Anonymous wrote:
Good stuff Jeremy,
I didn't know the shunting lateen was such a 'late' invention, The Sprit rig was the Pacific standard, how it was shunted is beyond me.......
A shunting split rig is a hand full if you're short handed. I learned that the hard way, shunting Crystal Clear was about as hard as pulling a U turn with a semi trailer.... I never imagined it would be so difficult. The problem with "CC" was that it was hard to bring her to a stop during the shunt, as one sail would always keep driving her while I was flipping over the other one, resulting in her ending up backwinded. I finally learned how to shunt her, but it was hard work and there was no way I could do it alone. That kinda broke my spirit, forcing me to go deeper and deeper into the whole concept of shunting and build smaller proas that are easier to test sail and cheaper to make mistakes on..........
As for fouling sheets on the tack, I can't see a solution except the 'standard' double sheet solution.... I'm happy with it even though the 'lazy sheet' is left drooped over the sail's tack... Still not ideal, since the more there is, the more can go wrong...
I totally agree with you about those big double canoes, I guess every play has it's audience, and as long as someones paying the show will go on......
Yea, thanks for reminding me......
"Keep Shunting....."
.....and all d best.
rael.
Rael, there are a number points to cover and to make a start, the double sheeting is probably the best one to kick off on, just as you are doing or have done.
This is in any case required whether the rig is to be a junk type or a split Oceanic one.
Drooping the sheet tails over the tack part/luff edge, has got to be the way to go, although with a junk sail it would be better to hang the sheets onto the mast (where mast and boom cross) and this is where euphroes could be useful bits of gear.
leaving aside the junk rig (because there is so much development still to come) we could consider the advantage that a SS(split sprit) presents over a SCC(split crab claw).
So the SS is essentially a rig that keeps the mast standing fixed(eliminates raking), with spars rigged so as to be more easily managed- mainly because of reduced dimensions over a single sail) and also because there is no need to adjust mast rake when ends are changed(shunted).
This works with a spritsail (as compared to a CC, because(in the case of a shunter) the mast, spars and the sail can be handled independently, but still linked when shifting CE.
Having a sail that can be hoisted or dropped on a stationary mast, is probably the single important factor in Pacific rig development for handling in all weather, whilst the mast stands erected....where the junk rig excels, concerning items of early technology.
We can be sure that the Tongan Fijiian drua shunters provide a date for change over from hoisting a Lateen yard(by using a halyard), on the double canoe rigs of the central Pacific, which subsequently rendered the prop type mast obsolete.
Hundreds years years before this, the early Spanish(Magelan etc.) had noted the 'Latino or Lateen' sails of the Micronesians, and it would be an odd thing if the wide-ranging Oceanic seafarers remained oblivious to how the different regions configured their different but technologically similar rigs.
Even so, before Spanish contact, turning blocks (those with sheaves) would have been an unlikely rig item(unless we accept Chinese influence), so we need to see sail handling being possible with nothing more than crutch headed masts and spars- making the getting on/off of sail with smaller SS type rigs a no brainer option... no doubt the reason why it was the big Lateen that had to wait for running rigging advances noted by Cook.( before shunting showed up in Tonga, where the Lateen sail had grown big)
Note also, that it was the eastern Pacific shunters that had the ladder-like rat lines to the masthead.
As well, the mast was stepped midway between the hulls, and had a prop in the place of a w/ward shroud, that acted in safety against backwinding on the rig.
I am doing away with with the prop, because the rig will stand equally as well as a Wharram catamaran rig (of equal beam and mast height dimensions) with synthetic shrouds only.
For clarity in explanation, it would serve well to describe how an SO Pahi rig works/would work on a Wharram, if less rocker, for reduced yawing tendency is included as a required characteristic.
Then, we should be able to agree that the canoe will hold alignment to wind direction while shunting-because of yaw resistance.
Held steady against spinning in the wind, the sail's leading edge spar hangs down with the tack ends alongside the safety rail on the lee(of lee hull).Here the sheet ends are conveniently to hand... hooked onto the luffs.
There is a linked tack line between the leading edge spars, which is continued toward each each end of the lee hull.
Now, as per the original sprit sail, the luff can be be hauled up or down this leading edge spar, while the sprit is managed separately.
My rig will have a tubular headboard in place of the loose concave sail head, and a halyard system for hoisting it.....making single handed sailing a possibility.
Going (caught) aback can/should thus be handled by scandalising or dropping the sail, while the rig remains standing.
Sheeting becomes the complicated issue, which might or might not be made easier on a balance Junk boom with a euphroe taken out by a 'messenger' type endless line... if in the instance a split aero Junk sail is used on one mast.
Thinking of such complications has me leaning toward a wishbone boomed luff-spar with Junk reefing. soft wing, that has reefing lines and halyard rotating with the sail.
Cost is evidently as important to you as it is to me, so this is why I am happy to continue with the SS option, in this discussion.