On Sailing a Vietnamese Junk and a comparison with our Lug experience.

The Rare Experience of Sailing a Real Junk

Ken Preston is a chap I follow on the net from time to time. He travels and documents and often documents boats. Here one of the few records in photos and text of actually sailing a real Junk.

It had no motor and from the pic you can see it moving right along.

Ken junk sailing vietnam 02 lug and Junk rigs: storerboatplans.com

To see more photos of this wonderful boat you will have to drop in on Ken’s website. Well worth a prowl. The photos are first class.


I received a letter from Ken where he starts contrasting the lug information we publish, which he uses on his own boat, and with the traditional lug rigs.

Before going onto that discussion another section that I recently liked on Ken’s website.

Another fascinating page is how flat bamboo mats are shaped into 3D boats

That article on Vietnamese basket boats is republished here.

But back to Junks … another of Ken’s posted photos.

Ken junk sailing vietnam 02 lug and Junk rigs: storerboatplans.com

Basically I congratulated him on one of the few recent accounts on sailing real junks and on the super photos.

He replied!

Hi Mik, I’m back home a month now and finally noticed you’d commented on the blog post about the sailing junk. You’re right, they are scarce on the ground. . .I’m reasonably positive that one is the only one of the sort in Viet Nam, and I understand they’re all gone from Hong Kong now. . .anyway, I’ve written a big article for Woodenboat to look at, so may get some more information out there and a lot more photos.

We can only hope so!

Ken uses our lug rig info! 🙂

I’ve used your articles on rigging a lug rig to very good effect. . .so thank you very much for that. The Vietnamese south of Halong Bay routinely used a standing lug rig until recently. . .forty years ago there were thousands of them in use. Since they used woven matting or really cheap fabric for sails they developed schemes to set the sails without putting a lot of luff tension into the weak “sailcloth”.

This is an interesting observation. What we know with modern sailcloth and the lug rig is that a lot of tension is needed to get the vanging benefits of having the downhaul set back from the luff so that the leach is tensioned to reduce sail twist particularly as the mainsheet begins to be eased.


From the information we gathered from Brian Pearson who had sailed a Lymington Scow which has been raced with a balance lug for a century we found there were a bunch of options for controlling the sail we knew of several ways of getting the vanging effect. Most of the Geese and Goat Island Skiffs have gone for the simpler third version below.

bleeter and vanghaul - useful setup tips for lug rigs on small boats - article on storerboat plans For the fleet of Oz Geese in the Philippines we have gone with the so called “bleeter” which prevents the boom moving forward with tension from either the mainsheet or the downhaul … or to think of it now also from aerodynamic loadings. The result of not enough downhaul tension, which is quite high is a crease in the sail from back end of the boom to the front end of the yard. Here you can see on Oz Goose sail number #2.

that crease in a lugsail is from insufficient downhaul: storerboatplans.com

The crease happens because with inadequate downhaul tension the bottom forward of the yard swings up, the top back end swings down. This increases the distance on the diagonal of the sail where we see the crease develop.

Dinghy and fractional rig sailors will recognise the mechanism which is similar to the overbend creases in a mainsail caused by a too flexible mast or not enough luff round in the sail.

To avoid this we typically we set up the boats with quite dramatic downhaul tension on the beach so the crease is the other way. It smooths out when sailing as the mainsheet is tensioned and the sail is loaded by the wind. Tension is quite high as can be seen on the boat in the foreground.

This is all summarised in an article on our sails website. It includes diagnosis and removal of “That Crease” in a lug sail

 Removing “That Crease” on a LugsailWhy does my lug sail have that crease? How do I fix it? storerboatplans.com

But what about traditional sails that might be made of woven leaves or hand woven cloth that can’t sustain such loads.

In essence the junk rig “cradles” the sail cloth by hanging it between the support of the mast and the sheetlets controlling the back edge of the sail and have the battens taking the major structural loads.

This is also devilishly clever because the junk is cut totally flat and it is the sail SAGGING between the support of the mast and sheetlets that gives it camber/curve which gives it power by allowing the sail to bend the battens

Without sheetlets a flat cut junk sail is not a junk sail. It is a balance lug with an oriental outline.

So how does the sail avoid the yard falling back and putting a crease into the sail .. the tension of which could damage the weak traditional “cloth”.

Ken continues:

Most obvious was a vang from the heel of the yard down to the base of the mast, to peak the yard without having to use the luff tension.

So spars, battens and back edge of the sail are located by structure and the sail fits within that framework.

He continues to talk about the current state of traditional small boats and sailing in Vietnam.

Disappearing …

As recently as 2013 there were still a few sailing rafts using such sails off the wind and diesel power upwind (tow the net down under sail, motor back up to try another tow. . .) Also there are a few small, canoe-like boats sailing off the beaches north and south of Hue in Central VN that set a single small lug sail or rowed, no power at all. Very marginal economically no doubt, but fun to see. But that’s it for sail in VN. Sigh.

Ken has been working on a book to record his experience and what he has been able to find out in the last couple of decades. If the photos are as good as on his website and the text as full of surprises I’m very keen to see copies become available.

My book will be published late this year or perhaps early 2018 in English, with a Vietnamese edition (after translation is complete) in mid to late 2018. This one only will cover fishing boats of the coast. . .nothing about river boats on the Mekong or the Red River. Those may never happen, we shall see. Anyway, it was a treat seeing your comment. Thanks for writing.

Keep an eye on Ken’s Blog.

Here is another great page from him on different Viet  and Cambodian boats.


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