Self-Draining Skin Fitting Location

[Roach1948]

Roach was designed with a self-draining cockpit and the only skin fitting was located on the aft starboard quarter. To access this from the inside it was quite a reach in a cramped locker, so I have decided to turn this locker into a dedicated gas locker and use that skin fitting as the gas overboard drain instead (to modern safety regs).

So I now need a new location for the self-draining skin fitting as I was thinking of the transom. The advantage is that I can easily access the seacock from a large Lazarette locker - the down side is I can only get 3" from the top of the cockpit and worried I might hit some transom fastenings when I drill through.

Has anybody has any experience of transom mounted drains close to the waterline? Will she flood when loaded? Any better ideas?

 

[DanTribe]

I'm not clear if the outlet you are proposing to use for the gas drain is below or above water. If below, it won't drain.
The depth of the actual outlet for cockpit drains is not important, only height of sole above water level.
Traditionally cockpit drains were taken one from each side of the cockpit and crossed over to opposite side. I think this was to stop the cockpit flooding when heeled, as the lee side could then be below water level.
Draining cockpits through the transom above waterline always seems more sensible as there is less to go wrong.
Dan

 

[Roach1948]

The new gas outlet is just above the boot topping so I hope she sits to her marks with the new engine in so the gas can drain!

I think that maybe she did have crossed-over drains at one point, but I reckon she had a plank replaced on her other side and the previous owner never got round to re-fitting the second drain.

I would prefer to have the self-draining cockpit drain in the transom as I have decided to have a fully watertight cockpit sole. Before it was in sections and therefore hard to seal. Water dripped on the engine and the sole bearers rotted. Now, to get into the engine bay, you will have to lift the whole cockpit floor, and therefore it will be hard to access seacocks if they are of the cross-over style.

The idea now is that the drain is through a single sea-cock in the transom, and that if I need to lift the cockpit sole out completely, I can, by turning the seacock off (in the easily accessed lazarette) and undoing the hose.

 

[Mirelle]

I would most certainly avoid any kind of opening in the floor of a self draining cockpit.

 

[Scarboroughsloop]

I was planning on a raised hatch in the cockpit sole to be dogged down on to a gasket. Do you think this would cause problems? I canot really see another way of gaining engine access.

 

[Mirelle]

I should have added: "If humanly possible!"

Other than a four inch diameter bronze screw down plate, which gave access to a Stuart Turner shaft greaser, I have never seen a hatch in a self draining cockpit sole that did not leak and cause trouble.

Even those that dog down onto a gasket "go home" due to the gasket not doing its job right.

I believe that a good cockpit cover will greatly improve things, though. A few drips of spray at sea don't matter; twenty summer's worth of rain water on the mooring does matter!

 

[Roach1948]

Gosh, re-read my post and it hardly makes sense!

Allow me simplify: is 3 inches above the waterline is high enough, given full loading on a 4 tonner, not to back flood the cockpit?

 

[Roach1948]

Hi there S.Sloop,

Well that is exactly my problem! I have now decided to go for a solid cockpit sole with numbered lift-out bearers underneath so that I can gain access to the engine easily. Dallimore has a raised engine hatch in his design, but as Mirelle has noted, it will eventually cost dear; In my case a completely new cockpit!

To make access easier I am putting a 1 inch upstand frame along the whole edge of the sole so that it can take rain and spray - Like a huge tray. Teak duck boards will rest on this upstand - on a small yacht I prefer narrow duckboards as they provide better grip on a heel (and look better in my opinion). The sole is designed to be lifted from the Port edge (the other side from the throttle mounting) and is routered to fit without jamming at 70 degrees. The fit is so tight that a vertical lift will snag.

The down side is the access to the tradiational self-draining mechanism and your crew will need to lift their legs when doing an engine inspection. Removing the whole sole will also need removal of the self-draining hose too ofcourse - and that is one of my dilemmas. I need to make sure that sea-cock is OFF. I am thinking of installing a one-way valve for safety - and a bungee to hold the hose above the syphon level if disconnected.

 

[Mirelle]

I suspect not; because you are going to pull up a stern wave, under way.

 

[Roach1948]

Good point - I have been on dry land for so long I forgot about hydronamics caused by movement!

Would not want to forfeit the SD feature. Do you reck' a rubber flap or one way valve sufficient?

 

[Scarboroughsloop]

Maybe you will have to revert to the 2 seacocks draining from each quarter? This is the way I will be going (actually with a canoe stern I do not think there is another real option.)

 

[Mirelle]

Mirelle has two crossed over lines to seacocks.

Originally these seacocks were under the cockpit and accessible only by a highly trained ferret - so much so that the second owner, from whom I bought her, had spent 33 years without discovering their existence!

They were 3/4" diameter with sweated lead piping, so when the cockpit got rebuilt I replaced them with 1 1/2" diameter ones, and moved the seacocks forward to a position where they can easily be got at from inside the cabin. This has no effect on their ability to drain the cockpit, which is excellent.

Classic Marine sell a very posh American bronze fitting for the cockpit end of such drains, incorporating a captive ball that acts as a non-return valve, which might be useful.