Slieve McGalliard wrote:

Oops! I've just heard from Edward that they are forecasting gust of 39 kts round the back of the island so they have decided not to start the race. Very sensible.

 

So no split rigs in the RTI this year? 

Oops! I've just heard from Edward that they are forecasting gust of 39 kts round the back of the island so they have decided not to start the race. Very sensible.

Slieve

Scott.

One of the things I have stressed many times is the need for big, efficient and preferably balanced rudders. This is particularly important if the JR is of the sloop type and with a wide chord sail. Far from all off-the-shelf yachts have rudders that will fill this requirement.

The problem is not to make a boat balance reasonably well to windward. The problem is to deal with the rise in weather helm as one falls off onto a reach or run (reach is worst). I have therefore started to compare the chord of the sails with the waterline length of the boat.

On Johanna that ratio is 0.84. Thanks to Johanna’s initial neutral helm and a good, balanced rudder, she coped well, although I would not recommend her rig-boat combination as a round-the-world setup.

On Frøken Sørensen the same chord/wll= 0.57. In addition, FS has an enormous, streamlined and fairly well-balanced rudder, all the way aft (sail plan below), so that vessel is ideal for a sloop JR.

On Ingeborg, the chord/wll=0.80. I guess that is close to maximum of what I would have on a go-anywhere boat. Ingeborg has a big rudder, quite well aft, but the rudder area is unbalanced. The Folkboats didn’t come with those long tillers for no reason. Paul on his La Chica got a lesson about the heavy steering with unbalanced rudders, and solved it brilliantly by replacing the original one with a much better, balanced NACA foil.

I would think that the split junk rig, SJR, is more forgiving on a reach in this respect than the low-balance sails that I use to make, since there is about 30% balance in the sail of a SJR. In other words, if you get the balance right for close-hauled sailing, it will stay quite right on a reach as well. I am sure Slieve can verify that.

The fact that I initially missed a bit on Ingeborg’s balance, was partly because I got a bit sloppy, and partly because the good, balanced rudders I have had on the three last boats, have spoilt me. Luckily, it seems to be easier to set Ingeborg’s sail in the forward position, than in the original, so I was lucky there.

Frankly, I think it is easier to get the balance right if the boat has a fin keel and spade rudder, than with the rudder working in the eddies, right behind a long keel.

Arne

 

Scott Dufour wrote:

Arne,

The ability to make those balance changes on your sail has me thinking about whether using a split-rig gives that up.  Are the balance adjustments you've been doing of a magnitude that they would have put a the jiblet/main split in the wrong place on the mast?

I moved the sail forward 150, or maybe up to 170mm which is 2.5-2.8% of the wll. I cannot tell what that would be on your boat, or if it would move the slot into an awkward position. It takes a bit bad luck to miss as much as I did here.

Balance problem solved

Today we had a third sail in Ingeborg. This time I made ready a longer tack parrel which I replaced the first one with, after hoisting sail. Then, this time I set up the yard hauling parrel, YHP, before the throat hauling parrel, THP. As you can see on the attached photos, this has shifted the sail about 150mm forward, compared to on the test-sail, two days ago (on Johanna I developed the habit of hauling in on the THP first, to bring the sail aft, and remove lee helm).

This had the desired effect. In light winds Ingeborg is now next to neutral on the helm, and it remains light as the wind picks up. The resulting position of the CE is still 150mm (2.5% of wll) aft of the Bermuda rig’s CE, which is as it should be. A bonus is that THP- and YHP forces seem lighter than with the sail hauled aft. At the end of the little trip, the sail was lowered and came down as it should. Win-win!

I also tested the home-made tiller brake/lock, similar to the one used on Frøken Sørensen. This is the last and final development step of it, starting on Broremann in 2009 (Check “Broremann” on Youtube). Ingeborg went straight as an arrow across the fjord, with it on, see photo below.

That’s more like it. I am still doing fine-adjustments to the sheetlets, and I also have to find optimal cleat positions for the sheet, the YHP and the THP. But it is about to become fun!

Arne

The album 4 was lost by Wild Apricot, so I let you have this from Photo Album 5, taken in 2017