Sailing Downwind Offshore - how to stop rolling ?

[kiwin]

And I always put the pole on the sheet, not on the clew.

[justsammer]

Originally Posted by kiwin

And I always put the pole on the sheet, not on the clew.

Thanks very much. So to tension the leach as you described, do you set the pole in a lower position than the clew, and that forces the sheet to come into it a more downward angle? Or do you just make sure that the jib lead is forward enough to get the tension on the leach you want, irregardless of where the pole is?

[Jolly Roger]

Bermudian sails are not designed to go downwind, the pressure on the triangular sail is uneven, and even with a preventer pole the sail will frequently collapse, causing great strain on everything when it refills.
There is an easy way to sail downwind, without any of the problems of roll, pitch, broaching and steering. Not surprisingly, it lies in the history of tradewind sailing—it is a square sail.
I fitted one to the foremast of my schooner with the following benefits:
The boat hardly rolls at all because the pressure on the sail is evenly distributed through five different attachments on the boat, two sheets, two braces and the mast attachment.
I have run my squaresail in 40knt of following wind and a heavy sea, without any appreciable roll.
The sail will never collapse and there is no chance of broaching.
The course can yaw anywhere up to 20 degrees either side.
The steering is light and my autopilot loves it.
My squaresail is a somewhat complicated device, because the sail rolls up inside the yard, all controlled from the cockpit. Being infinitely reefable it is very safe to fly in high following winds, because I just wind a portion of it up.
I’m not suggesting anyone should go to these lengths. A simple telescopic pole could act as a yard, and the sail bent on with rope. It can then be hauled up the mast, using lifts on each side and center. If there is a track up the mast a slider with a simple rope gooseneck will hold the yard to the mast. There is also no reason why a sloop cannot be fitted with a squaresail either.
If you are planning a long downwind passage, it would be worthwhile making a squaresail. When I was first experimenting, I used a cheap tarp’ as a sail and it worked fine.
If anyone is interested in this, PM me and I will be happy to advise on any particular questions.

[kiwin]

'even with a preventer pole the sail will frequently collapse"
Uh...no. Just not true.

If the headsail fairlead block is moved as far forward in it's track as possible, this generally provides alot of downward pull. Obviously it's best to have a pole downhaul led forward as well, but it's possible to sail without it

[lo2jones]

This thread may be on its last leg, but…This is Downwind Sailing is the best book ever written on spinnaker sailing and handling a boat downwind. It is out of print, but is available on line. Every time I “loaned” a copy out, it was never returned at the sailing school where I taught for 30 years… If you use preventers, be sure to have a “weak link” that will break if the boat rolls and buries a spinnaker pole or boom. The pressure at 6 knots plus will probably break something so make it something cheap and replaceable.

[bgytr]

My boat is a 40 ft Hood centerboarder that draws 4 ft with the board up and 11 feet with it down. I put the centerboard halfway down if we start rolling which just about eliminates roll.

[Dockhead]

Originally Posted by barnakiel

Hi,

What are the best ways, any ways, to lessen monohull rolling on a down-wind ocean passage?

It is a small mono of older design and so she rolls quite a lot.

Which sail-combinations are known to roll less?

Will weight distribution help? If so, how to place the movable ballast?

Please let me know your advice.

Best regards,
barnakiel

Ha, ha. Barny, even big monos roll. Why God made cats, I guess.


I crossed the Atlantic this year on a 67 foot Discovery, and for several days of the passage, we rolled our guts out. There were really big storms about 10 degrees N of us, and big swells were coming down from the North, creating a confused sea state. You can't sleep or really hardly do anything in that state -- all my muscles were sore from trying to keep my balance. Even in my bunk. The rolling was as if malicious -- the boat heels over, then snaps back up and then over to the other side. Rinse and repeat. The g forces were impressive.


If there's something you can do to prevent this, I don't know what it is. Certainly no "sail combinations" helps anything. We were mostly under spinnaker.

[carstenb]

We've made a number of downwind passages and have never had an excessive rolling problem.

