Rig Design........ long post with pictures

[Owly055]

     We all have our own criteria for what we want in a boat.  The old adage about the best boat to got to sea in is the one you have holds true, but we can always dream.  In my case, I don't currently own a sailboat.  The process has centered on cruising trimarans for a number of reasons, and the selection within my budget is a bit narrow.   

     As I've mentioned before, a free standing mast and a junk rig are must haves.  Whatever boat I do finally settle on, I will immediately be looking at what it will take to do this conversion, while sailing under the original rig initially.   I don't want a stayed mast for the simple reason that there are dozens of components to the standing rigging, any one of which if it fails can bring the whole works down.  Dismasting is really pretty common.   I don't want the Bermuda rig because it means stuffing the boat full of sail bags, and wrestling head sails up and down, as well as having a limited number of reef points on the main and having to wrestle a wildly flapping sail while tying in a reef.   I've done enough of that, and what I want is easy relaxed sailing where I don't have to leave the cockpit in rough conditions.   Not that there aren't roller furling headsails and in boom reefing, etc, but they are not in my opinion "simple and reliable".

     The junk rig is pretty simple in terms of handling, and has the advantage of being able to incorporate all of or more sail area into one sail as compared to a small Bermuda rigged sloop.  It reefs by simply releasing the halyard, dropping one batten at a time into the lazyjacks, each batten effectively being a reefing point, giving typically 7 to 9 reefing points, and leaving the top panel(s) as a storm sail.   The sail can have as much as 35% forward of the mast, meaning gentle behavior as compared to a Bermuda rig during tacks and gybes, no stays or shrouds to crash into.  People even sail them with the wind passing across the sail in the wrong direction at times, and they work.   

     The term "junk rig" covers a multitude of variations, and the performance of the more basic rigs is not great.   The Hasler McCleod flat junk rig started the modern junk rig movement..... which remains a small movement, and the majority of the junk rigs today use this flat sail design.   The modern junk rig is evolving if slowly, that evolution is slow only because the numbers are small.    The Cambered junk rig is the first real evolutionary step, and men like Arne Kverneland have done a lot of pioneering and inspired others to take it to the next level.   Slieve McGalliard took the junk rig to the next significant evolutionary level.   His split junk rig creates a rig with a main and jib on common battens, rather than having the sail lay on the mast on one tack.  The sail flies clear of the mast on both tacks and the jib directs air over the main creating a slot effect.   The split junk performs pretty close to a Bermuda upwind and outperforms it as a rule from a beam reach to a run depending on how much canvas they hang out there.   I personally have no interest in racing.
     The camber panel and split junk rig both utilize Arne's camber panel design that involves broad seaming or sewing in a shelf foot on each panel, as well as batten pockets.  This is relatively simple technology and easily understood, but it is a lot of sewing and is somewhat intimidating to those of us who do not have a lot of sewing experience.  It also requires a lot of room to build.    The famous solo sailor Roger Taylor developed a novel solution of making panels with alternating short batten pockets like a piano hinge for  his lower panels on MingMing 2.   This was to address space limitations in his living room, and it has been successful.   He's logged many thousands of miles in the high arctic with his Achilles with this rig.   
     I skipped an evolutionary step..... Oops.  There was a relatively brief period where hinged battens were used to achieve camber, and this was not very successful for various reasons, and hinged battens have been supplanted by cambered panels.
     On what I consider the "bleeding edge" is a many by the name of Paul McKay with his extremely innovative Aerojunk.   Paul took Slieve's split junk to the next level... at least in my opinion.   Paul uses a flat sail, and that sail has no battens attached.    Instead it flies within a set of airfoil shaped battens that pass around the mast.   The jib portion and the main portion  are separate sails like Slieve's split junk, and the battens define how the sail lays on each tack.    The leading edge of the jib (luff) is attached at the forward end of each batten, flying inside it of course, and the aft edge has grommets that travel on a piece of dynema cord so that it always lays on lee side of the batten, whichever tack you are on.   The entire set of battens shifts with relation to the mast of course because the battens are wider than the mast.  This leaves the mast well to the windward of the sail.   The mainsail portion aft of the mast attaches to the center of each batten at both the luff and the leech.   The main does not actually contact the batten in the first third of the distance from the luff to the leech, and this combined with the contact behind this point creates a very nice camber.    There are very few photos of this sail, the only ones I can find are of an early experimental version that is relatively crude.   I will try to attach several photos of this, as it is pretty clear.   Keep in mind that this is an early iteration of this design.
     In the first photo, you can clearly see the simplicity of this design.  The engineering goes into the design of the battens, and the sail is a flat piece anybody should be able to make.   Because of the light loading of a junk rig sail compared to a Bermuda rig, very light an inexpensive fabric can be used.  The one liability of this design as compared to the camber panel or flat junk rig is that there is no "rip stop".  On a conventional junk rig, you can blow out one panel and it will continue to sail fine.   The last photo dramatically illustrates this.  Kehaar is an enginless junk rig that was caught in a storm off a lee shore, and forced to beat against the wind for an extended period of time to avoid being driven up on the rocks.   The boat was sailed into some Chinese port in this condition.  A dramatic testament to the strength of the junk rig.
     Junk rigs are often considered to be less efficient aerodynamically than Bermuda rigs.   Inefficiency means a reduced lift drag ratio.   Lift equals drive, and drag equals heeling force.  Nobody seems to have quantified this with wind tunnel tests, so this is entirely subjective.   Clearly the cambered panels and split rigs are a big step forward.     
     On a light trimaran, weight is an important consideration, and a free standing mast is not likely to be light.......... But eliminating a bunch of standing rigging, spreaders, and hardware helps to balance this out somewhat if not completely.   No matter how you look at it, it appears that there will be a weight gain from converting to a junk rig.   This means that maximizing efficiency is critical.    A shorter mast, and a lower aspect ratio sail plan just makes sense, and the subjective observations of Paul suggest that his aerojunk with a smaller sail area outperforms the original Bermuda rig.   It is also attractive to me for the obvious reason that the sail does not require a lot of complex seaming, the seaming being confined the edges.  Looking at what's happening in the first photo with the foot of the sail, I would probably eliminate the airfoil shaped boom here, and use a conventional straight boom, and use an attachment method of the foot to the boom that would achieve an airfoil shape, or perhaps even build a shelf foot into the sail at this point, where it would function as a endplate to block flow  around the foot of the sail.  A sail is a wing, and spanwise flow robs a wing of lift.   Well on the other hand the airfoil shaped boom keeps the lazy jacks where they should be for proper stacking when reefing, but I do believe a shelf foot would be an asset here anyway.   
     I can see this sail on a trimaran.........  on MY trimaran.

