Cross-strapped above DWL scupper throughhulls

[Sven]

Maybe cross-strapped is the wrong term ? What I mean is port drains to starboard and vice versa.

The current scuppers on Senta II are probably 1" or maybe 1.5" and there are only two. There are a few other things "wrong with this picture" but first I want to address the drainage question.

My first thought was to simply plumb a 2" or 2.5" rigid FG tube from the scupper in the cockpit angled only so much that it would empty above the waterline. I thought about putting in some 1-way valves or other method of preventing backflow, but that started getting too complicated.

Now I'm thinking of doing what I've seen on several sailboats on the Baltic and that is cross-plumbed scuppers. It would no longer be a rigid pipe (probably) but it would still be simple and let us reduce the number of holes in the bottom. The right scupper drains to port and the port scupper drains
to starboard, both drain above the waterline and only large overtaking seas from behind would have a chance to backflow into the cockpit.

Thoughts ?


-Sven

 

[Emerald]

Hi Sven,

do your current lines criss-cross below the water line, or do you at least have two seacocks for the scuppers on opposing sides, even if the lines are not currently done in a criss-cross? The Independence 31 is done this way, and it seems to work well, and I can't think of any advantage (other than freeze issues, which I don't think apply to you) to bringing them above the water line, given how she was originally setup. Only in the more extreme heeling with I'd say the aid of a little wave action from behind have I ever seen any signs of water in the leeward scupper drain with the lines criss-crossed below the water line. It was actually kinda cool as we were hauling butt and and the small amount of water starting to slurp up was kinda like confirmation of how much fun we were having

 

[Sven]

Hi David,

The advantage is that we'd get rid of two holes under the waterline. Right now there are only two throughhulls we don't close when we leave Senta and those are the scuppers' (unless someone else is working on the boat and we worry they will start the engine without opening something ...).

We have to redo the size anyway so this seemed like a good time to do it right.

The drainage on La Petite was an eye opener. We plugged the scupper and filled her up to just below the companion way ... I bet it took 30 minutes for her to drain.

I guess the current setup, increased to 2-2.5" with rigid FG tubes might do the trick too, even below the DWL.

BTW, don't assume we will be in non-freezing conditions


-Sven

 

[Emerald]

I've always wondered how long it would take to drain Emerald's cockpit with the two original seacocks. I believe they're 1 1/4", but it's been awhile since I was looking at them. I'm guessing not even close to fast enough. I need to do a test.

I think you would be better with a high grade reinforced scupper line - not stuff like what came originally, than rigid fiberglass tubes. Just thinking if you are in freezing areas, better to have a line that could hopefully flex and expand without cracking if it did freeze.

 

[Loren Beach]

This may help a bit...

http://www.ericsonyachts.org/infoexchange/showthread.php?t=6261&referrerid=28

Previous cockpit drain thread.

LB

 

[Glyn Judson]

E31 cockpit scupper seacock size.

David, If your seacock, ball or gate valve is like mine was, it is indeed 1 1/4". I had one seacock aft of the engine on the starboard side that had two scupper hoses lead to it and the port one led to the galley sink. That one went right away so I had all three lead to the one starboard seacock, not good. My 2006 haul out saw me enlarge the starboard one to 1 1/2" and add an identical sized one to the port side, aft of the engine as well. I now have the starboard and aft center hoses led to the starboard seacock and the port hose to the new port seacock. I still need to cross the hoses as I do get a bit of back flow when really tearing through the water on a good heel. It's just a matter of buying more hose and sending Marilyn in there to swap them out because at their present length, they're just a bit too short to cross. Glyn

 

[HughHarv]

Scuppers

I added two additional 1.5" scuppers aft, crossed the hoses and ran them to thru-hulls well above the waterline. I didn't mount the new scuppers all the way to the rear as I might want a propane locker back there some day.

Then I went to work on the original scuppers, they were the original thin wall pipe and were cracked and leaky so I replaced them with a couple of new 1.5" scuppers. I sat in the lazarette a long time measuring angles of heel and decided to install seacocks a few feet aft and just above the waterline. Now, if the boat were heeled way over with topsides submerged amidship, I doubt that a large wave would be able to push a much, if any, water up the hose and past the ball in the scupper. It it did and didn't drain fast enough between waves, I could just shut off the one forward seacock.

I also teed the bilge pump hose into one of the forward hoses in lieu of the galley sink. I removed the original gate valves and thruhulls below the waterline and glassed over the holes. Felt good to get rid of two more holes in the boat. Hope this information helps speed you along on what to do or not to do.