GNAV...

But of course like nearly every other 'new' development this was first used in victorian times, or more recently in the Int Moth class !
see pic of a Moth from 1974 with a kicker strut ( gnav is such an ugly word )



Edited by I luv Wight

Originally posted by I luv Wight But of course like nearly every other 'new' development this was first used in victorian times, or more recently in the Int Moth class ! see pic of a Moth from 1974 with a kicker strut ( gnav is such an ugly word )

Well, I'll be ......somethinged.

Where'd the pic come from? Do you know who it is? Damn they were good times in the Moths, those days.

Ahh, that young Pattison chap must have just fluked that result, he will never amount to anyfink.

I don't recognise the boat 'tho I'm no expert. Unusual to have an Aussie skiff in '74. Just possibly an old Daring Moth; probably not a Brown "Good Grief" because he says his had scow-type sterns and this one seems to be very flared at the back. Plus I thought he created it in '74 or later. I can't see any hint of a chine, though.

The boat may be Aussie but I never heard of GNAVs out here in those days.

Innnteresting, very interesting.

Do you have any info re Victorian era inverted vangs? I've seen nothing.

BTW, I must modify my earlier claim; if it wasn't in Canoes, Rs or Moths, it wasn't invented. OK, maybe add N12s (U shaped hulls). Oh, and 18s (modern Assys) as well. Yeah, well maybe Firefly (first SMOD?) too.

Of course, most of the Moth ideas were in Canoes first......


Edited by Chris 249

Originally posted by Matt Jackson But the effect will be the same because the mast is still fixed at the same points - if you supported a mast on a chair at either end and pushed it down in the middle then pushed it down 1/4 along it's length it will form the same shape, it's just easier at the middle. Like I said mechanical advantage but you could get the same effect by adding a block or 2 to your kicker cascade - if there's room.

Don't you think that's a bit over-simplfied. The mast is anything but two ends on chair, what with all the other bits dangling off it like shrouds and probably lowers. I can't be bothered to make a model to test this, but even given a mast with just shrouds and kicker a kicker produces a point pull towards the boom at the heel and a point push from the boom at gooseneck. The Gnav produces the same point push at the gooseneck, but the pull at the heel is replaced by as push higher up the mast. Either way all the forces balance out on the tube, but I strongly suspect the extra point load changes the sgape of the bend curve.

I agree that strange things might happen if you add lowers into the equation but I think my anaology holds true no matter how many points you constraint the mast at. The vang/gnav will always have the same effect and it's the contstraints that change the bend curve.... although I could just be arguing for arguments sake now - it's been known!