Dangers of composite construction

I just read a report from the "Gotland runt" race in Sweden. There were a number of Seacart30s competing, and one of them had an accident. The reports say the centerhull burnt down to the waterline, leaving the crew with just the gear they carried when the accident happened. They managed to make some sort of "raft" from the two outrigger hulls and survived 6 hours on this "raft" before they were rescued. They were all rescued in relatively good conditions.

Over to mye question: How could the centerhull burn down to the waterline (or further down, what do I know) in mere minutes? If they carried loads of gasoline or similiar in the centerhull cabin I could understand it, and I dont know if they did.. But is there something inherent in their carbon/epoxy/core (honeycomb core?) construction making them more inflammable than other construction?
I dont have many theories, I did not think carbon fibers, applied epoxy and possibly paint burnt that well..


If you can read scandinavian languages, ref: http://www.skota.se/race/files/b164e6ae8da685d60f6ce5719e385ddf-670.html

Epoxid and polyester resins are hardly combustible. Some paints not. Furnishing could be another source, maybe sails from nylon.

Cheers,

Klaus

Maybe a shortcircuit in the batteries, they are usually stored as low as possible.

Fibreglass, carbon, etc burn tremendously well. I've seen a couple of boat fires, and once the hull starts burning, it's pretty much out of control...

There's one thing you guys are forgetting:

Rum !!! Who knows how much of it...

On a more serious side-

Plastics are combustible, fibers are not, they may burn but won't sustain the fire.
Rolf -if you are to make a spontaneous fire scenario you should take into account:

Source- maybe engine fuel, rum bottle or any other combustible material that can catch a spark and ignite

Materials that will sustain the fire - plastics, sails, gear, hull epoxy

Oxigen - if an opening provides fresh oxigen - it will raise the temp of the fire.

Temperature of the fire - once a certain temp is reached a "flashover" phenomenon occurs, at that point combustible materials starts to burn instantaneously, like paper, cloth etc

At some point the materials of the hull will deform and the structure will collapse very quickly, so the whole "thing" won't even have to burn because the hull integrity will be compromised, leaving afloat only the foams that have not burnt completely, and the other incombustible stuff.

For such a fire to grow inside a ventilated **** with some combustible materials close by, it won't need too many minutes to develop enough heat to deform the hull, that might appear as the hull burns much quicker, but actually a part of it sinks.

It's not necessarily the fire itself doing most of the harm, but the hot gases and raised temp that deforms the structure.

And don't forget the rum.

There's also the very good chance it started as a galley fire. Those boats have outboards, so likely any engine related fuel is outside of the the main cabin (unless a spare tank or the main tank or even the engine was being stored on the floor of the cabin while under way, big goof). But the galley stove may be an alcohol or butane (my F-27 has a two-burner alcohol stove). A goof fueling/prepping the stove or cooking up lunch can cook the boat - out of control flame on the stove catches interior materials, etc, etc, etc, Even if the boat itself resists burning, crew bags, towels, charts, rolls of paper towels, cushions, or anything else stowed below can stoke the fire.

The main hull doesn't have to burn completely to detach from the akas/amas, it only has to burn to the point of structural failure around the attachments.

Maybe we'll see a write-up in the Boat U.S. insurance magazine...

Polyester resin burns like a nutter, I always thought that epoxy did not.
I am building in epoxy/foam at the moment, i will have to try a test on a sample and report back.

paul

Paul


What are you building?

The standard test to determine glass fibre ratio is to weigh a small sample of the laminate you are interested in, then burn the sample leaving just the fibres, then weigh the fibres. So glass fibres don't burn at the same temperature as polyester resin.

I can use that info, Thanks

Darryn