Thread: 56 tonne bomb

Originally Posted by CraigE

The reality is it takes some sort on impact explosion to detonate the AN. Firefighters got there just at the wrong time. Hence why we would have to respond so quick to AN trucks with fire or brake probs before any sort of explosion occurred or a contained vessel heats up to point where it will go bang. AN burning on its own will not explode.

That was my point, after 30 min (or thereabouts) everything would have been very hot, and a truck by its very construction and purpose is a mixed load. It may only take a drive line/shock absorber/something else exploding from heat to provide the trigger.


Martyn

Tragic for those involved, but bloody rare considering the massive amounts used. Id be more concerned about how fatigue and inexperience or road conditions contributed. There's more chance of people being injured due to the road or inexperienced or fatigued drivers of heavy vehicles carrying feather pillows than by AN transport explosions.

Those reminiscing fertiliser use, this AN is minimum 99.5% AN 3mm 'coated' non porous prill (vs fertiliser grade around 40%,non-coated and larger diameter porous prill), its coating reduces water absorption thus increasing shelf life as AN is naturally hygroscopic (absorbs water), the water acts as a desensitizing agent. And diluting/washing away with water is actually one of the emergency response or clean-up procedures for any spill. But that doesnt mean the fertiliser grade stuff didnt work very well it just isnt as efficient, but is/WAS cheaper. Even the 40% grade is restricted as it has been used in 'dirty' ANFO bombs. The only fertiliser grades available at the nursery are sub 20% (if at all).

Yes AN by itself is very safe unless boiling and contained as this may have been, if this was a MMU (hard to tell from photo remains) then it may have had a mixing tank of diesel, but it would not have been mixed as ANFO during transport, that's not how its done, only mixed when loading holes (OK for the experts, bagged ANFO is shipped on pallets and isn't as popular nowadays, even still, requires an explosion to detonate it - number 8 det sensitive). The accident may have allowed the two to mix by rupturing the compartments, but its all speculation until the investigation is published.

Alternatively it may have been AN emulsion for wet holes and greater density, even still, this would not have had a sensitiser added until being loaded into drill holes, again, a rupture may have occurred, still to be investigated.

There are some comments from other shotfirers/blast crew/mine rescue/knowledgeable workplace types - that are factual, any overreactions at this stage (before incident investigation results) are not helping the public perception of the true hazard on the roads. Should we discuss the amount of cyanide and sulphuric acid that gets trucked around? LPG and BLEVE blasts (Boiling Liquid Expanding Vapour Explosion)...I wouldn't want to live near a petrol station with an LPG bullet/tank, even though they have venting valves, which are mechanical and could fail to vent quickly enough...or at all.

But best wishes to those injured for a quick recovery.

Download the relevant code here: Australian Code for the Transport of Explosives by Road and Rail - 3rd edition - Safe Work Australia

http://archive.wired.com/science/dis...dayintech_0416


April 16, 1947: Ship Explosion Ignites 3-Day Rain of Fire and Death




I read this story about 30 years ago in a Readers Digest. I later worked for the Road Transport Training Council of Aust. Qld branch and one of the subjects that I use to teach to licence standards was The carriage of Dangerous goods By road The above story I use to use as an example of the powers of this product.
Hodgo

This is a good read...lots of other dangerous goods on the roads, need to look at the truck technology as NSW is.

Fuel tankers are among the most dangerous vehicles on the road, carrying loads that make them vulnerable to rollover and explosions. Two recent, fatal accidents involved tanker rollovers, but recommended safety measures specifically designed to reduce rollovers haven’t been followed through. Ann Arnold investigates...

...On the Princes Highway, with only a bit further to go in their seven hour drive, tragedy struck, in the form of an out of control fuel tanker. The tanker, owned by Cootes Transport, had taken a bend too fast and was swivelling and swaying towards them at an estimated 80-90 kph.

After striking two other cars and injuring their occupants, the tanker rolled into the Bridge family’s car,...


