WW2 claims three more lives

[cosmicalstorm]

It says the bomb blew up an hour before they were supposed to start defusing it, wonder what went wrong? Maybe someone wanted his picture taken with it before they started?

World War II bomb kills three in Germany

Three people have been killed and six injured trying to defuse a World War II bomb in central Germany.

Workers building a sports stadium had earlier unearthed the bomb in the town of Goettingen.

It was not immediately clear why the bomb, reportedly weighing 500kg (1,100lb), had detonated.

Unexploded WWII bombs dropped by Allied planes are frequently found in Germany, though it is unusual for them to explode unexpectedly.

A special commission is investigating the causes of the explosion, while prosecutors are considering whether the team leader should face charges of manslaughter through culpable negligence, the BBC's Oana Lungescu reports from Berlin.

The blast happened an hour before the defusing operation was due to start.

Officials said the three men who died were experienced sappers, or combat engineers, who over 20 years had defused up to 700 bombs.

More than 7,000 people were immediately evacuated when the 500kg bomb was found. Several schools, a kindergarten and local companies remain closed.

Last week, another device was successfully defused close to the site.

In Berlin, four bombs have been found in the past two months, including one near the capital's main airport.

[Pelranius]

Sometimes bombs go off due to internal factors (i.e. something corrodes badly enough that volatile explosives or the fuse go off) or being exposed was enough to destabilize the bomb.

[Sea Skimmer]

I think its around 10-15 people a year who are killed by UXOs in western Europe each year. It really is a shit job for the guys who have to defuse these things, since even when you can identify the type of bomb or shell, you cannot be certain what kind of explosive it was filled with. Some just decay into rubbish, while others will crystallize and become incredibly shock sensitive. Since this bomb went off before they even started defusing it, I'd get the explosive had become very shock sensitive, and went off because it no longer had earth cover to dampen it.

[Zor]

Not really suprising, every now and again some poor french farmer gets blown up when his combine goes over a great war era artillery shell.

Zor

[Temujin]

Not really suprising, every now and again some poor french farmer gets blown up when his combine goes over a great war era artillery shell.

Zor

And often times they can be chemical shells as well.

[Darth Fanboy]

Can anyone explain to me why the bomb was being defused and not remotely detonated instead? Is it because the bomb was so big that it would have cause too much damage to the surrounding area? What is the maximum amount of property damage a device has to cause before ruling out detonation?

[General Zod]

A somewhat more detailed article

Germany is mourning the loss of three bomb disposal experts killed yesterday by a 2,000lb World War II aerial mine.

Three others were seriously injured by the explosion which occurred when a bomb disposal team was cutting through the acid fuse of the bomb buried 24ft down in the university city of Goettingen.

Fire brigade spokesman Frank Gloth said, 'Evacuation measures were far advanced for 7,200 people in a wide radius from where the bomb lay.

Rescue forces hard at work following an unexpected explosion of a Second World War bomb in Goettingen, Germany

Rescue forces at the scene of the blast which took place in Goettingen, Germany, when a World War II bomb went off

'Work was proceeding with a water cutter to get through the fuse of the bomb when it went off. It was due to be defused at 10.30pm but detonated at 9.45pm.

'Altogether, there were 13 bomb disposal workers in the area.'

Goettingen was bombed several times during World War II by both the RAF and American planes.

The bomb that killed the disposal team was being left until late to be made safe to allow an inter city express train to move through Goettingen station towards Hanover.

Bomb experts in Goettingen (pictured) had worked to defuse the bomb before it detonated, but were unsuccessful

Authorities had evacuated 7,200 residents before experts attempted to defuse the 500 kg bomb

Several houses had their fronts blown off by the blast. The bomb was found as builders dug the foundations for a new sports hall.

Germany remains contaminated with unexploded bombs that are becoming increasingly unstable with age.

In the whole of Germany, more than 2,000 tons of American and British aerial bombs and all sorts of munitions ranging from German hand grenades and tank mines to Russian artillery shells are recovered every year.
Enlarge lancaster bomber

In Germany, more than 2,000 tons of American and British aerial bombs are recovered every year

The bomb which went off in Goettingen is of a type containing a vial of acetone which bursts on impact and is meant to trickle down and dissolve a celluloid disk that keeps back the cocked firing pin that then ignites the TNT inside.

Hans-Jürgen Weise, one of Germany's most experienced bomb disposal experts, retired two years ago after four decades spent making Germany cities safe.

He warned in 2008 of the danger of rotting detonators. 'The last few years we’ve found that the detonators we take out of such bombs are increasingly brittle.

