Co2 Systems

[MAKANA]

Has anyone replaced the cumbersome co2 system in the engine room?(Mine is
due for removal and hydro-testing) If so please tell me what you replaced it with and what the cost was. Any response will be greatly appreciated.
Makana
1978 53' MY

 

[mike]

it may be cumberson, but cheap at twice the price given the alturnatives. Best case your looking at having to use the new replacement for Halon, which ain't cheap and requires a complete redo of the sensors and plumbing. CO2 works, and works best if you can isolate the eng room vents with a trap door that uses a meltable link to release the door at a predetermined temp.

 

[Genesis]

I replaced mine with a FE-241 can which was LESS than fixing my CO2 system. You DO need an electrical box to do shutdowns if it fires, but that's not a huge deal.

It was much smaller and easier to handle. The firing system is simple - a thermosensor on the head that goes off at 155F.

Simple is good.

 

[MikeP]

Genesis, In the 53MY, the CO2 is plumbed to both engine compartments and the generator compartment from a single large (about 5+ft tall) CO2 bottle. There are outlet nozzles located in several spots in each room. Would the FE241 replace the large bottle? It sounds from your description as if they are stand-alone bottles with the nozzle intergrated into the bottle sort of like a hand-held extinguisher. Is that correct?

I would like to get rid of the huge CO2 bottle for access reasons and the stand-alone bottle(s) would seem to be fine if they can cover the area. What do you think?

 

[Genesis]

Correct. If you have multiple zones you need multiple bottles.

 

[Fanfare]

I looked into replacement, but ended up keeping the original CO2 system. It covers both engines and the generator, it's simple and reliable, and, because it's something I hope never to need, I don't worry about the fact it will hit all diesel compartments indiscriminately. Hydro doesn't cost that much, your cylinder will probably be fine and if not a used one may be available. They don't wear out, they just rust out. I got 37 years out of mine before it finally failed hydro, and that was because it had a base shaped to the bottom of the tank which apparently collected water. I drilled a drain hole in the base so expect more from its replacement.

Always brief guests that if system goes off to immediately run abovedecks. The CO2 will displace the air (and the oxygen) and smother anyone below as well as the fire. But you don't need an engine shut-down system to kill the diesels like you would with Halon. All diesels will be stopped by the CO2.

Jim Grove (Fanfare)

 

[MAKANA]

Thanks to all for your input. I must now get some prices and make a decision.
Makana
1978 53'MY

 

[Pascal]

i have the original CO2 system which was tested and certified about 2 years ago.

i will eventually replace it with halon type individual bottles (fe241 or whatever it's called). on the 53, that would be 1 in each ER plus 1 under the galley.

it will provide round the clock automatic protection, nice to have in case of an electrical fire when not aboard.

 

[MikeP]

Pascal.

Doesn't the CO2 system provide round-the-clock protection? I thought it triggered with heat just as the "current" systems do.

After thinking about replacing the CO2 for a day, I decided...Why bother? The only advantage to the newer stuff is that it is smaller. Then again, it is actually just as large because now three bottles are needed, one in each area, where currently, one large bottle is in the starboard eng room.

The large bottle makes access to the starboard glendinning cable retractor somewhat difficult but other than that, it really isn't a problem. Sometimes I think I try to create a problem to fix where none exists!
Pulling the waste hose from the aft cabin to the forward tank...now THAT's a problem!!

 

[SKYCHENEY]

MikeP996,

I agree with that entire post......except the Glendening part. My sychronizer in mounted on the stb aft bulkhead and my CO2 is located on the stb fwd bulkhead. It does get in the way of my Naiad tank a bit though.

Now.....as for the aft head hose......Let me know how you get at that and replace it. I will need to replace mine soon and I think I will need a larger diameter hose for the Raritan than I currently have with the GalleyMaid.

 

[Nonchalant1]

I had my entire CO2 system recertified this year. It operates without any electricity. If there's enough heat, it goes off by itself. When it does, if the batteries have power, it also sets off the audible Crozier fire alarm via an interconnect.

In the 53MY, people are not killed by the CO2 as there are engine room doors and genny room trap door. Each door has a red sign indicating not to open the door after the system goes off due to CO2 hazard in the engine rooms only. The commercial inspector said it's still a great, simple system that works. He inspects lots of them for commercial towboats running the barges.

If it ain't broke.............

Doug

 

[Pascal]

Mike

does it operate automatically? on mine i don't see any evidence of any trigering device. just a pull handle in the galley near the steps.

 

[MikeP]

Unless I misunderstand the information in the original manual for the boat, the fire system will automatically activate if any of the temp sensors in the engine/genny room trigger. The engines will shut down and Co2 will discharge into the eng/genny rooms. This can also be done manually using the pull handle which is located in the main salon at the top of the galley stairs. There is a reset button which must be set to restart the engines after the system has discharged.

I'll re-read the info this evening to make sure that I'm correct in thinking it is totally automatic.

Along these lines, last Saturday a 2 year old 35ft Carver berthed in our marina caught fire and sank in Long Island sound. Family of 5 on board. The CG got there within 10 mins of the Mayday call and pulled them off the boat. Soon afterward, it went up in a fireball and sank. The wife says she smelled "electrical smoke" just before the fire. I was under the impression that new boats had engine room/compartment fire suppression systems - either automatic or manually activated. I guess not. They had refueled at the marina when they left that morning so had around 400 gal of gas when she caught fire.

