Sliding fwd hatch of Swan 47 leaks

Hello:

On longer passages upwind, particularly if the bow if burried repeatedly, our forward hatch leaks. Some folk tell me this is a "well known issue and the only answer is to replace the hatch." Do other people with sliding forward hatches have any experience in this matter? I look forward to your comments.

Best regards,

P Milo

Dear Milo,

Yes! Same problem! We are considering a new hatch.

Many regards

Sidse & Carsten

Cygnus Peña 47 # 20

Hi again Milo,

I see that you have a anchor winch. Please describe where you put your chain.

Do you have a chain gate or do you let the chain directly down i the forward room?

We would be happy to see some pictures, thanks.

Many regards

Sidse & carsten

Hello friends,
I don't have a S&S 47 but looking at your picture it seems that your hatch is exactly the same of my S&S 411.
I admit that I have never endured severe storm conditions but I have experience of going upwind in choppy sea with frequent deck washing. I have had water entering easily from the windlass chain chimney but I never had problems with the forward hatch.
I am sure that a large well built modern hatch is fully waterproof but still I would not give up the one almost perfectly designed by S&S.
My guess is that if you have leaks, they do not come from the original design but from problems that occurred later due to misalignment, gasket wear or else.

If I were you I would check those items when the hatch is fully closed:
1) the hatch should dip few millimeters lower than when on the rails and set firmly under the proper latches. There should not be any possibility to lift the lid without sliding it backward.
2) the gasket on the upper flat part of the passage should adhere to the perspex lid and render it almost waterproof.
3) the overhang forward part of the perspex lid should be long enough to reach and adhere to a gasket fixed to the fixed forward wood frame. An aluminum band fixed to the wood frame overhanging and protecting the line of contact from above could be added – I am planning to do it myself sooner or later.
4) the lower inner aft part of the moving wood frame should have a gasket that goes into contact with the fixed frame.
Besides:
1) the perspex should have aluminum bands on the sides that act as overhanging shields.
2) water that seeps under these shields should be able to flow freely out.
3) all screw heads in the perspex should be embedded in some caulking compound.
4) there should be two small latches inside that, once closed, prevent the lid from sliding backward.

I am pretty sure that you already knew most but… this is just to assert my belief that it is difficult to devise something better than what was conceived by the designer of our boats.

Daniel

Daniel already described the proper approach very well.

I would like to point out two important things - that the hatch actually drops down on the seals when closed, and that it is forced down so seals are properly compressed. The latter can be done in several ways, a good one is to install latches at each corner with recessed hooks in the perspex

Kind regards

Lars

Dear Sidse and Carsten (on Cygnus Pena):

As you will see from the attached pic, the chain runs down the chimney in the forward cabin. This sytem works well with two exceptions:

1. Unlike my land-loving friends on the mainland USA, I sleep every night with my wife and a silver pole. Some nights we have our heads facing forward, but on other nights we kick the pole around with our feet. Not sure which is best just yet.....

2. On one occassion while raising teh anchor, the chain fell in such a manner that the chain formed a perfect pyramid in the anchor well. The well would not accept anymore chain as it was jammed at the bottom of the chimney. I realized what was happening and quickly went below and corrected the siutaion (pushed the chain pyramid over). We have 200 feet of chain and usually lay out about 100-125 feet.

I hope this helps.

P Milo

s/v The Last of the Normal People

Swan 47/048

Oh, one other pic of the anchor well.

Cheers.

P Milo

Dear Daniel and Lars:

Thank you for your input.

We have 4 latches and all manner of gaskets. I will recheck them for integrity. Our hatch works much as you described it with the hatch dropping or dipping onto the seals, etc... I do not want to replace the hatch, but we are going off shore next year and the leak was an issue when we sailed from Annapolis to St. Thomas (12 day trip).

Stay tuned.

P Milo

s/v The Last of the Normal People

Swan 47/048

Dear Milo,

Thank you very much for your pics. I appreciate your quick answer.

I don´t know why, but when I suggested a brass pole, my wife did´nt like the idea. :-).

Why do you not use the forward room?

Once again, thanks for your promt answer.

