Stavanger, Friaday

Wow, lots of action here:

Edward wrote to me:

Hi Arne,

I agree re your lovely and very effective fully cambered 'ordinary' junksails.

But in actual fact 'Amiina' has 5 jib panels (all identical), 5 main panels (all identical), & only 1 top panel. So only 3 different panels, compared to Johanna's 4.  Which is easiest to make?

Also which has less stress?  Which can never have a 'fan-up'?  Which is so well balanced down wind that it doesn't need an extra large rudder. etc. etc.  K.I.S.S.  ;-))

You may be right, Edward, the planform of Amiina’s sail looks easy to make. Besides, whether we spend 8 or 12 days on making a sail is not such a big deal if the sail lasts for over 10 years. The fan-up is certainly a serious challenge  -  I hope to find a simple cure this summer. BTW, my Frøken Sørensen and your Amiina have about the same size of sails. You write that your mast is 25’ (7.62m) above deck. That is the total length of FS’ mast  - I could have added a panel if I had had a mast of Amiina’s length ☺. We could go on and on  -  but actually I should like to fit a split junk sail to my FS  -  if I can muster the energy to make one...

David Tyler wrote to Paul:

«I'd certainly like you to add my junk-based soft wing sails to the list. «

I am not sure on this. In JRA newsletter/magazine 45 both David’s soft wing and Sunbirds Swingwing from 1982 is described. To me they are principally the same thing, apart from the size of the wishbone and the blunt versus sharp leading edge. What have I missed?

David wrote to me:

Arne,

You advocate an oversize sail, which is clearly the right solution to a rig for sailing in Stavanger Fjord. But is it ocean robust? Take a cruise across to Scotland this summer, and come back and tell us whether a more moderately sized sail wouldn't have been easier to live with, day to day, on a cruising boat.

David, you should rather ask if I am ocean robust, which I recon I am not  - or, at least, I feel no wish to find out these days.

However, I cannot see what should rule out Johanna with her JR from ocean travelling. Her mast is no taller than that on Jester, but at 25cm (Jester: 18cm), Johanna’s mast is well over twice as strong. Then it is just a question of having stout enough battens, yard and running rigging. Håvard has bashed up and down on the outside of our coast in Edmond Dantes (copy of Johanna’s rig) and has had no problems.  My point with piling on sail area is that the junk rig’s easy reefing really works.

On the other hand, my earlier sayings, such as “Any SA/disp below 20 is for chicken”  -  should clearly be moderated. As the boats grow over 5-6 tons, it turns next to impossible to achieve such high numbers. There simply is not room for so big rigs and their sheets. Therefore one must often be happy enough with SA/disp of  15 – 18.

Cheers, Arne

PS: I cannot claim to be the inventor of the cambered panel JR. At best I am a re-inventor. Back in 1965 Joddy Chapman’s father (George?), presented an experimental multibattened squaresail with Chinese style sheets/braces, in an AYRS newsletter. Each batten panel had been cut to a perfect barrel shape to achieve camber in the sail. I only learned about this when Slieve sent me a copy in 2006.  Besides that, I was inspired by Vincent Reddish's early article  -  and last but not least, the photo of the real junk at the Introduction in PJR clearly  showed that the panels could have some camber. There is nothing new under the sun...

Edward Hooper wrote:

David Tyler wrote:Paul,

Sorry, blame a memory that is nearing  the end of its seventh decade.

Edward,

All well and good - but nobody yet has made a serious offshore passage with a split rig, have they?  Please correct me if I'm mistaken. The proof of the pudding for me will be at the very least a 500 mile qualifying passage for one of the short handed events. 

David,

I agree entirely, and see many reasons why a split-junk rig should be eminently suitable for such a passage.  Unfortunately I am not in a position to undertake it, but would whole heartedly support such a venture.

Paul McKay wrote:Perhaps the JRA can now categorise and list the JUNK RIG as 4 distinct types.

Original flat straight-battened sail.

Cambered straight-battened sail. (Arne)

Cambered straight-battened Split-Junk. (Slieve)

Wishbone-battened flat Split-Junk. (Paul)

Any further thoughts?

Paul

Arne Kverneland wrote:

May I be bold enough to claim that an ordinary, but generously cambered junksail, of ample sail area, is also quite effective? As these two write-ups show (1 and 2), boats fitted with properly made junksails are fully able to keep up with boats of similar size and with pointy rigs.

In addition, I think the cambered panel junk sail, for instance the Johanna-style sail, with its several identical panels, is the easiest one to make.

 

Cheers, Arne

 

PS:

However, I don’t claim that The Cambered Panel JR will out-perform the really modern racing versions of pointy rigs (..they are, BTW, not so pointy any more...).

Paul McKay wrote:Dear Edward, thank you for your generous comments but as we seem to be having a general 'punch-up' may I attack your comments! You wrote - 

....................
I agree with your 3 negatives but your 7 advantages apply in 'Spades' to my recent AeroJunk design!  It certainly looks that way at first sight.

 

Shall we just agree that an original Standing Lug Rig, equipped with full-length battens to become a Junk, then split into a Jib and Main and given profiled sailcloth will have an upwind performance similar or equal to a Bermudan rig? That way we do not need to champion one design or another. Then it comes down to a simple - flat cloth sail v shaped cloth sail and single straight battens v doubled 'wishbone battens.

Regards, Paul