Explosions fires rescue at sea

[Checkswrecks]

Originally Posted by Montanan

F-500 does not appear to be an Aqueous Film-Forming Foam Concentrate.
Reference data slide below.

Also video link:

Interesting Montanan - I'll need to look into it when I can. My son is a licensed fire protection engineer, I'm a systems and vehicle guy. Thanks

In fwiw for others, the problem with lithium battery re-ignitions is visible in the video just before they cut it. Once ignited, never assume a cell or battery is dead.

[Montanan]

Additional comparative information on advantages of F-500 Encapsulant

http://http://www.hct-world.com/wp-c...antages_V3.pdf

[bobatkins]

Originally Posted by Cpt Pat

[Reference post #72]


Bob,

That looks like an excellent setup! One question: Is there any venting in the steel case to prevent a pressure build-up in case of catastrophic venting? If not, the assembly could turn into a bomb. One could always drill a hole, and if I did, I'd find some way to vent the case overboard that could withstand hot gasses.

If I took that a step further, I'd install the cases below the waterline, and run the vent pipe through an always-open-undereway seacock to a through hull below the waterline but higher than the case that was sealed with a pressure cap. That way, if the batteries started venting, the pressure would blow out the vent plug, and when the pressure dropped, the case would be automatically flooded with sea water. Then you'd have to close the seacock. Just a crazy thought...

You make a good point. The case is not sealed airtight - there is no gasket on the lid so venting can occur. Interestingly, most all plastic cased batteries are sealed air tight. I had one manufacturer actually make that an issue by pointing out that salty marine air could not intrude into the interior of their battery case and cause corrosion of the various internal components.

[Cpt Pat]

Originally Posted by bobatkins

You make a good point. The case is not sealed airtight - there is no gasket on the lid so venting can occur. Interestingly, most all plastic cased batteries are sealed air tight. I had one manufacturer actually make that an issue by pointing out that salty marine air could not intrude into the interior of their battery case and cause corrosion of the various internal components.

I agree with the manufacturer's assertion. The cells should be sealed. But to prevent an explosive release of gases caused by cell failure, each cell should also have a pressure release vent that should only open when pressure significantly higher than ambient builds up inside the cells. Venting is a one-time event: once a cell vents, it's ruined. The vent is the pressure equivalent of an electrical fuse. If a cell ever does vent, throw it out. Treat it with all the trepidation of an unexploded bomb. In fact, I'd throw out the entire pack because of the likely heat and internal chemical damage to the other cells. If the cells are identical and one cell vents, I would presume they were all seriously over stressed. It's not something to take chances with. I wouldn't gamble on that one cell being an anomaly.

[bcboomer]

Originally Posted by Montanan

Additional comparative information on advantages of F-500 Encapsulant

http://http://www.hct-world.com/wp-c...antages_V3.pdf

That looks like an excellent extinguisher to have on board even without lithium.
It should be effective for pretty much any boat fire and you don't have to worry about toxic fumes or dry chemical getting everywhere.
The only problem I see is where to mount the big extinguisher.

Anyone see any other shortcomings?

[Montanan]

Originally Posted by bcboomer

That looks like an excellent extinguisher to have on board even without lithium.
It should be effective for pretty much any boat fire and you don't have to worry about toxic fumes or dry chemical getting everywhere.
The only problem I see is where to mount the big extinguisher.

Anyone see any other shortcomings?

I haven't yet spoken to the manufacturer of the F-500 encapsulant to learn about its stability for extended storage when mixed with water and retained under pressure in a portable extinguisher. Obviously one has to be concerned about the extinguisher not be stored below freezing temperatures, albeit the encapsulant may invoke some degree of anti-freeze to lower the freeze point a bit. It seems to raise the boiling point of the water.

If I find out more information I endeavor to pass along with a new post.

The large systems appear to use the encapsulant with an inductor to mix in the encapsulant as water is being discharged rather than storing large amounts of water in a tank or cistern.

