Subject: [harryproa] Re: crossbeams
From: "Robert" <>
Date: 11/9/2006, 7:47 PM

-My mind is still on a schooner rig with the masts and crossbeams in
one plane. For a single mast it would not work unless you increased
the height above the crossbeams on the lw hull.
Being caught aback is a concern for the crossbeam loads but the lw
hull is less than half the weight of the ww one when in cruising mode.
I really can't see how they can be caught aback provided the clew
doesnt go forward of the mast, but I suppose when running free in a
gale this is a possibility, but you'd need an enormous wind shift
from something like a thunderstorm or a nearby cliff. I was wondering
if the rigs could foul each other if one caught aback in these
I can see why the crossbeams are so wide front to back considering
the shock loads boats experience. Theoretically there should be less
of these shock loads with the differences in lengths of the hulls not
fighting each other when meeting seas at an angle and the easy and
early entry of the bows

> G'day,
> I don't understand what you mean. Lines from the mast to the ww
beam ends will divide the trampoline into 3 areas. Using the rails
as tension members has some merit, but you also need +/-45 structure
to take the sheer loads. They will also need to be a lot stronger
than would be required just to stop you falling over them. There
also needs to be enough strength for the beams to work if caught
aback, so I doubt you will save much weight.
> By the way, thanks for your help on the Mhml.
> regards,
> Rob
> ----- Original Message -----
> From: Robert
> To:
> Sent: Tuesday, November 07, 2006 11:56 AM
> Subject: [harryproa] crossbeams
> I have been thinking about cross beams. I can see the point of
> masts but I was wondering if it might be worthwhile having stayed
> crossbeams. To avoid falling overboard fore and aft, it is good
to have
> safety rails. It is possible to make those rails as tensile
> supporting the load of the ww hull. One cable from the base of
the mast
> to the ww hull just at the base of the crossbeam and another from
> base of the mast horizontal to the ww hull above the crossbeam
> Robert
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