Author Topic: Good hatch design?  (Read 79 times)

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Offline SeaHusky

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Good hatch design?
« on: September 08, 2017, 03:10:16 PM »
A little diversion from all the hurricane worries. I have been thinking about hatch design. My boat has the standard "two slotted boards and a sliding cover" main hatchway. This is neither strong, nor even remotely watertight in case of a knock down. Roger Tailor on MingMing and others have mounted one or two Lewmar hatches but that is not really practical on a cruising boat. Does anyone have any suggestion for a more seaworthy construction or modification that is still cruiser friendly?

Sailing an Allegro 27 "Mikaja" in the Baltic.

Offline Owly055

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Re: Good hatch design?
« Reply #1 on: September 20, 2017, 10:09:35 AM »
     We of course are not looking at Ming Ming or Ming Ming II here.  Roger used only a single Lewmar hatch on the entry.    This large sloped sea hatch in your photo looks very practical with the hand rails.   Lewmar makes some sea hatches that are quite large, 30" being the largest I know of.  That's pretty big.   I know a few folks who wouldn't fit through a 30" hatch, but they aren't people I'd care to take along ;-)      The solution might be to fabricate a sloped hatch opening with an large opening similar to the original opening except sloped.   Use a washboard system and a dodger for normal conditions, but stow a bolt on cover with a good gasket system somewhere for rough weather.   The bolt on cover would use a clamping system with the clamps on the inside of the opening to compress the seal, and a Lewmar 77 sea hatch would allow you to enter and leave the cockpit without the big opening, and maintain water tight integrity.   In a knockdown you have numerous places for water to get in.... stove pipe, lazerette, anchor locker, portlights, hull to deck joint, mast boot / partner, etc.....    To maintain water tight integrity in a knockdown or capsize, requires a major campaign to find all the places water can get in.   Roger fiberglassed over the hull to deck joint, a significant offender.    Chances are you won't be battened down tight with zero ventilation, and you are going to find ALL the leaks.    If you're really serious about being completely water tight, the only way to test is to intentionally capsize the boat... drain the oil out of the engine, and pretty much remove anything loose inside the boat, hook a line to the masthead, down through a snatch block attached to a mooring block on the bottom, and to a winch on another boat, and pull it over.     It would be an interesting exercise.   I can see swinging the boom out to the side and tying it that way, with a fork of some sort to run your line through so the initial pull is outboard of the boat.  Once the masthead is well off to one side, it's going to go over fairly easily.    I can just imagine being inside while this is going on.  No matter how confident I was, I'd still want to have scuba gear aboard and a wetsuit, as well as a way to equalize pressure so I could open the hatch and escape if necessary.   It would be exciting to say the least.   I've never read of anybody doing this....... it would take confidence, determination, and huge balls!!

Below is a photo of Roger Taylor on Ming Ming II, and you can see his single Lewmar hatch and dodger setup.    He did an extensive series of Utube videos that are well worth watching.

                                                   H.W.


Offline SeaHusky

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Re: Good hatch design?
« Reply #2 on: September 20, 2017, 12:12:18 PM »
Owly, you are correct!
I don't really mean submarine tight and shouldn’t have written knock down. I think I was carried away by Roger Taylor’s reasoning (I have his books). What I am thinking about is that almost every time you read about people having encountered bad weather during a passage they need to dry out every cushion, mattress, bedding, clothing, carpet etc. due to having taken in large amounts of salt water. This to me seems unnecessary and I would like to have something better than the drop boards and sliding hatch that I, and everyone else, has that do not even stop all the normal sea spray that may reach them. Taylor addresses this problem after his crossing to Tasmania and one of my favourites, Sven Yrvind, says that "every housewife knows that the washing machine door must be watertight or you will have a wet floor. So far though, no production boat has had a watertight companionway".
This is him rollover testing his latest boat:
https://www.youtube.com/watch?v=KdOgULeFTfM

You may have a quite good idea about replacing the drop boards with a single panel that has a lewmar hatch. I will have to think more about that!