Often I see very small fire extinguishers mounted on board yachts, which extinguishers have very modest capacities. One has to get the fire extinguished and hope it does not backburn or reignite. With lithium battery fires each cell becomes a reignitioning event. Hence the need to reserve one's usage of ordinary fire extinguishers because they will generally not cool a battery fire adequately to suppress the battery from reigniting. Nothing worse than running out of extinguishing capacity to find the fire start anew.

The approximate discharge time for large extinguishers with 10 to 20 pounds of dry chemical ranges from 10 to 25 seconds. Generally don't expect more than 10 seconds of full strength discharge and this only if the fire extinguisher has been properly maintained with refilling and proper pressurization.


Class A Ratings

A fire extinguisher rated for class A fires is intended for use on fires involving Ordinary Combustibles such as wood, paper, cloth or plastics. Class A extinguishers are rated from 1 - A through 40 - A. The number in front of the A represents an amount of water or, if another extinguishing agent is used, how much fire that extinguishing agent will put out as compared to the rated amount of water. A Class 1 - A water extinguisher contains 1 1/4 gallons of water; a Class 2 - A extinguisher contains 2 1/2 gallons of water, or twice the 1 - A capacity.


The Coast Guard requires boats to have at least one B-1 marine fire extinguisher on board. Depending on the size of your boat you may need more than one. Boats less than 26' have to have at least one B-1 fire extinguisher on board. Boats 26'-40' need to have at least two B-1 fire extinguishers on board, or one B-II.

Class B Ratings

A fire extinguisher rated for class B fires is intended for use on fires involving Flammable and Combustible Liquids and Gases such as gasoline, oil, lacquer, paint, mineral spirits and alcohol. Class B extinguishers are rated from 1 - B through 640 - B. The rating is based on the approximate square foot area of a flammable liquid fire that a non-expert operator can extinguish. The non-expert operator is expected to be able to extinguish 1 square foot of fire for each numerical rating or value.

So the USCG requires for a boat up to 26 feet in length an extinguisher that a non-expert can use to put out a fire of just one square foot in size. For a boat of 26 to 40 feet to have fire extinguishing capacity for a two square foot fire.


A fire extinguisher with a rating of 2 - A, 10 - BC should extinguish the same amount of fire as a 2 1/2 gallon water extinguisher or extinguish a liquid fire that is 10 square feet in size and the extinguishing agent will not conduct electricity.

[bcboomer]

I have 4 of the 10-B-C and a 2.5 lb Halon 1211.
I'd grab the halon first and only go to the dry chemical as a last resort.
Looking at the F-500 information, I don't think there would be any danger from my 12 volt system using the misting nozzle.
I'll ask about storage under pressure.
The nearest distributor can only ship large containers of the stuff so I need to find a source.

[Cpt Pat]

Originally Posted by bcboomer

I have 4 of the 10-B-C and a 2.5 lb Halon 1211.
I'd grab the halon first and only go to the dry chemical as a last resort.
Looking at the F-500 information, I don't think there would be any danger from my 12 volt system using the misting nozzle.
I'll ask about storage under pressure.
The nearest distributor can only ship large containers of the stuff so I need to find a source.

I agree. The chemical extinguisher agents destroy everything they touch. In terms of collateral damage, you might as well put out the fire with a sledge hammer. I too have both: the A-B-C extinguisher the CG requires I carry (the regs require I only have one extinguisher) and a Halon 1211.

[Montanan]

Battery fire suppression

https://www.youtube.com/watch?v=mDaymBTYySw

[bcboomer]

Originally Posted by Montanan

Battery fire suppression

Looks pretty quick but what about the heat from a lithium battery affecting the surface it is on? Or the bag of stuff it is probably going to be in on a plane.
I don't know how good it would be with a multiple cell battery.

[Checkswrecks]

Originally Posted by Montanan

Battery fire suppression

bcboomer -

If the fire is on a flammable surface or in a carry-on bag, then a battery fire would be the same as having a plastic or wood fire on that surface or in that bag. The size of fire in the video demo was about right for a multi cell booster pack or tool battery.

