Unforeseen Consequences

[Gafferbill]

………most caravaners are familiar with screws falling out and various bit and pieces working loose due to the rigors of towing their caravans.
Now my caravan is getting on in years but owned from new and I have always thought that the way the gas fire was secured was .......pathetic.

The fire sits on a rectangular hole cut in the caravan floor.
This floor like most caravans is a laminate of two outer pieces of thin plywood bonded to a much thicker layer of polystyrene.
The fire, which is relatively heavy, was fixed to the caravan floor with 3 self-tapping screws down one side of its rectangular baseplate.
The screws have always worked loose and are impossible to tighten.

The Unforeseen Consequences
Since the pipe was rigidly attached to the underside of the caravan and to the fire, the movement of the fire caused a metal fatigue fracture.

This problem was found because I do rigorous checks before and after every trip and in this instance I smelt gas when testing the system.
The fracture was not visible as it was in a union near an olive seal.
The leak has now been rectified and the fire is now bolted to the floor.

With hindsight I should have done this before or better still so should the makers of the caravan!

PS ……my caravan wheels are balanced.………the fire has been free to move around on its mountings during towing resulting in the cooper gas feed pipe breaking clean through causing gas to leak.

 

[Gafferbill]

The above post was altered during saving resulting in changes to the text hopefully it will appear here correctly

　
………most caravaners are familiar with screws falling out and various bit and pieces working loose due to the rigors of towing their caravans.
Now my caravan is getting on in years but owned from new and I have always thought that the way the gas fire was secured was .......pathetic.
The fire sits on a rectangular hole cut in the caravan floor.
This floor like most caravans is a laminate of two outer pieces of thin plywood bonded to a much thicker layer of polystyrene.
The fire, which is relatively heavy, was fixed to the caravan floor with 3 self-tapping screws down one side of its rectangular baseplate.
The screws have always worked loose and are impossible to tighten.

The Unforeseen Consequences
………the fire has been free to move around on its mountings during towing resulting in the cooper gas feed pipe breaking clean through causing gas to leak.Since the pipe was rigidly attached to the underside of the caravan and to the fire, the movement of the fire caused a metal fatigue fracture.
This problem was found because I do rigorous checks before and after every trip and in this instance I smelt gas when testing the system.
The fracture was not visible as it was in a union near an olive seal.
The leak has now been rectified and the fire is now bolted to the floor.

With hindsight I should have done this before or better still so should the makers of the caravan!
PS ……my caravan wheels are balanced.

 

[Steve L]

So Gaffer, you've used one of your 9 lives. Joking apart mate, that was a very lucky escape.

Unfortunately caravan construction regs are not as rigid as those for motorhomes. Niether of them go through the stringent car design and accident conformity tests. As motorhomes are classed as a converted commercial vehicle which comes under different sections of the regs.
To be quite honest this is another example to quantify bringing MOT testing to caravans and updating motorhome test's to include gas testing and installation checks for both variants.

There's a large percentage of caravanners who don't know how to check their caravan is safe and road worthy.
Or what to do if they smell or hear gas escaping.

Many years ago I saw a guy who had been told "there was a petrol leak under his car" go looking for it with his cigeret lighter. He managed to escape with minor burns but his car and two others on the pub car park were destroyed.
I had a VW LT35 diesel that suffered cracking injector pipes frequently. That was put down to vibration. I had the pipes changed to ductile copper ones and replaced them every year as a precautionary measure.

 

[Gafferbill]

Steveinleo...........I grew up on a working farm.
I used up at least 9 lives before I was 10 years old! .....

 

[waffler]

Horrendous! We had a similar scare in in previous van. Cooking toast on the grill the smoke alarm went off. Pressed the button to no avail. Took the battery out and it continued to sound. Turned out to be the carbon monoxide detector! The grill in a new caravan was giving off CO. The message is get a CO detector.

 

[seth1]

But although its a good idea,an mot on a caravan would only test the road worthyness of it,would a gas fire come into the test?
I bet the fuel pump was loose on that LT steve,seen loads of them doing that.

 

[ProfJohnL]

The OP's experiences is clearly unsatisfactory. But I have to say the insecure fixing of heaters is far from uncommon. Most heater manufacture actually supply clamping strips or other systems specifically designed to cope with the floor constructions weaknesses. I know from past experience that whilst these devices are supplied often caravan manufactures choose not to fit them.

