Salcombe - RIB explodes

[Mollers]

Originally Posted by willk

No joke really

When I had the Searay, It did often cross my mind that I was kissing my kids goodnight and putting them to bed next to a tank of highly explosive liquid, a bank of batteries and a heap of Mexican wiring.

The next kip aboard will be an oiler or possibly rag and stick.

[Nos4r2]

Originally Posted by Bigmuz7

which suggests petrol vapour is heavier than air

It is-that's why fuel stores have vents in the doors next to the floor.

It's not online but when I did the ADR course, they show a video of petrol vapour being poured a good few feet down a piece of guttering to a flame and the flame backtracking to the can.

[free]

I do a demo most years with about 2m of speaker cable as a dead short across a battery (controlled conditions before the H+S types pipe up.) After about 4 seconds you realise that there's no need for any additional fuel, the insulation does a good enough job.

free

Glad it was only the boat.

[neilda]

Very sorry to read that you've lost your boat - thank God none of you were aboard.

[DJS]

Very sorry to hear of the loss but just a thought re cables and or battery connections, if they are loose or corroded and there is a current draw this will result in significant heat being generated.

[Hightower]

First. I'm glad that no one was hurt.

What ever happened, I for one would want to know how this happened, for my own peace of mind.

I'm sure the insurance investigator will be down to have a look, but I would also get MAIB involved, there are many clues left behind a fire of this intensity.

[nikster]

Originally Posted by Mollers

When I had the Searay, It did often cross my mind that I was kissing my kids goodnight and putting them to bed next to a tank of highly explosive liquid, a bank of batteries and a heap of Mexican wiring.

The next kip aboard will be an oiler or possibly rag and stick.

Hey Mollers - In my late teens doing marine engineering I used to PDI Sea Rays when they came in the country and the 180 bow Riders - ooo eeee - we had a batch come through with the wiring on the fuel gauge to sender the wrong way round....... bugger me that was close...4 boats with a hot wires straight to the tank...! I seem to remember a service bulletin coming straight out that week..!

[Jizm]

Originally Posted by nikster

Hey Mollers - In my late teens doing marine engineering I used to PDI Sea Rays when they came in the country and the 180 bow Riders - ooo eeee - we had a batch come through with the wiring on the fuel gauge to sender the wrong way round....... bugger me that was close...4 boats with a hot wires straight to the tank...! I seem to remember a service bulletin coming straight out that week..!

Bloody hell... Surprised that got spotted on a PDI.

[Mollers]

Originally Posted by nikster

Hey Mollers - In my late teens doing marine engineering I used to PDI Sea Rays when they came in the country and the 180 bow Riders - ooo eeee - we had a batch come through with the wiring on the fuel gauge to sender the wrong way round....... bugger me that was close...4 boats with a hot wires straight to the tank...! I seem to remember a service bulletin coming straight out that week..!

I had 260 Sundancer. Searay were the pick of the US mass produced boats when the imports kicked off in the late 70's, but by the late 90's cost cutting had taken it's toll.

[Jizm]

There was a programme on discovery a short while ago where they filmed in the Sea Ray factory, looks like they've made some major investment in there in the last few years...looked quite impressive.

[Bigmuz7]

Originally Posted by Nos4r2

It is-that's why fuel stores have vents in the doors next to the floor.

It's not online but when I did the ADR course, they show a video of petrol vapour being poured a good few feet down a piece of guttering to a flame and the flame backtracking to the can.

One of the curious things I remembered whilst reinvigorating my interest in chemistry whilst tutoring my son for his intermediates (just a fave subject for me) was that a 'vapour' is a curious state of a liquid moving to a gas (or vice versa), and is highly dependant on a number of factors.

Whilst in a transitional phase.. petrol vapour may in bulk may be heavier than air ... but its made up of quite a few volatile and aromatic hyrdocarbons, like benzenes in particular, which all have different rates of evaporation dependant on ambient temperature for example.. so that suggests, that whilst you may smell their presence immediately, once their concentration has diminished, there may be less aromatic vapour present, and thus residual vapour is less detectable, but no less flammable.. particularly in an open boat but in an enclosed space with dodgy electrics, its got to be trouble.

This we all know, but the risk of not being able to detect the stuff when its a confined vapour next to electrics is I think what would be helpful to know how to detect/avoid..and infact something most of us if we are honest, is a part of normal boating we just live with unless you only use external tanks .. which on a 5m+ RIB is not common,.. so thats pretty much many of us

Merlin .. I think because of the violence of this incident it would be very helpful if at least you could give us a layout plan/sketch of your boat.

