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Old 27-08-2003, 01:12   #1
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Junk Rigs

Does anyone have a boat with a junk rig? Anyone not but have some strong opinions?

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Old 27-08-2003, 07:15   #2
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sail_the_stars,

I don't have a junk rig, nor have I ever sailed on one.I do think they are interesting though.Some sailors might not realize it,but in the book "The Voyages of Joshua Slocum" he tells of when he ran a schooner aground and eventually had to strip her down.He took the lumber and made a junk rig called the "Liberdade", or something close to that name. Really good reading...check it out.
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Old 29-08-2003, 05:36   #3
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I really don't understand this whole fascination with Junk rigs. If you have ever sailed junk rigged boats, you quickly find that they really do not point very well. They tend to induce excitation rolling on a run and so are only good through a narrow wind angle range. The are prone to a lot of chafing of the sail, expecially on the tack where the sail abraids against the mast. They are complex to sail as they require a lot of tending except at very deep wind angles. They sail differently on each tack (one tack the sail compromised by being pressed against the mast and the other the leading edge of the sail being compromised by scalloping. They impart a lot of load into the hull because of their typically larger sail areas required to produce the same drive and ideally freestanding masts. They have a lot of weight aloft compared to a Bermuda rig reducing stability. They are expensive to build,requiring parrels, lots of small blocks, and large amounts of line. They don't hove to easily because there is no easy way to back the foresail.

This was a rig developed for reaching along a coast and performs more like a square rigger than a modern rig. Even a gaff rig is a major improvement over a Junk rig. I just do not get it.

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Old 29-08-2003, 08:50   #4
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Appeal of Junk Rigs

Let's see, let me take a stab at this. What is the appeal of junk rigs? While they're not the type of boat that I would probably personally buy, I can see where others have different views. Some of the junks I've seen in pictures are very pretty.It appears they have all kinds of room down below, but then again,I've never been aboard one. They must function pretty well because they'e been around a long,long,time.In comparison,I remember the first car I ever owned.It was a 1957 Pontiac Catalina that I bought from my Grandma for $100.(Yes, she only drove it to church on Sundays!) It was during my senior year in high school. Even though the car was in mint condition, it wasn't very typical looking compared to all the other cars kids were driving. In fact, it kind of resembled the "Bat mobile" with it's long fins along the tail end of the car. By all logic, is was a very illogical car to have. It didn't look all that good, it was a gas guzzler,steered like a tank, and wasn't exactly a chick magnet. What it did have though was character.All my buddies would give me a hard time about the "El Dorado", but they always wanted me to give them rides in it.We would all pile in it and cruise.We had a great time with that car.No one cared about how fast it would go, or how it looked,we just liked it. The interior was huge and we could load a bunch of people and junk in it. Why the backseat was like having a double bed(sometimes the car did work as a chick magnet? )To this day my buddies still talk about that car when I see them. I think some things in life shouldn't be about efficiency,equations,or logic. I believe sailing is one of those things.Happiness aboard means so many things to different people.Of course safety is a major consideration, as is what you intend to do with the boat. If you're going to coastal cruise with it, who cares how long it takes to get there? If you're concerned about having a fast boat, why would you even consider a junk rig? I mean, I've never seen any pictures of them in a race rounding the marks? Just my 2 cents worth...well $ .673458 after inflation
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Old 29-08-2003, 17:34   #5
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Maybe I missed something here, but I thought that the question was about 'junk rigs' and not 'junks'. I can understand why someone might want to own a junk on aethetic grounds and because they potentially offer a lot of volume in a short sailing length. Of course what we call 'junks' are really a very diversified collection of highly divergent types that avry with region and purpose. The hulls vary from hard chine to round bottom, and the rigs vary from the fully battened standing lug that we normally think of as a junk rig to rigs that are much closer to square sails or lateen rigs.

The hull designs that we typically associate with junks while extremely burdensome, really are not great sailing vessels, offering extremely poor stability, tracking or resistance to leeway. The so called junk rig is ideal for that hull form where the hull design is the real limiting factor in the sailing ability of the boat. Unlike many other culturally evolved working water craft junks were not great sea boats. Oriental literature is full of multiple accounts of hundreds and even thousand sof junks being destroyed in a single storm.

But all of a sudden I hear of people wanting to adapt the junk rigs to all kinds of western and polynesian hull forms and it is here that I don't even begin to understand the logic. As I said and explained in my previous post, as rigs go, the junk rig is a miserable rig. In my mind there is no logic, or even aethetic basis that I can wrap my mind around for installing a junk rig on a western style hull using modern materials, except as some kind of wierd affectation.

My point has little to do with speed, and everything to do with safety, ease of handling, expense to build and complexity of maintenance.

Respectfully,
Jeff
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Old 29-08-2003, 20:11   #6
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Junk rig superior?

I've never sailed one but I am interested in them.

http://cruisenews.net/images/FastestRig1.jpg

http://cruisenews.net/images/FastestRig2.jpg

http://cruisenews.net/images/FastestRig3.jpg

http://www.friend.ly.net/~dadadata/j...nese_sail.html

http://kastenmarine.com/junk_rig.htm
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Old 29-08-2003, 21:42   #7
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Junk rig?

