Boat Fire Safety

[skipmac]

Originally Posted by rwidman

Whatever dude. You can be whatever you want to be on the Internet. I'm not going to waste my time arguing with you.

I can assure you that Maine Sail is exactly what he claims. Arguably the most thorough, meticulous person I've ever encountered in regard to boat systems, electrical systems in particular.

I have a degree in EE and I learn more about practical boat electrical from Maine Sail almost every time he posts on the forum.

If you want to argue a point with him you better do your homework and back it up with real world data. If you have not done so you might find it very educational to look through his web site.

Compass Marine How To Articles Photo Gallery by Compass Marine How To at pbase.com

[Doug Brown]

Hi Paul L -

I have seen propane installations that have scared me to dead, and I have seen a propane explosion but did not investigate it (wasn't my case).

There are a couple of videos on U-tube (I think) that shows what a leaking 20-lb propane tank can do to a boat when they ignite/explode. Very scary.

I should have mentioned propane/LPG in the "leaky hose" section. I have seen little fires (with an actual little flame) in LP gas hose installed behind stoves & refrigerators (the fire burned off the gas, so there was no massive explosions).

I have seen steel propane/LP tanks that have exploded when they have been overfilled and left in direct sunlight - but there was to resultant fire since there was no ignition source. But add and ignition source and it would have been very ugly.

I have seen propane tanks - especially aluminum tanks - explode when in a fire (aluminum tanks will fail at about 1000F when pressurized and in a fire) and these are quite spectacular and dangerous - both from the fire ball and the flying debris.

I have seen 33-gal steel propane tanks that have exploded when a forklift has been on fire. The exploding tank actually indented 1/4" steel over 1/2"!

I always stress to land based fire fighters to try and find where the propane tanks are stored and to discharge a hoseline in that area if it is involved in fire. Us boaters are very clever in hiding where are propane tanks are stored onboard!

Same advice to anyone that is going to try and fight a boat fire. You don't need a propane tank exploding in your face!

If you have propane onboard, install it safely, have big overboard drains in case of a gas leak at the tank/regulator, lots of anti-chaff protection and a shut-off at the tank. Check all parts of the system at least a couple of times a month, more so if you see any corrosion on the tank, fittings or lines from fresh or salt water.

The small propane tank fires that I have fought at fire schools (these were a 20-lb tank and manifold fire) can easily be extinguished with a 5-lb dry chem.

However, plan ahead, because once the fire is out, the gas is still leaking and can explosively re-ignite! Buckets of water or a washdown hose to full extinguish any smoldering embers is highly recommended, as is closing the tank valve or throwing the tank overboard.

[Wotname]

Originally Posted by GordMay

Teflon extrudes at such high temperatures that tin plated wire has to be replaced with silver plated stranding. This makes it expensive.
I thought (could be wrong) that Tefzel has been the insulation of choice in aircraft for about 25 years.

Originally Posted by a64pilot

Your probably right, just us red-neck types seem to call any slick white colored plastic, teflon.

Yep, Tefzel is the "goto" wire choice in aviation and most of us rednecks think "teflon"

FWIW, some details on insulation types are here http://nepp.nasa.gov/npsl/wire/insulation_guide.htm

Originally Posted by a64pilot

I've wondered why not use teflon coated "aircraft" wire for my boat, especially if I add a battery bank. I believe it's tinned, anyone know why I shouldn't? Only drawback I can see is it's stiffer than "marine" wire.

No reasons apart from cost and that it usually white or white. Colours are manufactured but are not so commonly available. I think the "stiffness" is due more in part to the insulation rather than the conductors.

It is tinned.

[Wotname]

I also support overload circuit protection in starting circuits - at least in the starting circuits one would usually find the sub 50' sailboat.

It isn't difficult to design and fit suitable OCP.

[hellosailor]

FWIW, "fire blankets" used to be simply cheap, tightly woven WOOL blankets. Wool burns very reluctantly, and wet wool is close to impossible to light on fire.


