Boat Fire and Sinking in Route du Rhum

[donradcliffe]

Pretty dramatic rescue from an Imoca monohull. Before the multihull types jump in, the boat was totally engulfed in flames before it sank.

https://www.routedurhum.com/en/actualite/575

I started this thread under Lithium Power Systems because from the following description of the incident I am 98% sure the fire and explosion was the boat's lithium battery bank.

Sunday morning: everything is fine on board and I'm having a great race. The boat is flying hard in the squalls and the sea is heavy. Suddenly, I realize that my ballast has exploded on a wave and that I have several hundred liters of water in the boat. I stop to be safe and start to empty everything. At that moment, the batteries are immediately affected by the water and failed and I had a complete blackout on board. I have no more electricity: no more autopilot, no more computer, no more electronics. I decide, in consultation with my team, to proceed cautiously towards Cascais.

Sunday afternoon: big smoke on board the boat. I use the extinguisher, I put on my TPS (survival suit) I alert the race direction who asks a competitor in Imoca to divert to assist me if necessary. The smoke eventually stops. I decide to resume my passage to Cascais. I meet James Harayda, the skipper of Gentoo who had come to the area to help me. I thank him and resume my passage. I completely dry the boat and prepare myself for a difficult passage I slept two hours last night to recover from my emotions then steer 6 hours tonight.

Again 2h30 of siesta then 7 hours on the helm. Shortly after 12:30 p.m today more new smoke on board. Followed by an explosion. I grope my way back into the cabin and manage to retrieve my TPS. My Grab bag (survival bag) had remained in the cockpit. I'm going back to get my wedding ring. I hit the fire extinguisher but nothing happens. The smoke is not white like yesterday but yellow. The cockpit warps and yellows. Seawater spray sounds like the sound of water hitting a saucepan. I understand that I will have to evacuate. I warn my team of a possible evacuation. When I hang up, I am then at the back of the boat ready to trigger my survival: a torrent of flame comes out of the cabin and the coachroof. I am caught in the middle of the flames. I can't even open my eyes. I manage to push the life raft into the water and jump.

Normally the end that holds the liferaft to the boat is supposed to let go. It doesn't let go. The boat, which I had time to steer but which is still going forwards pushed by rough seas, pulls it and it fills with water. I manage to get on board without letting go. I think that's where it all happened and things turned the corner to work out right. I say to myself “if you want to live you have a few seconds to find the knife and cut”. The Imoca pulls me back towards it. The waves bring me dangerously close to it. I finally find the knife and cut. My raft is drifting downwind the boat which is fully on fire. It takes 30 minutes to sink.

[boatman61]

Scary stuff.. glad he got away okay.

[Franziska]

Was it a LiIon battery from equipment or a LiFePo4 as main battery pack?

The latter ones are fairly save the first ones not.

Big difference in chemistry and safety.

Highly unlikely that a LiFePo4 bank explodes and catches fire.
Sounds like the explosion might have been something else. Perhaps initiated by something still smoldering.
The LiFePo4 can fail when a lot of water gets into it and it can give off a lot of heat, but the battery itself is unlikely to explode.

[ItDepends]

Oh this one is going to be FUN!!!!

[donradcliffe]

Originally Posted by Franziska

Was it a LiIon battery from equipment or a LiFePo4 as main battery pack?

The latter ones are fairly save the first ones not.

Big difference in chemistry and safety.

Highly unlikely that a LiFePo4 bank explodes and catches fire.
Sounds like the explosion might have been something else. Perhaps initiated by something still smoldering.
The LiFePo4 can fail when a lot of water gets into it and it can give off a lot of heat, but the battery itself is unlikely to explode.

It sounds to me like the battery bank got a lot of salt water in it and failed rather quickly. What was different in this case was that it was dried out and there was no remaining water to cool it. The two separate smoke and fires sound like different parts of the pack experiencing thermal runaway, much like some reported EV fires.

If anyone reads French, it would be great to know the chemistry and design of the battery.

[Chotu]

Having just ordered brand new LIFEPO4 batteries that are on the way now to replace my lead acid trusty Trojan T105s, I do not like this post.

Ha ha ha.


For what it’s worth, lead acid batteries can also explode, but not so much burn the boat down usually.

Would be very curious to know the battery chemistry. And what was blowing up.

[boatman61]

Originally Posted by Chotu

Having just ordered brand new LIFEPO4 batteries that are on the way now to replace my lead acid trusty Trojan T105s, I do not like this post.

Ha ha ha.


For what it’s worth, lead acid batteries can also explode, but not so much burn the boat down usually.

Would be very curious to know the battery chemistry. And what was blowing up.

Yeah.. but they at least give you warning by gassing and screaming before they do.. and if one ignores those signs one deserves everything that comes after..

[MicHughV]

I plan to follow this thread with interest. My track record with batteries is enough for a book. You'd think after 35 plus years afloat, I'd know a thing or two about batteries, but maybe it is a thing or two less about batteries

[HeywoodJ]

Late last year Hager Group announced their sponsorship of Amadeo and said they would be fitting his boat with their E3/DC product. The datasheets simply say:

Battery chemistry: lithium-ion certified as intrinsically safe in accordance with IEC62619

They did have some announcements at the beginning of the pandemic that production curtailment at LG Chem might affect delivery of their products, which might point to NCM/NCMA chemistries, but that is circumstantial at best.

