Gas explosion in a Hymer in Oswestry, Shropshire

DBK

LIFE MEMBER
Jan 9, 2013
15,963
36,112
Plympton, Devon
Funster No
24,219
MH
PVC, Murvi Morocco
Exp
2013
The price is £40k at the start of the story then suffers a degree of inflation I think. Glad no one hurt.

Subscribers  do not see these advertisements

 

Hollyberry

LIFE MEMBER
Apr 24, 2011
5,600
42,296
New Forest.
Funster No
16,134
MH
None.
Exp
4yrs
Do you think they meant 40000. Can't imagine what you'd build into a motorhome to make it almost half a million pounds. And the insurance on it would be astronomical.

Lucky family weren't in it at the time.
 

jollyrodger

LIFE MEMBER
Oct 1, 2012
5,625
23,409
Devon/Cornwall
Funster No
23,107
MH
MONCAYO MEDITERRANEO
Exp
Since 1970'ish
Police say they are keen to speak to this man who was seen leaving the area

:D
Wanted.jpg
 

Tootles

Funster
Deceased RIP
Sep 14, 2013
9,512
34,790
Lancaster
Funster No
28,093
MH
Coachbuilt
Exp
Was a newbie, now a Middie.
'It highlights how dangerous gas canisters can be when involved in a fire - they can go bang.'
said Ian Leigh, Fire Service station manager and fire investigation officer for Shropshire Fire and Rescue Service.

Wish I was bright enough to be a fire investigation officer. :(:(
 

vwalan

Funster
Sep 23, 2008
8,808
5,666
roche cornwall
Funster No
4,148
MH
lynton5th wheel
Exp
since a child
lpg bottles shouldnt go bang thety have pressure release valves on them . they should release a quantity of gas that flares up that all. only very small canisters dont have them .
oxy bottles do go bang .
 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
12,186
40,902
Planet Zog
Funster No
3,243
MH
A Class Le Voyageur
Exp
since 2008
lpg bottles shouldnt go bang thety have pressure release valves on them . they should release a quantity of gas that flares up that all. only very small canisters dont have them .
oxy bottles do go bang .

If the rate of gas boil off exceeds the capacity of the safety valve then pressure will build and build until something gives. Result is a catastrophic explosion called a Bleve......
http://en.m.wikipedia.org/wiki/Boiling_liquid_expanding_vapor_explosion

You don't want to be anywhere nearby when that happens. There is some scary footage on YouTube. Hampshire fire service demonstrated to us on a gas firefighting course some years ago using a butane cigarette lighter refill
 

vwalan

Funster
Sep 23, 2008
8,808
5,666
roche cornwall
Funster No
4,148
MH
lynton5th wheel
Exp
since a child
but with lpg it doesnt exceed the release valve . using a gas lighter refill is just to frighten you it doesnt have a release valve .

Subscribers  do not see these advertisements

 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
12,186
40,902
Planet Zog
Funster No
3,243
MH
A Class Le Voyageur
Exp
since 2008
No, it was to demonstrate the effect not frighten us. We served on 40,000 m3 gas ships.........

Look at rail cars - there is a famous bit of footage where the cameraman was killed along with a lot of others due to a bleve. Please don't try and say that rail cars don't have safety valves. They do. I've seen and worked with enough of them.

Having said that, the Hymer explosion would not have been a bleve. Please read the science behind it. They can and do happen, which is why the fire service cordon off any cylinder fire or fire where cylinders are suspected to a great distance..... But hey ho, what do they know?
 

icantremember

LIFE MEMBER
Sep 2, 2010
7,604
14,602
Near to Watton in Norfolk
Funster No
13,512
MH
Hymer T-SL668
Exp
since 2005
I've never seen an LPG cylinder of any sort with a safety valve? Where's it hidden?

On Calor cylinders and probably most other makes the "Safety" outlet is on the valve directly opposite where the tails are screwed in and is marked to keep hands off.

I believe it is a plastic material designed to melt before the cylinder explodes.

Subscribers  do not see these advertisements

 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
12,186
40,902
Planet Zog
Funster No
3,243
MH
A Class Le Voyageur
Exp
since 2008
On Calor cylinders and probably most other makes the "Safety" outlet is on the valve directly opposite where the tails are screwed in and is marked to keep hands off.

I believe it is a plastic material designed to melt before the cylinder explodes.

Yes, that is right......... Though it will not be enough in some circumstances. The below from Wikipedia

In a fire, the pressure in a gas cylinder rises in direct proportion to its temperature. If the internal pressure exceeds the mechanical limitations of the cylinder and there are no means to safely vent the pressurized gas to the atmosphere, the vessel will fail mechanically. If the vessel contents are ignitable, this event may result in a "fireball". If the cylinder's contents are liquid, but become a gas at ambient conditions, this is commonly referred to as a Boiling Liquid Expanding Vapour Explosion (BLEVE).

Medical gas cylinders in the UK and other countries have a seal of Wood's metal between the valve block and the cylinder body. This seal melts at a comparatively low temperature (70°C) and allows the contents of the cylinder to escape in a controlled fashion, lessening the risk of explosion.
 

hilldweller

LIFE MEMBER
Dec 5, 2008
658
36,083
Macclesfield
Funster No
5,089
MH
Zilch Mk1
Exp
From Aug 2007
If the rate of gas boil off exceeds the capacity of the safety valve then pressure will build and build until something gives

I've watched them being tested at HSE. Put tank in a pit and set a fire all around it ( can't remember what the fire was ) then eventually Woooooooooooooooooooooooooooosh when it vents.

The words of the explosives guy "if anything is left it's a fire, if nothing left it's an explosion", you get this picture from all the middle east bombings.
 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
12,186
40,902
Planet Zog
Funster No
3,243
MH
A Class Le Voyageur
Exp
since 2008
I've watched them being tested at HSE. Put tank in a pit and set a fire all around it ( can't remember what the fire was ) then eventually Woooooooooooooooooooooooooooosh when it vents.

The words of the explosives guy "if anything is left it's a fire, if nothing left it's an explosion", you get this picture from all the middle east bombings.
Yes, even with a lighter fuel can it was spectacular - simply on a bit of concrete block in a tray of burning diesel. In the video below they heard the whooshing noise which was the venting but finally it all became too much for the cylinder. What happens is that the heat is conducted away by the liquid, but in the vapour space the metal heats right up causing stress in the cylinder. Finally the pressure gets to be too much and cylinder failure results - with a whole load what was was liquid suddenly turning to vapour due to the huge pressure drop. Ker-bang!!

upload_2014-8-10_9-46-16.jpeg ► 1:46► 1:46
www.youtube.com/watch?v=Xf3WKTwHpIU

Subscribers  do not see these advertisements

 
Last edited:
Top