Today's "fire blankets" are often very expensive aramid or Kevlar, which are both much thinner than wool but way more expensive than an old wool army blanket.

[Roy M]

Again, from the Yachting Monthly Crash Boat series, a propane explosion:

https://www.youtube.com/watch?v=Yxm3uMy6MPI

Go on YouTube and check out the entire series.

[Reiziger]

Originally Posted by Doug Brown

Hi Paul L -

I have seen propane installations that have scared me to dead, and I have seen a propane explosion but did not investigate it (wasn't my case).

There are a couple of videos on U-tube (I think) that shows what a leaking 20-lb propane tank can do to a boat when they ignite/explode. Very scary.

I should have mentioned propane/LPG in the "leaky hose" section. I have seen little fires (with an actual little flame) in LP gas hose installed behind stoves & refrigerators (the fire burned off the gas, so there was no massive explosions).

I have seen steel propane/LP tanks that have exploded when they have been overfilled and left in direct sunlight - but there was to resultant fire since there was no ignition source. But add and ignition source and it would have been very ugly.

I have seen propane tanks - especially aluminum tanks - explode when in a fire (aluminum tanks will fail at about 1000F when pressurized and in a fire) and these are quite spectacular and dangerous - both from the fire ball and the flying debris.

I have seen 33-gal steel propane tanks that have exploded when a forklift has been on fire. The exploding tank actually indented 1/4" steel over 1/2"!

I always stress to land based fire fighters to try and find where the propane tanks are stored and to discharge a hoseline in that area if it is involved in fire. Us boaters are very clever in hiding where are propane tanks are stored onboard!

Same advice to anyone that is going to try and fight a boat fire. You don't need a propane tank exploding in your face!

If you have propane onboard, install it safely, have big overboard drains in case of a gas leak at the tank/regulator, lots of anti-chaff protection and a shut-off at the tank. Check all parts of the system at least a couple of times a month, more so if you see any corrosion on the tank, fittings or lines from fresh or salt water.

The small propane tank fires that I have fought at fire schools (these were a 20-lb tank and manifold fire) can easily be extinguished with a 5-lb dry chem.

However, plan ahead, because once the fire is out, the gas is still leaking and can explosively re-ignite! Buckets of water or a washdown hose to full extinguish any smoldering embers is highly recommended, as is closing the tank valve or throwing the tank overboard.

+1

After an LP explosion happened on a friends boat, that burned him severly, I installed a mechanical count down timer/switch to cut off the LP solonoid.

Like this one.

[leftbrainstuff]

Originally Posted by skipmac

From those that have been there I hear fire on a boat is arguably the most urgent problem you can have. I did have a fire once from "safe" alcohol fuel stove that could have become serious and it sure got my attention, fast! I did have an electrical fire once. New boat the stbd engine was installed on top of the main wiring harness. Fortunately as soon as I shutdown the engine it cut power to the shorted wire and it went out.

For electrical fires on my current boat I have one master ON/OFF switch that shuts down all house systems except the main and two emergency bilge pumps and that circuit is fused right at the battery. Similar setup for the engine battery. Rule one, any fire of undetermined cause kill the main power immediately. This is part of the new crew orientation that also includes location of all seacocks, location and how to use the propane solenoid switch, all high load dangers like anchor windlass, sheet winches etc, man overboard and basic boat handling even for non boating guests (in case I fall overboard and they need to come get me, assuming they want to after all the orientation I force on them ).

Also have multiple extinguishers, large for serious stuff and small portable for quick, easy access.

Good succinct advice.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[leftbrainstuff]

Originally Posted by a64pilot

I've wondered why not use teflon coated "aircraft" wire for my boat, especially if I add a battery bank. I believe it's tinned, anyone know why I shouldn't? Only drawback I can see is it's stiffer than "marine" wire.

Corrosion from sea water is why not. Aircraft aren't expected to experience sea water based contact like boats are subjected to. Aircraft wiring is not tested or certified for marine use.

