Welcome to the Junk Rig Association (JRA)

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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
 

November 2018 - Mirror dinghy design

This project never proceeded beyond the design stage which was mostly carried out in 1990. At the time I had too many boats and not enough time, so it was put on the back burner. Now, I am 78 and probably my dinghy sailing days will be limited to my junk rigged sabot (8 ft) Ah Sup.

However I still think a junk-rigged Mirror would be wonderful, and I would be really pleased if someone else would use the design.

I thought at the time that a two masted junk rigged Mirror would be good for someone who wanted to sail longer distances or who liked to leave the boat rigged for longer periods. So I designed one of those as well. The sail area is approx the same as the single master, but with a lower centre of effort, and a more versatile rig for different wind conditions.

However I realise that most people would be interested in the single master,for the type of sailing that most Mirrors are used for.

The sail area of the single master is 8.74 sq metres (94 sq ft) which is 34.28% larger than a standard mirror of 70 sq ft. This may sound excessive to some people, but my junk rigged Sabot carries 38.8% more sail than the standard Sabot and it sails very well. Even with that sail area it doesn’t heel as much as the standard Sabot. To windward it matches the other Sabots and reaching and running it leaves them behind. And if the wind gets up I can reef it without moving from my position. Manageability is what should determine a boats sail area.

The centre of effort is 490 mm (19.29 ins) higher than the Mirror CE. This is partly due to the boom being raised so as to clear a mans head when he is sitting on the seat/buoyancy tank and give him clear view. He won’t have to duck. But again I remember the junk rigged Sabot with a considerably higher CE than the standard Sabot . Going to windward it doesn’t heel anywhere near as much as the standard Sabot.That is, of course, because it doesn’t  need to be pulled on as hard when going to windward. It doesn’t luff. There is very little load on the sheet,and therefore very little heeling. Wonderful. Going to windward I always have a big smile on my face.

In his classic "Junks and Sampans of the Yangtse" GRG Worcester points out that the trading junks which followed the trade winds had, generally, fewer battens than junks that worked the rivers and estuaries. Trading junks, that had to deliver their cargo into a river, had more battens than those that did not. He concluded that the more battens, the better the windward ability. I thought 8 battens would be a reasonable compromise for a boat that would do a lot of tacking and would be judged on its windward ability.

It may be noticed that the distance between the battens on the leading edge, reduces toward the top of the sail. This is to reduce what I call batten creep.That is, the tendency for each batten to land a little abaft the one below as the sail is dropped. In some cases the yard can end up aft of the mast. Not good.

In terms of scantlings, my untried design allowed for:

Yard. 40 mm OD , 2 mm wall thickness aluminium

Battens. 12 mm OD 1.2 mm wall thickness aluminium.

Boom. 25 mm OD , 1.6 mm wall thickness aluminium.

Mast. I guess that 8.74 sq metres could be safely carried by 60 mm dia 3.25 mm wall thickness.

The mast is free standing and is located on the forward face of the buoyancy tank bulkhead. Because of the difficulty of installing the mast socket in this location, it was my intention to remove a piece of the forward deck, to give me easy access, and then replace it on completion. The buoyancy tank bulkhead and the forward deck would provide good lateral strength.

Because of the shape of the sail and its location in relation to the stern of the boat, the best sheeting system has to be double sheeting. One set each side. At one stage, with my experiments with junk sails on Ah Sup, I had a sail with double sheets. It is quite common on Chinese junks and it works just fine.

The sheetlet system I show on my drawing is common for Chinese 8 batten sails. They, of course, use euphroes where I have shown little blocks. My reasons for doing so are that euphroes assist in keeping the sail twist and distortions to a minimum, by adding a little friction. Once the sailor has given the sheetlets a tug here and there, the sail tends to stay that way until a change of direction prompts him to do it again. In our case this is not practical, as the sheeting on a dinghy needs to be self adjusting.  I had to slightly modify the standard Chinese 8 batten sheetlet system to use little blocks instead of euphroes. The modification involves doubling the power of 3 of the sheetlets to account for the area of sail they support, and the angle of pull on the sheetlet. (The steeper the direction of pull, the less lateral force on the batten.) It works fine on my current boat, self adjusting as I change direction and sheeting.

I include a drawing showing the different stages of reefing.  As the sail is reduced, it will be necessary to shorten the lower sheetlets (shown by the longer tails). This just entails pulling them through their beckets, tying a stopper knot, and somehow tidying up the tails.


I hope one day someone will build this and tell me if it all works.


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.


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       " ...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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