How to compromise junk to trimaran?

Rigs with complicated controls are more work. A simple rig that doesn't need running rigging to control needs less work. That is why all the cheap production boats use simple rigs. How can it be less demanding when you need several persons on deck each time you tack or jibe?
A masthead rig does nicely with a straight section. Fractional rigs need taper masts which are more expensive. Once you reef the mast makes weird curves. Also, if you diminish the foretriangle, the mast needs to be higher to compensate for the sail area lost. That means a multiple spreader, higher, more expensive rig.
With a jib furler you don't change sails. However, I carry a small storm jib set flying.
No, you talked about changing headsails. Stick to your position or concede. Anyway, a marconi sail drops over the boom and can be easily furled.
Now you are dropping numbers to try to support a position. Those are just bogus numbers. Marconi rigs are quite forgiving. I notice that you don't give numbers for a badly set junk rig. The marconi rig is not basically less efficient, but vastly more efficient. Even if it did lost the bogus 20% it would still be superior.

 

"Rigs with complicated controls are more work. A simple rig that doesn't need running rigging to control needs less work. That is why all the cheap production boats use simple rigs. How can it be less demanding when you need several persons on deck each time you tack or jibe?"
What I did say, the work of tweaking is physically less demanding as sail changing. I cheerfully leave sail changing work to anyone who think otherwise. Yes, with more controls there more strings to pull, but this is more mental as physical challenge. As i mentioned in my previous post, (I will try to say it more clearly) if rig is not excessively lightened, or pushed with spinnaker force 6, runners could be almost ignored during a maneuver. On 12m, 10t yacht it goes like this: helmsman release the old runner from winch (chekstay is connected to it), step to other side, pull in the new runner per hand, and that is it for the time being (this is enough to keep mast from falling down during tack or gybe); after genoa is cranked in, sheethand build necessary tension with winch. No more people required!

"A masthead rig does nicely with a straight section. Fractional rigs need taper masts which are more expensive. "
Both are done with and without taper.

"Once you reef the mast makes weird curves."
Masthead is much more prone to this -once reefed, the mast tend to invert.

"With a jib furler you don't change sails. However, I carry a small storm jib set flying."
. You set flying jib. Some carry several furlers: light genoa/100% jib/storm jib; less work at sea, but expense in hardware. Some set big or small sail before leaving port. Sails are still changed.

"Now you are dropping numbers to try to support a position. Those are just bogus numbers. Marconi rigs are quite forgiving."
What numbers are bogus? Marconi (masthead?) rigs are forgiving in sense they are not quick to fall down, for best windward performance they are demanding for sail quality, sail choice, correct sail trim. I have raced both masthead and fractional boats.

"I notice that you don't give numbers for a badly set junk rig."
I do not have enough firsthand experience to speak about badly set junk rig. With bermuda rigs, I speak from published data, firsthand experience and observation.
With junk rigs I rely on published info and engineering knowledge.

" The marconi rig is not basically less efficient, but vastly more efficient. Even if it did lost the bogus 20% it would still be superior."
I said junk is basically less efficient to windward, not marconi.
bogus 20% come from regatta statistics -"amateurs" in same hull boats finish up to ~20% behind "racers".

 

Ah. That would explain why Tom Colvin junk rigged schooners were all designed with unstayed masts.

Not.

Sorry oldsailor, your lack of knowledge is showing.

PDW

 

