The S-mine, or "Bouncing Betty", was a a type of bounding mine developed by Germany in the 1930s and used by them extensively during the Second World War. When tripped, the body of the mine was propelled 3–4 feet into the air, where the main charge was detonated, spraying fragments at roughly waist height. A profound psychological effect on Allied forces caused by the mine's tendency to maim, rather than kill, was observed, and its performance in the early stages of that conflict prompted the United States and other countries to copy its design.
The American M16 mine was developed directly from captured S-mine designs and derivatives were later produced by the Soviet Union, the People's Republic of China and Yugoslavia. Presumably one of the latter was the source of the "Bouncing Betty" mines used against U.S. forces during the Vietnam War.
Using official statistics, around 16% of total American lethal casualties in the Vietnam conflict were caused by land mines, although much higher figures have been claimed. For the Marines in Vietnam, the percentage of lethal casualties was 23%. The effect of these devices far surpassed their lethal capabilities. Prominent military journalist and former United States Army colonel David H. Hackworth would later assign blame for the My Lai massacre on mines and booby traps, stating that American soldiers "went mad" after weeks of seeing friends blown away by mines and booby traps.
A Wide Variety of Devices
Since no indigenous arms industry existed in Vietnam at the time of the conflict, many of the devices used against U.S. ground forces were of a relatively primitive nature. Booby traps, command-detonated land mines and anti-vehicular mines were commonly home-manufactured from dud U.S. bombs and artillery shells. Sometimes a .50 caliber round, normally used in heavy machine guns or sniper rifles, was inserted into a bamboo tube which was then buried beneath the ground surface. Stepping on the tube would cause a nail to be rammed into the round, setting it off. Mines on the roads were a constant hazard and every major road had to be cleared each morning before being opened to traffic.
The level of sophistication of explosive devices encountered in Vietnam varied by area of operations. In regions where wheeled vehicles were commonly used, more powerful landmines were employed by the enemy. In the highlands, where ground transportation was by foot, small booby traps were often created from American fragmentation grenades. Regardless, when advancing by foot, the line would be kept spread out, with a defined minimum distance between one "grunt" and the next, to minimize injuries should a mine be set off.
The M113 armored personnel carrier, the most widely used armored vehicle by the U.S. in Vietnam, was very susceptible to mines and improvised explosive devices, due to its thinly armored bottom. The enemy quickly discovered this vulnerability and learned to take advantage of it. U.S. Army troops adapted by covering the floor inside the APCs with sandbags.
Frederick Downs Jr., author of The Killing Zone: My Life in the Vietnam War, served as a combat platoon leader in Vietnam in 1967-68 with the U.S. Army 3rd Brigade, 4th Infantry Division. A couple of decades after returning from his abbreviated tour of duty, he opened an opinion piece in the Washington Post as follows:
TWENTY YEARS AGO this month, in Tam Key, Vietnam, I stepped on a land mine. It was a type we called a "Bouncing Betty," because when you stepped on it, it bounded into the air and exploded waist-high, so that it would do maximum damage. My left arm was blown off; grievous damage was also done to my right arm, both buttocks, both legs and both feet. Five of the men in my platoon were wounded along with me.
In 2009, Vietnam's Ministry of Defense claimed that more than one-third of the land in six central Vietnamese provinces remained uncleared of land mines and unexploded ordnance, and that more than 42,000 people had been killed in accidents involving land mines and unexploded bombs since 1975.