Aft cockpit drainage / backing up

[gareth harris]

I am about to cut new through hulls for drains for the aft well in the cockpit, keeping the old through hulls for the forward well only, so as to speed up drainage should a large wave flood both wells. I intend to cut two through hulls just above the (level) water line, and cross the hoses to the far corners of the well deck.

I am sure I have read from 35-3 owners (but can not find it now with a search) that they have had a problem with water backing up when heeled over: what arrangement gives that problem?

By measuring, it looks as though the corner of the cockpit will fall below the water line at about 30 deg of heel, I am guessing that with surging waves water may come up through the drains at somewhat less heel than that. With the arrangement I have described, I can cut the holes in the hull anywhere in a curve from about 18" out from, and abeam, the rudder stock; to 15" out on a 45 deg line aft of abeam the rudder stock. I doubt it would make much practical difference where on that curve I cut it.

Has anyone tried this, or thought of a better arrangement?

Gareth
Freyja E35 #241 1972

 

[NateHanson]

If you put your thru-hulls above the resting waterline, and cross the hoses, then the cockpit won't flood because the low scupper hose won't have any water in it. That thruhull is far above the waterline at that point.

However, if that puts the scupper hose at a negative slope (water in cockpit has to go uphill to drain out) when healed, then the cockpit won't drain at that angle if it takes a wave.
I think to have it drain all the time, and not backflood when healed, you need to cross the hoses, and angle them down so that the hoses are not beyond horizontal when healed. So if a typical angle of heel is 30 degrees, your hoses need to be 30 degrees below horizontal going down to the thru-hulls. That may dictate how far aft you put the thru-hulls to keep them above the waterline. (Only the angle when looking from astern matters. i.e. The actual angle of the hose could be 25 degrees, but when viewed from directly astern, the angle appears to be 30 degrees. That's all that matters.)

I think[i/] I'm figuring that out correctly. Everyone else can straighten me out if not.

 

[rwthomas1]

FWIW, on my E38 there are 4 drains at the aftmost area of the T shaped cockpit. The two inner drains cross as Nate has indicated and empty above the waterline about a foot or so off centerline on each side respectively. The two outer drains connect to a T under the cockpit and then drain out a single 1.5" thru-hull under the galley sink. It will drain when heeled over. RT

 

[chaco]

Strange as it Seems

Gareth....I to have this Cockpit Drain arrangement.
Just a thought....being that you are makeing this modification for an
emergency situation from rogue waves, keep the existing drains for normal
operation and add the new drains higher on the sides of the cockpit to make
the fall to your new thruhulls. That way large amounts of water can drain
quickly, leaving the rest to the original cockpit drains :nerd:
Really depends on what the conditions are where you sail and are you making
the modification for Cruising safety in unknown waters.
Here in SoCal we would not have these conditions and that is where these
boats were built. From what I can gather on how my boat was stock
equipped in the 70's, a weekend trip to Catalina Island 20 miles OffShore
was the Design Guide. The great thing about Ericsons is that you have a
stout well built boat that can be modified to sail anywhere :nerd:
I have never liked the cockpit drainage to below water line Design.
Would recommend SeaCocks instead of ThruHuls for those Monster 1 1/2"
holes in your hull. There is something about putting a hole in a boat that
makes you really think hard before you pull the trigger on the drill

Good Luck to you Matey

 

[gareth harris]

G
Would recommend SeaCocks instead of ThruHuls for those Monster 1 1/2"
holes in your hull. There is something about putting a hole in a boat that
makes you really think hard before you pull the trigger on the drill

Good Luck to you Matey

I had the X marked, the 2 1/8" hole saw munted, and got cold feet.

Interesting thought about the double drainage.

Also, Nate, good point about avoiding water sitting in the hose as much as possible. The furthest aft I can go is limited by the height of the sea cocks below the deck, but the extra inch higher it would get could make a difference.

Gareth
Freyja E35 £241 1972

 

[rwthomas1]

FWIW, the outer cockpit drains that are connected to a T and draining through a thru-hull below the waterline are draining through a SEACOCK! I would never suggest, imply, install or recommend any below waterline fitting without a seacock. I have a bronze Groco 1.5" on mine. I always close all seacocks when I leave the boat. The two above waterline cockpit drains easily keep up with rainfall, etc. The system is not without flaws however it does drain well when heeled. RT

 

[chaco]

Another Option

Gareth
Another option that I am looking at is the the Forespar (www.forespar.com)
90 degree cockpit drain fittings. You only need 1/2" fall per 1ft (4%) to plumb
your drains safely. That's close to 2" fall to go directly out the hull above the
waterline. The CrissCross piping design will prevent the SeaCocks from backing
up in to the cockpit while healed. The drain should be a minimum 2" above the
waterline when the boat is at rest (IMHO) :nerd:
Will measure it up and report back to the E35II Teams

Happy Cockpit ReDrainage

 

[Cory B]

Gareth,

Another datapoint for you... in our 35-3 the crissed-crossed aft drains usually work just fine. However, in short 4-6' seas it often develops a small puddle on the low side, gurgling up and down with the waves, and just high enough to sometimes get over the sole of your shoes and get your feet wet. I wonder if going straight to the stern (w/ a slight downward tilt) might solve this.

 

[gareth harris]

Cory - where are the exit drains on a 35-3?

Gareth
Freyja E35 £241 1972

 

[Cory B]

The drains are under the stern in an area which is about 1 foot above the waterline when the boat is at rest. Once the boat gets going, it picks up the waterline back there, but its usually not an issue until the boat starts to heel. I'm not talking extreme heel, I'd guess they start to gurgle at around 10 degrees, and water starts puddling up at 15-20 degrees.

I think theres a "plumbing" drawing in the 35-3 manual on this site that might give a more accurate description of how the cockpit drainage system works.

 

[WhiteNoise]

No problems for me

I never liked the below the waterline idea so I modified mine last year. (30+) Having to leave the boat with the sea cocks open so the cockpit didn't will with water never sat well with me.

Haven't had an issue yet.
I've put the boat on it's ear, sailed through rain, and no issues.

I will say I have not taken a wave on the deck.

I will post some pics.