The explosive risk of fuel tankers - Background Briefing - ABC Radio National (Australian Broadcasting Corporation)

Originally Posted by Greatsouthernland

Tragic for those involved, but bloody rare considering the massive amounts used. Id be more concerned about how fatigue and inexperience or road conditions contributed. There's more chance of people being injured due to the road or inexperienced or fatigued drivers of heavy vehicles carrying feather pillows than by AN transport explosions.

Those reminiscing fertiliser use, this AN is minimum 99.5% AN 3mm 'coated' non porous prill (vs fertiliser grade around 40%,non-coated and larger diameter porous prill), its coating reduces water absorption thus increasing shelf life as AN is naturally hygroscopic (absorbs water), the water acts as a desensitizing agent. And diluting/washing away with water is actually one of the emergency response or clean-up procedures for any spill. But that doesnt mean the fertiliser grade stuff didnt work very well it just isnt as efficient, but is/WAS cheaper. Even the 40% grade is restricted as it has been used in 'dirty' ANFO bombs. The only fertiliser grades available at the nursery are sub 20% (if at all).

Yes AN by itself is very safe unless boiling and contained as this may have been, if this was a MMU (hard to tell from photo remains) then it may have had a mixing tank of diesel, but it would not have been mixed as ANFO during transport, that's not how its done, only mixed when loading holes (OK for the experts, bagged ANFO is shipped on pallets and isn't as popular nowadays, even still, requires an explosion to detonate it - number 8 det sensitive). The accident may have allowed the two to mix by rupturing the compartments, but its all speculation until the investigation is published.

Alternatively it may have been AN emulsion for wet holes and greater density, even still, this would not have had a sensitiser added until being loaded into drill holes, again, a rupture may have occurred, still to be investigated.

There are some comments from other shotfirers/blast crew/mine rescue/knowledgeable workplace types - that are factual, any overreactions at this stage (before incident investigation results) are not helping the public perception of the true hazard on the roads. Should we discuss the amount of cyanide and sulphuric acid that gets trucked around? LPG and BLEVE blasts (Boiling Liquid Expanding Vapour Explosion)...I wouldn't want to live near a petrol station with an LPG bullet, even though they have venting valves, which are mechanical and could fail to vent quickly enough...or at all.

But best wishes to those injured for a quick recovery.

Download the relevant code here: Australian Code for the Transport of Explosives by Road and Rail - 3rd edition - Safe Work Australia

My understanding is it was just a road train with AN only. Not an MPU or MMU as you have highlighted. Should not be being a B double. I know here in WA the MPUs are only supposed to be rigid vehicles and not supposed to carry a mixed load on public roads (though there are certain exemptions in mining towns areas of short transport). As said when we got MPU fires we would get a little nervous, but never had any go bang.

Mrs Hay Ewe showed me some pictures yesterday and we talked about it.
I think what happened to make this more devastating is this:-

Truck travelling along the road. A fair few of us know how narrow the roads are, how there is not much, if any, of a defined edge.
I believe it was a road train or at least a B-Double
It looks as though the road dips down to the creek crossing.
Some how for some reason, the truck became out of control and rolled over in the creek bed OR some how the center of the explosion was in the creek.

This channeled the explosion and shockwave along the creek to remove the normal crossing and damage the rail bridge.

If it had happened on a normal flat section of road, I would not expect as much damage to the road as the shock wave would have gone upwards and outwards.

as this was in the creek bed, it travelled the creek and as the underside of the bridge was hollow, took that out.

Originally Posted by Hay Ewe

.....

This channeled the explosion and shockwave along the creek to remove the normal crossing and damage the rail bridge.

If it had happened on a normal flat section of road, I would not expect as much damage to the road as the shock wave would have gone upwards and outwards.

as this was in the creek bed, it travelled the creek and as the underside of the bridge was hollow, took that out.

And this channelling, mainly by the bridge approach embankment, would appear to have saved the lives of all those who were injured!

John

The Beirut explosion was apparently due to a large pile of ammonium nitrate that had been sitting around for six years “It is unacceptable that a shipment of 2,750 tonnes of ammonium nitrate has been present for six years in a warehouse, without taking preventive measures and endangering the safety of citizens”.

Lebanon explosion: Huge blast rocks Beirut

Regards,
Tote