At the moment, no idea what happened but the owner had trouble with wiring harnesses; several had been replaced under warranty. The thought around the marina is some sort of electrical fire initiated it and then the gas was ignited by an existing fuel leak or possibly the electrical fire eventually burnt through a fuel hose.

I felt really bad when I heard this because I constantly told the admiral every time we saw the Carver (Mariner) that it was the ugliest boat in the Marina. Thought maybe I jinxed them.

 

[Nonchalant1]

It's fully automatic and requires no electricity. See previous threads. Check your engine compartments and I think you'll find a red circular pillow shaped sensor with a copper tube running to the CO2 cylinder firing head. When temperatures rise enough in the engine room, the heat expands the air in the sensor heads and the pressure goes through the tube to the sensor in the firing head and releases the CO2 into all 3 engine compartments at once. It can be tested by disconnecting the head from the tank and aiming a hair dryer or heat gun at the red sensor pillows (see previous threads).

It shuts down the engines because the CO2 replaces oxygen in the air intakes and they just stop running. Engines can be restarted after enough of the CO2 clears out of the engine rooms (you can use your blowers), and whatever started the fire is taken care of.

There is a reset for the firing head, but after it fires, the cylinder needs to be refilled. There's a reset for the crozzier alarm interconnect, where you just push the button down to reset.

Doug

 

[tomrealest]

Last year at the Hatteras 1510 Club rendevouz a Marine Surveyor spoke on the CO2 issue. He had an impressive resume. Coast Guard Academy, Coast Guard Officer retired, Insurance Company staff surveyor, etc. He said without question he would keep the co2. He said it was a better fire suprressant and had seen more damage with other sytems using different retardents. I was ready to change mine because of the physical size but after hearing him give real life examples, I haven't and won't think about it again.

Tom Earnest
Needs, Wants & Desires

 

[Genesis]

CO2 will do SEVERE damage to running diesels due to shock cooling. It will definitely shut them down, but it is not kind to them when it does.

Halon is banned, of course.

FE241 is clean, produces no mess, and is not significantly adiabatic when it is released. However, it requires shutdown systems in order to insure that diesel engines are killed when it fires, as it will not kill a diesel on its own. It DOES kill gas engines without assistance.

The other problem with CO2 systems is that they are large and involve high-pressure cylinders which must undergo hydro every five years. The usual mounting in many Hatts (including mine) exposes the bottom of the cylinder to bilge water intermittently, which WILL cause it to fail cert within 10-15 years and require replacement. This is not inexpensive.

Finally, CO2 systems are subject to systemic failure as they rely on capillary tubes to fire the actuator. There are more and fussy bits involved in them. A FE241 system has a sprinkler-head style actuator which is mechanically fired due to the boiling of an alcohol in a capsule (happens at roughly 155F.) Dirt simple, zero risk of failure - if it gets hot, it goes off.

A CO2 capillary tube that has a leak is invisible to inspection and requires that the head be dismounted and tested in order to determine that it is defective.

If you can mount a CO2 system in such a way that it is not at this risk, then I'm all for them PROVIDED they are fully tested at least annually. This is MUCH more involved than a FE241 bottle, which requires ONLY weighing it annually to determine that the agent inside has not leaked out (and the gauge is stuck.) If you are not prepared to FULLY test a CO2 system at least annually, then you are at significant risk of it not going off when you need it!

Understand, however, that if ANY clean agent system (CO2, Halon, FE241, etc) is set off whatever damage doing so does is FAR less severe than the consequences of letting a fire burn out of control.

 

[MikeP]

As promised, I reviewed the Hatt documentation on the CO2 system in our '80 53MY. The system will activate automatically if the sensors detect a fire (I don't remember what specific temp is required to set off the sensor). When the system triggers, it first activates the fuel shut-off on the engines and genny and then releases the CO2 into both engine compartments and the genny compartment.

Per the instructions, the engines will not start until the system reset button is depressed since no fuel will be supplied until this is done. They also add a nice "caution," explaining that since the fire system has been discharged, there is no longer any automatic fire protection until the system has been recharged.

Heck - and all this time I thought it was self-recharging!

 

[Pascal]

correct, I forgot about those detectors... darn...I feel like a complete idiot!

the system complexity is also why I'm thinking about adding individual FE241 bottles, much more simple system altogether.

 

[Nonchalant1]

I agree, it should be inspected anually. After you have seen it done professionally, you can easily do it yourself, since there's no magic or special tools required, just wrenches, an heat gun, a scale that'll measure tank weight and a gorilla to lift the tank onto the scale for you. However, that won't meet USCG requirements if you do commercial work.

Also FYI - CO2 tanks require hydro testing every 13 years, if they have never been fired and every 5 years if they have ever been fired. Also on the 1978 53MY, the factory stationed it on a wood deck above the bilge in the standard sb engine room position so it doesn't get wet on the bottom.

What's the cost and bottle hydro test frequency on the FE241 systems? I like simplicity.

Doug

 

[Genesis]

FE241 bottles must be weighed annually and, if within limits and the gauge is green and there is no physical issue, are ok for continued service.