/0021/VN]
  • Section Commander Corporal Joe Danyluk of NSW (right) and Private Dick Bligh of Qld, of B Company 8RAR, ‘take five’ before beginning their search of a Viet Cong bunker system in the Long Hai mountains during Operation Hamersley, February 1970. [AWM WAR/70/0160/VN]. Once inside the tunnels, the Australians encountered a range of defences; lethal panji stakes, spiders, centipedes, snakes, hornets, bats, fire ants and bees were all used by the Viet Cong to kill or injure intruders. Snakes were hidden in bamboo tubes and tied to pieces of wire on the tunnel ceiling, waiting to be knocked out of the tube by the larger American or Australian tunnel ‘rats’. In the Cu Chi tunnels the VC used to take boxes of scorpions with a tripwire and that was a booby trap. You tripped the wire, the box would open and the scorpions would come into the tunnel. [Lieutenant Jack Flowers in The Tunnels of Cu Chi, Hodder and Stoughton, London, 1985, p. 125]
  • A diagram of the Cu Chi tunnel system displayed at the tunnel entrance at Cu Chi. It shows over 200 kilometres of arterial tunnels (not including the branches). [AWM P01293.017]
  • Cu Chi has become a popular destination with many tourists keen to see the narrow and claustrophobic tunnels. [Image courtesy of Anna Sabiel]
  • A typical Viet Cong booby trap recreated at the Cu Chi tunnels. [Image courtesy John Newman]
  • A barely visible air shaft in the undergrowth at the Long Phuoc tunnels. [Image courtesy John Newman]

The Viet Cong were ready, having been bombed, shelled and seen reconnaissance aircraft overhead they knew that such preparations were followed by an offensive. The tunnels’ defenders were heavily outnumbered, many of them were teenagers, some even younger, but in the kind of fighting for which they had been trained none of these factors were disadvantageous – space underground was limited and one or two men, familiar with the tunnels’ layout could hold up a force and inflict casualties out of all proportion to their numbers.

The Australians and Americans had difficulty finding any enemy, but Viet Cong snipers caused a steadily rising number of casualties. As they moved through the Cu Chi district, United Stated and Australian troops encountered mines, foxholes, trenches and caves, but of Viet Cong there were almost no sightings. There was little fighting of the type expected in a major offensive and even when it became apparent that the enemy were present in tunnels beneath their feet, the difficulty in finding entrances made pursuing the Viet Cong difficult.

For the Australians, who had been dropped as a blocking force on Crimp’s northern perimeter, the operation was a frustrating experience. By the third day their area of responsibility had been covered but no Viet Cong had been killed, or even seen. Only one conclusion could be reached, that the enemy were underground and as the Australians occupied the area they began to find the tunnels.

Thanks to the tunnels, we could remain with the Americans and see how their troops behaved and reacted, watch their mistakes. Our observations helped us decide what kinds of booby traps to set and where to set them. [Lieutenant Nguyen Tanh Linh in The Tunnels of Cu Chi, Hodder and Stoughton, London, 1985, p. 51] Part of a model showing a typical section of the Cu Chi tunnel system. This display is in a visitor briefing room in an area about 10 kilometres from Cu Chi where some of the tunnel complex has been preserved, Thanh Pho Ho Chi Minh Province, Vietnam 1988. [AWM P01293.013/ P01293.014]

Part of a model showing a typical section of the Cu Chi tunnel system. This display is in a visitor briefing room in an area about 10 kilometres from Cu Chi where some of the tunnel complex has been preserved, Thanh Pho Ho Chi Minh Province, Vietnam 1988. [AWM P01293.013/ P01293.014]

Over the next four days the Australians, along with the Americans, uncovered nearly two kilometres of communication tunnels, bunkers and underground chambers. During their introduction to tunnel warfare Australian troops found caches of ammunition, food and numerous booby traps. While they were developing systems for exploring the tunnels during Operation Crimp, the Australians had yet to devise methods of engaging in underground combat. By the time the operation ended on 14 January, the number of Australian dead in Vietnam had doubled from eight to sixteen. Behind them the Australians and Americans left empty and burnt villages. Their populations, considered too close to the Viet Cong, had been relocated.

Operation Crimp showed that the Viet Cong were a determined and well-organised enemy who had the ability to fight on their own terms, even against a major operation. The existence and the extent of the tunnel systems surprised the Americans and Australians. One year after Operation Crimp the Americans launched another offensive in the Cu Chi district and even after this second series of attacks, the tunnels survived. They were used as a base from which the Viet Cong launched attacks on Saigon during the 1968 Tet offensive. After the grievous casualties sustained by the Viet Cong in Tet, the war against America and its allies was carried more and more by the North Vietnamese Army and the role of the tunnels diminished. They had been crucial to the Viet Cong’s prosecution of the war but in 1969 carpet bombing by United States aircraft rendered the tunnels uninhabitable.

The Cu Chi Tunnels have become a popular tourist destination. [Images courtesy of John Newman]

Such was the rate of attrition among those who fought in the tunnels that of the 300 Viet Cong engaged in their defence when Operation Crimp began, only four survived the war. By Vietnamese estimates, some 12,000 Viet Cong and civilians lost their lives in Cu Chi during the war. The province has become a well-visited tourist destination because of the remnants of the wartime tunnels.


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Instructions for use of the ‘Mighty Mite’, a smoke-generating machine used to locate Viet Cong Tunnel entrances. [Lessons Learned no 52 – Operation 16/65 VO Dat Do Rice Bowl 21 November – 17 December, Operation New Life, AWM 273/14]

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A brief on ‘Lessons learned in past operations’ 27 August 1965. The brief outlines Viet Cong tactics and the characteristics of their tunnels. [AWM 273 – Operations. Orders of battle [26]

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View video of '30 Viet Cong tunnels'. Using a special detector, Australian troops found more than 30 Viet Cong tunnels and underground hides in an area about 4 kilometres south of the Task Force base at Nui Dat.