No, the question is whether an active or passive system can be designed (at any cost) which will satisfy each of SOLAS, the flag state and the insurers, and remain operational for more than a few days.
Automatically closing vents must be considered down-flooding points, so when calculation the down-flooding angle, you must consider them to be open (for SOLAS purposes).
The only exception (which is rarely granted) is for ball-type automatic closing air vents, which are not suitable for cabin ventilation as they close with negative pressure.
> the question is whether an active or passive system can be designed (at any cost) which will satisfy each of SOLAS, the flag state and the insurers, and remain operational for more than a few days.
We went to the moon. :) Or more pertinently we have diesel submarines with snorkel masts which automatically close (and even more importantly the diesel engine automatically shuts off) when submerged.
So we know it can be done. I can't even imagine how expensive those things are on a submarine, and how expensive all the maintenance must be.
I know this sounds crazy but changing regulations (or rather realistically obtaining exemptions) is "just a cost" too. A huge cost for sure. And an uncertain cost. But it can be done, especially when one does all the requires engineering work to show that the new solution is safer than the old one.
I understand that most people when they say "at any cost" what they mean is "at any cost reasonable within our means for this kind of thing". But when taken literally "at any cost" is quite expansive.
> Automatically closing vents must be considered down-flooding points, so when calculation the down-flooding angle, you must consider them to be open (for SOLAS purposes).
Presumably the SOLAS calculations were already fine with the down-flooding angle as is. So we can still treat the vent as open (for SOLAS purposes) while at the same time have an auto-closing feature on them.
> We went to the moon. :) Or more pertinently we have diesel submarines with snorkel masts which automatically close (and even more importantly the diesel engine automatically shuts off) when submerged.
What a non-sequitur. The issue isn't whether it can be built - but whether you can certify and insure it. Apollo couldn't have been run as a commercial pleasure spacecraft, either.
> Presumably the SOLAS calculations were already fine with the down-flooding angle as is. So we can still treat the vent as open (for SOLAS purposes) while at the same time have an auto-closing feature on them.
At anchor, but not at sea, where to achieve it's CE rating, the offending vents would be required to be closed.
That's the misunderstanding then. Because I'm specifically answering whether it can be built or not. This was the original question which started the thread: "So it's not possible to design ducting for HVAC/engine exhaust that either closes automatically at a certain angle, or has some mechanism that lets out gases without letting in water?"
> but whether you can certify and insure it.
You said "at any cost". At any cost I buy Lloyds, instruct them to work with my army of engineers until they find a way to satisfy their requirements, and we insure it. That's within the "at any cost" budget you set.
> At anchor, but not at sea, where to achieve it's CE rating, the offending vents would be required to be closed.
Okay. I'm not seeing the problem with that. You will have to explain to me why does that prevent us from making the vents automatically close at anchor when the boat is capsizing. Where do you see the problem with this?
> You said "at any cost". At any cost I buy Lloyds, instruct them to work with my army of engineers until they find a way to satisfy their requirements, and we insure it. That's within the "at any cost" budget you set.
And then buy the IMO and your own country to certify.
> Okay. I'm not seeing the problem with that. You will have to explain to me why does that prevent us from making the vents automatically close at anchor when the boat is capsizing.
There are no automatically closing vents certifiable for human ventilation, so you cannot have an automatically closing vents and just manually cover it when necessary.
> Where do you see the problem with this?
I think the problem is with you, who cannot seem to believe that marine engineering with centuries of experience could have found reasonable trade-offs in the regulations.
> I think the problem is with you, who cannot seem to believe that marine engineering with centuries of experience could have found reasonable trade-offs in the regulations.
You are putting something in my mouth which I did not say. Can it be done? Yes. Physically it can be built. Is it a reasonable trade-off? I don't think so, and I didn't said that it is.
Automatically closing vents must be considered down-flooding points, so when calculation the down-flooding angle, you must consider them to be open (for SOLAS purposes).
The only exception (which is rarely granted) is for ball-type automatic closing air vents, which are not suitable for cabin ventilation as they close with negative pressure.