Engine Compartment Fire Extinquishing System

[romantic comedy]

I think that ss hose has rubber hose on the inside. That most likely would not take a lot of heat, but might take this application, since it is water/AF inside.

The cost would be more then having a real jacketed system fabricated, I am sure. probably about 4 dollars a foot. I used 110 feet.....

I wonder is you could get a ss hose 100 foot long? lol

It would be quite the challenge to wrap that around the exhaust while it is in place.

I could see anti freeze used. I think it would not flow very much, due to the long length. There would need to be a second inlet to the heat exchanger to accept the flow. That part I am thinking about.

[hanleyclifford]

Found this: http://www.ushosecorp.com/images_pro...files/USCX.pdf

[romantic comedy]

maybe we can get a ss hose with a 2 inch or larger diameter. Then pull it over the black pipe, like a condom? And some systems are longer then others.

[ndutton]

I'm all for innovation, thinking outside the box as it were provided the solution doesn't become more risk prone and cumbersome than the problem it was trying to remedy in the first place. Some observations/thoughts:

1. I noticed in the picture the hot pipe still had the wrap before the copper tubing was coiled around it. That's a good thing. If the copper were in direct contact with the black iron it's certain the copper would erode over time and develop leaks. The wrap prevents that. Also with the wrap in place you're not counting on the copper to handle all the heat by itself. The benefit of the copper is supplemental to the original design.
2. As mentioned by others, I don't think you want this to be an integral part of the engine's coolant path. If something clogs it up you don't want it affecting engine operation (think impeller bits and the manifold exit elbow). This concern suggests an independent system with its own pump and HX . . . . and raw water flow . . .and raw water discharge . . . no doubt with anti-siphon protection . . . and . . . and . . . and.
3. Which brings us to the topic of added complexity. Does the benefit outweigh the liabilities? Not for me to say.
4. And one of those liabilities is expense. Prototype development can often run 3 - 4X the cost of production units once the bugs are worked out. I hate to tell you how much I invested in the EWDS over a couple of years not to mention a pile of earlier prototypes and left over parts (there were several iterations) but it was one of those cases where the project took on a personality of its own. This may well be one of those projects. I see an awful lot of copper there, YIKES!!

About the braided stainless washing machine hoses, they're rubber on the inside.

[hanleyclifford]

If you think you need to run with your engine box off to mitigate the risk of fire on your boat, that to me is about as big a liability as I can imagine, the correction of which moves to first priority including doing whatever it takes to make that correction. When Neil speaks of weighing complexity/cost with benefits he clearly cannot be including safety in that analysis. Some things are absolutes on a boat; one of those is fire prevention.

[ndutton]

Hanley,
I'm all for safety but I discounted it only because of the considerable number of Tartans out there without a predisposition for fires (that I've heard of at least) whether they're caused by exhaust or not.

If such fires were commonplace why would anyone even own a Tartan? Seems to me they do just fine with wrapped hot sections and tall standpipes. As mentioned in point 1 of my previous post, the heat sink coil strikes me as an enhancement to the existing configuration.

But that's not really the point. As I recall, the desire was to place an automatic extinguishing system in the engine space and the concern was the ambient heat may trigger a false event. I think it was Ed who suggested installing fire ports as an alternative.

Maybe air condition the engine space? Lots of boats have air conditioning.

[romantic comedy]

Neil, ever since I fist got my Tartan 34, I felt that it had a potential to run way too hot. After looking thru many other Tartan 34s, I believe that this problem is the same with every one. At least the ones with the original exhaust set up.

Maybe i am being overly concerned. I think that when i touch a piece of wood cabinetry and I cant hold my hand on it, it is too hot to be safe.

Since most boats are used for day sailing or at least short motoring, the problem has been ignored, or unnoticed. It is a problem that has not been adequately addressed among the Tartan crowd.

When I motored any distance, I have kept the engine box open. On longer journeys I used fans blowing on the exhaust pipe. There is a real problem here. my tubing experiment is really just that, and experiment.

The more I think about it, the more i think better air flow would be the way to go.

[ndutton]

I appreciate the concerns, I'd probably feel the same and want to make it better, completely understand.

If ventilation is to be the strategy my caution to have a method to shut the ventilation off immediately or even automatically in the case of fire is critical however.

Of course I don't have a Tartan, never saw a Tartan but it seems to me since heat rises you may be trapping a super heated air pocket under the engine cover. Maybe providing an avenue for it to find its way up and out would be an improvement, a stove pipe of sorts. I bet the lower portion of the same engine cover is much cooler.

[ArtJ]

Impressive inputs guys.