The ignition would be a subject for debate, but a plan of where evrything was might be helpful to us all, and to you, to help shed some light here

[Mollers]

Originally Posted by Bigmuz7

Whilst in a transitional phase.. petrol vapour may in bulk may be heavier than air ... but its made up of quite a few volatile and aromatic hyrdocarbons, like benzenes in particular, which all have different rates of evaporation dependant on ambient temperature for example.. so that suggests, that whilst you may smell their presence immediately, once their concentration has diminished, there may be less aromatic vapour present, and thus residual vapour is less detectable, but no less flammable..

Well I'm Wiki'd, I'd always had you down as thick as mince.

[Bigmuz7]

Originally Posted by Mollers

Well I'm Wiki'd, I'd always had you down as thick as mince.

I dont need Wiki to find your credentials fella

Originally Posted by Polwart

you might want some constructive comment rather than Mollers' pish.

give me another go ?

[Mollers]

Only teasin'.

[Bigmuz7]

Originally Posted by Mollers

Only teasin'.

Aye .. ... next time I might not be so subtle ..






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. away and make some pasties tosser

[Mollers]

Originally Posted by Bigmuz7

. away and make some pasties tosser

I would, if I could only remember how to make 'em.

[HUMBER P4VWL]

Originally Posted by Polwart

Sorry to hear about your issues, glad you are all OK. Might be worth reporting it to the MAIB as if there is a "lesson to be learned by everyone" then they should investigate and share that - even if its just a preliminary examination. I'd hope that they would take it seriously enough to come up with a likely cause (possibly with some sort of fire investigation expert) rather than speculation. I for one will be examining the condition of the main battery cables where they leave the console as clearly any chaffing causing a short here is a likely suspect that I've probably ignored. That's after my "isolator switch" - but I don't fancy getting to the switch if the console is alight! So thanks for sharing.

We have just had a misfiring fault diagnosed on a 2 year old 175 opti with 70 hrs as a wire to the compressor chafing through causing a short. Certainly worth checking wiring as Polwart says on any areas where chafing can occur. Considering this occurred within the engine where the design is mass produced, the likelihood of other wires retro fitted when putting consoles together would be much higher imho.

Glad you are all OK.

I'm very curious to look further in to the likelihood of fire when there is a console with 150l of fuel underneath and a bulkhead to separate the batteries, isolators etc from it.

[ecoXR24]

The good old Recreational Craft Directive calls up various standards to prevent this sort of situation. When purchasing a RIB with fuel tanks under the deck - or where fuel could get into the bilges - its worth checking these points with the manufacturer:

- larger boats must have a permanently installed fuel system
- spaces with fuel tanks must be vented, with rules about the area of the vents
- electrics in spaces which could get fuel vapour in should be ignition protected to ISO8846
- fuel filling points should ensure no uncontained fuel can get below deck
- fuel filling points should be more than 400mm from any vents
- there must be a means of preventing siphoning from the tank(s) if the fuel system fails
- metal tanks must be earthed

These are just the main points - there are lots of others. In practice this means all the components below deck, like bilge pumps, fuel valves, switches etc should meet ISO8846. All other electrics, including the battery, must be completely separate from any spaces that can collect fuel vapour. If split fuel can get onto the deck, any deck plates should be completely water-tight. The space vents should be big enough to prevent fuel vapour accumulating.

As far as I can see, if a RIB meets the rules then an explosion can't happen.

[Chris]

Originally Posted by ecoXR24

The good old Recreational Craft Directive calls up various standards to prevent this sort of situation. When purchasing a RIB with fuel tanks under the deck - or where fuel could get into the bilges - its worth checking these points with the manufacturer:

- larger boats must have a permanently installed fuel system
- spaces with fuel tanks must be vented, with rules about the area of the vents
- electrics in spaces which could get fuel vapour in should be ignition protected to ISO8846
- fuel filling points should ensure no uncontained fuel can get below deck
- fuel filling points should be more than 400mm from any vents
- there must be a means of preventing siphoning from the tank(s) if the fuel system fails
- metal tanks must be earthed

These are just the main points - there are lots of others. In practice this means all the components below deck, like bilge pumps, fuel valves, switches etc should meet ISO8846. All other electrics, including the battery, must be completely separate from any spaces that can collect fuel vapour. If split fuel can get onto the deck, any deck plates should be completely water-tight. The space vents should be big enough to prevent fuel vapour accumulating.

As far as I can see, if a RIB meets the rules then an explosion can't happen.

I cant think of many that would meet those rules

[Chris]

Originally Posted by Chris

I cant think of many that would meet those rules

on investigation my electronics (blue sea panel, battery switch etc are all ISO 8864 rated. The rule about the fuel filler and vent is an interesting one as I have a perko filler that has the vent built into the fitting as well.

THe tank in my rib is under deck and there are no vents or holes into the deck to vent it. Can't see how that would work?