Sounds like the perfect discription of a spider web of a sail. Sailing one around the sound durning a holiday or some other occasion might be fun. But, to run one full time would be chaotic.
It's no wonder you never see one far from port. It would wear you out trying to keep it trimed.
They do have a bit of an artistic look to them. But so did Sir Thomas Lipton's SHAMROCK V
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Old 30-08-2003, 03:17   #8
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A junk rig is something akin to a three-legged race - perhaps appealing to our masochistic tendencies.

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Old 30-08-2003, 03:30   #9
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My interest at this point was based solely on aesthetics. There are several styles of junk sails I think are beautiful. They are so different in form from "traditional" sails.

I am giving very serious thought to a correspondance course in naval architecture; it is just as important to understand what works as to understand what doesn't. Personally I don't care about how well they perform as to how they work.

I've heard that they are signifigantly different. One analogy is the difference between a bee and a bird; according to physics a bumble bee shouldn't fly.

I'd like to understand sail design to be able to understand if there is such a difference. Such an explanation on this chatboard is probably out of the question; it would lack some of the visual aids I'd prefer.

Can anyone suggest any good books on sail design and theory that includes junk rigs as well as "all" the others?

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Old 30-08-2003, 06:32   #10
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Junk Rigs,

Apparently, I missed the boat....errr at least the rig on this post. I assumed the original post was referring to the old Chinese junks. I can see where someone would find them a interesting boat to have, but I don't understand why someone would want to take the sail configuration of one and add it to any other type of vessel I've never heard of this being done,so I guess that' why I didn't make the tie in. You have to admit though,the story about the 57 Pontiac was pretty good
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Old 30-08-2003, 07:53   #11
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I have a couple book suggestions. The first is Manfried Curry's seminal work on sailing hydrodynamics called "Yacht Racing". This book was written in the 1930's. Curry was able to obtain access to the German Goverment wind tunnels did some amazing research of sail shape. he tested sails or a wide range of shapes and also tested actual bird wings. He also looked at classes that used identical hulls and limited sail size but not configuration. This was still a time when gaff rigs were common so that the results of that study included gaff as well as other sailing configuration. (Amazingly enough, the most efficient configution was a rig that looks very much like a modern America's Cup rig or high performance Catamarran rig which is a fractional rig with bendy mast, a large roach mainsail and a small minimally overlapping jib.)

In a later book he rigged actual full sized sail boats with a series pressure guages which allowed him to map the positive and negative pressure on a sail while the boat was sailing. His work is well written and easy to understand and clearly anticipates the next 75 years of aerodynamic research. Unfortunately, both of Curry's books are out of print but I see them quite frequently at used marine book stores. I bought my copy for $5.00.

C.A. Marchaj has written two excellent books on the aerodynamics of sails, "Sailing Theory and Practice" and second called "Sailing Hydroynamics and Aerodynamics". He looks at varying sail shapes as well.

Bethwaites' "Performance Sailing" also contains a wealth of information.

You may find Unesco's report on alternative sailing vessels would provide a lot of information on the performance of alternative rigs. This was a 15 year long study of small fishery fishing vessels all over the world. It looked at the problems associated with third world fisheries switching to petrochemical material constructed and fossel fuel driven craft. The study was quite comprehensive and included wind tunnel and field tested comparason of a wide range of rigs. Its results were very different than the study shown above.

The article labeled "Fastest Rig" is full of glaring inacuracies. For one, the ideal sail plan form is one that produced an eliptical loading and not an eliptical shaped sail. On slow speed foils this means a plan form similar in shape to a WWII era Spitfire wing of a modern America's cup boat mainsail.

Dispite the claims of the article, this was not the first or last time that different rigs were tested on identical boats. As early as the 1920's there were very elaborate testing of varying rigs and plan forms in identical boats with very different results. When you talk about doing testing in a catamarran the windward performance of the hulls and foils will be the limiting factor. Cats have a lot of wetted surface and when you do a study using a heavy cat as the test bed, the factors that would make a particular rig work well to weather on a lower drag vessel, do not come into play.

The article ignored the reasons that gaff and lug rigs generally do not do well in most other studies, sag and tip vortex drag. In any boat controling twist is critical to performance on almost any point of sail. Controlling twist is very difficult in a quadralateral sail because the peak wants to sag off to leeward. In the article, the testers rigged spencer vangs to the peak of the sail allowing them to control twist. Spencer vangs act like a barber haul on a jib sheet and allow the peak to be pulled inboard to control twist. Spencer vangs work poorly on a typically narrow hull form but would improve the windward performance of wide craft like the cat in question and especially over a backstayless masthead bermuda rig as used in this article. The large forestay sag in the photo's would account for a major performance drop just on its own (especially when the jib is approaching 40-50% of the sail area of the rig).

