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Thread: Sail Seminar - Downwind Issues

  1. #1
    Join Date
    Sep 2007
    Posts
    2,541

    Default Sail Seminar - Downwind Issues

    Do you realize it's only four months to the start (plus a few days)? So let's have another seminar to help you along in your preparations - Monday, 2/15 at our usual haunt - the Oakland Yacht Club (Alameda). 1900 to gather, 1930 we'll start.

    Synthia Petroka, SHTP Race Chair in 2008, SHTP Division winner in 2006, Pac Cup DH Division winner, and sailmaker extraodinaire will present her "world-famous" SHTP Sail Selection and Repair Seminar. Don't miss it!

    Whomper or twins? With those twins, would you like one whisker pole or two? Code Zero or flat reacher? Snuffer or net? End-for-end or gybe with two poles? Outgrabber or thong? Boxers or briefs? So many decisions - Synthia will have all the answers!

    Plus what you should have in your sail repair kit and how to use it.

    Questions? SHTransPac@yahoo.com
    Last edited by BobJ; 02-17-2010 at 06:33 PM.

  2. #2
    Join Date
    May 2009
    Location
    Novato
    Posts
    122

    Default Thanks!

    Thank you Synthia! Thank you also to the SHTP vets and R/C who came to lend support and share their experience. The dialogue helped me resolve my one remaining sail selection quandry, and even though we got caught short with time, the sail repair information and advice was really great. So thanks again Synthia and the rest of the gang.

    Paul
    Culebra

  3. #3
    Join Date
    Sep 2007
    Posts
    2,541

    Default Twin Headsails

    As things were winding down at the seminar, Paul asked about twins and whether they were worth having, vs. flying a spinnaker as much as possible and winging out a jib the rest of the time (I think that was how he asked the question). So here are some random thoughts and experiences using twins:

    1) I have assymetric spinnakers so I'm not able to sail quite as deep as the symmetric-spinnaker boats. Once you're in the trades (basically the second half of the race), it's all about downwind VMG to Hanalei. When it was really windy, I was tired, or late at night, the twins allowed me to get excellent VMG with virtually no effort or drama. Of course I could always get better VMG with the spinnaker but I had to sail higher angles for speed which, when it was windy (20+) meant I was more likely to broach. As Greg has said, this race is not about sailing as fast as you can, but sailing fast for as long as you can.

    2) If you have symmetric spinnakers you need to test and see how hard you can push in the ocean. I believe your spinnaker flying time will be significantly limited if your autopilot cannot steer the boat reliably in "windvane" mode, preferrably to the True Wind angle (vs. Apparent). You may want twin headsails if you aren't confident the boat can handle flying the kite without your constant attention.

    3) In terms of sail area, twins will get you more bang for the buck on a masthead rig (obviously). When planning your setup remember you are trying to get projected area - you want whisker poles as long as your rating and sail size will allow. To borrow Synthia's term, "elephant butt" due to shorter poles gives up projected area. On the other hand, the flatter you get the headsails the more stress is put on the poles.

    4) I used the Forespar "Line-Control" poles so I could adjust their lengths. The downsides are they are heavy, they don't telescope without sticking (no matter how well you clean and lube them) and they aren't designed to end-for-end so when using a single pole, gybing it is awkward. However you don't have much choice if you want a pole you can use with multiple sizes of headsails, plus the storage issues.

    5) This race really puts your pole track to the test. Make sure the screws are tight, you keep checking them during the race, and maybe take some big plumbers clamps or similar to strap the track to the mast if it starts coming loose. (This may affect your ability to reef the main however - best to watch the screws!)

    6) In 2006, I used approx. 112% LP twins made from nylon and flown from a common luff (i.e. "butterfly twins"). I bought them used, otherwise I would have had twins with a longer LP. I used a single whisker pole which in my experience largely defeated the sail handling benefit of twins - the ability to gybe without having to go forward.

    7) For the 2008 race I used 155% LP twins and two poles. This allowed me to project a sail plan 35 feet wide on a 30 foot boat! I hoisted the two #1 genoas together in the twin grooves of the aluminum foil of my Harken furler. To avoid chafe on the genoa sheets, I attached them to the clews with Yale "Loups" (Dyneema), then clipped the pole jaws into the Loups. I also put a short strop at the tack to lift the sails slightly, reducing the chafing of the sails' foots on the pulpit. This was a great setup - until I broke one of the poles.

    8) When sailing with the twins, you can pick up additional boat speed by sailing a bit higher (than DDW), to get some wind flowing across the sails. You have to experiment and watch your instruments to see what angle results in the best VMG. Remember, it's all about VMG to the Tree!