Many regards

Carsten

Hi Carsten:

I cannot think why your wife would not approve.   :)

The configuration we have is as it was when we bought our boat 18months ago. The forward cabin was renovated long before we came along. I imagine you may be able to use the most forward locker for chain storage, but weight may be an issue from a safety (bow more likely to bury) and also speed perspective (if you race). We keep our deck wash hose in the forward compartment. But as I say, this was all designed and built many years before us.

Cheers,

Milo

Dear Carsten and Milo

A chain box needs to be high and narrow in order to function properly and not entangle the chain when the boat heels. Further some empty space above the stowed chain is required to avoid blocking of the chain pipe as described above. The height requirement is such that it usually can not be met where the fore cabin is used for sleeping.

If chain size and length is known guidelines can be given for box dimensions

Kind regards

Lars

Hello to All regarding anchor chains....
As for the anchor locker and pipe, have attached photos of what I believe is a creative solution to the “necessary”... aesthetics does play a key role sometimes, and the stainless pipe was impossible for me (thank you Sidse for understanding). it’s not even centered on Aorangi! therefore, I covered it with a natural cording of 12mm (after having put a plastic sheath around the stainless to avoid corrosion) and it seems to be quite a bit more acceptable than before. we also made a teak cover for the motor unit and added a mechanical barometer to the front of it recently so the whole thing looks sort of nice now. Hasn’t solved the problem with the pyramidal chain accumulation of course, but then nothing has. We’ve tried several different solutions to no avail, and thought of making an electric sway pipe to help out. We are obviously not the only ones, as the there is a new Lofrans product designed for this purpose. (little pricey) In any case, will keep you posted as to how our homemade version works out.
Would like to ask for proper box dimensions, but fear to know the answer seeing that height is an issue. in any case, we have 250ft. of 3/8"chain. (Thank You Lars).

Ciao for now.
Jayne
Aorangi 47/047

Dear Milo,
Am touching iron (knocking on wood as well) as I write this, but have not had any leaking to date with the forward hatch. Matter of fact, would like to know what the original material is that includes the entire counter frame (gasket), as it is going to need to be replaced on one side sometime soon (seems a resin/mesh combination). Would prefer to stay with this material if at all possible instead of aluminum. As for the hatch itself, we still have the original system as described by Lars, with four latches on all corners inside. Only use the forward latches during navigation, and to date even during serious weather conditions they’ve done the trick. Would like to know what material you used for the new hatch, as it reflects like glass and looks very smart. Thanks. Jayne

Jayne

Recommended box dimensions for your chain size and length:

Square cross section with 12" side, or corresponding circular area, and 73" high. The box needs proper support also sideways, chain is quite heavy. Makes it less noisy if the inside is painted with deck mastic. Chain dead end could be attached with a piece of line to an eye inside the box - when all chain is paid out the line will come out on deck, and can be cut with a knife in an emergency. Chain pipe to be sealed in a seaway, or a pump installed for the box.

Lars

Jayne

The material around the hatch is Micarta, but you can also use acrylic. The machining of Micarta produces bad fumes and some shops refuse to work with the material.

I guess the new hatch is of scratch-resistant acrylic with a surface treatment.

Lars

Jayne, Lars, Daniel and company:

I am attaching some pics of the forward hatch as there seems to be some interest in this matter. Pics from anyone else would help at this end, too. Lars has described the construction material, thankfully, as my description would have served to confuse and not clarify. Still very new at all this big boat stuff you know.

Hope I am not taking up too much space with the pics. Please let me know if this is an issue. Looking at the black seals, I think they are weathered and need replacing. Any thoughts on who I contact for replacement seals? Is there a way to make the seals?

Cheers,

P Milo

Forward hatch closed.

Milo.

Forward hatch closed (from above).

Milo

Forward hatch closed (looking aft).

Milo

Dear Milo
many many thanks for the info and pics, a great help to everybody
Fair wind!
Matteo (38/067 Only You)

Dear all

Good pictures. Pls also note the aluminium grooved section on three sides outside the hatch frame. This section is intended for a canvas dodger over the hatch, and particular care has been taken to make the corners watertight - this detail actually was one of Rod Stephens inspection matters. The dodger has boltrope along the edges fitting into the groove and keeps most of the water away from the hatch, this reduces the watertightness requirements. With the dodger extended some distance aft, and fitted with battens holding it up the hatch can even be kept slightly open for ventilation at sea.

Lars