Junk rig conversion

I’m considering converting my Wanderer dinghy to junk rig from the existing bermuda rig. This obviously raises the question why! It is a lot of work and the existing rig has a very good reputation.

Reason number 1 is I like tinkering with things.

Reason number 2 is that I sail with two small children. Normally, when sailing, one has 100% concentration on the weather, waves, wind, what the boat is doing and how the sails are responding. This is great fun. However, with my current sailing, one child has just dropped something over the side and the other is making a spirited attempt to drop themselves over the side. I need 95% of my attention on the kids, and the remaining 5% is mostly making sure that I don’t hit anything. Both children also want to steer and this is to be encouraged as I want them to learn and to enjoy themselves. With a child steering a boat with a bermuda rig I would always be worried about a gybe – where the sail flicks across the boat with the wind behind the boat – as a bad gybe can damage the rig or capsize the boat.

Why is a junk rig easier to sail?

The main advantage is the ability to instantly reef or drop the sail, at any time and on any point of sailing. If I see a gust coming across the water I can reef for the gust, then put full sail back up when the gust has gone through. If I am approaching a jetty downwind I can drop the sail as I approach. If I misjudge the approach and need a bit more sail then it goes up again instantly. It is hard to describe how much easier this makes sailing!

Gybes are easier too. There is sail area in front of the mast which slows the gybe down, There are also no mast stays so there is nothing for the sail to hit. This means I don’t have to worry if my 3 year old wants to steer round and round in circles.

If you put a bermuda rig head-to-wind the sail flogs, or thrashes around. This is noisy and the things can hit people. A junk rig sail can be let out fully on any point of sail (pretty much – you propably don’t want to do this fully downwind) and will just lie there quietly – no flogging, no thrashing. I took my kids out in a bermuda rigged boat (Wayfarer) and they found the flogging very disturbing

Of course there isn’t a jib, so no jib sheets to worry about. Tacking only requires the tiller to be moved. A jib would actually be useful to give the kids something to do, but these can be fitted to a junk rig.

The rig relies on subtlety and interacting design elements rather than strength and high-tech materials. The Chinese junk rig was originally built with woven grass sails so low-strength materials are fine. There is no risk of not being able to furl (drop) the sail, unlike bermuda roller-reefing systems. Materials can be cheap and use whatever is easily available.

The overall result is that I wouldn’t take my kids sailing with a bermuda rig – it would be too stressful. However, with a junk rigged dinghy I feel relaxed and we all have a great time.

Disadvantages of junk rig

The biggest problem is that you’ll have to design and build your own. There is plenty of help available but it isn’t a trivial job – there are lots of details to think about. The actual construction is straightforward – the designs have been refined over the years to be easy for a home constructor to build.

When you build your own rig you’ll want a free-standing mast. A junk rig can be used on a stayed mast but you won’t get the full benefit as the stays will restrict the angle of the sail. Some might feel that a free-standing mast won’t be as strong, but this isn’t true:

  • A free-standing mast won’t be as rigid – it will bend under load – but if you don’t have any sails on stays (i.e. a jib) then this doesn’t actually matter. Since the junk rig doesn’t require tension anywhere the mast can be quite bendy.
  • If you have stays then some of the tension keeps the mast upright, but the tension mostly tries to compress the mast through the bottom of your boat. Columns are not particularly happy under compression as this causes buckling.
  • A free-standing mast will bend before it breaks. You can see the bend and take action – e.g. reef the sail – if the amount of bend is scary. A stayed mast won’t show any stress until something fails, at which point it will break very quickly and generally without you being able to do anything about it. The failure could be in any component associated with the mast – clevis pins, turnbuckles, wire swages. A free-standing mast is much simpler with less to go wrong.

Engineering a free-standing mast is a combination of following what others have done and following cantilever design principles. Getting the optimum takes time – the mast needs to be light, strong and as cheap as possible!

Other sailors can be a bit reserved about the rig. It isn’t what they are used to. However they are much more enthusiastic when they see the performance that the rig can achieve.

Books & References

The one book you will need is Practical Junk Rig or PJR. It isn’t a cheap book but when you read it and find out just how much information is in it, it is astonishingly good value.

Joining the Junk Rig Association is cheap and makes you part of a world-wide community of enthusiasts. There is plenty of friendly advice too.

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