'We had three extracted detonators go off with a pissssh sound while they were being transported away, all it took was a bit of vibration.

'One day such bombs will be so sensitive that no one will be able to handle them.'

[Sea Skimmer]

Can anyone explain to me why the bomb was being defused and not remotely detonated instead? Is it because the bomb was so big that it would have cause too much damage to the surrounding area? What is the maximum amount of property damage a device has to cause before ruling out detonation?

A 1000lb bomb can make a 20 foot diameter crater and can break glass a half mile away; fragments with lethal energy could come down the better part of a mile away. Direct blast damage would be over a several hundred yard radius depending on what is in the way. Any bomb bigger then maybe 50-100lb is unreasonable to blow in place in an urban area if any other option exists. All the more so since has the article points out, they find these all the time in Berlin and other cities. Its not like this is a special case, just an unfortunate one.

http://www.youtube.com/watch?v=LptXaQ4Wkjw&NR=1
This is a 1,000lb explosion, it is not small and it probably didn't even use a military grade of high explosive since that stuff costs more then the ammonium nitrate they use for most large Mythbusters blasts.

[Alyeska]

http://www.youtube.com/watch?v=LptXaQ4Wkjw&NR=1
This is a 1,000lb explosion, it is not small and it probably didn't even use a military grade of high explosive since that stuff costs more then the ammonium nitrate they use for most large Mythbusters blasts.

You would be correct. That is the 2nd most powerful explosion on Mythbusters. The most power explosion was created using only 700 pounds of military grade high explosive.

[Darth Fanboy]

snip

Much obliged. Zod's article was also very good, but it also leads me to repeat the second part of my question of "how much potential damage does it/should it take before authorities consider detonating the bomb instead of risking lives defusing it? Especially given the last line of the article where the expert says that someday it will not be possible to handle these devices.

[Sky Captain]

Can anyone explain to me why the bomb was being defused and not remotely detonated instead? Is it because the bomb was so big that it would have cause too much damage to the surrounding area? What is the maximum amount of property damage a device has to cause before ruling out detonation?

A 1000lb bomb can make a 20 foot diameter crater and can break glass a half mile away; fragments with lethal energy could come down the better part of a mile away. Direct blast damage would be over a several hundred yard radius depending on what is in the way. Any bomb bigger then maybe 50-100lb is unreasonable to blow in place in an urban area if any other option exists. All the more so since has the article points out, they find these all the time in Berlin and other cities. Its not like this is a special case, just an unfortunate one.

What if the bomb is detonated in deep pit? It should direct most of the blast upward and also contain most of the shrapnel. I remember a case here when an old bomb was found at construction site in a nearby town and deemed too dangerous to transport. A ~5 m deep pit was dug nearby and bomb pushed in by remote means and then detonated.

[Sea Skimmer]

That's got to be a sketchy operation to have lifted the bomb in the first place to move it to the pit if you thought it was that unstable and still live fused. Are you sure the bomb was not defused, but then blow in place anyway because of the instability of the explosives?

A pit would help a lot with blast, but you'd still have fragmentation going up and coming back down from a bomb this big. Whats more digging the pit and making the move all will take a lot of time, during which you have a mass evacuation in this case. Its really not a sound policy to blow in place when you are regularly faced with the task in an urban area. The fact just is UXOs are pain to deal with, we will have no good solution until we can make a robot that is capable of very sensitive movements and field deployable into situations like a 1000lb bomb at the bottom of a hole on a construction site.

[Sky Captain]

That's got to be a sketchy operation to have lifted the bomb in the first place to move it to the pit if you thought it was that unstable and still live fused. Are you sure the bomb was not defused, but then blow in place anyway because of the instability of the explosives?

I don't know exact details of the operation, it was just briefly said on the news that bomb was deemed too dangerous to move to bomb range so it was decided to dig a pit and detonate it there. It was in sparsely built up suburban area so relatively few people had to be evacuated for the duration of the operation.

[Night_stalker]

Yeah, and moving a 60 year old 2,000 lb bomb to a pit would require taking it on the roads. God helps us if the truck gets into a traffic accident despite he police cars that I'm sure will be clearing the way ahead of it. Plus the EOD experts must have decided it was safe enough to try and defuse it, rather than detonating it.

[General Zod]

Yeah, and moving a 60 year old 2,000 lb bomb to a pit would require taking it on the roads. God helps us if the truck gets into a traffic accident despite he police cars that I'm sure will be clearing the way ahead of it. Plus the EOD experts must have decided it was safe enough to try and defuse it, rather than detonating it.

Or if the truck simply hits a pothole and the vibrations set it off.

