What I meant, not what I said. The reefing clew out on the roach moves the sheeting angle more downward and less outward making the sail slightly fuller. A new clew ring further in would potentially fix the problem, but I'm going to sail it as is; it's a minor detail.
Sail by Triton Sails in Mississauga, Ontario. Great guy to work with.
Edited by jeff96 on Jan 31, 2020 - 01:56 PM.
"The cats out of the. Bag" (pun attempted), I presumed noone took notice that in speeds up to 12ks I lifted a rudder out of the water to gain an advantage and always in low wind conditions. dart 18s use spanners ( lines that attach from aft clew/grommet on main(boom less)next to where blocks attach spanning below main to bottom of mast where down haul and wishbone are located. I attach small blocks at either end to tighten spanner to achieve best pocket in main for sailing conditions. Tried to use spannerson Nacra.5.2,5.5,5.7 &570 but no advantage seemed to be gained. Brexit Brits know much more about Darts since they race and Darts are very popular in Northern Europe where small cat sailing thrives
another note- caution on overstressing the hardware on Dart 18s with larger sails in high wind conditions. Yes i have oversized side and forestays/shrouds(murreys said the ones they fashioned fpr me are suitable for a Stiletto size cat, and i always carry in rear hatch approximately 100 feet of amsteel rope which you can cut to size to replace a stay and actually is stronger - Ive sailed for weeks on amsteel forestay until i replaced stay- All Americas Cup craft only use it not stainless) but i had to replace chainplates/shroudplates/bowplates on one of my Dart 18s at the bow foreward! They are ugly, my friend Joe Pogostin made them up and they are 3 times as thick as the stock plates(its tricky to install you may lose inside of the hull fastener/ nut when removing discarded chain plate! remember metric hardware) ps mast base is referred to as mast foot by Brits wishbone is referred to as a spanner. Also i spray abundadant silicon on mast base and bottom of mast before raising mast, hobie and prindle sailors use silicon wafers but even when "molded" to fit these dont work with Dart 18 mast
I'm not sure what rigging size a Stiletto uses. Hobie 20 and 21 uses a 5/32" shroud; same as the Dart. It looks like there is already redundancy built in with the shroud diameter.
A larger sail will only increase loading on the rig if you can keep the boat upright in heavy winds. So unless you're doing twin trapeze with heavy crew on wings along with that extra sail area, I don't see the point in having rigging sized for a boat that's almost 3 times the weight.
Edited by jeff96 on Feb 02, 2020 - 03:49 PM.
Rigging oversized to cope with larger issue posted on Beachcats before maybe under mushroom anchors- we moor our cats on great south Bay in Fire Island National Seashore waters and are only permitted to use the beach we use to leave cats on 'back in the day' all year round, to put up & down sails and to let off or on "passengers/crew. Initionally the Park Rangers,who openly carry 357 magnums-we are in bathing or wet suits- punished us for leaving cats on public beach hardly used by anyone except other boater by literally cutting up one Nacra and cutting up masts taken off cats and left over bay dune, that partially washed away,to ride out hurricane Jose! Since then they have mellowed quite a bit and looked the other way for up to 2 weeks or more when i had to make repairs to my Dart and my Nacra 5.5SL (which I gave away in Sept) after monster freak summer storms , perhaps a tornado winds clocked at 79 mph(a close friend competitor swimmer drown!) pulled several cats and Flying Scotts from our moorings! After I oversized rigging my masts stopped coming down. I oversized on my Florida Dart as well since Lake Emerald rose 2 feet and beach there now under 18 inches of spring fed pure emerald blue water and now cat cant be left on beach there either. Global Warming?
upsizing your sails to deal with summertime doldrums may not be the best option.
in our area (same area the poster sails in): on typical summer days there is a light easterly breeze in the am which is met and overtaken by the sea-breeze around 1pm. Sailing in that transition time can be very painful as it is light wind and shifty.
If you wait till the sea-breeze you don't need oversized sails. and if you sail into the afternoon you may be sailing in 15 knots and you certainly don't need oversized sails
I think if you improve your weather-man skills you would be better served.
If you keep a close eye on the overall weather you will know when we are under a strong High pressure and that is when we will have almost no wind. If we aren't directly under a H, and it's not overcast ... there is a good chance for a seabreeze. esp in apr/may early june before the water catches up with the mid day air temps
I can only speak to a few days sailing in the Saint Petersburg area last November. There were a couple of days where we would have put up all the sail that we could and more. We also had a few days with a good sea breeze. My son is 180 lbs and was on the trapeze a bit but not really hanging out. With the two of us, we didn't use the reefing points, but I would have put in a reef if I was sailing solo. I think the OP was suggesting having a dedicated light air sail as well as his regular stock sail. Makes sense to me. The dart was built for heavy winds; in my opinion 15 knots is just starting to wake the beast. I do like to push the boat hard; it's going to depend on the sailor's preferences and experience.
yes having different sails for different weather is a great thing (i own 8 differently sized sails for my mystere's).
i have found this very beneficial to depower in higher wind days. But unless i am trying to "beat" my buddies to the next island, oversized sails aren't that powerful of a sailing aid
but what i am talking about is: we have (very) variable winds here in the summer
light to non existent in the am - building to "more than enough" in the afternoon on a typical summer day
having extra sq of sailarea will make you a little faster than without - but it doesn't make your boat easier to handle, or require less technique in light air
2 - 4 knots of air - it's all technique at those speeds -
no extra sail area is "needed" in 10-15 unless you want to push the limits of your sailing skills and rigging
I think most of the OP's issues can be overcome by timing his sailing to days that aren't controlled by high pressure overhead and sailing around the known wind habits
I believe it is 1/3, 1/3 and 1/3
2/3 are spread out or applied to the "above the head" area
but i think the take away is at full hoist the mast compression would be only t (1/3rd the mast compression vs double without the system, or 50% with the hook) Edit: this is wrong and confusing:jeff96's compression is 1.5 t .
