: Part Dux...
My previous comments were clearly qualified... I will cut and paste them here:
"Many rigs, (like front stayed triangular rigged rotating masts and such), have slack leewards, OR such a stout extrusion, (often with SS wire diamonds), that these changes in tune could be tolerated. I know that a lot of boats do fine with synthetics, and for some, there is a lot to be said for the stuff. I just want to point out that IF you plan World cruising, with a broad temperature range, (or locally for that matter), AND you have a tall tune sensitive rig, like we do, then wire is still the better choice IMO... from hot season to cold season." END QUOTE.
This is not just guessing, it is based on my experience, (and that of other rigger pros)... experimentation, and a profound understanding and application of the scientific process.
I never said that there were not appropriate applications for the stuff, or that it was not used successfully by a lot of boats, only that: for Searunners, (or boats with a similar rig) that want to keep the mast straight with longevity, chafe resistance, and broad range of temperature compatibility (with an aluminum
extrusion), synthetics do not seem like a good match. It is a nobrainer!
If one had a short stout extrusion, and only sailed locally in a stable moderate climate, then these coefficient of expansion caveats become less of an issue. For OUR Searunner, with it's extra tall rig, the way we sail... I know that synthetics would be a disaster. This is a fact!
IF YOU HAVE TURNBUCKLES RATHER THAN LASHINGS, with synthetics:
You can indeed avoid your upper shrouds hanging slack on a cold day, (like my runners do), by putting on say... 1,500#s of preload @ 85 degrees F. The thing is, on a 100 degree day, that may well increase to 2,500#s of preload, (EACH), just from the expansion of the mast, more than the synthetic shrouds did. This is way too much static load, as the compression
load on the mast is the SUM of all of the rig's preload. This can actually bend or crush the boat!
So, (hypothetically), if you start out with just 900#s of preload (on an 85 degree day), to minimize the previously mentioned static stress, the 1,500#s (each shroud) you might end up with, on a 100 degree day, are more tolerable. Thing is... that same starting point of 900#s preload, on an 85 degree day, might only be 3 or 400#s preload on a 45 degree day.
There is no way that such a shroud
could keep MY mast in column, under full sail, in over 30 knots of wind
. Being longer, the uppers would loose proportionately more of their preload than the intermediates, and the % of preload lost
on the upper and lower shrouds & stays would vary in proportion to their length. It would likely do this in the opposite direction than I would want it to, in order to keep the mast in column.
Like I said several times, for tall/skinny tune sensitive rigs, (like ours), that sail in extremely varied seasons, and must get at least 15 years from their rig, wire is a much better match. No one really knows the lifespan of synthetics yet, but 5 years or so, is all that they can confidently offer, at this point. Bear in mind... My newish DUX runners have chafe already.
My decision to go up from 1/4" to 9/32" Dyform (type) 316 wire on the uppers only, was after 17 years of observation, thought, research
, and professional paid consultation with other more experienced riggers. Conclusion:
Imo... This way I can achieve less stretch on these upper 4 wires, with minimal extra windage and weight. The current
wires are already at maximum preload, so I can't get less stretch, (in an expansion/contraction compatible way), without this proposed upsize modification. It is not more strength that is the issue, it is less stretch. I should be able to achieve this with "compact strand" wire, while substantially lowering the wires' preload from what it is now. This will result in less load on the hull altogether.
My previous point about the synthetic "weight advantage", was that with a TOTAL rig weight of around 400 to 500#s, (counting steps, radar
, lights, sails
UP, running & standing rigging
, everything), using synthetics to knock say... 50#s off of the rig, IS an improvement in the boats "motion" in a seaway, but will not improve ghosting ability on a flat sea. Only more sail, OR a far lighter boat will accomplish that. I think that this was more what Jack was observing... The rig's total weight "higher up" has the most effect on motion (and to a lesser degree speed), and weight down low has very little. Switching to synthetics is a reduction of the TOTAL rig's weight of < 10%, but not >50%, as is implied when comparing the weight of the standing rigging alone. Rig weight matters, A LOT... but imo, keeping the mast in column, (no matter the temperature), trumps the 10% lighter rig, hands down.
I have seen Brion Toss's "act" at an SSCA meeting, spoken to him personally, and conversed on line. I have also read his books
and articles. He is a very entertaining guy, but very opinionated, and has a strong bias toward synthetics, probably for business reasons. He is very well known, but the last rigger I would go to for advise...
Since I have such respect for Jack Molan, and appreciated his sending me a slew of trimaran trailer
photos in the past, I made it a point NOT to mention my "undeniable observations" about DUX, until AFTER I understood that his boat had been sold. (I didn't want to create a problem with the sale). Only then did I share with the Searunner community about the caveats of synthetics on these tune sensitive rigs.
It was later that I learned that Jack's first sale
actually fell through. I wrote to apologize for any difficulties I may have inadvertently created...
In personal emails, I went out of my way to try to help him sell his boat, while also being honest about the pros & cons that one would be getting into. I explained this to Jack in the kindest terms in PMs, but he never responded. Like I said to you personally, Jack... Sorry if I stepped on your toes, it was not intended.
Having said that:
I would point out, that he apparently never cruised this boat through a broad temperature range (>80 degrees of range), and never lived on it and cruised year in year out. I haven't heard of him pushing it through 40+ knot
winds on dozens of occasions, or regularly reaching double digit speeds, and any comparison to his use of DUX for pulling nets on a commercial
vessel, are totally meaningless... different application altogether! In short... He really doesn't know what his synthetic rig would be like, to live with and cruise
with, as a full time endeavor, over decades. So why all the passion???
It may no longer be true, I don't know... But I was told that Jack is financially invested in the DUX rigging business, which makes his position as such a passionate advocate, make more sense. Salesmanship!
I, on the other hand, am NOT invested in selling wire, and as a 40 year professional, (including lots of rigging), do less rigging work all the time. I'm getting too old. So, I have just been trying to give back in the way that I can. I never state opinion as fact, unless they are one and the same.
LIKE I SAID:
I love my DUX rigging on running backs, as our "quick adjust" turnbuckles, and usually slack status, makes the material's expansion caveats null & void.
IF I had opted for using turnbuckles... it might have also worked well on my old SC 28, with it's STOUT extrusion, and double triangulated spreaderless rig.
I just think that for our Searunners, if they are used as true multi climate "cruisers", the pros for using synthetics are vastly exceeded by the cons. If it had a carbon mast, however, that may not be the case...