: I been thinking about using "saddle mounts" with lashings ala
: Wharram, instead of the pocket mounts CLC uses to secure it's crossbeams
: to the floats and kayak of my trimaran.

: I originally directing the crossbeam into a socket would be the best way to
: go. But now that seems more of a stress riser. The crossbeam always trying
: to "force" it's way through the mount and out the side of the
: float's hull. The crossbeam would not be tied directly into the shear
: clamps. The pocket would also collect water. Where I'm not to worried
: about airing out a daysailer like SWIFTWOOD, this would be a problem on a
: bigger sister. There would have to be some sort of drain hole. On the
: other hand any upward force would serve to hold the joint together.
: Mechanical fasteners are really only necessary on the windward side to
: keep that hull from falling off, since its up in the air.

: Let's look at the saddle mount. The first thing that can be done is to run
: simple beams straight across all three hulls, then make the appropriate
: saddles to keep the height and orientation, keeping the floats angled out.
: This would eliminate the need for a hole in the top of the hull. One could
: even kill the bulkheads. Four are required in each hull since one has to
: box in each of the holes. This would make the hull a single compartment.
: Is this a good thing? Well, you could inspect the entire float with one
: inspection port.
: But as far as stress is concerned, should at least on bulkhead be placed
: under each of the saddles?

: If this is to be the route how are the saddles to be constructed? The
: simplest method is to make them out laminated plywood and bolt them to the
: shearclamps. These mounts would be kind of low in the water, a problem
: more for the floats which regularly run up ( and sometimes past ) them.
: You could streamline them as CLC does by bolting an angled piece of metal
: to the shearclamp which swings the saddle to the top of the deck. But why
: not just fasten them to the shearclamp through the deck?

: The saddles could also be changed out. So variations on mounts and crossbeams
: can be tried out, which appeals to me. I'd like to see what difference
: straight verses curved beams make. The curve at the saddles would serve a
: different purpose than socket plugs. The ends could be bowed like that of
: a crossbow, and the loads would be quite different. Experiments with soft,
: sprung crossbeams could be taken.

: But I diverse...
: Thoughts?

Hi Brian,

I agree about no wood sockets or pockets and attaching from above. Especially for the yak.

If it was me, I would go back over the yak and trim away as much wt as possible and just have slightly larger sheerclamps only in the vicinity of the 'saddles'. This means most braces, mast braces etc gone. Bulkheads below amas for stiffness and maststep connection.(spreads load)

Then put 2 blind anchor nuts on ea side of ea saddle say 4in apart w/ say large rectangular washer connecting both below the sheerclamp. Want firm bolting without crushing sheerclamp. epoxy seal the wood.

Or if you want to lash, put like a figure 8 lapped webbing loop around the sheerclamp coming up thru the deck making 2 loops either side of the brace. You could drive a wedge thru these or a clamp or a tie or a bolt, etc etc. Like from one pc of webbing coming up either side of the sheer clamp to make 2 loops on either side of the brace.

I would then make 2 crossbow shaped forms out of 2 layers of 1/2in ply separated by 1in spacers w/ a bump in the middle to exactly the cross sec deckshape of the yak at the 2 locations and the amas at the end.(hey if you have two ama's do you have s'amama's??? hehe. [lets copyright it]) The front location is right thru the mast.

Cut a whole bunch of laminations say 5in wide for the front and 1 1/2 or so for back and clamp and epoxy up to say 1 1/2 thick on ea form. In plan view of the front cut the front beams arms to the same 1 1/2 in wide but keep the 5 in in the ctr and cut a hole thru it for the mast. It gets used as the main mast upper support. Pvc tube or glass better down into yak w/ wide flange in base.

glass it and bolt on the saran wrapped deck for a perfect fit. Remove saran. plastic bolts to fill holes when not used. maybe even a little silicone gasket to eliminate scuffing and make the fit perfect. Some glass (1/2in or so)overhang
the edge of the yak for placement.

The idea is to fit it to the deck and forget angles etc. You'll have amore positive attachment.

Basically light as possible and so the yak is usable on its own.

-mick