                                                                             H.W.

[maxiSwede]

A very interesting post, thanks for that!

I too, hav looked into junk rigs but I am not quite convinced.

All those "windsurfer" style booms must create a LOT of turbulence/vortex.....whatever to make efficiency suffer?!

Though I have obviously zero personal experience eve sailing a junk.

last year I met a guy here in FrPol, who owns a Wharram Tangaroa ( 36 ft older JW design) built and fitted as junk by a German guy who sailed to the Caribbean, where the current owner bought it and crossed to Tahiti. He seems quite happy with it. It has a mast on each hull, which to me makes good sense on a catamaran configuration. Downside, the masts take lot of room down below on those narrow veed hulls....


At any rate, I am still quite interested in these ideas, so grateful for your posts.

BTW, Annie and Pete Hill ( " cruising on a small income") sailed a junk rigged boat for quite a few years and long distances.... But today I. Believe they are both, separately, sailing Bermudarigged vessels....wondering why?

[Owly055]

A very interesting post, thanks for that!

I too, hav looked into junk rigs but I am not quite convinced.

All those "windsurfer" style booms must create a LOT of turbulence/vortex.....whatever to make efficiency suffer?!

Though I have obviously zero personal experience eve sailing a junk.

last year I met a guy here in FrPol, who owns a Wharram Tangaroa ( 36 ft older JW design) built and fitted as junk by a German guy who sailed to the Caribbean, where the current owner bought it and crossed to Tahiti. He seems quite happy with it. It has a mast on each hull, which to me makes good sense on a catamaran configuration. Downside, the masts take lot of room down below on those narrow veed hulls....


At any rate, I am still quite interested in these ideas, so grateful for your posts.

BTW, Annie and Pete Hill ( " cruising on a small income") sailed a junk rigged boat for quite a few years and long distances.... But today I. Believe they are both, separately, sailing Bermudarigged vessels....wondering why?

