So you've discovered a gas leak

Re: So you\'ve discovered a gas leak

[ QUOTE ]
I like the Coarse Yachting story of the crew who, on discovering gas in the boat, decided that as it was heavier than air they would bail it out with saucepans. Passers by were treated to the sight of the crew appearing to pour out nothing over the side!

[/ QUOTE ]

Ah yes, Michael Green's "The are of coarse sailing", a seminal work. A coarse sailor can be defined as one who in a moment of nautical crisis shouts "for gods sake turn right!"

Surely the problem with attempting to bail the gas out of the bilge is the risk of getting right down in the bilge to start bailing and then overcome by the gas thats there? Depends on the layout I 'spose and whether you can bail from the cockpit. I think at least opening every hatch & window and flooding the bilges to displace the gas before retiring a safe distance for a period of time would be best course of action.
 
Re: So you\'ve discovered a gas leak

[ QUOTE ]
My gas card details below - some detail taken from the Blue Book; (and I'm prepared to be shot down!)



GENERAL

Low Pressure Gas (LPG) is heavier than air and, if released, may travel some distance whilst seeking the lowest part of a space. It is therefore possible for gas to accumulate in relatively inaccessible areas, such as bilges, and diffuse to form an explosive mixture with air.


[/ QUOTE ]

All good advice. On a pedantic note, however, LPG is the abbreviation for "Liquefied Petroleum Gas", not "Low Pressure Gas".

On a non-boaty topic, I did once get Transco to move themselves by applying a naked light to a gas leak. We'd had a smell of gas in the street outside our house on-and-off for about 5 years. We had called the gas emergency number on several occasions, they had come, investigated and said that they could detect gas, but that it couldn't be their gas because there was no main nearby and anyway the constitution wasn't right (the methane/butane/propane ratios were wrong). They suggested decaying organic material.

So I wondered whether there was enough gas coming off to be usable (if it wasn't their's, then it might as well be mine). I shoved a piece of half-inch pipe into the ground to act as a collector, and lit the gas coming off. Result: ten inch high flame. And then I compared that flame with the flame on the boat cooker, and reckoned it was bigger than all the burners combined. When we are cooking for a full crew on the boat, a 2.5kg bottle lasts a week, with the gas in use for say a tenth of the time. So my 'organic material' was producing gas at about 25 kg per week, and had been doing so for about 5 years. That's more than 6 tons of gas. Now I happen to know that rotting organic material gives off about 1% of its weight as gas, so apparently I had about 600 tons of decaying material under the road verge. And Transco had said that only about one square metre of the verge showed significant concentrations, so apparently I had a 1 sq m column of material weighing 600 tons. I was a little doubtful, so called Environmental Services from our local council. After seeing flame and calculation, they called Transco, who then produced a "SENIOR ENGINEER". After taking me to task for lighting the gas because it could have exploded in his main, and my pointing out that it couldn't, because they'd told me several times that it wasn't their gas, they took more measurements and again said that it wasn't their's. And this time they took a sample in a bottle so that they could test it in the laboratory, not just with a field instrument. Next day they confirmed their finding.

Two days later I had a cringing phone call to say that they were wrong, and that it was their gas. I asked about their analysis, and was told that they had found their lab chromatograph was "wrongly calibrated". "But what about your field chromatograph?" "Well, we calibrated that against our lab instrument, so they were both wrong."

If I hadn't set light to it, I reckon I would still have a gas leak outside my house. Not that I would recommend it as a way of finding leaks.
 
Re: So you\'ve discovered a gas leak

/forums/images/graemlins/laugh.gif Brilliant story.

What about the bit where they said there was no main nearby - did they admit to being at fault there too!
 
Re: So you\'ve discovered a gas leak - or have you?

[ QUOTE ]
ASFAIK there haven't been (m)any on-board explosions due to gas flooding.

[/ QUOTE ]
Lord Trenchard springs to mind!
 
Re: level of smell

I think you'll find that the concetration of "smell" is intended to make sure it is noticed long before the danger level is noticed, but that does not mean there is not a dangerous level lurking in a confined space some where waiting for a source of ignition.

Also some people have a much less acute sense of smell than others.
 
Re: So you\'ve discovered a gas leak

A few years ago in St Peter Port the was a smell of gas coming from a boat in the marina, the firemen arrived and with a large water powered fan (100cms) and air pipe blow the down the fore hatch and out via the main hatch anything that not bolted down out of the boat. They kept it going for a good 20 minutes.
 
Re: So you\'ve discovered a gas leak

The main was on the other side of the road. The leak was in the pipe from the main to my neighbours house. The escaping gas got trapped under the cambered concrete road, but at one point near the verge the concrete had been cut away. The trapped gas was coming up at that point in such density that there was a bare patch on the verge where nothing would grow. According to Transco's measurements, the gas coming out of the ground was 84% methane.
 
You must log in or register to reply here.

Share this page

Top