Gas locker drain hole below waterline?

[Tim Good]

So I have a nice gas locker built into the port bow of my boat. Very nicely done and it has a drain hole at the bottom naturally. That hole has a pipe which goes down inside the boat, behind my galley cabinets to a seacock and a scupper vent just below the water line.

Ok so if you're sailing it comes out of the water enough to drain any gas but at anchor or in a marina it clearly would not drain any gas should there be a leak.

I assume this isn't normal and an error in behalf of the builders? Just assessing my options.

 

[pvb]

I assume this isn't normal and an error in behalf of the builders? Just assessing my options.

Not just abnormal, it's seriously wrong.

 

[sarabande]

A gas locker at the sharp end sounds very odd. I can understand an anchor or chain locker.....


Has it been "converted" ?

 

[VicS]

So I have a nice gas locker built into the port bow of my boat. Very nicely done and it has a drain hole at the bottom naturally. That hole has a pipe which goes down inside the boat, behind my galley cabinets to a seacock and a scupper vent just below the water line.

Ok so if you're sailing it comes out of the water enough to drain any gas but at anchor or in a marina it clearly would not drain any gas should there be a leak.

I assume this isn't normal and an error in behalf of the builders? Just assessing my options.

If it helps ( and it is what I have had to do) you can connect the "drain" to the gas locker higher than "at or near the bottom" if the "volume beneath the drain-opening is minimised
by the use of suitable material" (BSS 7.3.2/R)

This may enable you to connect to an outlet above the waterline

 

[boatmike]

Not just abnormal, it's seriously wrong.

I would agree on two counts. The gas needs to drain above the WL freely obviously, but when I was building commercial vessels to MCA regs the recommendation was to site LPG in a place that kept it clear of potential collision zones. The bow locker is about the worst place for that. I would suggest it was never designed that way and what you have is an adaption of a chain locker where the drain can certainly be below the WL and often is to avoid dribble stains in the topside gelcoat.

 

[Tim Good]

A gas locker at the sharp end sounds very odd. I can understand an anchor or chain locker.....


Has it been "converted" ?

No it's a good 12 ft aft of the bow but still in the foredeck.

 

[Tim Good]

I would agree on two counts. The gas needs to drain above the WL freely obviously, but when I was building commercial vessels to MCA regs the recommendation was to site LPG in a place that kept it clear of potential collision zones. The bow locker is about the worst place for that. I would suggest it was never designed that way and what you have is an adaption of a chain locker where the drain can certainly be below the WL and often is to avoid dribble stains in the topside gelcoat.

No it's definitely an original design as I have the plans. It was even designed in the shape of two gas bottles at a perfect height for a calor 4.5. Locking kid also. I think I may just put a small white vent just below the locker and then cap off the only seacock for some potential use down the line.

 

[macd]

That is very strange, northcave. Even as a liquid, gas is substantially lighter than water and wouldn't drain out. On the face of it it's also dangerous but, since it can't possibly go down the drain, where would gravity take any gas escaping from the locker? If it would simply flow through deck scuppers, perhaps your underwater seacock is simply to allow water to drain out?

 

[Tim Good]

That is very strange, northcave. Even as a liquid, gas is substantially lighter than water and wouldn't drain out. On the face of it it's also dangerous but, since it can't possibly go down the drain, where would gravity take any gas escaping from the locker? If it would simply flow through deck scuppers, perhaps your underwater seacock is simply to allow water to drain out?

Well yes it certainly needs a drain for water as the locker is flush deck and not water tight. Maybe that was the thinking... That if there was a leak then it would only fill the space of the locker before spelling out onto the deck which I presume then wouldn't be an issue.

Do you think that sound a acceptable or maybe back in 1996 then gas drain holes were just not required and they simply only considered a water drain.

Odd given it is built to a very high standard in Falmouth.

 

[macd]

A photo might help, northcave.
But if the only way it can leak is onto the deck, and from there in to the sea, then that should be no problem. This would, of course, mean that the entire internal structure of the locker must be utterly gas-tight.

