Fire Suppression Systems

[Sdpaddler50]

A few comments:

Halon is not harmful to humans, just the environment so it was banned in 2000 if I recall correctly. The Gov\Defense has a large stock pile for legacy equipment they want to protect from what I have been told.

Dry Chem Powders: as others have noted, best to avoid these. A major mess.

Clean agents are best, and there are lots of good Halon replacement agents in the market.

Engine shut down: it is absolutely correct that it should be wired to shut down prior to agent activation in order to prevent the removal of the gas by the engine. These gasses work on a specific design concentration, so the amount of gas required for suppression is dependent on the engine room volume, and the space should theoretically be tight and not allow gas leakage. Now here is the part others will not like: I can’t get my head around having an auto shut down on our single engine trawler. The chance of an automatic shut down occurring are low, but it’s not a risk I am not willing to take in case it shuts down at a really bad time, through an error. With that said, I am running a fairly new boat, diesel fuel (no gasoline), have numerous large hand held extinguishers on board, coastal cruising not far offshore, and am extremely careful and diligent operator. I know people will disagree with my logic which is fine. It’s how I chose to approach it based on the risk analysis for my situation.

BTW, those Maus extinguishers look interesting.

[Paul L]

Originally Posted by Sdpaddler50

A few comments:

Halon is not harmful to humans, just the environment so it was banned in 2000 if I recall correctly. The Gov\Defense has a large stock pile for legacy equipment they want to protect from what I have been told.

Dry Chem Powders: as others have noted, best to avoid these. A major mess.

Clean agents are best, and there are lots of good Halon replacement agents in the market.

Engine shut down: it is absolutely correct that it should be wired to shut down prior to agent activation in order to prevent the removal of the gas by the engine. These gasses work on a specific design concentration, so the amount of gas required for suppression is dependent on the engine room volume, and the space should theoretically be tight and not allow gas leakage. Now here is the part others will not like: I can’t get my head around having an auto shut down on our single engine trawler. The chance of an automatic shut down occurring are low, but it’s not a risk I am not willing to take in case it shuts down at a really bad time, through an error. With that said, I am running a fairly new boat, diesel fuel (no gasoline), have numerous large hand held extinguishers on board, coastal cruising not far offshore, and am extremely careful and diligent operator. I know people will disagree with my logic which is fine. It’s how I chose to approach it based on the risk analysis for my situation.

BTW, those Maus extinguishers look interesting.

An unintentional shutdown is rare, but it does happen.
A friend was motoring in French Polynesia when their older auto extinguisher shut the engine down and went off. If they had been in the cut of an atoll at the time, it could have turn out very bad.
I was talking to an engineer on a large US Coast Guard cutter. The main engine is heavily monitored and auto shutdown by a host of sensors. When they are doing a bar crossing these auto shutdown systems are disabled, just in case.

[tkeithlu]

The central problem with a fiberglass boat is that the resin burns like greased paper, and the smoke produced is both extremely toxic and in large volumes. If you are in the cockpit and hear the battery fall over and a buzzing noise, you may not be able to fight the fire from anywhere other than the fantail as you step into your life raft.

Let's hear it for systems that are either automatic or which allow you to extinguish a fire in you engine spaces without opening a single hatch.

[Tupaia]

Originally Posted by Sdpaddler50

A few comments:

Halon is not harmful to humans, just the environment so it was banned in 2000 if I recall correctly.

Studies by US authorities; Halon 1301 exposures were shown to be safe, but Halon 1211 resulted in arterial concentrations in exposed individuals that reached levels that could potentially cause cardiac sensitization.

[Alterboy 65]

Hi All , This is Alterboy . I started this thread and want to THANK YOU all for your ideas. Keep them coming .

I was EXTREMELY LUCKY . I was in a boat yard . I was on my way to Happy Hour and was just about to leave the boat when I saw a thin line of smoke in the salon thru the sun coming in the windows. I then smelled burning wires. My first instinct was to run outside and yell fire which I did. A worker at the yard heard me , ran over and immediately shut off the shore power.From the main doorway we now saw black smoke coming up from the starboard side of the boat . I have a 5 lbs extinguisher right next to the salon door so..THinking I had to try I guy it , told the guy where I was going in case I did not come back , took a deep breath and ran down the stairway. By this time I could see nothing . So by feel I went forward and emptied the extinguisher toward the blast of heat that I could feel. Out of breath I ran back outside . All this took approx 30 - 45 seconds.
Two other workers were at the boat. Smoke was seeping out of the forward hatch . We got a hose from the dock and got ready , opened the hatch and poured water in . You could still feel the heat from the fire coming out of the hatch. But we got it to where we could no longer feel the heat. We evacuated the smoke with a fan . I went back down the inside stairs and soaked the whole compartement. This All took under 2 minutes.

I was told by licensed electricians and shipwrights that I was within 2 minutes of losing the whole boat. The Fire was in the forward starboard [Catamaran] compartment. THe Water heater was charred . The bunk above the water heater had almost burned thru and the plastic parts storage bins were melting.

Clean up is another story. But at least I had a boat to clean up .

All this is to say that I agree the best scenario is to have a way to turn on a system from the cockpit. I like the anchor washdown idea but what about using the freshwater pump or both . Still working on a valve system and location . Any ideas ??

AB