I know Pete Hill was sailing Badger, a junk rigged Benford Dory in June of 2015 when he lost his wife Carly overboard while he was sleeping below in the Indian Ocean.  He and Annie had split up.  Annie bought a Bermuda rigged boat and it was not long at all before she had converted it to a junk rig.   The advantages of a junk rig are many.... maximum performance is not one of them, but modern cambered junk rigs generally are very close to a Bermuda in the upwind points of sail, and often kick ass downwind.   The lack of standing rigging is a huge benefit......... as I've mentioned before.   You lack dozens of cables and fittings that are frequently in the way, any of which if it fails can bring down the mast.    It's a LOT of points to worry about, and of course metallurgy is such that things break with no warning in many cases.   The position of the boom is not limited by the shrouds, and lacking a jib or any foresail in most cases, you aren't faced with all the problems that can entail.... You aren't having to work the fore sail around the forestay or baby stay, or getting lines tangled, and the mechanism of a self furling device is not there to let you down, or go crazy and tangle itself up if you are a bit careless.   The entire sail area of both main and jib are encompassed in one sail.   Uncontrolled gybes are a non-issue due to the balance area forward of the mast.  Forces are quite light and controllable.   You don't need preventers, one less line to handle.... in addition to the lack of a jib sheet and halyard, or a pole to pole out a headsail.   You also don't have a v berth filled with sail bags, and you basically do no deck work.  Sheet loads are very light with balance area of between about 15 and 33 percent balance area.  The sail fabric is very lightly loaded, as the wind force is transmitted only between two battens, not the full area of the sail.   A tear will not propagate and blow out the sail, because batten pockets block it.  The aerojunk has no internal battens, so I feel that for a cruiser, seams providing a "rip stop" function would be of benefit here.   Reefing is a process that can be done with a cup of coffee in one hand........ You just release the halyard, and drop as many panels into the lazyjacks as you want to reef, and they stack like Venetian blinds.   Tacking and gybinig  are non events.  There is no traveler, or preventer, and the sheeting can be on centerline.  Because of the balance, there isn't the violent action that can knock you in the head, or has been known to rip shroud attachments out or break a boom.    To tack or gybe, all you do is put the rudder over, and perhaps adjust the sheet as needed.   Because reefing is virtually instant, you don't tie in reefs in anticipation of weather to come...... you reef when the weather gets there, and that alone makes a huge difference.   Junk rigs can carry more sail longer because of this.  Who want's to stand on the coach roof or side deck wrestling with a wildly flapping sail trying to tie a reef in while being rained on or showered with spray.   That might have been an exciting challenge when I was younger, but I no longer want to do things the hard way, and I'm NOT interested in getting hurt.   Most junk rigs use either no winches, or just a single one for the halyard.  That equates to less maintenance.  It all equates to less work, and less cost in the end.  What you don't have, can't break!!
     It's a mystery to me why anybody would not take a serious look at the MODERN junk rig, unless you thrive on all the hustle and bustle and deck work.   I'm fundamentally lazy.   I don't want to deal with stuff I really don't need.  Watch Roger Taylor's Utube videos of his sailing into the high arctic in Ming Ming, and Ming Ming II.   He rarely has to expose himself on deck.  He reefs and adjusts the sheets, and adjusts the self steering, all without exiting the hatch that leads into the cabin.    It's not the exciting sailing of having various line and sail handlers, and a helmsman working as a coordinated team in a race, raising and lowering a drifter, etc.   
     The last photo in the post is a testament to how rugged these are......... A Bermuda rig would never have made it to port with the sails in that condition.  You can read all about Kris Larson and Kehaar at Atom Voyages:  http://www.atomvoyages.com/articles/sailor-interviews/107-krislarsson.html   You see a junk rigged boat with shredded sails..... I see a survivor, and a boat that didn't let it's skipper down.   This is the result of being caught off a lee shore in a storm in an enginless yacht.   He spent many hours beating off a lee shore in a violent storm, an incredible feat of sailing that must have left Kris battered and exhausted in a physical and emotional condition to match that of his sails.  This was no mean feat of seamanship, and the boat never let him down, or the photo would be of a battered wreck.........

      To paraphrase an old redneck sailing that is not politically correct...... "Go Junk, and you will never go back".   

                                           H.W.

[CharlieJ]

James Baldwin is a pretty interesting dude himself. Twice around on Atom. One and one half single hand, then he met Mei

I spent a day with he and his wife Mei at their house a few years ago when I was anchored close by. Fine sailor, and she made a mean lunch:)

[maxiSwede]

Owly;  i stand corrected on the Hills. I recall reading Pete Hill sailing a small sloop a few years ago, but that was perhaps just a race or "jester Challenge" then.