Of course the root cause may be the modifications for the new foils, looks like the structural folk may have pushed the envelope a bit too far:

Once we’d located the foils, we then had to put together a team to carry out the refit. At that point, Fabrice Amedeo decided to bring an English contingent into the project and work with them. “The team which had participated in the construction of the last Hugo Boss was available, explains the skipper. We agreed that they would build the foil casings and come to Lorient to fit them.” As a result, Team Nexans – Art & Fenêtres has been joined by four English boat builders from Pro Build Composites. “They removed the current foil systems from the mould and will set up the new foils 55 cm further forward, so they’ll pierce the hull again, then the deck and finally fit the new systems.”

Meantime, a team of five lamination specialists are working on all the ‘structural reinforcement’ under Simon Chevallier, head of composites for Team Nexans – Art & Fenêtres. “The zone where the major slamming loads occur due to impacting the ocean will be further aft due to these larger foils. As such, a whole series of structural reinforcements are needed under the hull around the keel area. After that there will be a whole body of work associated with the class measurement. All this modification will weigh the boat down, but she still has to satisfy the 180° test: if she capsizes, she has to be able to right herself on her own. As a result, we’ll have a slightly larger cuddy with greater buoyancy”, adds Fabrice.
source

[wholybee]

So, he lost his electrical system, presumably because the batteries became submerged. He mentions he dried everything. What about the batteries. Did he leave them connected, and start using electronics again? Or were his electronics still out? Getting the batteries disconnected would be VERY high on my list of things to do to stabilize the boat. On my boat I would probably have them disconnected before the water was fully pumped out, and then get them into the cockpit. I'd even do that for lead acid. We also don't know anything about the installation. Was there a manual disconnect, or was it a relay/contactor controlled by an also submerged and malfunctioning BMS?

One way to look at this is that the battery was submerged in salt water and didn't become a danger for 24 hours. That's outstanding.

If the batteries were not disconnected after being flooded, that explains it, but doesn't confirm at all that the batteries themselves are what caught fire. Just as likely, something else shorted from salt water, and caught fire.

LFP are extremely difficult to get into thermal runaway, and by the reports I have read of experiments that manage it, what they experienced wasn't actually thermal runaway, as the batteries got extremely hot, but stabilized at temperature, and didn't "run away." To me, that only means they caught fire. That temperature was hot enough to make wood smolder, but not ignite it. (I don't recall exactly wat it was)

It was recently reported that ABYC did everything they could, including setting a boat on fire, and couldn't achieve an explosion.

Anyway, we shouldn't jump to conclusions about the cause of the fire or explosion, as the Lithium battery (whatever chemistry) is just as likely to be incidental and not related at all.

[wholybee]

Originally Posted by boatman61

Yeah.. but they at least give you warning by gassing and screaming before they do.. and if one ignores those signs one deserves everything that comes after..

By my reading of the experience, on Sunday afternoon the batteries vented, he used a fire extinguisher (but there doesn't seem to have been a fire-or at least it was small and manageable), and not until the next day at 12:30pm was there an actual fire followed by an explosion.

Anyway, LFP will also vent long before there is a dangerous condition.

[psk125]

Cheechako posted another thread about lithium batteries which seems to have bearing here. Read down to what is reported to be a letter from the ABYC about their testing process and results. Note the difference between LiFePo4 batteries and LiIon.
https://www.cruisersforum.com/forums...on-270253.html

[ItDepends]

Originally Posted by wholybee

By my reading of the experience, on Sunday afternoon the batteries vented, he used a fire extinguisher (but there doesn't seem to have been a fire-or at least it was small and manageable), and not until the next day at 12:30pm was there an actual fire followed by an explosion.

Anyway, LFP will also vent long before there is a dangerous condition.

LFP batteries will vent under some very unusual conditions, and therein lies the issue... The electrolyte is a flammable organic solvent. Not quite so flammable as gasoline, but much more so than diesel. Venting as a hot gas... if there was a spark, could easily cause a boom and fire.

I don't think that lithium batteries are significantly more dangerous that lead, but the drumbeat of fanboys claiming they can NEVER be dangerous under ANY conditions is just tiresome in its wrongness.

I personally know of several boats with FLA batteries that have had hydrogen explosions (never an AGM of GEL though) all with minor damage, but never have I heard of one burned down by LA batteries because of the battery chemistry. Many boats however have burned from bad DC power wiring...

Now if you flood a FLA battery with salt water you have a lot of problems... Apparently the same is true of LiFePO. Not exactly a surprise.

[goboatingnow]

Originally Posted by ItDepends

LFP batteries will vent under some very unusual conditions, and therein lies the issue... The electrolyte is a flammable organic solvent. Not quite so flammable as gasoline, but much more so than diesel. Venting as a hot gas... if there was a spark, could easily cause a boom and fire.



I don't think that lithium batteries are significantly more dangerous that lead, but the drumbeat of fanboys claiming they can NEVER be dangerous under ANY conditions is just tiresome in its wrongness.



I personally know of several boats with FLA batteries that have had hydrogen explosions (never an AGM of GEL though) all with minor damage, but never have I heard of one burned down by LA batteries because of the battery chemistry. Many boats however have burned from bad DC power wiring...



Now if you flood a FLA battery with salt water you have a lot of problems... Apparently the same is true of LiFePO. Not exactly a surprise.

LFP gas or electrolyte IS NOT flammable. When will people stop promulgating nonsense about lithium.

[ausnp84]

No surprises here - electrics operating outside their design window failed. Blaming the lithiums without much proof is a stretch; a part-flooded boat has plenty of potential fire points.

FWIW I know of a brand new AGM that failed and blew a considerable hole in the bow of a 75ft cat as well... once you add power to anything, there’s always a chance of a fire....

N