Too much string? - junk rig (continued)

[Michael Rogers]

This is my suggested new thread to remedy the hijacking of the sailing canoe thread.

Anders' very reasonable request (see the other thread), for a picture of the junk rig I've been going on (and on) about, made me nervous because on IT matters I'm a Bear of Exceptionally Little Brain. However this brilliant website includes 'how to do it' instructions, so I took the plunge. The result so far is some cryptic script at the top of the page, so I presumably have to trust that this converts into pictures when I press the Button. Here's hoping.

I don't have any good action shots of Cadenza. These were taken in the Menai Straits off Caernarfon in September 2009 at the JRA Welsh Rally. At this point there wasn't really enough wind to fill the panels; an hour later, when there was apparently no-one around with a camera, there was a stonking breeze and the sailing was glorious (please note - force 3-4, no reef necessary). Since then I have replaced the far-too-heavy aluminium mast with a CF one, which is fantastic; and simplified the topping lift.

Michael

[Michael Rogers]

Part 2. Only one picture materialised, so here's another.

[BrianP]

Here'a what a decent sail shape looks like.



Brian

[Michael Rogers]

Beautiful, Brian, but it wouldn't have looked like that in the fitful breeze on the Menai Strait, so the comparison isn't at all fair.

I rather regret responding to Anders' request from a completely inadequate picture collection - but I'm not half looking forward to our Keyhaven challenge (see the other thread)!

Michael

[BrianP]

Yes it would. That's the point. With 6:1 downhaul and 4:1 kicker pulled on so hard the sail shape stays where it should. Yard and boom bend flattening the sail. I race that sail in up to 30 knots and never reefed it. Yes the 30 knots was in the river and it was ridiculous, but I have regularly raced in 20 to 25 knots. With such good sail control I can just sail higher and higher, taking only the amount of power I need.

The girls simply, drop the rig, quietly tie a reef, re-hoist and race on. No issues.

I don't mind you having your delusional ideas about how good your JR is. It's just I don't think less experienced people should be mislead by your inexperience of modern high quality lug rigs.

Watch this video on the 2010 LRS Nationals. By the third race is blowing a steay 20 knots plus. I am in a borrowed Scow, LR365 with an orange sail. Just missed winning the Championship by 1 point in case anyone thinks I am not qualified to talk about how good, how handy, how perfect lug rigs are for small dinghies.

http://www.youtube.com/watch?v=WcF4WPfgO4U

Brian

[BrianP]

Michael, two things I don't understand.

One, how can it be right that the lines hold the leach from opening in a gust. Everything I know about strong wind sailing is that the leach opens in gusts, if you have a well designed sail which matches the bend of the spars under load. 12 years windsurfing depended on this.

Secondly. In your pictures in the Swallow boat, that nice long pointy stern gives you a sheeting angle which clears the leach of the sail. In your new boat, I cannot see how you can gain sufficient clearance unless you are going to add a boomkin. See with the Scows in the video, 11'11' long, just over 65 sq ft and the boom is past the stern. No way you could have leach lines running there.

Brian

[simplesimon]

For the record (and so I can find it again ) the dimensions of Brian's mainsail are:

Maximum
A Luff length 1.06 m
B Foot length 2.92 m
C Head length 2.92 m
D Leech length 4.33 m
E Clew diagonal (clew point to throat point) 3.20 m
F Throat point to half leech point 1.22 m
G Half leech point to half head point 2.30 m
H Head point to aft head point 0.035 m
I Batten length 0.395 m

and it sets on a yard (not a gaff - someone should tell the LRS Rules Committee!) of 2970mm long, 37mm mean dia, weighing nearly 2kg, and a boom 3020mm long 50mm dia weighing 2.6kg.

It appears to sail off a PY No of 1350 to 1475 - a bit slower than a Mirror.

Cheers
Simon

[Michael Rogers]

I am being put well and truly in my place here - or what some people evidently think should be my place. I've obviously stumbled into a somewhat (for my liking) 'intense' approach to sailing-for-pleasure - perfectly valid and probably the majority view, just not mine (probably why I feel so at home in the DCA). I actually don't race because I'm not that combative by nature. De gustibus non disputandum est. I certainly don't wish to argue with a national-champion-minus-one-point. I take strong exception to the suggestion that I am deluded. I'm an enthusiast and like to share my enthusiasms, but am very very concerned at the idea that I might be leading anyone astray. I have also, I realise, put myself at an absurd disadvantage in the photo stakes.

So, if I have caused annoyance or worse to anyone, I apologise unreservedly. I shouldn't have made the claims I have done in the way I did. It was well intentioned.

I'll respond to the two points raised by Brian and then shut up, for good on this thread which I'm sorry I started.

1. In JR jargon, partly to avoid confusion with leech lines which are something else, the lines between the ends of adjacent battens are referred to as sheet spans. They are controlled by the sheet proper, and their length can be critical to avoid twist in the leech. If by 'the leech opening' you mean the sheet doesn't tie the clew end of the battens down to the boom and to each other when reefing, it just does. Again, different types of sailing: when the wind surfers go out (in the mast-bending conditions they enjoy) I, I suspect along with most other sailors, come in - or, with JR, simply take in another reef or two. I'm sorry if you've been having 'problems' with the leech of your high performance lug sail.

2. My new boat's rig. I don't currently have a sail plan scanned into my computer, so can't post it. Apologies that my measurements (which are actually off the sail, so that spars will be about 2'' longer) aren't to the nearest millimetre. There is 9 ft (108 ins) between mast and transom. The yard, boom and all but one of the battens are 7ft 6ins (90 ins). 12 ins of the boom will be forward of the mast, which leaves 6 ft 6 ins (78 ins) between mast and transom. That leaves 2 ft 6 ins (30 ins) horizontally between the clew and the tip of the transom. The top batten is unsheeted. The next batten down, the first sheeted one, will be extended by 9 - 12 ins (trial and error on first sailing trials) beyond the leech, keeping the uppermost sheet span and attached part of the sheet clear of the lower spans. Overall this should be more than enough clearance aft of the sail for effective JR sheeting. There are four battens. The unstayed mast is 15 ft from step to truck, the peak about 1 ft (vertically) above the mast truck. Sail area about 80sq ft. Thus a fairly high aspect rig. With an exceptionally stable hull (beamy, flat bottom), a CF mast and light rig, and easy reefing, she should sail well. I will say nothing more about upwind: off the wind I hope she will fly.

Michael

[Michael Rogers]

PS Third line from the bottom - that should read five battens (not four).

M.

[BrianP]

Michael, it's great that you are enthusiastic about the JR. Also that you have experience in actually using it. All I ask is to keep to JR and it's good and bad points and how it works.

That way we can all learn from your experience.

For instance, it seems to me, with my total lack of JR experience, that although the lines off the leach will just clear to the transom, the pull on the battens will be almost vertical, around 10 degree off the vertical or so. It just seems too straight down off the batten and I wonder how the battens will cope.

Brian

[Anders]

Thanks for posting the photos. It makes understanding things easyer.

I like what I see and I still find JR to be interesting but not on a dinghy where I want to be able to take down the whole rig easily and row.

One thing more. I think you devide sailors to much in racers and not racers. I never race now and havent raced for decades. But when I´m out there, one of my greatest pleasures is to have a sail with a really good shape and control it to optimum pleasure. I always put all the extra control lines in a sail and if I can bend a mast, I always fiddle with that as well. The feel you get in the tiller of a well trimmed boat is something very different from the feel you get when the sail is not trimmed well. Even on relatively big and sluggish boats like my Albin Vega 27.
I dont know if a Junk Rig can give me this pleassure