Thread: Is that a 12' GIS I see hull down on your horizon

I showed a certain Mr Eggins (of NS14 design fame) the concept drawing and it has his interest too!

Wow... Bruce!

Well ... Mr Eggins should feel something very familiar!!! A lot of the basic geometry is very NS14 derived.

If you see him again can you ask him if he has any data on wooden NS14 masts. I have some on the Bethwaite Cherub rotating masts which I would guess would be much stiffer to handle the loads of a kite/spinnaker.

I just bought mine stock from Gary Fogg, my sailmaker at the time for the class. But measurements for any of the NS14 over rotating masts would be hugely valuable.

Michael

Originally Posted by Joost

Rick should stop playing around (nice jeep!) and get on with the job! We (well me) are dying to see what she looks like in the flesh.

I hope this will not turn into a Biting Midge building schedule...

SCHEDULE?

Did I hear someone say SCHEDULE?

If it has a schedule it isn't a hobby!

Cheers,

P
(Hurry up Rick!)

I'll probably see him on Sunday but if not I'm planning on taking Hakuna Matata for a blat on Salamander Bay during next week. He's asked me to let him know as he wants to see the GIS in person and maybe have a sail. I've been talking it up as he was telling me he was thinking of designing and building a boat around 16' specifically for Port Stephens to sail, row and motor and it has to have a low aspect reefable rig. It must be able to handle the big chop we get there. Well, I thought, he needs a Goat Island Skiff!

This time of year we get pretty gusty off shore 15kt breezes with flat water, but he should get the idea.

Brian ... while you are around here ... what is your take on Dyneema for standing rigging. Bruce noticed that a British manufactured trad style boat was being sold here in OZ with it as standard

I know the Australian Sharpie and 505 guys tried it here but found that to resist stretch it had to be quite bulky. It was still much lighter than SS wire. But they didn't like the bulk.

Looking at smaller dinghy type boats ... like ... um ... 12ft with a deck stepped mast as one option.

MIK

Just for fun

[ame=http://www.youtube.com/watch?v=yCDL_oXWIYM]Baby Goat Kicks Other Goats - YouTube[/ame]

Originally Posted by Boatmik

Brian ... while you are around here ... what is your take on Dyneema for standing rigging. Bruce noticed that a British manufactured trad style boat was being sold here in OZ with it as standard

I know the Australian Sharpie and 505 guys tried it here but found that to resist stretch it had to be quite bulky. It was still much lighter than SS wire. But they didn't like the bulk.

Looking at smaller dinghy type boats ... like ... um ... 12ft with a deck stepped mast as one option.

MIK

Interestingly I had just come to this thread to post about using dyneema, so MIK your question is well timed.

Having raced for 10 years with stayed lug rigs I am 100% convinced that the upwind performance advantages are huge and overall benefits, if you want to really enjoy the best of your rig.

I last three years were spent racing with dyneema shrouds. They were a bit small at 3mm but much much nicer than wire. The 3mm would stretch a bit during heavy wind racing and then re-tighten, so a version with pre-stretch would be better or 4mm would probably do it. I can confirm that the racing included very strong wind racing with no reefing and she was unbeatable in those conditions.

It's 100% the way to go for a home built boat. It's easy to splice, low cost and much more pleasant to live with than wire.

As for a Goat mast, I also think using dyneema shrouds and a higher peak yard so it misses the forestay, would mean the cheap standard 63.5 mm OD would be plenty stiff enough. It's twice as stiff as the 50mm mast I used for the 65 sq ft sail on the Scow.

So in answer to your question, yes it would be great for a 12' deck stepped mast and I think 4mm would be plenty stiff enough. This 5mm is twice as strong as 3mm and is listed as used for shrouds

Excel D12 Max 78

Brian

Haha, I nearly wet myself. Must be where the saying "acting the goat" comes from.

Cheers.

Looking at it for the 12 footer which will probably have a bunch of more conventional sail options. Just looking for nice ways to minimise cost and bring labour back to the builder rather than specialists. The single braid dyneema/spectra lines are so easy to terminate and create loops etc rather than talurits or swages.

MIK

I did quite a simple eye splice. This Marlow demo video is the bees knees, and will not slip when there is no load.

D12 Brummel Lock Splice - YouTube

Using these reasonably low cost lines and cheap local alloy tubes keeps nicely to your plans for allowing home builders to do a good job at much lower cost. I also found the 50mm tubes I used had standard Holt plastic mast end fittings. I think they might have been from the Opi fittings.

Brian

I think the way to go is to try the low cost dyneema and use a simple low tech 6:1 lashing on the forestay for tensioning the rig. Sure the cheap stuff will likely stretch a very small amount, but the amount is not going worry our 12 footer. The SK78 can be a bit pricey and I don't think it would offer much advantage over the standard stuff for our little boat.

The Moth class is divided on synthetic stays with the majority still using 1.8mm SS wire. Some use C6 but we can discard that option as it's way too expensive and besides, it's quite fragile stuff.

While 3mm dyneema should be fine and would be my choice, 4mm would have a bit less stretch. If 4mm works OK for the prototype, then we can at least tick the box. It would also sexy the boat up if a nice bright colour is used!

I agree with Brian. The stuff is a doddle to splice and there are many good video tutorials on the net. Use of a cheap thimble would help durability.

Hi Bruce ... is 3mm Dyneema with a bow tensioner the way the moths do it? They also have a mast gate up quite high which helps support ... if we go that way ours won't. Simple three stay rig.

I should move this over to the 12ft Goat thread.
MIK

Brian,

With your boat ... using the 3mm Spectra/Dyneema ...

Is the mast traditionally (and still on every boat) supported by the step and partner. I have a vague memory that the cat rigged versions had freestanding rigs then the shrouds were added to provide more mast support.

I could be totally wrong here.

MIK

The Mach 2 use a simple forestay lashing method like most stayed dinghy rigs. In the video, you get an idea of the sort of tension being used. Quite a lot, with the foot employed in the process! See around 2:30m into the vid.

Rigging up 101.mov - YouTube