The modified SPRAY type, BERTIE, has carried a stayed junk rig for nearly 30 years. The secret is a very high peaked yard, shrouds going as high as possible and good space between the masthead and yard. Not all junks lack shrouds. Here's a photo of a 'big eye chicken junk", a great example of 100' freighters that kept working until the 1970s. They have wire shrouds and a sail design adapted to them, all developed around 1880 when wire rope became widely available. They have the very high peak, the forwardmost cloth of the main being a straight line from tack to peak. Look at the seam lines in the photos of BERTIE's main.
I have no experience with the rig on multihulls but BERTIE sails much better than others of her type with gaff rigs. The main is heavy but can be easily reefed, dead downwind with the sail pinned to the shrouds, in total darkness. It is not a high performance sporting thing intended for a light to medium displacement modern canoe-hull type, but an industrial technology for profitable commerce, which means cheap to build, use, repair and replace. It does not take well to high-tech approaches though some things can be improved, like batten material. Here we used 6063t6 aluminum pipe instead of bamboo, wood, f/g, etc, because it is absolutely zero maintenance. In the photo you're looking at the light wood chafe batten, lashed butts and no finish, that backs up the aluminum pipe on the hidden starboard side of the sail.
The other photo is the same sail being bent on, brand new, with the boat hidden behind others, but shows the pipe battens.
Generally, junk rig works very well, when combined with a compatible hull, and designed and rigged by people who understand it, and that only comes with experience no matter how many books one reads.
Hasler's JESTER is a great example of a successful blend of western hull and junk rig and his book "Practical Junk Rig" is basic reading in the subject.

 

pdwiley: I have to agree with oldsailor7 on that. He said "some boats", which is correct.

Permstress: You are comparing a junk rig to a marconi with overlapping genoas. A selftending jib is very easily handed. I like to discuss comparisons, but really irks me when people twist facts to try to win.

 

Sorry, this was how I did understand your words about marconi superiority...
Please tell, what fact I did twist?
By the way, i like to discuss things, in order to to share and gain knowledge, come to conclusions otherwise not possible to come at, not to win at all costs. Please excuse me, if my manners not always soft enough.

Of course there are things and topics I am well versed in and otherwise. These topics, as a rule, do not coincide with that of other participants. This I see as a perfect starting point for discussion, sharing of knowledge and (with some luck) creating some new knowledge. Arguments and numbers are most respected and useful in this kind of discussion, in my opinion.

 

Nothing wrong about getting excited in a discussion. I think that junk rigs have to be discussed in two parts: when they are to windward and when they are to leeward. Like lateens and gunters, they behave in very different ways.

 

Chinese lug's performance is very similar to gaff, in general, but easier to reef, easier to get the twist out, and much more resilient (can tolerate damages in high winds that would destroy a gaff sail) due to the spread-out loads. It is heavier, though, and this is a major factor, especially inertia loads when pitching hard.
I sailed with my old mainsail for years with worn out cloth and gaping holes, didn't seem to make much difference and the holes never got bigger in squalls.

 

How it appear form the published info, junk is reasonably efficient to windward and quite good at reach and run.
However, main virtues of it are:
* very small performance loss due to low quality/tech materials used to make its elements
* very small loads both inside sail and on control lines.
* resulting resilience to partial damage (added after post #38)

As nobody yet performed boat-for-boat tests at measured distance with identical boats close to each other (if anyone know anything about such test ever performed, any data/links will be cheerfully applauded ), precise numerical information on performance is unlikely to exist.

 

BERTIE has raced many times against gaff-rigged SPRAY copies like JOSHUA and Culler's SPRAY, has always won and seems to be generally faster and go to windward better. These are not identical boats, but very close. It may simply be because BERTIE's mainsail is bigger at 1000 sq ft.

 

Going to windward better than a SPRAY is no great feat.

 

As Bertie has nearly the same hull, than junk rig is at least equal to gaff, when close hauled .

 

Re-read it. He said that the junk rig depends on an unstayed mast. This is unqualified and incorrect. He then went on to say that on some boats this might be a problem.

There are 2 statements there and the first one is incorrect as I said.

PDW

 

oldsailor didn't "say" anything....he directly quoted the Wikipedia entry on Junk rigs.......

Look here to see my comparison notes concerning Jester's performance against typical masthead sloops crossing the Atlantic......http://www.boatdesign.net/forums/sailboats/chinese-junk-rig-5703.html

Tom Colvin did the direct comparison of junk vs western marconi rig on the same hull (a sharpie I think) about 30 years ago.......I recall his conclusion was it didn't make a significant difference......

 

Absolutely. But BERTIE continually surprises other, more modern gaff-rigged vessels by her performance, especially in light airs. The huge main really makes a difference then.