Skin fittings and cockpit drainage

damo

damo

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Apropos the skin fittings debate below, what thoughts do folks have about the following situation?

I have a centre cockpit boat with 2 x 1.25" drains which cross over to seacocks. I have just replaced the gate valves with ball valves, and while the engine was out I have glassed in pads to take two more drain seacocks. The thinking behind this is that offshore regs deem the current setup inadequate for rapid draining, so if I ever manage to do an OSTAR I would either have to change to BIG through hulls (no room round the engine) or fit 2 more, hence the pads.

Even if I don't do an offshore race, present design thinking is that the drains are too small for the cockpit volume. I have already got rid of 3 other redundant skin fittings (log, galley seawater, heads sink drain).

So which is the greater risk - 2 more holes in the boat, or a (deep) cockpit full of water for twice as long?
 
At the risk of becoming some kind of pseudo expert on skin fittings, which I most definitely am not. Nor of self draining cockpits on monohulls. But at rest the drains will be above the waterline, yes no.

You see, mine are, so I, in this instance can only assume this is the same of all boats. If they do drain underwater then I have no comment.

If above then I see no problem, I am thinking off adding 2 more myself. In your case, (I sail a multi), if one failed you could level the boat or even change tack and carry out a repair, no?

On the mooring a fail would at worst mean water might lap in and your pumps should cope?
 
If they are below the water line, I think they would only drain when you are moving at some sort of speed, what about a sump and pump system, or one of those inline pumps?
 
[ QUOTE ]
If they are below the water line, I think they would only drain when you are moving at some sort of speed, what about a sump and pump system, or one of those inline pumps?

[/ QUOTE ]No, they drain at any time as long as the water inside the cockpit is higher than the water outside the boat. Movement isn't required for draining - it's just gravity!
 
Cockpit + water above sealevel = empty cockpit + higher waterline after a while

I think I'd rather KISS thanks /forums/images/graemlins/smile.gif

I've only ever had a few bucketfulls in the cockpit, but I have to consider big waves breaking over the boat.
 
I had the cockpit on my Rival 32 full a few times, and was very surprised how quickly it drained, although I thought the drains could have been bigger. But on the present Nic 32, I have 4 drains in the cockpit, to 2 thro hulls, I have grave doubts the cockpit would drain quickly, it,s much bigger than the R32, but the thro hulls are the same I think.
One aspect of modern design, I very much approve of is the huge transom draining capacity on a lot of modern boats, and possibly higher cockpit soles.
 
We have a centrecockpit with underwater drains. We have 4 drains - each of 2 inch diameter (from memory) - bigger than any other seacock on the boat I know that for sure!

Yes - we do have 4 seacocks below the waterline for cockpit drainage - however one also serves as the sink / shower drain for the aft heads so this is dual purpose.

It all comes down to personal choice and intended sailing. If your liveaboard and crossing oceans - I imagine extra drains are worth the extra seacocks. If you do coastal cruising and leave the boat on a mooring then I suspect less seacocks would be more important.

Just my thoughts ....

Jonny
 
I've no pretentions to expertise on skinfittings and seacocks either, but fwiw, here's my 2 penny'th.

From memory, the bridgedecks on a Warrior 35 are on the low side, so draining the cockpit quickly if you do take a wave might be quite important. OTOH, sudden complete failure of a big skinfitting would sink the boat in short order. It's a balance of risk.

It seems to me that skinfittings fail because they're the wrong material or they've suffered physical damage; most often, I suspect it would take both.

Bronze or dzr brass fittings/cocks will last for years if maintained properly. I have cocks on Jissel that I'm pretty sure are 37 years old with no problems apart from simple wear. Failure of such items would be gradual - a slight leak that gradually gets worse until you decide to do something about it. Catastrophic failure is very unlikely to be related to the metal bits; hose failure is much more likely, but neither will happen without severely defective installation or maintenance. It seems to me that a nose round every few months, including operating the valves so they don't seize, a good welt with a rubber hammer on the valves at haulout time and changing the hoses as soon as they start to look tired will make the probability of serious problems at sea vanishingly small. Even if you were sold plain brass fittings by a dishonest or ignorant supplier, the welt with the rubber hammer at haulout means they'd fail when it was only an inconvenience

I'd go for the good drains.
 
Agree with all you say Steve, except, "I would go for the drains", I dissagree only if you go with 4 drains/holes when two, slightly bigger dia would have the same effect.
I say that ,cos, my Nic has 4 drains in the cockpit floor, but illogically, 2 thro hulls, all piping the same dia?
Many Years Ago in France(30+), I saw a home made boat, steel, with ONE thro hull, with a stand pipe(above the water line) and lid, I thought at the time what a good idea, but never pursued it, even though I subsequently built a steel 44 myself. But I still think why not, tell me??? Bill.
 
"how quickly it drained..." What sort of time would you estimate? Trawling through the web I've come across a single example which gives a timed test: it was a C&C 29 where the cockpit had 4 off 1 1/2" drains (I.D. or O.D?). For the test they put 8 cubic feet of water (about 500 lbs) in: it took 1 minute 40 to drain. The total volume of the cockpit was 38 cu.ft. They extrapolated a time of 7m54. Which seems long...The tester thought this was fast...
I think there is often confusion regarding the size of the drains...a 1 1/2" drain would have an outside diameter of nearly 2" (and require a 2" I.D. hose...). Drains are more usually 1" requiring 30 mm I.D. hose.
Regs usually call for selfdraining cockpits to be 10" above LWL.
 
10", thats mine out of their spec, doubt if they are 5", btw, the boat with a single thro hull I quoted, the thro hull was about 4/5" which accomodatecd all intakes and outlets, no bog on that boat of course, but the principle I think is worthy of consideration.
 
This may be a silly suggestion but could you fit another drain which exits safely above the waterline? Although I have never seen this, you don’t necessarily need the extra drain to be in the cockpit floor. It could be fitted to the side of the cockpit and would function to initially help remove deep water. If it was a little lower than your bridgedeck, it would help to prevent water getting into the cabin. Once the water level had dropped below the bridgedeck, the existing drains would cope.

I've just been thinking my suggestion through - it is silly. /forums/images/graemlins/blush.gif
 
Its not a silly suggestion at all - I have seen Contessa 26's with a drain similar to what you have in mind. These Contessas did not have self draining cockpits, so the ones I saw had improvised a very neat drain tube in the aft vertical side of the cockpit well about 8" above the floor, and exiting the transom just above the waterline.

This drain would help enormously towards getting rid of the main bulk of the water in the cockpit fairly quickly.
 
Not silly at all! I have considered that, as well as glassed-in pipes which would do away with the need for hoses and seacocks. The problem is with the floor being about a foot from the waterline, and needing to have access to the engine, shaft and shaft seal. As it is, I have to remove the drain hoses, autopilot and water trap and go caving through the hatch I cut from the aft cabin!

The other problem with the Warrior is a bridgedeck about 3" high /forums/images/graemlins/frown.gif
 
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