Edited by MN3 on Feb 04, 2020 - 06:25 PM.
This issue was partially addressed before on this site. My friend Joe does not "hook in" his Nacra 570 to top of mast but ties halyard down to bottom of mast where there are several jam cleats- I proposed doing the same with Dart 18 mast &/ or attaching main & jib halyards to 2 large chrome cleats i affixed to nere bottom of mast (approx 8 inches from bottom); because both main halyard and jib halyard are "hooked" and you cant release them when underway and if hit by a sudden squall or less u r SCR WED! Experts opined that either deviation puts too much stress on the mast! Solution and comments invited.
how much is too much is the real issue:
it is well documented and agreed that (see chart above)
- hooking the head of the sail at the top of the mast = t (or standard/stock compression - see above)
- securing a halyard around a turning block and back down the mast doubles the compression on the mast (2t)
- using a 2:1 in your system =1.5t or 150% of the hooked head
so sailing around cleated on the bottom of the mast is double the compression on your mast. put that in med/heavy air with 2 or 400 lbs on the wire and you are pushing your mast hard (again how much is too much is the real question)
using a 2:1 add's some compression (50%). spread out in 3rds. If you have reduced sail area /lowered the sail down, (thus reducing the forces on the sail) the 50% increase in compression shouldn't be that severe since the forces on the sail have been reduced
Edit: I think jeff96's solution has increased compression and not reduced forces when sailing fully hoisted but not certain of the actual physics since a maj of the load is slammed to the top of the system.
"reefing" isn't for sudden "anything"
reefing is to make sailing in heavier air manageable and much less prone to pressure related incidents
to reef: your clew, tack and head have been reset to a lower location - this requires some rigging adjustments to reset all 3 spots on your sail - your mainsheet and downhaul attachment points and halyard
and if you can't get your sail off the hook while wet / you need a more reliable solution
on my 6.0 i have a reefable main
if i am out and overpowered and need to reef i will either duck behind an island or find a lee off somewhere if possible - or i will anchor up
then i will take my main off the hook just like i was at the beach (it may take an extra attempt or 2 because the boat may be dancing on anchor but my 6.0 is pretty well tuned for this)
there is an inline spinlock to secure the halyard after it is off the hook and lowered to accommodate the lower position
Edited by MN3 on Feb 04, 2020 - 06:43 PM.
- hooking the head of the sail at the top of the mast = t (or standard/stock compression - see above)
I'm not sure what system you think I have. I use the 2:1 that you have sketched a few posts above. The compression force isn't going to jump higher if the hoist is fully up or down to a reef. The physics remain the same.
On the watertribe site, I brought this subject up. Here's what one of the members had to say about it:
My Cross 18 tri uses an old Hobie 16 mast, a Prindle 16 square top main, a large jib and small asym spinnaker. All on a fractional rig with line halyards for everything to jam cleats screwed to the mast base. Had her out in 35 knot winds several times, Reefed down tight of course, I have three slab reefs in main and a roller furling jib. Seems to be no trouble. I find compression bend is not an issue on older heavy duty beach cat masts. At least I haven’t found it troubling. Here she is on second reef main with all sail flying in 25 knot wind. https://youtu.be/u-0dRWxe5lU
Your results may vary.
my questions are about where the actual loads are spread out when your sail is
a. off the hook but fully hoisted like your set up and
b. where the loads are when the main is reefed and the 2:1 has a few feet of line in it
sorry for any confusion: math makes my head hurt
That light mast extrusion without diamond wires is a limiting factor. Coupled with the boat was never designed for more sail area, changes the sailing characteristics dramatically when you start messing with it. We experimented in the early 90's with more area via increased roach with pin top sails (squares weren't in favor yet). It resulted in snapping 2 masts and rudder cavitation in heavy air.
The Stampede 20 is really a different boat if you're looking to compare and yes, I've sailed several that were modified and the performance was negligible.
Here's my advice from a guy who's owned and sailed quite a few Darts (and absolutely loves the boat): Keep weight positioned correctly (forward) and have the boat tuned properly for light air - from standing rigging, battens, downhaul, keep the tramp tight, etc. If still lacking in desired speed and upwind ability, consider another boat. Above all, call me should you decide to sell that one - I've always lusted after the Tahitian color combo and it's like unicorns pissing rainbows of sailing bliss in anything over 15kts.
Agreed that a different boat would go faster in light winds. I like my Dart though, even though winds in Ontario can be light and flukey, unless they're strong and flukey. @Headhunter I find it surprising you were able to break a mast.
When we decided on the new dimensions for a square top, we superimposed our proposed sail plan over the old sail. Even with a 2' wide square top, there really isn't a lot more sail area. I haven't had the new sails all that long, but with a combined crew weight of 380 lbs, we drove our Dart straight through several waves. In heavy winds the crew has to move to the transom to keep the rudder in the water, but that was the case with the old sail too. Helm balance seems to be about the same as before albeit with a slightly oversized jib
Here's a novel idea....Add a gigantic screecher! Or Code 0 if you prefer.
Edited by flightlead on Feb 06, 2020 - 04:45 AM.
Flightlead Bimare F18 HT SpaceCoast