I totally agree on your description of the pros of the Junk though and I am a bit intrigued. Maybe one day I will get the opportunity to sail on one to get a feel for it. I do like active sailing and don't mind sail handling on deck. In principle that is. Once on a longer passage, with lack of sleep coming into the picture, I rarely sail the boat to its potential though, but tend to slow down to be comfortable.... So wouldn't think the possible less performant junk rig would make much difference there,but then day sailing and overnighters are different, when I truly enjoy "sailing the boat" meaning steering and trimming to get the most out of it.

I conclude that for most cruisers, whom 95% have already bought into the "stay int the cockpit" type of sailing, a junk would make even more sense.

The added cost, hassle and maintenance/failure issues with (multiple even) roller-curlers, booms and poles etcetera is far from KISS, that's certain  ;D ;D ;D. And also, it makes their boats look like floating condos or even junkyards quite commonly....  8)

[Owly055]

     I've been gone for a bit, and just got home.  Visiting family almost a thousand miles away, and camped my way home in my Subaru.........  Wednesday AM when I came down out of the hills and turned on the radio, it became clear that it was time to go on that extended cruise.   Sometimes it takes a kick in the pants to get moving!    I'm ramping up from casual browsing to serious shopping, and will immediately begin the process of liquidation and closing down.    I'm 61 this year, and there's nothing holding me back but inertia.   Let the younger folks fight the battles.   

     There are a number of boats available that meet my starting criteria.  Not all trimarans would convert easily, the searunner 31 being about optimal along with a few others.   The conversion is a big job, and then there's the sea trials with the new rig.   I've concluded that the rig that suits me best is the aerojunk with it's external battens and flat sail that is shaped by the battens.  My own abilities and experience make this the best choice for me.

     On a long ocean passage, particularly solo, the less one exposes oneself to risk, the better.    Unfortunately deck work is often under the worst of conditions, exactly when you don't want to be there.  What's a joy in Chesapeak or Puget Sound under F3, can be a nighmare in the middle of the Tasman Sea when the southern ocean blows up a storm.

     That said, I'd like to have a mizzen mast to fly a jigger to fine tune and balance the boat.   I've yet to sail a yawl, but the utility of having a sail with that much leverage in relation the main is appealing.   Unlike a jib, it's completely accessible from the cockpit.   Cold saltwater showers get old fast!

                                                                     H.W.

Owly;  i stand corrected on the Hills. I recall reading Pete Hill sailing a small sloop a few years ago, but that was perhaps just a race or "jester Challenge" then.

I totally agree on your description of the pros of the Junk though and I am a bit intrigued. Maybe one day I will get the opportunity to sail on one to get a feel for it. I do like active sailing and don't mind sail handling on deck. In principle that is. Once on a longer passage, with lack of sleep coming into the picture, I rarely sail the boat to its potential though, but tend to slow down to be comfortable.... So wouldn't think the possible less performant junk rig would make much difference there,but then day sailing and overnighters are different, when I truly enjoy "sailing the boat" meaning steering and trimming to get the most out of it.

I conclude that for most cruisers, whom 95% have already bought into the "stay int the cockpit" type of sailing, a junk would make even more sense.

The added cost, hassle and maintenance/failure issues with (multiple even) roller-curlers, booms and poles etcetera is far from KISS, that's certain  ;D ;D ;D. And also, it makes their boats look like floating condos or even junkyards quite commonly....  8)

[SeaHusky]

I too have been very interested (convinced) in the junk rig and using "Practical junk rig" as a guide I designed and drew junk rigs for all the boats I was interested in, including the Allegro 27 I now own. However as the fix up turned into a complete refit I have put those ideas on the back burner for now and am spending money on the existing bermuda rig but I have the junk rig in mind and am putting a chain locker were the junk mast step would go. This way I have the possibility to change to a junk rig if and when I would like to. If I were you I would buy the boat best suited to your needs and if it has a bermuda/gaff/whatever rig keep it for now but keep designing that junk rig on paper. When you loose your mast in Tahiti, that is the time to put the work and funds into a conversion!

[Frank]

Thought you would enjoy this.
A Compac 19 conversion

https://m.youtube.com/watch?v=SD55DYEgFXg


Go to post #29 below

http://cpyoa.geekworkshosting.com/forum/index.php?action=recent;start=20

[SeaHusky]

Sorry Guest, you are banned from using this forum!
This ban is not set to expire.

Thats a bit harsh.
I was just looking...

