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LAPD blast containment truck fails, seventeen people injured 6

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I wonder if they left a vent closed or somthing.
 
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These total containment vessels are highly engineered devices.

What is interesting is the LAPD may have been using a single use protocol on this "controlled" detonation, which means the vessel would have had to be replaced regardless.
 
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My guess- there's a rating for X lbs of pipe-bomb (pipe with smokeless powder) or something like that and they got something a little more energetic than the normal home-made bomb.
Here's how to open a container: Note that when the box fails, it doesn't just fail a little bit.
 
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It looks like the door failed. The vessel rocket propelled itself forward in to the cab of the truck.

Screenshot_20210701-141801_nx2xa9.png


As for th quantity of explosives, it appears these units are rated for 25lbs of TNT.
 
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The chamber uses a system similar to o a v-band clamp to hold the door on. There are two relatively small threaded rods that pull the clamp halves together. All of that assembly is missing in the picture. I would be interested to see if the vessel can verify proper setting of the clamping system (limit switch). If not, there may have been some movement of the door to cause an impact which broke the clamping system off.
 
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If this is accurate, the charge in the bomb truck should have been within limits, or perhaps a bit over (they might not have a scale on site, so the weight might be an estimate).
[URL unfurl="true" said:
https://www.mercurynews.com/2021/07/01/large-fireworks-explosion-in-south-la-injures-at-least-9-people/[/URL]]The blast happened in the area of East 27th Street near San Pedro Street at 7:36 p.m., according to LAPD Chief Michel Moore during a news conference Wednesday evening.

The explosion occurred while the LAPD’s bomb squad was attempting to dispose of a cache of illegal fireworks that were discovered earlier in the day, Moore said. Police seized more than 5,000 pounds of illegal fireworks in the same area and took one person into custody. . . .

Moore said that there were less than 10 pounds of total charge inside of the containment vehicle, which was rated to handle up to 15 pounds of total charge.
Click to expand...
 
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Oop's back to the drawing board ...

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
 
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Don't know why they didn't just soak it in a dumpster in water which would have rendered the black powder useless and removed the instigator for the plastic.

Depending what form the sodium and the lithium was in you might have got a bit of heat reaction but by that point the black powder would be dead and wouldn't fire which would just leave the plastic which could then be taken to a burn pit.
 
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This is the SE version on a car trailer.

image_ihlzf7.png


It has a rotational lock.

image_fk00jb.png


image_nthx3u.png


And it can open as little or as much as needed, usually not more than to get what ever they are putting in there in.

image_swszcz.png


It also have a cradle, of fabrics in there so the explosives lay in the cradle so it can't bump around when driving.

image_nkzrkq.png


When this is used they always takes it away and detonate it at a secure location.

With really small objects they can detonate them where there at, if they deem it secure, as they did here in Umeå ones


BR A
 
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Hmmm,

These things look very much like pig trap doors / quick opening enclosures found on many pipelines, pressure vessels etc.

I can't find what pressure they think these things should be rated to but at the size of the units seen, those closure yokes actually look rather weedy. Add in the shock element of all this and their issue is that you need them to be already quite highly stressed simply to seal the door via the wedge shaped closure halves. Then add on the internal pressure.

There are much better design IMHO, which use a moveable element to engage a large forged ring and hence it is then the shear strength of the ring to hold it in place.

But they really should be taking a leaf out of large gun doors which usually use some sort of key and turn action.

My suspicion looking at a few of these is that either the ring was over tightened too many times and the ring started to fail at the high stress concentration or that someone has started small, gradually increased this in size and scaled up without realising that some of the forces go up as a square of the size.

That is one big door - I reckon 36" or maybe even 42" and in internal shock pressure of what 250/300 bar? or 3,500 to 4500 psi. At 42" that a force on the door of 5 million lbs or 2,250 tonnes and that's non shock load. That clamp is way undersized and a poor design. Too many sharp corners and not thick enough.

They want something more like this.... which is a gun barrel by the way and not a pig trap.

image_lhflib.png


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
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That swedish one is much much better as the forces trying to pull it apart are direct contact forces / shear forces on those keys on the ring.

Clamps are just not as good as you have bending forces on the U shaped ring which concentrate in the top of the U. Add i the cat that people will over tighten them or need to generate force on the screwe which is then multiplied several time by the shallow angle inside the clamp and Bang - it fails.

It would be great if they could find the parts of the clamp, but I guess the manufacturers won't wont this to get out into the wild....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
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We use a thing called a pig stick for that sort of stuff. Its official name is a disrupter.

Its classed as a fire arm but its basically a tube filled with water with a explosive charge to squirt it when fired.

The basic ones are free floating and you set them up with what ever is around and then tie a rope or something onto them because they go whizzing off in the opposite direction when you fire them. Then its a swine trying to find them afterwards. It kills the electrics if it is a device. And as 99% of the time suspect bags are false alarms it means they can be in and out and no fuss or damage.

When you start using point charges there is usually a lot of collateral damage mainly windows and you run the risk of the charge triggering the main explosive charge.
 
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Yes I can see that, that metod is better.
The SE national bomb squad, actually managed to blow up the a parking garage to a polis building in a controlled blasting. haha [lol]
Luckily no one got hurt.

image_slffhe.png


One of the police's storage buildings in the garrison area in Linköping was completely destroyed during the night until Tuesday in a detonation.

At four on Monday afternoon, the evacuation of the Garrison area in Linköping began after the police found explosive dough in the saddle of a moped, according to information to Aftonbladet.
The explosive dough must also have been covered with nails.

The moped was with the police in the room for stolen gods and was just to be returned to the owner when the discovery was made. 170 people were evacuated and a total of about 3,000 people were affected in the immediate area.

The national bomb squad was called in and at midnight a loud bang was heard over parts of Linköping.
That was when the bomb squad carried out what would be a controlled explosion of the object.

But something went wrong and the explosion became more powerful than the police had thought.
Pictures from the scene show one of the police buildings that has been completely destroyed.

- It probably did not go quite as one had hoped while it was such a passing heavy detonation.
At the same time, they had taken this into account, which is why the area was evacuated, says police spokesman Erik Terneborn.
Click to expand...
.

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
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Our boss in our Sapper unit was felix high threat Northern island trained. There is a remit that all Royal Engineers are trained with basic battle field EOD.

Our boss had been doing for it over 5 years in NI and then got his commission and sent on his way to a normal unit. But due to his qualification level and experience he used to keep a lot of the kit with him.

He also had the contacts and skill set to have access to a hellva lot of bang with very little restrictions where he could train with it.

So basically every time we went on exercise there was always some sort of bomb scare which we would need to deal with. He also used to get roped into any callouts in London and they had multiple shouts on going. But because he knew them all, if they needed heavy plant and labour they would just give him a call and he would send us lot out. It was good fun so there was no shortage of volunteers for his on call list. But we would take it there and hand it over to the real team and then take it back when they were finished.

If you want to see what a UK EOD unit is like have a google for bluestone42 its pretty accurate in my experience.





 
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