World War II Bomb Disposal Slightest Movement Can 'Trigger A Catastrophe'
Following the deaths of three bomb-disposal workers in an explosion in Göttingen last week, Andreas Heil, head of explosives ordnance disposal firm Tauber, explains what went wrong and why it's so difficult to defuse the more than 100,000 unexploded World War II bombs still littering Germany.
SPIEGEL: Last week on Tuesday three of your colleagues were killed preparing to defuse a World War II bomb in Göttingen. What went wrong?
Andreas Heil: We still don't know exactly. But bombs with long-delay fuses, like the one in Göttingen, are the most dangerous. The problem is that you cannot tell the condition of the fuse just by looking at it.
SPIEGEL: What makes these kinds of long-delay fuses especially dangerous?
Heil: They have high tension detonator pins on springs, which are held back by a piece of plastic. Looking at the bomb from the outside, we are unable to tell whether the plastic disk is still functional or whether it has crumbled and the detonator pin is now just being held back by some, small mechanical effect. Under certain circumstances, the slightest movement or a change in temperature can cause the pin to move and trigger a catastrophe. Presumably in Göttingen there was a chain of tragic circumstances. What is clear is that the bomb itself was at fault. I knew two of the three on the bomb team that were killed. They were highly experienced specialists.
SPIEGEL: What could be done to avoid this in the future?
Heil: State and private explosive ordnance firms are very well equipped -- that is not the problem. The tragic thing about such accidents is that those who can tell us what went wrong generally do not survive the explosion. The last fatal incident was in 1990 in Wetzlar (in the German state of Hesse) with the same sort of detonator. Two colleagues died there.
SPIEGEL: Does it become more difficult to deactivate unexploded bombs from World War II over time? Because basically they are more than 65 years old and rotting from the inside out.
Heil: That is correct. It gets even more dangerous if the groundwater levels fluctuate and the detonator gets wet a few times, then dry a few times. Even so, the fuses were made from the best materials: The British fuses were made out of brass and the American ones out of high-alloyed aluminum compounds. They don't corrode. It was the very best of high-precision engineering. These things still work.
SPIEGEL: Which of the old munitions are especially dangerous?
Heil: Large mines like those that were used to booby trap bridges, or torpedo warheads. Both are just as dangerous as bombs with long-delay fuses, but they are rarer. It's estimated that the number of unexploded bombs in Germany totals more than 100,000, and each year several hundred are defused.
Interview conducted by Cordula Meyer