So again, fire blankets can be very effective, if just as a way to protect or smother surrounding flammable materials like cabin cushions or varnished bulkheads. Hopefully people in this thread understand the value by now to pick up one or two blankets.

And as mentioned a few times, there's all sorts of stuff on the market with big mark-ups. The video is an example and their 30" x 30" blue fire blanket ought to be darned pretty for the $290 price tag!!! The pillow is essentially a non-flammable cover on a nylon inner bag that will melt and release the sand (SiO2) contents. (See their Safety Data Sheets for specifics)

[Tudorsailor]

Apologies if I have missed this earlier in thread, and for slight thread drift.........

This thread got me researching fire extinguishers although it seems that they are not the best way to deal with a lithium battery fire.

I found this video of extinguishing various types of fire with a water mist extinguisher.

https://www.youtube.com/watch?v=gNFD-z4hXXQ

As one extinguisher seems to work on the common sorts of fire, I have ordered one for home and one for yacht.

TudorSailor

[Cpt Pat]

Containment seems to be an important step. If the batteries are in a steel box, or if the burning object is tossed into a steel box, what have you got? A very hot steel box.

For containment, how about a steel box lined inside by rock wool insulation? Rock wool insulation is made from steel slag: it won't burn, won't shrivel up like fiberglass, won't absorb moisture, and it's cheap. You can buy it at Home Depot. Welders use it for thermal isolation because you can blast it with a welding torch without affecting it. The heat still needs to be dissipated, but dissipating it slowly may mitigate secondary ignition of surrounding materials.

Here's a practical demonstration of the flammability of various common insulation materials:

https://www.youtube.com/watch?v=8NC79e0oztM

[Montanan]

[QUOTE=Cpt Pat;3076503]Containment seems to be an important step. If the batteries are in a steel box, or if the burning object is tossed into a steel box, what have you got? A very hot steel box.

For containment, how about a steel box lined inside by rock wool insulation? Rock wool insulation is made from steel slag, it won't burn, won't shrivel up like fiberglass, won't absorb moisture, and it's cheap. You can buy it at Home Depot. Welders use it for thermal isolation because you can blast it with a welding torch without affecting it. The heat still needs to be dissipated, but dissipating it slowly may mitigate secondary ignition of surrounding materials.

/QUOTE]

Rock wool would be an excellent thermal conduction limiter for placement within a steel box, which steel box requires venting capacity. The rock wool would also act as padding for the batteries. It would seem easy enough to just place layers of rock wool between batteries. The rockwool would also inhibit flames, e.g., from emitting out the ventilation holes.

[donradcliffe]

A great thread, with lots of good information. The battery industry has created a lot of problems with their generic "Lithium" label for quite different battery chemistries. The suppression of information about the hazards of each chemistry is going to limit the adoption of the technology.

I just bought an ebike conversion kit, and a 48v battery pack to go with it on Ebay. There were at least 3 competing battery chemistries available, but they were all labeled "Lithium", and it was impossible or very difficult to determine what I was buying. I think I chose an NMC battery because it was cheaper and lighter, but I will have to wait till it arrives to see what I really bought. If it is a LiPO I may reconsider using it at all--they seem to have more numerous and more spectacular failures.

I have already decided to part company with the ebike in the event of a deflagration (which is truly an explosion if you look at definitions). I will also never charge it indoors and unattended.

I recently bought a Makita cordless grinder with a cutoff wheel, with the idea that it would be handier than my existing corded one in case of a dismasting. I didn't relish the idea of using 120 volts on deck with the occasional dose of salt water. Now I'm not so sure....

The Lithium battery pack 28v Milwaukee right angle drill will cut off before the drill stalls, which looks like a good thing. It will not work again until you put it on the charger.

The RV crowd is also hungry for Lithium house banks. Winnebago has gone with the Pure3 48v NMC variety, which probably has PI lawyers rubbing their hands with glee.