LPG Bubble Tester essential?

[doug748]

Yes, and I must say that I made a mistake on the post number I was referring to it was in fact post three - of yours. : -}

 

[paulieraw]

How on earth do you think a bubble tester would have found the loose connection at the cylinder? Do you know how bubble testers


Not if the gas locker had been properly gas-tight, as it should have been.



The report into the explosion said that the bilge pumping procedure was basically worthless, and "have the undesirable effect of giving crews a false sense of security". Maybe that's why the crew weren't unduly bothered when the gas alarm went off twice the day before the explosion. Maybe that's also why the crew weren't bothered when they came back from the pub and could smell gas in the gas locker. If the crew had enjoyed a healthier respect for LPG, the explosion wouldn't have happened.

Yes, that is why I said they should have tested the bottle with liquid.
The locker was not gas tight as there was a hole in it, many boats don’t have gas safe lockers.
The bilge pumping was not used as the boat was in harbour, the principle works at sea. It is pump to dry and an on other 20 pumps.
Bear in mind the JSASTC do more sea miles than most, they have less incidents if you take the miles into account. The processes do work, but relying on any system and ignoring your nose is not a good approach.

Lest be straight LPG is potentially dangerous in a boat. There is enough evidence of explosions to demonstrate this. That lest mean it can’t be safe with common sense, but there will always be risk.

 

[AntarcticPilot]

Yes, that is why I said they should have tested the bottle with liquid.
The locker was not gas tight as there was a hole in it, many boats don’t have gas safe lockers.
The bilge pumping was not used as the boat was in harbour, the principle works at sea. It is pump to dry and an on other 20 pumps.
Bear in mind the JSASTC do more sea miles than most, they have less incidents if you take the miles into account. The processes do work, but relying on any system and ignoring your nose is not a good approach.

Lest be straight LPG is potentially dangerous in a boat. There is enough evidence of explosions to demonstrate this. That lest mean it can’t be safe with common sense, but there will always be risk.

Obviously, different pumps will clear different volumes, but I'd guess that 20 pumps clear at most 20 litres of air/gas from the bilges. That strikes me as an insignificant volume. and it will be coming from the location where the sump is, which could easily not be connected to a location where gas will flow to from the gas locker, so you are pumping 20 litres of air from the cabin. And that's assuming the bilge pump works effectively with gas; it may well not!

 

[JumbleDuck]

Having known of a boat go up in Poole harbour where the Skipper lost his leg, LPG should be treated with respect. The boat belonged to Military and I know they have a principle of gas on at the bottle, light the stove, gas off at the bottle then turn the stove off when it goes out. That reduces the risk.

I'm not sure we should all be adopting procedures which have failed so dramatically.

 

[JumbleDuck]

The other thing joint service crews do is hand pump the bilges dry plus 20. This pumps any gas out of the bilges ...

Only if a system designed to pump water also pumps gas and only if twenty strokes removes all the gas and only if there is no time for diffusion to take place.

 

[JumbleDuck]

Gas is heavier than air so sits and remains in the bilges. Unless you get the gas out it will build eventually to an explosive mixture.

Not true. Although both propane (molecular weight 44) and butane (58) are both heavier than nitrogen (28) and oxygen (32) they aren't very much heavier and mix quite fast by diffusion. If they didn't, there would be no risk of explosion, which in any case only exists when the gas has diffused enough to be below the upper explosive limit (9.5%) but above the lower limit (2.4%). A slow leak will diffuse away fast enough to avoid ever becoming explosive.

Some interesting experimental results at http://www.inpharmix.com/jps/Propane_dif_polycarb.html

 

[JumbleDuck]

I will disagree, I've seen at close quarters how the military train, repeat, repeat, repeat until you don't need to process an action in the higher cortex..

Very useful in some circumstances, I expct, but perhaps where gas safety is concerned more intelligent decision making and less learned reflex would be useful?

 

[pvb]

It wasn't deleted by me, the wretched mobile site deleted it for me! Can't be bothered to type it again, suffice it to say that LPG on a boat is perfectly safe if the crew is sensible.

 

[LittleSister]

I'm not sure we should all be adopting procedures which have failed so dramatically.

+1

Only if a system designed to pump water also pumps gas and only if twenty strokes removes all the gas and only if there is no time for diffusion to take place.

+1

Not true. . . .A slow leak will diffuse away fast enough to avoid ever becoming explosive.

+1

Very useful in some circumstances, I expct, but perhaps where gas safety is concerned more intelligent decision making and less learned reflex would be useful?

+10!

 

[duncan99210]

I will disagree, I've seen at close quarters how the military train, repeat, repeat, repeat until you don't need to process an action in the higher cortex..

You have a misplaced faith in the military if you really believe that! After 35 years in the military, I can tell you that you're missing an important element: train, repeat, supervise, repeat, supervise, repeat and so ad infinitum. Remove the supervision and all the good habits disappear overnight and the easy way of doing things is readopted.