Operation Crimp was a military offensive of the Vietnam War. It was conducted by American and Australian forces in Binh Duong Province, in South Vietnam, from January 8 to January 14, 1966. Under the overall command of Major General Jonathan O. Seaman, about 8,000 troops of the US Army’s 1st Infantry Division, which included the US 173rd Airborne Brigade and the US 3rd Infantry Brigade, participated in Operation Crimp. Attached to the US 173rd Brigade was one Australian battalion from the 1st Royal Australian Regiment.
The main objective of Operation Crimp was to destroy the Vietcong headquarters which lay in concealment underground in Cu Chi, in the Province of Binh Duong. There was a system of tunnels which led to the main headquarters. They covered more than 120 miles. During the battle, specialized sappers, called tunnel rats, were sent in on search and destroy missions to annihilate any hiding enemy soldiers and to plant explosives to destroy the tunnels.
Preceded by artillery fire and napalm and airstrikes, Operation Crimp was initiated at 09:30 hours on January 8. Airmobile operation began with the first American units being inserted by helicopter to the north, west and south. The US 3rd Infantry Brigade, commanded by Colonel William Brodbeck, was inserted by helicopter and by road. In the north, 1st Royal Australian Regiment was inserted into its landing zone (LZ March) 1.9 miles to the south-west. Amid strong resistance, the Australians fought their way through the maze of bunkers, punji stakes and booby traps but they were eventually able to force a Viet Cong regional force company to withdraw as they continued their advance. This area was heavily seeded with trip wires connected to shells and grenades dangling from branches.
The task of breaking into and exploring the communist tunnels started on January 9, with the objective now switching to the location, clearance and destruction of the tunnel complexes. Whereas standard US Army practice was to seal, blow up or otherwise attempt to render tunnel systems unusable with smoke, tear gas and explosives before quickly moving on, the Australians spent the next few days laboriously searching and mapping the complexes they found using military engineers. Led by Captain Sandy MacGregor, the Australian sappers from 3 Field Troop systematically tackled the tunnels, using telephone line and compasses to plot the subterranean passages. Small-scale contacts between the communists and the Australians continued and MacGregor was later awarded the Military Cross for his leadership.
The Australians kept on searching the tunnels, finding a large quantity of documents and equipment, and by January 10 they had seized 59 weapons, 20,000 rounds of ammunition, 100 fragmentation grenades, one 57-mm recoilless rifle, explosives, clothing and medical supplies. At least 11 Vietcong had also been killed in the fighting. Contact also continued, and overnight the Australians killed another five Vietcong outside their perimeter, while numerous actions occurred during the day as the US 173rd Brigade maintained its sweep. The US 3rd Brigade subsequently uncovered a significant tunnel complex themselves; while they attempted to clear the tunnels, heavy hand-to-hand fighting broke out above ground and Lieutenant Colonel Robert Haldane was later awarded the Silver Star for his actions when he rushed a bunker while under fire armed only with a pistol, in order to give first aid to a number of wounded soldiers. His courage inspired his men to complete the assault, and ultimately helped ensure the successful evacuation of the casualties and the capture of their objective.
More than 11 miles of tunnels had been uncovered and searched by the Australians. A large quantity of documents had been recovered, including more than 100,000 pages detailing operational structure as well as the name of agents operating in Saigon. 90 weapons were also captured, as well as thousands of rounds of ammunition and enough equipment. During Operation Crimp the brave Australians had faced stiff resistance, suffering 8 killed and 29 wounded, while claiming 27 Vietcong killed and a further 30 probably killed. The Americans had also been involved in heavy fighting and their casualties included 14 killed and 76 wounded. Total communist casualties included 128 confirmed killed, and another 190 probably killed, as well as 92 captured and another 509 suspects detained. Half of the American and Australian troops that were killed in this battle were lost to booby traps rather than to enemy gun fire.
Below, troops of a reconnaissance platoon advancing amid rice paddies during Operation Crimp