Romantic - You are in a good position to try out the cooling system
either on the existing pump or with salt water. Why not try either or
both methods since you already have the tubing in place.
Wet Solution
Another thought - a number of years ago Tom Stevens removed
his stack and dry exhaust and replaced it with a water lift muffler
If I remember correctly, the " Pot" was installed in the space either
below where the standpipe was or in the bottom of the adjacent Nav Station
cavity on a shelf. The exhaust hose itself was no longer side exit at
waterline, but hose traveled thru a triangular space running at ceiling level above the
quarterberth to a transom exit

I believe he still had dry pipe up to the " Pot" , but don't remember
the details, although he shared some pics at the time.

Dry Solution
On a earlier occasion, Tom referred me to some Industrial "steampipe"
like hard insulation which contained a powdered substance which
i believe was called "calcimate" or something similar .
It was simply sawed with a handsaw to make lengths and 45 degree
elbows, then clamped and wired in place.

The issue
with this coating was that it shed powder continually, although
the mfr also sells a spray on coating to prevent this.
This was tried out by myself with a dry exhaust as a covering.
It was ss wired and clamped on . I didn't stick with it , as I
discovered the exhaust wrap solution. But it may have been
a better solution to the dry exhaust w/o cooling.
It probably better imitated the original Tartan design concept
of using asbestos plaster as insulation.

I still have a quantity of this stuff, but it is in a hard to access spot
currently, but could be retrieved.


BTW Romantic - In answer to your earlier post, I have ran numerous 24 hr constant runs up and down the New England cost with
the engine cover removed. It does help, at least with the heat inside the engine box.

[ArtJ]

Art, my hot section is only 1/2" from the bottom of my teak plywood galley cabinet. I bought some of that self-adhesive firewall insulation lots of folks put in their cars...it at least keeps the wood from catching fire by close contact and disperses the heat.

No solution for your immediate issue of an extinguishing system though.

Shawn
Do you know a source for this sticky insulation?
My boat has some aluminum foil faced sticky insulation around the
engine cover box. I would like to possibly add some around the hot
section plywood area. Does it have aluminum facing?

Best Regards

Art

[ArtJ]

The tartan 34 runs a hot section of exhaust. It goes up an enclosed cabniet which gets quite hot. I have left mine open for years. The problem is that the bilge blower is part of this cabinet. Poor design really.

I think that the problem could be solved with more air flow, probably using a fan or two. I did put the tubing on as a fun project. Now I need to run a long distance under power to see how hot it gets.

I have also thought of blowing air thru the tubing. have not come up with a way to do it yet.

Just to mention again I have taken many trips up and down the New England
coast often exceeding 100 miles and have motored over 30 hrs at a time
often. I leave the cover off the engine and run the blower constantly.
Heat isn't a issue in the engine compartment. The plywood enclosure for
the standpipe
gets warm but no exceeding dangerous heat in all these years.

Best Regards

Art

[Jwixted]

T34 that did have a fire!

Hi all - anyone still following this thread?

New owner of T34 #233, with rebuilt A4. As near as i can tell, the bilge blower burned, now replaced.

The exhaust pipe wrap seems brand new (engibe rebuilt/installation last August.

Picture of the exhaust system attached.

There is no room for the blower out end to have a hose- i suspect this is to ventilate the stack?

1-why is the hot section so high? So long as it somewhat downhill to the thruhull couldnt it be 6-8 inches shorter? Less height, less heat?

2- how can i tell if the rebuilt A4 is Moyer Marine?

3 - considering expanding the cabinet an inch all around and lining with HeatShield mat. Or leaving it alone ....

There must be a better design for this?


Thank!

Jack

[hanleyclifford]

Wow. I would not tolerate an exhaust pipe that close to plywood on my boat.

[romantic comedy]

Jack. Maybe MMI has a record of the serial numbers of his rebuilt engines.

Your exhaust is much different the the original. I would not call it a standpipe at all. But I dont know what others might say.

The original blower configuration had a partition between the intake blower hose and the exit. It went around the pipe and sealed the box so the exit would blow up and out.

You can see my pictures on this thread.

here are 2 more.

BTW I am lost soul at the t 34 forum

[Jwixted]

Thanks for the reply! The T34 site wouldnt take my phone pics easily.

My blower intake has a manifold to pull out air from below; the air out tho goes into the cabinet above the manifold; this manifold essentially blocks the lower end of the cabinet thus i presume the air goes mostly up and out as the cowling at the top would provide least resistance. Would give, as you note in the thread, some convective cooling, but need to run the blower full time.

I have not run this enough to determine the operating temps in/around the cabinet.

But i bet its high.

Would be simple enough to enlarge the cabinet over the port bunk a couple inches and line the whole thing with heatshield.

Jack