[Night_stalker]

Exactly, it's just too risky to even move it.

[salm]

Yeah, and moving a 60 year old 2,000 lb bomb to a pit would require taking it on the roads. God helps us if the truck gets into a traffic accident despite he police cars that I'm sure will be clearing the way ahead of it. Plus the EOD experts must have decided it was safe enough to try and defuse it, rather than detonating it.

Well, i guess you could transport it with a helicopter if you wanted to avoid roads and potholes.

[Starglider]

Well, i guess you could transport it with a helicopter if you wanted to avoid roads and potholes.

You'd have to have an extremely good vibration isolation system, and if the helicopter has any kind of glitch (mechanical failure, wind gust, software glitch...) the bomb could hit something and go off.

This might be a good application for a cargo airship, assuming you can wait for a very calm day to carry out the operation.

[Broomstick]

Well, i guess you could transport it with a helicopter if you wanted to avoid roads and potholes.

You sir obviously have little to no experience with helicopters. They are loaded with vibration, not to mention any loads under them are subjected to all sorts of swaying and such - NOT a good idea in that situation!

[Oskuro]

Would burying such a device and then detonating it do any good? Or would it make things worse?

Maybe cover it in dirt, and then extend a somewhat flexible mesh over the blast area to minimize the possibility of debris? (you know, like those huge metal meshes they cover rock walls with to avoid loose rocks from falling on roads).

(yes, it is a wacky idea I just had, I have no idea about bomb defusal procedures)

[General Zod]

Would burying such a device and then detonating it do any good? Or would it make things worse?

Maybe cover it in dirt, and then extend a somewhat flexible mesh over the blast area to minimize the possibility of debris? (you know, like those huge metal meshes they cover rock walls with to avoid loose rocks from falling on roads).

(yes, it is a wacky idea I just had, I have no idea about bomb defusal procedures)

Considering the region they uncovered the bomb I don't think that would be a very practical solution.

[CJvR]

Not really suprising, every now and again some poor french farmer gets blown up when his combine goes over a great war era artillery shell.

IIRC they found one of the mines that didn't go off at Messines in WW1, it is under some poor fellows farm! Another one blew in 1955 from a lighting strike... Hundreds of millions of shells were fired on the narrow strip of France where the trenches were if even tenth of a % were duds there will be echoes of the barrages for decades yet.

Every year baltic fishers catch shellcasings and mustard gas in their nets, sometimes with very nasty consequences.

Disarming sucks, but you can trust the goverment to make it even worse!
We had a rather amusing incident here in Landskrona, Sweden. We were not even in the war but being in a prime invasion spot we had some serious defences built to protect the harbour here. Unfortunately someone misplaced the mine maps to one of the fields and after the war the goverment offered 10000 SKr ( a small fortune back then ) to anyone willing to find and secure the mines. The first fellow blew up, the second guy finished the job and was given the reward - then they sent the taxman after him and took back most of the money...

[Night_stalker]

Then they sent someone with a bucket to clean up the first guy.

[Sea Skimmer]

Would burying such a device and then detonating it do any good? Or would it make things worse?

Maybe cover it in dirt, and then extend a somewhat flexible mesh over the blast area to minimize the possibility of debris? (you know, like those huge metal meshes they cover rock walls with to avoid loose rocks from falling on roads).

(yes, it is a wacky idea I just had, I have no idea about bomb defusal procedures)

Burying the bomb would help contain the blast a great deal, provided that what it was buried under was ideally sand or at least loose dry earth, not heavy clay or rocky soil that will rain down with big chunks. However the trick is... burying it. If the bomb is so unstable that you can't defuse it or move it, do you really want to go dropping tons of crap on top of it from a dump truck? This would be a time when a robot dump truck was useful to have around. The US has even done some trials with robot dump trucks and robot digging machines for digging up stuff on old bombing ranges, but they work very slowly and are only really suited to a very controlled area (not a random construction site in a city).

Metal mesh would be a bad idea, it would turn into fragmentation. Something like a large tarp made out of kevlar could be useful though. They have those for shielding pieces of buildings facing implosions. But rigging all starts getting very complicated and expensive to setup, and the people doing the setup have to be within the blast radius should the bomb go off sooner then was desired.

After all that effort it really makes more sense to just risk the bomb exploding defusing it, instead of ensuring it explodes. You are going to place human life at risk dealing with the bomb, one way or another, so why not risk it in the most productive and efficient way you can?

[Coyote]

Would a Zeppelin have the stability to pick it up and move it? So long as the wind is right (ie, pretty much still) it might have a good chance of gently hoisting it out and away..?