Welcome to the Junk Rig Association (JRA)

Webutation


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Public and Members' Areas.

This is the public Home page. Members should log in top right. This should take you to the Members Area - also accessible using this link, or from the menu, left.

For help , first try HELP, then email the Webmaster

Formed in 1979 at the Southampton Boat Show by a group of junk rig enthusiasts, the JRA (Junk Rig Association) is for its members and about their boats and their rigs. We aim to: promote the use of the junk rig by encouraging members to organise 'rallies' and 'junkets' (see About Us) and via our tri-annual Magazine and this site; encourage the development of junk and related rigs, the building or conversion of boats to the junk rig, and the use of vessels with the rig or its derivatives; create an international community of people who've already 'junked' their boat, are thinking of doing so, or are just interested in learning what it's all about.  


Members' photo gallery - hover mouse over image to pause slideshow


Junk Rig Glossary

The final version of the Junk Rig Glossary is now available and can be found under the Junk Information menu, or directly here.  This Glossary lists all the terms related to the junk rig, its implementation and use.


Where are we based?

We were formed in the UK, and although our 'office' address and banking remains in the UK we are run by an increasingly international Committee via the Internet. A number of posts become vacant every year, at the AGM, so if you choose to join you could also put your name forward to help run the 'club'. It doesn't run itself. Our membership is now more than   50% outside the UK. Click the chart for detail.


Boat of the Month
 

August 2017 - Bunny Smith's Fenix

Group Capt. I.R. “Bunny” Smith was an early investigator of the windward performance of the junk rig. He proposed what he called the Insect Flight Theory - concerning insects that are, according to aerodynamic theory, incapable of flight, and yet they do it. He explained this by the presence on their wings of 'turbulators' - irregular surfaces generating vortices, accelerating air flow over the upper wing surface, reducing drag and producing low pressure and, thereby, lift.

During the early 90's Smith described experiments with his Sadler 26 Fenix, creating camber using flexible battens. The battens were 'fanned' at an increasing angle from luff to leech with increasing height up the sail, producing further camber by 'scalloping', controlled by adjustable leech lines. Secondary (keep) battens on the opposite side of the sail from the main battens acted as 'turbulators'.

Subsequently Fenix would point inside 40° on each tack, with improved speed. Some who sailed in Fenix before and after were convinced this was a huge step forward in the junk rig development. Smith designed a similar sail for the Vertue Jillie, whose owner was equally impressed. Smith was convinced that having battens (turbulators) on the leeward side of the sail on both tacks contributed significantly to the improvement. The advantages of camber-inducing flexible battens and the keep battens were later supported by wind tunnel experiments (with rather small scale models) by Victor Winterthun.

Others were sceptical, particularly of the Insect Flight Theory, observing that boats do not flap their wings. Alan Boswell was one such, having sailed in the modified Fenix and Jillie, and was convinced the improved performance was due to camber induced by leech lines and by flexible battens. He noted that performance improved only at wind speeds over 12kts., at which speed the batten sections chosen by Smith began to flex significantly. Smith rejected this analysis, wryly observing that the latest Boswell-designed sails looked very much like those of the modified Fenix, incorporating most of his improvements including the keep battens.

Whatever the truth of the matter, Smith's efforts and the undeniable improvements in performance he achieved led the committee of the JRA to vote funds to support the wind tunnel testing programme he had called for, to evaluate the aerodynamic principles of the junk rig and to assess his theory and results. They also helped to stimulate experimentation within the JRA over the next two decades.



Our Boat of the Month Archive is here.


Get Started

Via this page you can, even as a non-member, access many of our resources and explore our services.

To get full access you'll need to become a member - click JOIN US in the menu on the left.

Some of the things you can do even before you join include:
  • Download Ash Woods'  easy-to read Beginners' Tour [pdf, 108 Kb]. Ash wrote this for us while he was still a 'newbie'. Thanks, Ash.
  • Watch a YouTube presentation created as a junk intro for yacht clubs, odownload as a pdf [7 Mb].
  • Download Arne Kverneland's pdf [987 Kb] 'Junk Rig for Beginners' in English or French. Arne has put much thought and energy into developing cambered panel rigs. This article - one of many which you can find here - goes back to basics. It's a great read before you tackle something just as essential - Hasler/McLeods' bible Practical Junk Rig.
  • Explore membership benefits in About Us - scroll up until you see the menu on the left.
  • Find out about junks in Junk Information.
  • Browse some of the latest forum posts (right).
  • Check out photographs of members' boats in our own ever-expanding Photo Gallery.

  • Watch these Google videos or see some stills by clicking on the mosaic at the top of this page.
  • Use the search box below to explore the public pages of the site.

So lower your sails (easy in a junk) and Join Us. For how to see the menu on the left). We're great value.

Converting your boat to junk rig is the best thing you can do to improve her safety and efficiency!



Note:

The adjacent posts are from selected public fora. To see all the public posts, use the menu at the left.


Only members can post on this site. On members' pages they are attributed by name, but in 'open' fora such as those used here, they may be shown as 'Anonymous' for reasons of privacy and security.
              

    

You can search the 'public' areas of the site using this Google box:




       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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