The other issue with quadalateral sails is tip vortex. When you talk about low speed foils, aspect ratio is a critical factor. Most of the drive of a sail comes from its leading edge. Except downwind, boat are pulled and not pushed by the low pressure that forms on the leading edge of the sail. Close reaching and above, the trailing edge of the sail is only there to prevent this low pressure from being bled off to the higher pressure side of the sail. Because sailboats heel, a lot of the low pressure bleeds off of the top of the sail and mingles with the higher pressure also bleeding off the top of the sail. This creates highly turbulent air, (the tip vortex) and that turbulent air creates a lot of drag. Drag is the enemy of upwind performance. The smaller the tip of the sail, the smaller the tip vortex, and the lower the drag. When you have a typical quadralateral sail, be it sprit, gaff, or lug rig (junks are lug rigs), in order to limit twist the head of the sail is typically quite horizontal. The head of the sail becomes the tip over which this vortex forms and its long length means that it forms with a vengence.

The other issue is weight aloft which is higher with these alternative rigs and which is not a problem with a heavy multihull test bed but of course is a serious problem with monohulls.

The Unesco study was interesting because it looked at the relationship of rig to the hull. Most workboat hulls have comparatively little stability and few need very good windward performance and most need a lot of power reaching. In that application, gaff rigs and sprit rigs do quite well. The real winner was a polynesian rig called a crabclaw rig. This is a horizontal lateen rig with wildly curved yrads and booms. Despite its low aspect ratio, it performed better than all rigs tested(Your bumble bee if you will.) It is not terribly adaptable as a cruising rig because it requires very a specifid shape and proportions which unfortunately precludes being able to reef or even depower.

Enough for now, I don't know about you guys but I want to get cruising.
Jeff
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Old 30-08-2003, 13:32   #12
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Hi Everyone;

Sorry that I didn't make too plain what my post was about; I was rather tired when I wrote it. In the end I was looking for technical answers and aesthetic comments; nobody let me down.

Stede: Yes, I really did like the 57 Pontiac analogy. That was good.

Thanks Jeff for the reading list. It was as thorough as I hoped.

Have a good weekend everyone.

I have to go cook and dream a bit of sailing.

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Old 03-09-2003, 23:46   #13
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Custom Junk rigged motorsailor FS on ebay

For all those interested.......................

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2430680354
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Old 08-09-2003, 16:24   #14
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Well, Junk rig...

There is the Yahoo group, formerly the eGroup about junkrigs:

http://groups.yahoo.com/group/junkrig

There is also the Junk Rig Association whom publish a quarterly newsletter.

Michael Kasten has an article here:

http://www.kastenmarine.com/junk_rig.htm

Here is Chris O'Donnel's page on Junk Rigs

http://www.friend.ly.net/~dadadata/junk/tutorial.html

From these you should be able to find all SORTS of good info on the rig.

From everything I have read, and I've been purty thorough having corresponded with Vincent Reddish and owning Derek VanLoan's book, The Junk rig has good things and bad things about it.. like ALL rigs:

- Lacks windward ability. The basic junk rig, cheap and dirt simple doesn't point very well However, junk rigs HAVE been designed that have overcome that problem.. they just end up costing as much as their bermudan brothers

- Is a heavy rig. Yep no way around this, so you'll have to have a boat with some bearing to carry em. Then again, you could use Bamboo for the battens

So yes, the Junk Rig has less pointing ability than a well tuned Bermudan. But then, I wonder how much better a poorly tuned Bermudan would be against a well tuned Junk?

Anyway, I like the Junk Rig because of several things:

1) CHEAP. My god its CHEAP. Nuff said For a rig that will last you 10 years with nothing but tip up maint, the Junk Rig cant be beaten for cheapness
2) Easy to sail. Wont jibe hard, easy to reef (done with one hand from the cockpit most of the time)
3) Long lasting. Since the stresses are distributed throughout the sail more evenly, the whole sail lasts much longer than marconi brothers
4) Less rigging. Junks require unstayed or lightly stayed masts. I like that.
5) If you really want to increase pointing ability, you can rig a stays'l or jib.

Ultimately, this is another one of those 'discussions' that occurs in cruising, along with hull material, politics and religion. The Junk Rig has been around for a REALLY long time and will definitely take you around the world safely. It is cheap, easy to maintain and easy to operate, but it lacks windward ability and is not a traditional sail. Its up to you to decide if the advantages and disadvantages line up to your plans.

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Old 02-05-2007, 11:46   #15
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Lots of strong opinions, but..

perhaps it would be most useful
to ask those with lots of experience.

Annie Hill (Voyaging on a Small Income, Brazil and Beyond),
Blondie Hasler (The Practical Junk Rig),
Bill King (junk rig circumnavigator), etc
might be surprised to hear that the rig
is "only good through a narrow wind angle range",
"you never see one far from port",
"is something akin to a three-legged race"...

knome gives some good websites.

My own strong opinion is this:
if the Brits had been exposed to the junk rig a bit earlier
the Marconi rig would never have been adopted.

Shas
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