Personal Experience during South African Border War.
In the South African army, back in the late '70s at least, during the South African Border War, we knew this mine as the "Cheese mine" due to its resemblance to a round of gouda cheese. However, far from having an operating pressure of 180kg, SWAPO employed bakelite detonators which required only about 7kg of operating pressure. Using the bakelite detonators made the mines almost undetectable to a metal mine detector and also made them fragile. If the pressure did not come directly from the top the detonator stems would sometimes snap off. Anecdotal evidence supported by personal experience demonstrated this. Bagoong (talk) 14:57, 9 April 2014 (UTC)