Explosion in Bristol

[Saleen836]

At a water treatment facility, sadly 4 dead with one being a 16yo lad just started out on his apprenticeship
https://www.bbc.co.uk/news/uk-55191585

[GadgeS3C]

Are you getting your news by carrier pigeon?

[Eric Mc]

Sack the pigeon, I say.

[anonymous-user]

No matter how slow the news it's such a sickener that the poor lad was just starting out in life.

[bristolracer]

Very sad
The news stories have said that dogs were used in the search
I'm imagining that the explosion threw them quite some distance, it must have been very distressing for all the emergency staff involved.

[normalbloke]

Plus the factor of what was in the tank that went ‘pop’......

[carinatauk]

normalbloke said:

Plus the factor of what was in the tank that went ‘pop’......

Anaerobic digestor = methane. Sparkless tools only, no naked flames for obvious reasons. Odd that the tank didn't have an expolsion vent or it was inadequate

[bristolracer]

carinatauk said:

Anaerobic digestor = methane. Sparkless tools only, no naked flames for obvious reasons. Odd that the tank didn't have an expolsion vent or it was inadequate

A friend of mine works for the HSE. He once told me that accidents are rarely as a result of one large failure. There is often a series of errors that lead to the catastrophic failure
So there probably was adequate equipment to prevent an explosion, but a failure or an operator error elsewhere in the system created the conditions for a tragic accident

[GadgeS3C]

bristolracer said:

carinatauk said:

Anaerobic digestor = methane. Sparkless tools only, no naked flames for obvious reasons. Odd that the tank didn't have an expolsion vent or it was inadequate

A friend of mine works for the HSE. He once told me that accidents are rarely as a result of one large failure. There is often a series of errors that lead to the catastrophic failure
So there probably was adequate equipment to prevent an explosion, but a failure or an operator error elsewhere in the system created the conditions for a tragic accident

The series of errors is described nicely in the Swiss cheese model.

Edit - link now fixed

Edited by GadgeS3C on Sunday 6th December 13:18

[bristolracer]

GadgeS3C said:

The series of errors is described nicely in the Swiss cheese model.

I get a 404 on that link?

[Teddy Lop]

bristolracer said:

A friend of mine works for the HSE. He once told me that accidents are rarely as a result of one large failure. There is often a series of errors that lead to the catastrophic failure
So there probably was adequate equipment to prevent an explosion, but a failure or an operator error elsewhere in the system created the conditions for a tragic accident

normally, but there's a few - a guy was sacked after sustaining burns on a rubbish tip site where they were collecting methane and running engines (50 litre V20) to generate electric. He had a donut shaped burn around his mouth leading to an obvious conclusion that despite strenuous denial, he wasnt adhering to the sites no smoking policy...

(That's not to cast any aspersions on the poor victims of this story of which I know nothing.)

[Dogwatch]

bristolracer said:

GadgeS3C said:

The series of errors is described nicely in the Swiss cheese model.

I get a 404 on that link?

Wikipedia

Think 'The Titanic'

[GadgeS3C]

Sorry - messed up the link: Swiss cheese model

[shep1001]

carinatauk said:

Anaerobic digestor = methane. Sparkless tools only, no naked flames for obvious reasons. Odd that the tank didn't have an expolsion vent or it was inadequate

It was a cake silo not a digester. The sludge had already been through the digestion process and the majority of the methane collected in those big white gas bags to the right seen in some of the photos. If the digesters or the gas bags had gone bang, it would have demolished half the site.

The digested liquid sludge once biologically inert is then separated by centrifuges producing a cake, that ‘cake’ is sometimes blended with a material like dry lime, creating an exothermic reaction, initiated by the moisture in the sludge which further enhances pathogen kill. Cake is then stored in those silos & removed by truck from the bottom.

What was in that silo is the fertiliser many farmers spread on their crops

Edited by shep1001 on Tuesday 8th December 00:10

[hutchst]

Somebody that knows what they're talking about. A rare beast indeed on PistonHeads.

[sgtBerbatov]

I watch a chap on YouTube called Plainly Difficult, and he's covered some explosions like this. More often than not, the silo's that do go bang will have inadequate venting (if at all), and that they're filled in such a way that allowed gas to build up in excess of what it was designed to take.

[GAjon]

shep1001 said:

carinatauk said:

Anaerobic digestor = methane. Sparkless tools only, no naked flames for obvious reasons. Odd that the tank didn't have an expolsion vent or it was inadequate

It was a cake silo not a digester. The sludge had already been through the digestion process and the majority of the methane collected in those big white gas bags to the right seen in some of the photos. If the digesters or the gas bags had gone bang, it would have demolished half the site.

The digested liquid sludge once biologically inert is then separated by centrifuges producing a cake, that ‘cake’ is sometimes blended with a material like dry lime, creating an exothermic reaction, initiated by the moisture in the sludge which further enhances pathogen kill. Cake is then stored in those silos & removed by truck from the bottom.

What was in that silo is the fertiliser many farmers spread on their crops

Edited by shep1001 on Tuesday 8th December 00:10

And the cake is generally fed by screw conveyors, from the dewatering presses, which have serpentine screws in troughs, they break occasionally and require welding repairs.

This was my first thought when I read about this very tragic incident, but time and a HSE investigation will tell.

[GloverMart]

bristolracer said:

Very sad
The news stories have said that dogs were used in the search
I'm imagining that the explosion threw them quite some distance, it must have been very distressing for all the emergency staff involved.

One of the red top parers said that one of the workers was blown 500 feet into the nearby lake.

Doesn't bear thinking about, poor bloke!

[Allanv]

In a previous life I worked in transport, and was bored in the office so decided to load a trailer.

I hold a C+E and back then forklift certs, there was an explosion which shifted the trailer a few feet.

It was this - https://www.hse.gov.uk/comah/sragtech/casealbright...

We had the yard nextdoor.

We were evacuated from Avonmouth very quickly, the helicopters and cop cars were telling us to go home and shower but we ended up at the bosses very nice house.

As far as I am aware no one died but it was a long time ago.

Condolences to those that lost their life's in the Wessex explosion.

[shep1001]

hutchst said:

Somebody that knows what they're talking about. A rare beast indeed on PistonHeads.

28 years in the industry since leaving school paddling about in sh*t all over the world last Friday. Give or take 30 minutes it could have ended at 27 years & 364 days......


Cake silos have been in use for years all over the country. This is the only one I am aware of where such a catastrophic event has occurred.