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

Started by Owly055, October 25, 2016, 11:41:35 AM

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maxiSwede

Modern western junk rig revisited

Thought this would fit bettet here than on carbon versus wood masts etc. I just posted on.

owly & others considering junk rig conversion or something Along those lines...

I've enjoyed some rare free wifi lately and among other things updated myself on the Junk Rig Associations site ( JRA.org)

I was very interested/ curious about junk rigs some 12-15 years ago since the advantages are many, in particular for world cruising

Simplicity, low cost, low stress are but a few.

A disadvantage at least to some is that there are but a very few around, thus pretty hard to find a used one that suits you....

And then, the deal breaker for me at the time. They just didn't go to weather worth a "dime"

Well this last huge disadvantage seems to have been corrected by a few enthusiasts since years, myself being totally ignorant. Sorry for that!

If you search the JRA.org there is in particular a Norwegian guy, Arne, who have converted at least 5 boats to junk, and with his larger area (compared to the original Bermuda) and cambered sails, they go just about as good to windward as the same hull with Bermuda. But the best part perhaps, off the wind it beats the h-ck out of any Bermuda rigged sister ship w/o spinnaker and sometimes even those with chutes. The reason is explained in his files, but aerodynamics theories are like Ancient Greek to me unfortunately.

Them there is another guy, Slieve, who seem to have invented the "split junk rig" which I understand has a slot close to the mast and about 35% of the sail forward of the stick! thus obtaining a fore and aft junk rig. Apparently this slot makes all the difference, since his boat is flying. Yeah, more aerodynamics.....good thing is, one doesn't have to grip all the theory in order to use it.

For me, I consider my future sailing, like the next boat. I've seen quite a few folks who swallow the hook due to age or rather fading strength and so on, and the low forces involved in a junk rig, together with the very easy handling and no need for sail changes etc. makes me believe that with this rig an average 80 y o would meet no obstacles to keep roaming the oceans.

Food for thought.
s/v  Nanna
Southern Cross 35' Cutter in French Polynesia
and
H-boat 26' - Sweden

svnanna.wordpress.com

Junkrig

Hi Owly,
Another option worth considering (if you can find one), is a Modified Junk Rig (sometimes called a "Junkette" rig).
I was fortunate enough to buy a Top Hat 25, with this rig in NSW, Aust. The previous owner didn't have a chance to sail it, so I didn't know what it sailed like, & took a chance.
I think I have stumbled upon the most perfect low maintenance, easy handling rig there is!.
The difference is the front of the mainsail is laced to the mast, which allows you to carry a small headsail.
cheers
JR



SeaHusky

Hi Junkrig!
Thats an interesting design and great to have someone with first hand experience.
What are the pro's and cons of this rig?
At a glance it looks like a full battened gaff rig. You have lost the "balanced" part of the junk sail? Is it completely unstayed apart from the for stay?
I look for subtle places, beaches, riversides and the ocean's lazy tides.
I don't want to be in races, I'm just along for the ride.

Junkrig

#25
G'day Husky,
Yes, completely unstayed apart from the forestay, which is just to hank on the headsail. There is provision (fitting at top of mast & chainplate) for a "swept back" cap shroud on each side. There was no shroud there when I bought it, & it doesn't seem to need them. If I was crossing oceans, it may be a good idea to add running stays to these chainplates.
But I don't really know much about the rig, & am very much just making it up as I go along! :)
The cons I have found so far is the poor windward performance in light air, as you just cant get much shape from the mainsail. But once the wind increases, having the flatter mainsail is really handy!
Another problem is what on a full Junk rig is called a "Fan Up", where the gaff goes up vertically & gets tangled in the mast. It can only happen when reefed & an accidental Gybe happens. I have added a downhaul line to the throat jaws which helps drag it down & back to where it should be.
There is also the large keel-stepped mast going through the v-berth, which takes up a bit of space.

The Pros are it is fast downwind, much faster than the Bermudan rig on the same design boat, even with more sail area on the other boat(except if the other boat is flying a spinnaker).
Reefing is so easy, simply uncleat two lines on the cabin top, while standing in the cockpit (Throat halyard & gaff halyard) ease them until the next batten is in the Lazy Jacks, then re-cleat. No need to go nose to wind. The worry of having to much canvas up is totally gone:), if you see a horrible squall coming, you can reef in seconds.
Low cost, low maintenance rig.
All external halyards.
Yes, its like a fully battened gaff rig, but there are sheetlets from the back of each batten, which is handy, as you can twist off the top of the sail or bring it in.
cheers


Owly055

Quote from: Junkrig on December 16, 2016, 11:46:21 PM
Modified junk rig

     To me this negates many of the advantages I value in the junk rig.   I simply do not want a head sail..... period.   The split junk rig  Maxiswede pointed out places as much as 1/3 of the sail forward of the mast as a jib.   I've corresponded with Arne and a number of others from the JRA, including the designer of the aerojunk, also a split junk rig, Paul Mckay.  The idea of the split junk rig is to have good balance so sheet loads are light, a split at the mast so the mast does not spoil the airfoil shape, and the jib is part and parcel of the main sail, the whole works reefing instantly by just releasing the halyard.    Because of the instant reefing, it is possible to carry a lot of sail.  Each batten is a reef point.  The entire sail area is contained in one sail, and men like Roger Taylor have increased the sail area considerably to enhance performance is extremely light winds.   
     Invariably when doing long distance cruising  / voyaging, if you have a head sail, you will end up on the foredeck in miserable conditions fighting with it while being doused in cold salt water.   Murphy says so, and I believe him.   I want a sail I can control from the cockpit without fancy mechanisms such as roller furling, that is known to fail at the worst possible moment.   Many early junk riggers did fly head sails, but most all of them have abandoned them, and built the footage into the main.  The various split junk rigs have made carrying large area forward of the mast feasible, allowing for more area overall.   I've considered a yawl rig for reasons other than drive, and at least that's aft of the cockpit, and small, and if there is a need to fly a mizzen staysail, you can do it.    In general I don't want a boatload of expensive wet sails.   I don't want to be swept off the foredeck while trying to hank on a storm jib.  Day sailing is one thing......... crossing oceans is another.   In the one case you choose your weather, in the other, you have no choice whatever........ you deal with it or drown like a gentleman.   
     I want to be safe and dry below decks when things get rough, with the wind vane steering me to my destination...... or riding to a drogue.

                                                                                                    H.W.

SeaHusky

Quote from: Junkrig on December 17, 2016, 07:03:53 PM
The cons I have found so far is the poor windward performance in light air, as you just cant get much shape from the mainsail. But once the wind increases, having the flatter mainsail is really handy!
Thanks for the info!
If you feel like you want to try and improve it you could look at sewing in some camber in the lower panels.
Apart from that, where are you sailing and what are your plans with the boat (possibly a topic for a different thread)?
I look for subtle places, beaches, riversides and the ocean's lazy tides.
I don't want to be in races, I'm just along for the ride.