Sea Sled madness. It’s in my brain.

Well, I don't mean to be negative but there is no way in hell I would have a forward facing door on a boat like that, open inward.

I've had a ton or two of water on the bow before. It was not a huge danger because the bow was enclosed. We wallowed for a moment, then rolled back up.

Your bow is a scoop, isn't it? Maybe with cargo in it?

If I had to recess the door two feet to to get it opening out, I would. It's either that, or sufficient framing that you can have four lock points, with bars back to a central rotating wheel like a commercial hatch or a safe.

I mean if you know for sure you're only ever going to run to Bowen Island or something that's one thing.

But you come around the south tip of quadra on a rough day with an inward opening door on the bow, I don't like your odds, personally.

 

Just remind me of the obvious that is missing..
You need to make sure you have a good height coaming for that door. I'd recommend the min of 380mm.... not flush!!

 

It sounds like its a slider that overlays the frame all around.

 

380mm?

75mm is nice, who wants to step up and over 14"?

on balance, well done, just not understanding the number

 

This is my thought for the arrangement immediately in front of the door. It's a safe step height up to the opening from the interior sole. I hope to avoid a coaming that high by having 2 soles outside the door. A water carrying sole, and then above that a tread grid to walk on. Hopefully this sketch is clear. It's mostly to scale.

 

Is this correct,:


This is all you have allowed for your coaming/sill height?
If so, what value is this?

 

Well, the sill height is 7" in that location. Keep going down to the bottom of the trough.

 

Ad Hoc,

It would appear the answer you seek is about 1 1/2"

I know what he's trying to explain.
It's like a driveway drain in front of a garage...
He's proposing ~5" round scuppers at each end of the "trough".
His objective is to reduce the step height through the doorway.
The scuppers would have "flaps" to keep seawater splash out.

John, please correct me if I am at all mistaken.

Oh, happy dance, got my "shot" this morning.

 

Yes. Enormous scuppers at either end of the 6" by 6" trough, below the cockpit sole. I expect to have fragile old folks going through that door. A 14" step up over the coaming to the interior sole, 7" below the the exterior sole, is more than most folks out of their teen years can manage.

 

You got your shot... well done.. lucky you.
Here in Japan they only just started this week.. for those over 80.... hopeless!!!!!... but anyway... I digress.

Yup... that's what it looked like.
This is inadequate.

A large wave over the bow will not think.... hmmm.. there is a scupper of some 5inches i will fill that first then think about going the extra 1 1/2 inches when it is filled.
The scupper will be filled quickly and over time, be full of dirt/grime/leaves... any debris of any kind...reducing the "sill" height of that 5' to zero in no time at all. Look at the guttering on your house, doesn't take long.

Thus, I would strongly urge you to make this 1.5 inches more fit-for-purpose.

A step over of a say 200mm or 250mm coaming is nothing, compared to green water flowing into your wheelhouse.

 

No doubt you are correct.

 

The drainage calculations provided by the stuff I can find are crap. Written by somebody who doesn't know enough fluid mechanics to know edge effects. They apply a scrictly linear relationship between opening area and flow rate, without even modifiers for shape.

 

Ad Hoc, if it helps, that gutter will not ever retain anything larger than a musty smell. The 6 by 6 box ends with a 6 by 6 hole at either end, covered with a rubber flap.

 

It's about direction of flow.
Ad Hoc, of course, is right.

John, If you can make your sole height equal, inside the doorway and out,
a high sill height won't be that big a deal for any elder who can negotiate the "Ram" in the first place.
It will allow you to move your scuppers up which only increases down flooding protection.
It also reduces the door loading potential by making the door smaller.

 

I assume you have just hand rails on the foredeck?

As a guide, you could use the same calculation provided for minimum freeing port dimensions?