Subject: Re: [harryproa] Re: sailing Elementarry
From: Mike Crawford
Date: 1/17/2006, 10:04 AM

  For going fast, I'm more a fan of Rob's schooner rig than the easyrig.

  This is partially because there are no concerns about forestay tensions, and fewer concerns about rig stiffness, and mostly because it provides for more sail area, with better foil shapes, and a lower center of effort.  When tacking downwind in light wind, two battened foil shapes are going to generate more lift than a main and jib, and when running the schooner could present quite a wing-on-wing profile.

  The schooner rig will require more winch work than an easyrig, but only when lazy sailing.  if you want to be competitive, you'd need all sorts of additional strings on an easyrig anyway.  I'd rather go with a pair of extra-tall mainsails for light wind, and reef them in normal wind, than to try to stiffen an easyrig with running stays and attempt to fasten additional headsails.


  Speaking of rig stiffness, I do feel the need to weigh in on the comments about Rare Bird's rig.  Yes, it's pretty flexible.  However, as the owner of a lightweight 27' cat, which can only be righted by another boat if capsized, I can appreciate a rig that will allow some of the gust energy to pass by the boat.  Going over on a beach cat or Elementarry is wet and inconvenient.  Going over on a 9+ meter boat is tremendously uncool.

  If you've got everything right on the edge, with the windward hull just skimming the water, it takes *very* little extra gust energy to suddenly whip the boat over.  The only solution is to be lightning quick with the mainsheet, but that's a tall order if you're going to be doing it for more than ten minutes at a time.  Flying a hull is great fun, but any look at the Stiletto nationals will turn up some boats that didn't hold that fine balance in a gust.  Even the skippers of the Reynolds 33 lose it now and then.

  When cruising, going past this edge is entirely unacceptable.  It's much better to have a flexible rig, with the addition of perhaps an outleader kite, than to risk gust-induced capsize (fool-induced capsize, of course, is rig-independent).

  When racing, though, there's still something to be said about a boat that can handle the gusts.  Let's say you can fly a hull with 40 sq m of canvas with a stayed rig, and 50 to 60 sq m of canvas with a more flexible rig.  The flexible rig provides two advantages.  First, in a gust, the flexible rig will either allow you to keep sailing without adjustments, or give you lots of time to adjust, while the stayed rig will require quick reflexes in order to avoid a capsize.  Second, those extra 10 to 20  sq m of canvas will come into play nicely in the lulls, do so automatically, while the stayed rig will need to either unreef or  hoist an extra sail to keep up.

  Supporters of a stayed rig will point out that the extra canvas will create extra drag, so in theory the stiffer rig will beat the flexible rig in some conditions.  This is true.  But a capsized boat eliminates all rig advantages.  Besides, we don't all sail in exactly 15 knots of trade winds, and changing wind conditions will likely favor the extra sail area and self-adjusting nature of the flexible rig.


  The one change I would make would be to go with an unstayed wishbone rig like they have on the Wyliecats.

  One adjustment line automatically handles sail shape, leech tension, and mast bend, with very little stress on the boom.  Sail shaping is very quickly done, the boom creates its own lazy jack pocket when taking the sails down, and a reduction in heeling moment can be achieved either by reefing, flattening, or both, allowing for some quick sail adjustments for a minimal amount of time and effort.

  However, I've never sailed a Wyliecat, so I can't speak from experience.  I just love the idea of it.

       - Mike

dominiquebovey wrote:

Boats as light and canvassed as HP's mostly sail "close-hauled" due to
their high speed, so they need a rather flat sail profile. But to
start you need a hollow profile, so the sail should be tunable quickly.

I would see a 8.5m proa (maximum of M2 class) for 3 crew (minimum
number for racing on Lake Geneva), with easyrig, around 30-40m2 sail.
I am persuaded the easyrig is OK for racing, provided it is stiff.

One of the crew would be adjusting the sail permanently (making it
hollower in the lulls, flattening it when speed increases). Another
crew would be running up/down the tramp to keep the LW hull just above
the water, and the 3rd one steering.
And all crew could be going on trapezes when needed. So you need
running sidestays which can be attached to several selectable points
on the WW hull or on the beams.
To go on trapeze, you unhook them off the boat, and hook them on your
trapeze pants/harness whatever-the-word-is.
Naturally the rig must be self supported without the runners, for easy

I know it is quite a new boat, something between Harrigami and EL,
with more displacement. The Elementarry lw "sinks" about 1cm for 15kg,
for the 8.5m the figure should be 20-25kg, so a less fine lw hull.
The Elementarry is unfortunately a little too light for 3 racing crew
I am afraid, as we discussed last year.


--- In, "Rudolf vd Brug" <rpvdb@f...> wrote:
> Hi,
> Possibly the difference in sheeting in between you and the Tornado
lies in the fact that they where flying a spinnaker.
> That sail is so much fuller in shape it would redirect the wind
passing it much more than a flatter sail (or no sail at all) would.
> Some time ago I read an interesting article on a una rigged mono
with a wing mast. It was designed not to fly downwind extra's.
> The owner did have a gennaker but it only gave him one knot of extra
boat speed. It was concluded the tighter sheeting angle of the main
might be responsible for this. The gennaker would generate so much
disturbance of the air passing at the leeward side it doesn't attach
to the main any more. Therefore the main doesn't generate lift as it
does whith no head sail in front and is only  producing drag which
helps downwind but not as much as lift would.
>   ----- Original Message -----
>   From: Rob Denney
>   To:
>   Sent: Monday, January 16, 2006 2:19 PM
>   Subject: Re: [harryproa] Re: sailing Elementarry
>   G'day,
>   Not sure the kite would have helped much as the apparent was well
forward of the beam.  Still intend to try it because they are such
great fun.  Interestingly, the Tornado was strapped in hard, traveller
on the centreline, whereas i was quite eased on the same point of sail
and at the same speed.   Lots to learn...

Yahoo! Groups Links