You see quite a few (usually older) yachts with gas bottles simply lashed to the mast, or in a deck-top locker adjacent to the mast, which drain simply and safely onto the deck.

 

[Tim Good]

A photo might help, northcave.

You got it...

 

[lpdsn]

The bow locker is about the worst place for that. I would suggest it was never designed that way and what you have is an adaption of a chain locker where the drain can certainly be below the WL and often is to avoid dribble stains in the topside gelcoat.

I've seen a few boats with the gas locker at the bow. IIRC, they were all Swedish designs. Drains were well above the waterline.

There's another disadvantage in that the gas bottle is more likely to be thrown around in heavy weather, so they usually seem to be strapped down.

 

[prv]

A gas locker at the sharp end sounds very odd.

It's what we have; or rather the gas bottles have a designed-in shelf in the bow anchor locker. I think it's a Swedish thing although the large Hanse my parents chartered in Greece this summer also had the gas in the bow. In that case it was a separate compartment accessed through a hatch in the side of the cavernous anchor locker.

Personally I can't get too worked up about the OP's arrangement, as any escaping gas cannot possibly get into the accommodation. It'll just overflow up out of the locker and over the gunwale. I'd be more concerned at the ease with which water can apparently get into it and rust the bottles and plumbing.

Pete

 

[pvb]

I've seen a few boats with the gas locker at the bow. IIRC, they were all Swedish designs. Drains were well above the waterline.

My old HR352 had the gas bottle on a shelf in the chain locker, using the existing drain holes as drainage for leaking gas. The bottle was secured with bungee cord.

 

[lw395]

My old HR352 had the gas bottle on a shelf in the chain locker, using the existing drain holes as drainage for leaking gas. The bottle was secured with bungee cord.

My Impala was like that.
It was a game to use gas quickly enough that the empty bottle wouldn't be too rusty to exchange.

So long as the Op's boat has good integrity of the locker so gas cannot leak from the locker to the hull space, I would be happy with it.
Or at least happier than with some boats I've sailed on.
The best way forward might be to leave the current drain to drain water, and add a gas drain a little way up the locker to cope with a gas failure.
Then try to seal the lid to keep the water out.

 

[PCUK]

Well yes it certainly needs a drain for water as the locker is flush deck and not water tight. Maybe that was the thinking... That if there was a leak then it would only fill the space of the locker before spelling out onto the deck which I presume then wouldn't be an issue.

Do you think that sound a acceptable or maybe back in 1996 then gas drain holes were just not required and they simply only considered a water drain.

Odd given it is built to a very high standard in Falmouth.

Gas lockers go back to the 50s and before, only 20 years ago in 1996 they were very much the norm. Your set-up is wrong and needs correcting.

 

[Arcady]

Your set-up is wrong and needs correcting.

Why is it wrong?

 

[charles_reed]

Why is it wrong?

Were you querying the didactism or making a genuine enquiry?
It is usual for gas lockers to vent, from their lowest point, overboard.
Some Inland Waterway inspectors would agree with PCUK - which doesn't make them correct, but could mean a survey fail.
Certainly the drain to below the waterline is utterly useless for minimising gas-escape risk.

 

[pvb]

Were you querying the didactism or making a genuine enquiry?

Didacticism, surely? If you want to impress with big words, at least spell them correctly!

 

[boatmike]

No it's a good 12 ft aft of the bow but still in the foredeck.

Now that you have said that and supplied photos, it changes the impression given by your first post considerably. It's not really in any collision zone and was probably sited there to keep the pipework run as short as possible. My guess is your cooker etc are sited not far away from it inside the boat? The drain is obviously for water. Probably the builders thinking was that the volume of the locker is not great and therefore a minimal risk. You don't have to conform to MCA regs so it probably isn't a practical risk but personally as it would be very easy to add a second drain slightly above the existing one (which would save unsightly water dribble stains) I would consider adding one.