Two stories of mad science this time about this vicious class of weapons, and one about how they ought to be done:

Radioactive Nazi Land Mines

Like Mad Science #1, the first story comes from Atomic Adventures (2017) by James Mahaffey.   Ordinary land mines have steel or aluminum cases, and so can be found by metal detectors.  These work by inducing a current in the object with a changing magnetic field, and then picking up the object’s field.  To defeat that, you can make the mine out of something non-conductive, and the Nazis actually built 11 million mines with glass shells.  These had the added ‘feature’ of riddling people with glass shards, which are hard to see on X-rays.

But you don’t just want to hide mines – you want  to be able to find them yourself.  So the Nazis came up with another idea – make them radioactive.   They can then be detected with Geiger counters.   In 1944/45 they built a class of anti-tank mines called Topfmines which were painted with a material called ‘tarnsand’.   No one seems to know quite what this was, but it appears to be tailings from uranium mining.   The mine’s case was made of pressed wood pulp, and it contained 6 kg of TNT.  It had a pressure plate on the top and a trigger that responded to 150 kg of pressure.  That’s heavier than a person (at least in those days), but would be set off by a vehicle.

They then mounted a Geiger counter called the Stuttgart 43 on a long pole and attached it to the front of tanks. It could pick up this mine long before they drove over it.

The Allies never caught onto this.   About 800,000 were made in 1944 and 45.   They were probably laid in France and Poland to stop Allied advances, and many may still be there, along with so much other unexploded ordnance.  The casings would degrade over time, and the charges would also deteriorate, but the radioactivity would last forever.  They’re just another memento of Nazi occupation.

British Nuclear Land Mines, Heated by Chickens

One expects craziness from Nazis, but an even madder project came from the British.   They started developing their own nuclear weapons in the 1950s after the US cut off research cooperation due to spying scandals.  Their first bomb was called Blue Danube, and went into production in 1956.   This was a huge implosion device, weighing about 5 tons, with about a 10 kiloton yield.   That’s a hard thing to move by bomber, so they thought about other applications for the same design.   They hit upon using it as a land mine on the plains of Northern Germany.   If the Cold War turned hot, and thousands of Soviet tanks rolled out from East Germany to attack the West, these would be set off by timers or miles-long wires for remote detonators.   The project was called Blue Peacock and two were actually built:

Yes, turning Germany into a radioactive wasteland just to block tanks was a deeply terrible idea.  But, they reasoned, it would be even worse if it didn’t work.   These bombs were just sitting there in the cold ground.  How could they be sure that the timers and detonators wouldn’t freeze up in the winter?  They considered swathing them in glass fiber pillows, but then hit on a much better idea – put a crate of chickens inside.  Their body heat would amount to about 10 watts per chicken.  Keep them from pecking at the wiring, give them some feed and water, and they would be fine, at least until they were vaporized.

This was discovered on April 1st, 2004, when the program was declassified after 50 years.  April 1st, eh?   But no, it wasn’t a prank – there were archival drawings of just where the coop would go.  Wasn’t that rather cruel to the chickens?   Well, when setting off an atomic bomb, the health of chickens is low on one’s priority list.

Although ten of them were proposed to be built, the whole program was cancelled in 1958 when they came to their senses.  However, the US did go on to build nuclear land mines, the Medium Atomic Demolition Munition, and deployed them between 1961 and 1989 in Europe, South Korea, and possibly even the Golan Heights.

Modern Mine Replacements

Land mines are horrible anyway, and injure many thousands of people a year, often children playing in abandoned fields.   Most countries are banning them under the auspices of the Ottawa Land Mine Treaty.  Unfortunately, the major military powers – the US, Russia, China, and India – have refused to sign.  In spite of spending trillions on their militaries, they still like this cheap and dangerous weapon, even though it injures their own people.

But if there have to be minefields, let’s at least make them safer.  A friend of mine suggested that instead of strewing a field with explosives, strew it with sensors.  When they detect a person or vehicle crossing a restricted area, signal an automated mortar.  It drops a shell on the detected position within a couple of seconds.   The signals are encrypted to prevent spoofing, and the sensors disable themselves if disturbed.  The whole thing can be disabled if your own troops are entering the area, and shut down when the front changes position.  This is just what DARPA was trying to do with its Smart Dust program in the late 1990s.

Given the progress in Internet-of-Things electronics, this could well be cheaper than minefields!  These sensors could cost pennies.   Maybe then this weapon class can be eliminated everywhere.