Here's a photo of John's forehatch as he emailed it to me --
John says,
"As you can see my son's head is peeking out of the forehatch which has been situated on the foredeck. This makes the siting of the bulkhead difficult.If I site it aft of the hatch, it would be some 9 inches too much in the cabin area. I have thrfore had to site it in front of the hatch further under the foredeck."
It's good having the picture, as not only does it show the hatch too far forward, it also shows that the hull is clinker. The only good thing to be said about the hatch is that the hinges are on the right side.
So my next question is, are there the right number of frames interspersed along the inside of the hull to support a clinker skin? This depends on the thickness of the planks of course, but it might be that the frames should be at about 9" centres or so.
Assuming the existence of sufficient frames to properly support the planking, then I don't think the bulkhead (which, as we now know, is presently missing altogether from John's boat) is a structural necessity. While no doubt it provides some marginal additional stiffness, the deckhouse structure, deck beams, and frames should, between them, provide quite sufficient resistance to hull stresses. (From memory the bulkhead is only 5/8" ply, and anyway has that large elliptical hole cut in it.)
I think the real purpose of the bulkhead is simply to separate the forepeak from the main cabin. But because there's such low headroom under the foredeck it was never intended that one should actually
enter the forepeak through the bulhkead as you might on a larger vessel -- rather, there's only that elliptical opening there to allow head, shoulders, and an arm through to retrieve warps from the shelf just visible in
Sanderling's photo, or to attach an anchor warp to a ringbolt on the keelson.
By kneeling on the cushion covering the head (aft of the bulkhead and just below the bottom border of
Sanderling's photo,) one can reach right to the stem to do these tasks. (I might add that the paler-coloured piece of ply across the lower part of the elliptical opening is not part of the original design. I placed it there, with turnbuckles for easy removal, to better retain wet muddy warps in the forepeak where they belong.)
So, summing everything up, I think the best answer is to build a new forehatch in the deckhouse where it was supposed to be in the first place, and to deck over the original hatch-opening altogether. Then the new bulkhead can go where it was always supposed to.
Failing that, I wouldn't bother installing the bulkhead at all, although you might consider building a very high floor forward of the existing hatch in order to retain warps stored in the forepeak. The hatch will still be very difficult to use because of the low headroom, and the forepeak will be considerably smaller than it was designed (and in my view requires) to be.
Failing that again, if a bulkhead is still considered necessary it could be held in place by epoxy-gluing butt-blocks to the planking forward of the bulkhead's location and against the after-side of the nearest frame, and then fastening the bulkhead to the blocks. In this case you would need to spile a new bulkhead shape to fit the narrower hull dimensions at the new location.
I hope all this helps.
Mike