That's why the low flying surveillance aircraft have issues. Australia has been battling this problem in our Orions for decades.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[hellosailor]

So from this we can see that a properly engineered coach roof and deck will be sacrificially blown away during an explosion, preventing the main force from breaking the hull and sinking the boat. Good engineering.




















Oh, and that propane must no longer be sold to the public in two pound canisters, it should be restricted to a much smaller quantity, to prevent malicious use as an explosive. I wonder, comparably, how dangerous the much smaller butane stove canisters are?

[Dockhead]

On our boat:

1. Sea Fire system for the engine room. That's an automatic Halon fire extinguisher with automatic fuel shutoff.

2. Remote fuel shutoff for engine and genset, operable from the lazarette.

3. Fire extinguishers in every cabin.

4. Fire blankets in the galley and other strategic places.

5. Care with wiring.

6. Safer 230v AC and 24v DC instead of fire hazard 110v AC and 12v DC.

7. Exhaust temp alarms for engine and genset.

What I don't have:

1. Smoke alarms.
2. Temp alarm in the engine room.
3. Fire pump (although that's required by regs for my size boat).

Needs to be done.

[Dockhead]

Originally Posted by Maine Sail

There is an "exemption" for starting motor circuits, they do not advise not doing it. Many professionals, myself included, do fuse cranking conductors when it is possible and it is possble of a large majority of engines out there..

Considering that I have literally hundreds of cranking circuits protected by OCP your statement about it being "useless" is simply flawed. It can be done and is done in ever increasing numbers......

When you get to massive engines it becomes more expensive and more difficult, so a conduit is a good choice. For the vast majority of marine engines out there, including outboards and most any small sailboat aux engine as well as many diesels up into the 350HP range OCP is easily done.

But hey don't just take my word for it...

I quote our good friend Nigel Calder here:

"The net result is that nowadays, electrical shorts are probably the number-one cause of fires on boats."

There is simply no excuse for not protecting all high-current circuits , including the cranking circuit."
Nigel Calder Cruising Handbook


The vast majority of marine engines in the world today can easily be protected with over current protection. If you own a boat with massive engines, please put your starting motor conductors in a protected conduit, if they can not be fused!

This boat was "exempted" and a single group 24 battery caused this..... Is this exemption right when a simple 100A fuse would have protected this boat??? Not in my mind....


What do we know about this fire, on a 15' Boston Whaler?


1- Electrical fire
2- Single Group 24 battery
3- Multiple children under the age of 9 on-board seconds before the fire! (Junior sailing program chase boat)
3- NO OVER CURRENT PROTECTION!!!!!

My boat has a circuit breaker on the main engine starting circuit. Seems like a good idea to me.

[SailRedemption]

Originally Posted by Dockhead

On our boat:


What I don't have:

3. Fire pump (although that's required by regs for my size boat).

Can you explain this please? I could look in the cfrs in the bridge right now but I don't feel like getting out of my chair haha..... /:

- Ronnie...on the geaux

[hellosailor]

Fire pump...thinking of Fahrenheit 451, that must be what we call a flamethrower in the States.(G)

[Wotname]

Originally Posted by leftbrainstuff

Corrosion from sea water is why not. Aircraft aren't expected to experience sea water based contact like boats are subjected to. Aircraft wiring is not tested or certified for marine use.

That's why the low flying surveillance aircraft have issues. Australia has been battling this problem in our Orions for decades.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

This is a somewhat curious statement .

Please educate me, what is the normal marine specification for a recreational cruising sailboat and how is it superior to MIL-W-22759 which is the common spec for general aviation use.

FWIW, the boats I encounter are normally wired with whatever PVC insulated automotive wire that is sold locally and none of it is a patch on MIL-W-22759.

I have re-wired two 50 year old flying boats and their wiring is subject to all the hazards of the marine environment as are helicopters primarily engaged in off-shore personnel transfers. The wiring holds up pretty well IME.

For anyone interested, some general info on this wiring can be found here http://www.casa.gov.au/rules/1998cas...c01.pdf‎