Sailing an Allegro 27 "Mikaja" in the Baltic.

Offline Owly055

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Re: Good hatch design?
« Reply #3 on: September 20, 2017, 01:45:53 PM »
Owly, you are correct!
I don't really mean submarine tight and shouldn’t have written knock down. I think I was carried away by Roger Taylor’s reasoning (I have his books). What I am thinking about is that almost every time you read about people having encountered bad weather during a passage they need to dry out every cushion, mattress, bedding, clothing, carpet etc. due to having taken in large amounts of salt water. This to me seems unnecessary and I would like to have something better than the drop boards and sliding hatch that I, and everyone else, has that do not even stop all the normal sea spray that may reach them. Taylor addresses this problem after his crossing to Tasmania and one of my favourites, Sven Yrvind, says that "every housewife knows that the washing machine door must be watertight or you will have a wet floor. So far though, no production boat has had a watertight companionway".
This is him rollover testing his latest boat:
https://www.youtube.com/watch?v=KdOgULeFTfM

You may have a quite good idea about replacing the drop boards with a single panel that has a lewmar hatch. I will have to think more about that!

I would go farther, and modify the opening so it was angled as shown in your photo.  That angle looks very good to me for ease of entry.  A grab bar above it would make entering easy when going in forward, side bars when backing down, actually angled grips for going down facing backward, or a pair of short tubular handles you could grab that were oriented laterally, and pointed inward or outward, attached to the verticals on the railing shown might be the best.   I put hand grips on my heavy equipment..... 3 yard loader, etc, which I have carefully and thoughtfully oriented to be in the most convenient location and orientation, so you always have something to hang on to with at least one hand.    I don't fall off of stuff!!    People laugh at my machinery with all it's mirrors and hand grips till they run it.   How many loaders have big west coaster mirrors with large wide angle spot mirrors below them?   I don't have blind spots and I don't back into or over things.

                                                                             H.W.

Offline SeaHusky

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Re: Good hatch design?
« Reply #4 on: September 20, 2017, 02:57:58 PM »
Good points but my boat is still a pleasure craft, will see 90% good weather and is meant to be sailed from the cock pit, sheltered by a soft sprayhood that I am thinking of replacing with a hard dodger. That isn't really compatible with the image in my first post?
Sailing an Allegro 27 "Mikaja" in the Baltic.

Offline ralay

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Re: Good hatch design?
« Reply #5 on: Today at 08:02:10 AM »
"almost every time you read about people having encountered bad weather during a passage they need to dry out every cushion, mattress, bedding, clothing, carpet etc. due to having taken in large amounts of salt water."

The crew themselves can bring in large amounts of water and any hatch has to let them in.  It's hard to get someone from the deck in soaking wet jacket, bibs, boots, harness, hat, etc into bed without getting anything else wet.  Your clothes are going to get wet sailing in anything but nice weather.  Carpet is going to get wet. Cushions and bedding stay dry to the extent you can avoid coming near them until you're totally dry.  That gets harder as your boat gets smaller and the number of crew increase.  You need places to hang foulies, boots, clothes, and towels to drip dry without getting that water on anything else even if they're tilted 25 degrees and flapping around. 

I think, for most people, who aren't taking breaking waves in the cockpit, the water you yourself bring down when you open the companionway is probably more significant than the rain or spray that would leak past a tight fitting companionway with a sea hood. 

For our boat, the hawse pipes are the biggest source of water intrusion in regular sailing.  Not a dangerous amount.  But enough for it to get flung from the bilge sump up into the turn of the bilge where it makes a mess in a boat without a liner such as ours.  A boat crossing an ocean could close them up, but for coastwise cruising, I'd rather have an anchor ready at all times.  Some boats have a separate anchor locker that drains overboard, but then you're restricted in how much rode you can carry and are forced to store the weight in the very tip of the bow. 
S/V Mona - Westsail 32