    9) If you sail higher you will ease the windward whisker pole forward. This slack in the sheet will allow the pole to sky a bit, opening the leech, and you will be tempted to rig a downhaul on the pole. If you do, rig it from the tip, not from the middle - otherwise you will snap the pole like I did.

    10) Similarly, it is possible to dip the pole into the water on a big enough roll - a pole downhaul or foreguy would not be wise in those conditions.

    11) With twins and a reefed main, you can blast right through windy stretches, get some rest and be reasonably assured of not breaking anything. Combined with the autopilot in wind vane mode, you can sail right through a squall with the boat pretty much taking care of itself.

    12) Again with two whisker poles, you can gybe at will by just turning and bringing the main across. This is great when it's really blowing. Imagine gybing your boat solo in the Slot, in big waves - you will do this on every significant shift in the trades (if you want to be competitive).

    13) On larger boats with symmetric kites, a sock can take a lot of the drama out of gybing. Pole forward, sock most of the sail, gybe the pole, unsock the kite on the other side. Be careful about combining a sock with a spinnaker net - it's very easy to get a tangled mess up there. (But now I'm getting into another subject.)

    Any comments from others about twins?
    Last edited by BobJ; 05-02-2010 at 11:41 AM.

  4. #4
    Join Date
    Sep 2007
    Location
    Capitola,CA
    Posts
    1,656

    Default

    Bob really covers the downwind issues. A couple of further thoughts:

    1) When running twins, one really needs a topping lift for both poles. A spare masthead or staysail halyard will work as there is not a lot of load. Topping the outboard end of the pole(s) in squalls frees the leech and depowers when on verge of control. Also helps keep the bow downwind.

    2) The inboard end mast attachment for twin poles needs to be separated from each other by 12-18". Or risk breaking a pole as they come together during sail handling.

    3) However strong one's pole track is attached to the mast, it is not strong enough. I doubled the number of fasteners.

    4) 1.5 oz. ripstop nylon a strong, forgiving, and inexpensive material for twins. (It can also be slippery when stepped on.)

    5) Hoisting twins can be a chore. WF's two twins had hanks that I staggered, and used baby yarn to stop both sails in preparation for hoisting. Same thing can be done w/ headfoil: yarn stops run thru small grommets along the luff.

    6) Difficult to practice w/ twins due to lack of manuverability in SF and Monterey Bay traffic, proximity to shipping and coastline, and running out of "runway." Solved practice issue by tying stern first to large (non-navigational) mooring buoy. While stationery, practiced hoisting, trimming, and lowering the twins, marking the sheets, finding chafe, foredeck dance steps, and taking photos to remind myself of the drill sequences. A reminder: 8 knots of wind when parked stern-first under sail is a pretty good breeze. Don't try this if TWS is over 15 knots and you aren't moving!
    Last edited by sleddog; 02-17-2010 at 08:31 PM.

  5. #5
    Join Date
    Jan 2010
    Posts
    235

    Default

    When using twins, I pole out the windward sail. It feeds air into the leeward headsail, which is trimmed more or less as if it were beam reaching. Looked at from above, looks somewhat like a trimmed symmetrical spinnaker attached to the headstay in the middle. Less rolling than with the 2 pole deal. My twins are 130% jibs attached to a common luff tape for my Gemini headstay foil.
    I generally use the twins at night when I'm anticipating squalls. Usually the night after being hit by a squall with the chute up!

  6. #6
    Join Date
    Jan 2012
    Location
    Santa Barbara Sometimes
    Posts
    166

    Default

    Santa Barbara Squall

    I’m regular crew on a J80 (Remedy) out of Santa Barbara and we raced in a CHRF event yesterday. It was a normal race except for a black-as-a tar-barrel cloud that loomed from the East and delivered torrential rain and then an extraordinary microburst as it passed. After rolling the jib (not an easy task), we were faced with a main on a boltrope with no reef points. Blowing the vang certainly helped but we remained overpowered. We had an exciting ride with powerful wind and unbelievably strong gusts that laid us on our ear a few times (round ups). Luckily the two crew with me were experienced and there was no panic as we white-knuckled off the wind surfing the suddenly-formed offshore wind waves. And then it was gone. The whole thing lasted a few minutes. But by the end, several boats had retired, at least one was capsized. We finished with a solid third place. Back in our slip, there was devastation: dismasted boats, unfurled and tattered jibs, junk floating in the water… The excitement made up for the fact that we ended up DSQ because we didn’t have a SBYC member steering… In fact, after that ride, it was kind of a funny ending.

    https://www.noozhawk.com/article/num...arbara_harbor?

    https://au.news.yahoo.com/video/watc...arbara/?cmp=st

    https://twitter.com/hashtag/microburst?src=hash
    Last edited by hodgmo; 09-04-2017 at 03:17 PM.

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