[Owly055]

I too have been very interested (convinced) in the junk rig and using "Practical junk rig" as a guide I designed and drew junk rigs for all the boats I was interested in, including the Allegro 27 I now own. However as the fix up turned into a complete refit I have put those ideas on the back burner for now and am spending money on the existing bermuda rig but I have the junk rig in mind and am putting a chain locker were the junk mast step would go. This way I have the possibility to change to a junk rig if and when I would like to. If I were you I would buy the boat best suited to your needs and if it has a bermuda/gaff/whatever rig keep it for now but keep designing that junk rig on paper. When you loose your mast in Tahiti, that is the time to put the work and funds into a conversion!

     I don't have the patience for that...........  The best place to build a mast is here and now.  Nowhere else are aluminum light poles, or flagpoles as readily available and inexpensive.  I don't want to deal with 3 or 4 head sails, and a V berth stuffed with wet sailbags.  I don't want head sails at all.  One main, and a yawl mizzen, both of which I can easily reach from the safety of the cockpit is what I want.  I don't want standing rigging, asking for an opportunity to fail, vangs, travelers, furling devices.  I want a clean, simple, and reliable rig.   My experience is that once you decide to "make do",  you will always "make do".

                                                                H.W.

[Owly055]

Sorry Guest, you are banned from using this forum!
This ban is not set to expire.

Thats a bit harsh.
I was just looking...

You are apparently a member.......... I'm not sure why you took that as being directed at you............

                                                                                        H.W.

[CharlieJ]

Used too have a picture of  Flicka with a junk rig. Nice boat. Wish I could find it again

[Frank]

Flicka:

[SeaHusky]

Wrong continent perhaps but have you seen this site?
http://www.sunbirdmarine.com/broke.htm

[CharlieJ]

Thanks Frank. I had an actual photo. I've sailed aboard a junk rigged boat a few times. Pretty interesting

[Norman]

CharlieJ I have noticed for years that junk rigged boats have multiple sheets, one for each batten.  When reducing sail, how do you deal with each of them as the halyard is slacked?

Do you slack the halyard, the start with the top one first, and work down until all are right?

[CharlieJ]

No- the top battens stay as is, You lower from the bottom in order-

Watched a junk come into dock against a current once. They dumped much of the sail ( it's held in lazy jacks) and edged in to the dock, sliding sideways. Finally  landing was made under the very top section. Beautiful boat handling.

Another time I was sailing a friends boat as we were approaching a draw bridge running straight down wind. I asked if we could clear the bridge, as he seemed completely unconcerned. He replied- No

Just as i was about to do a panic bail pout, he walked to the back of the cabin, ,un cleated the halyard, and dumped the sail down three battens ( almost instantly)  turned,, looked at me and said -but the mast will, As we cleared the bridge, he re hoisted the sail and sat back down. Like dropping a shade:)

I've been a fan of the rig for a long time, and even considered changing Tehani. Since she carries a deck stepped mast, and the interior would not work, I used the original.

As to the question on the sheetlets. They become slack as the sail is lowered, so you just take them  up as needed

[CharlieJ]

CharlieJ I have noticed for years that junk rigged boats have multiple sheets, one for each batten.  When reducing sail, how do you deal with each of them as the halyard is slacked?

Do you slack the halyard, the start with the top one first, and work down until all are right?

Here's a diagram of one method of controlling the sheetlets

[Norman]

So just one very long sheet, in series through blocks.

That makes sense, and explains how there are so many apparent lines but just one line to adjust.

Thanks very much, Charlie!

[Owly055]

So just one very long sheet, in series through blocks.

That makes sense, and explains how there are so many apparent lines but just one line to adjust.

Thanks very much, Charlie!

     In some cases there is an upper and a lower sheet where the designer or owner want's more twist control, but there are several arrangements of pulleys used with the sheetlets so as to achieve the desired amount of pull at each batten end.  There are numerous variants.

     Of some interest should be the fact that there is no need of devices and lines to tension the sail, a vang or a downhaul for example because the camber is in the panels themselves between the battens, and you can't really pull it out of the sail.  Likewise for the same reason you don't need a traveler, you just cleat the sheet off at a convenient location, and if properly located that location can remain unchanged during tacks.   You just put the tiller over and the boat goes to the other tack..... duck if the boom is low enough to hit you in the head.  The balance area forward of the mast makes the swinging of the boom much more gentle, preventers are not needed.   In short it's a much simpler rig to sail.  In theory at least, one should never have to get out of the cockpit.

                                                                                 H.W.