Monday, September 12, 2016

Tarawa With Spinnaclaw


There's good news and not so good news.  The spinnaclaw system works fine and would be good for a larger proa, I think at least 24'.  On my little 16' Tarawa, the short spinnaker pole interferes with where I'm sitting on the hiking seat.  I tried two different locations for the pivot point.  First I had it higher on the mast so that it would clear my legs, but that meant that the boom had to be quite high off the deck and almost level with a high CE.  I moved the pivot point down to deck level as shown in the photo but there was no way to make it work with my legs in the hull.
The good news is that it would work on a platform big enough that the crew could stay well clear on the windward platform.  Certainly the balance would be better on broad reaches.  So for now I'll go back to the shunting rail system I've shown in the book.


10 comments:

Michael Schacht said...

It's great to see you finally build this, Gary. Too bad about the leg clearance problem, couldn't you just cut them off so you take a test sail? :-)

Gary.Dierking said...

I knew someone would have a useful suggestion :-)

Anonymous said...

A schooner rig using spinnaclaws would be out of the crews' way, but shunting two rigs would be a lot of work. Maybe there's a way to gang either the poles or the tacks together, like tie rods for steering a car.

Wade Tarzia said...

Is this the rig that somebody mentioned on the old Proafile yahoo forum years ago and then illustrated in a brief animation (Michael?). -- Wade

Wade Tarzia said...

OK, I answered my own question above: yes it is (after going to proafile.com).

Now I note that the geometry is vaguely like J.B.'s attempt to automate the shunt on his recent prototype proa (Michael, you two had a phone conversation about this I believe), which was shunting a windsurfer sail (though I did not see the final iteration of this, and this project was eventually shelved, and the prototype given to the financial supporter's museum-like collection). Gary, I can now send you the photos if interested. -- WT

Gary.Dierking said...

Yes, do send.

Chris Luomanen said...

What if the pole was not attached to the mast step, but pivoted from the leeward gunwale? That would put all that mess to leeward of where you are sitting.

Gary.Dierking said...

That's what I'm trying next. First however I need to put some other structure out there to take the line from the end of the pole. So I'm extending the crosspieces, that hold the steering oar, out to leeward. Some fat bamboo between them would act as a minimal safety ama.

Owen Lightowler said...

Quick question. With the sale up what are the compression loads like on the pole and fitting to the mast? I was thinking about this before but surely on a scaled up rig a 'proper' gooseneck would be needed and the spinny pole would be under some serious loads?

robert gillies said...

You may consider possibly mounting the spinnaker pole traditionally on a gooseneck on the mast so that it's high enough to clear the crew's legs. Another idea is build a small dog-house for the legs in the vaka and relocate the gooseneck atop it's roof.