OK, I put the blame on the Corona half-shutdown and the never-ending rain here. Now I have sketched up yet another JR for that 11.0m/9.25 ton Seal.

David Tyler’s notes below made me sober up a bit. I can see his point that handling a very big, single sail can be too hard as the size of the boat grows. Problem is that we people stay at the same size no matter if we are sailing a nutshell or a ship. This time I have kept the chord of the sail moderate (5.71m), and made the sail taller by simply adding a panel to the last sail I showed to you. This way the sail area goes up from 57.4 to 65.6sqm and the SA/displacement  now reaches 15.1. The AR goes up from 2.15 to 2.40.The mast position is un-changed.

What I like with this is that we end up with a taller sail than the original, but still with a shorter mast. In addition, there is plenty of space for the (double, upper-lower) sheets. My hunch is that the boat will be at least as fast as with the original rig on all courses, and thanks to the moderately short chord of the sail, the downwind steering will be easy.

The biggest challenge is to build a tall and strong enough mast at a moderate weight and cost.

Cheers,
Arne

Eero,

As you may know, on a similar sized boat, Tystie, I went from 1 mast to 2 masts to 1 mast to 2 masts, over 15 years and 85,00 miles. After all that experience, I would venture to say that there isn't a single right answer, only a compromise that kind of works for you. I think that 55 sqm is as big as I would want to go in a single sail, unless that sail is either of maximum AR or is a SJR. Then up to 65 sqm becomes reasonable to handle, but really, the 80 sqm of Peregrine is way over the top for an offshore cruising boat, though it might be fun on short passages.

So, if you go for a single sail, I would make it with as high an AR as the the boat will stand, and I think I see in your sketch 3 that you think the same. With that single sail, maybe you could put some forward rake on the mast, as was done on Fantail with the aim of not ruining the bed. 

I like Graeme's suggestion of a SJR as well, but I think for this boat the sail should be of high AR, and would need 7 or 8 sheeted points, with upper and lower sheets. These are not nearly so bad to handle as port and starboard sheets on a schooner rig.

I don't see a better form of schooner rig than the one that you've drawn. The sheeting looks tight for single sheets, but not completely impossible.

On balance, I think I'd go for the single high AR sail in sketch 3 set on a mast with about 3˚ of forward rake, which should put it clear of the L shaped seat and water tank, leaving only the table to be rebuilt. On a practical, pragmatic level, the battens for this sail seem to be 6 metres long, which is sensible in terms of available materials and in manageability when rigging and repairing the sail.

Arne,

first: sorry for this long radio silence. My work has kept me busy and I wanted to do my homework and try to find suitable places for the mast(s)

Yes, you are right, it seems to be very difficult to fit the mast for a sloop version so that the lead is ok, but also not standing in the middle of my beloved bed. That is pity, I started to get fond of the sloop version because of its simpleness. Modifying the cabin layout leads to a major project which I try to avoid.

The schooner version seems a bit easier with the masts, but there seems to be very little space between the sails leading to double sheets and that sounds like a mess. I want to go for simpleness and not to make complicated solutions. Therefore, the sloop version seems so tempting.

When locating the CLR should I include the rudder? In this boat, with a big rudder it makes a difference as can be seen in the attached sketch. It bothers me that lead of the current version is more forward than the recommendation.

Eero

PS. I tried to upload a DXF version also, but the format seems not to be supported for upload.

Unbelievable! Arne, you made a sketch in no time! That is really cool looking, bold and handsome design! 

I have tried to make some sketches too. The starting point has been the present sails (roughly 63 m2) and their vertical center of effort. The sloop version version seems to interfere with the interior as the mast would stand in my nice king-size bed. The schooner version would be more gentle for the interior as I tried to keep the main mast at the present position and the forward mast would locate quite forward. This assuming that the sail area and the CLR -> CE lead should be kept roughly the same as before. 

It seems that you propose quite large sail. But I can see that your own boat also seems to have a quite big sail. You don't see it a problem that the sail is almost 80 m2? 

Location of the mast(s) is a bit headache to me. Easiest would of course be the present location. For another possibility I think it also could stand just aft of the main bulkhead. There is a water tank under the U-formed seat, but I think that could be moved.

I have some pictures in an advertisement I made. Recently I have changed my mind about selling the boat, but the advertisement is still there

hi david

please don't put someone's email into a public forum!

ueli

[Now resolved, JRA Chair]