That being said, it is actually quite rare for the gas pipe to fracture in the manner Gafferbill describes, and in no way an I belittling the seriousness of his experience, I do wonder if something else may have contributed to the failure.

Elsewhere I have seen fractured copper gas and water pipes inside compression fittings, and it has usually been shown that the fitting has either been separated and reconnected several times, or the coupling has been over tightened, witnessed by the deformity of the olive and pipe.

A compression fitting is designed so that as the fitting is closed, it squeezes the olive causing it to reduce its internal diameter to close onto the inserted pipe. The olive is malleable and so takes up any irregularities of the pipes outer surface and the internal surface of the coupling to provide a gas tight seal at working pressures.

In a correctly tightened coupling the olive deforms sufficiently to create the necessary seal, but over tightening compresses the olive further and the only way it can move is to reduce its diameter further. This in turn further compresses the inserted pipe, and at the point where the outer edge of the olive makes contact with the pipe, the pipes cross section changes and that causes the pipe to become weaker to bending motions at this point.

Additional crushing of the pipe not only occurs when a fitting is over tightened once, but also where a coupling is repeated opened and re-closed several times, even though the normal tightening routine or torque settings are used. This is due to the fact that the copper pipe and olive are malleable, and when a coupling is released, neither the olive of pipe recovers their original size and shape, so each re tightening reduces the diameter of the olive and pipe.

In the worst cases the internal diameter of the pipe can be reduced to less than half is staring diameter. and with such a reduction the pipe losses about 75% of its bend resistance.

Unfortunately it is common for a coupling to checked for tightness using a spanner to just tweek it 1/4 turn, but this has the same effect and will eventually reduce the pipe and weaken the pipe.

It reinforces the advice to have your gas appliances checked at least annually. It is particular pertinent to caravans and motor homes, as unlike most other gas installations they are subject to large amounts of vibration and other forces as the caravan is towed. And because they are often left unused for long periods of time often in less than ideal conditions, corrosion will build up on metal parts, and particularly insects find the tiny crevices in burners very appealing.

 

[Sproket]

Horrendous! We had a similar scare in in previous van. Cooking toast on the grill the smoke alarm went off. Pressed the button to no avail. Took the battery out and it continued to sound. Turned out to be the carbon monoxide detector! The grill in a new caravan was giving off CO. The message is get a CO detector.

Waffler !

I have just recently replaced our smoke alarms at home with two of these, it actually speaks & Say's if it's a fire or carbon monoxide alert.....
I will be replacing the one in the van with one of These

 

[Gafferbill]

Sprocket......wher yume bin ?

I too have a Carbon Monoxide alarm in my caravan though not a combined unit

..........at £20 you can't afford not to!!

 

[Jayster]

Horrendous! We had a similar scare in in previous van. Cooking toast on the grill the smoke alarm went off. Pressed the button to no avail. Took the battery out and it continued to sound. Turned out to be the carbon monoxide detector! The grill in a new caravan was giving off CO. The message is get a CO detector.

Waffler !

I have just recently replaced our smoke alarms at home with two of these, it actually speaks & Say's if it's a fire or carbon monoxide alert.....
I will be replacing the one in the van with one of These

We also bought one of those alarms Sproket.... As soon as you turned the cooker on to make a cuppa the damn thing went off... Even when the toaster was plugged in it would go off...
Middle of the night when everyone asleep every 10 mins you got Warning Carbon Monoxide Detected....
Tried it in the house while the van parked up... Not a peep... Put it in the van and shut the door with not a thing running or connected, you 'd hear the bloody thing singing to itself.....
Brought it back in the house to replace an old one works fine... Now use a First Alert alarm and detector....

 

[Sproket]

I have just tried my combined fire & Co2 alarm in the van with two gas rings going & the kettle boiling on one, i also put some toast in the toaster for good measure, the first slice was golden brown with no effect whatsoever on the alarm, i then turned up the toaster to burn a slice & see what effect it would have, well my original fire angel smoke alarm went off first & the a few seconds later the new one went off, the Co2 alarms did not activate on either alarm, i have just run a tape measure from the alarm to where the toaster is at the side of the sink & it is only 6' away.
Whilst doing this the door & the windows were shut the only thing ventilation was through the vents & boy did it get warm quick.
If mine was going off with a Co2 alert i would be calling for a gas engineer to find & sort the problem out & not changing the alarm ........
Maybe that the one that you have bought is faulty ?
These are the ones in the van at the moment & the top one went into alarm mode first

The culprit that activated the alarm