WE pole the jib our to windward and set a reefed mainsail. The genua pole is set with a line from the pole forward to the bow, another line aft to the midships clamp and then we use the spinnaker halyard as an uphaul for this, creating a triangle that holds the pole exactly in place.

We can adjust the position of the pole by tightening/slacking the uphaul or then line to the midships clamp.

WE rig a block at the end of the pole and run the jib sheet through that, thereby negating any chafe issues.

With this rig, we can reef the jib just as easily as we can it is flying normally.
We normally sail at about 30 degrees off the wind and no rolling issues

[meirriba]

I would check for the specific boat you are going to cross with, what angle downwind gives the best VMG to your next point of destination.
You may find that even if your next waypoint is exactly downwind, you have better VMG sailing higher.
I can tell from my experience when crossing the Atlantic that while we sailed ddw, for several days, every noon, we crossed paths with another similar yacht that jibed downwind. We had similar VMG, but we rolled and they did not...

[lo2jones]

If you don’t know what is a “polar diagram,” do some homework and find out. Then search your specific boat make and model for a polar diagram that someone has posted. Some manufacturers post diagrams that work well. Sailing down wind in less than 18 knots, it is a good rule of thumb to sail 20º or higher off off the. To test your own boat, sail DDW then head up until the jib is just full. That should be the sweet spot for the fastest and most comfortable downwind sailing.

[donradcliffe]

I have crossed the Atlantic downwind twice, and each experience was different. Much like crossing the Pacific, there are weather systems between you and the poles that can generate large swells that are at an angle to the current wind. The amount of roll is largely dependent on the difference between your course and that of the swells.

A main and poled out genoa are theoretically and factually more stable than a spinnaker, and a lot more controllable for the autopilot.

In my experience, a genoa alone will roll more than a main and poled out genoa, but may be safer in very high winds

In my experience a double headsail with one side one a pole and no main or a twizzle rig will roll less than a main and poled out genoa. It also is easier on the autopilot because the center of effort is further forward. In theory, it allows you to line the boat up with the swells without fear of accidental gybes, but there also seems to be some aerodynamic damping from the flow across the sails.

From over 10 years of racing cruising boats under jib and main, the best VMG is achieved by sailing wing on wing at a true wind angle of about 170 degrees unless the windspeed is under 5 knots.

[Na Mara]

Plus one for sailing angles downwind.

It’s more comfortable with less rolling and the boat will typically sail a bit faster. The apparent wind will move forward letting you sail 20-30 degrees off the apparent wind whilst being only 15-20 degrees off the true wind. You will also typically find that there is a making course (like there is typically a making tack), that will let you hold to a course through the night, keeping gybes to the daytime.

Finally, gybing from one broad reach to another is really easy. Hold course, center the main and tighten up the lazy runner (if you have them). Gybe through 70-80 degrees taking the Genoa over to the other tack. Release the lazy runner, let the boom off downwind as far as the rig allows, put the preventer on, and bring the boat off the wind until just before the main blankets the foresail. Auto on and make a cup of tea. If this is too exciting for you roll away the foresail, gybe under main alone and then roll out the foresail again once on track. If you are a real worrier then in all but the harshest conditions you can always tack around instead.

You will find that you will always be (almost) as quick to your mark sailing like this as making a DDW beeline for it. the sailing will be more comfortable and the steering more manageable and kinder to you equipment. There is also no messing with poled out for sails and no deck work. And all for the price of an occasional gybe/tack-around and a squiggly track on the plotter.

No brainer for me at least.

[meirriba]

Originally Posted by donradcliffe

From over 10 years of racing cruising boats under jib and main, the best VMG is achieved by sailing wing on wing at a true wind angle of about 170 degrees unless the windspeed is under 5 knots.

Have you raced different boats or only one all that period?
In my experience the best VMG angle (in any direction, also for DDW, depends on the boat hull shape and the sails wardrobe (e.g. relative size of jib vs. main and of course type and size of gennaker/spi)

[Cloroxbottle]

Originally Posted by Mariano

Buy a catamarán......[emoji48][emoji48][emoji48][emoji48]

Curious to hear from anyone who swapped their standing rigging from stainless to dyneema. Theoretically this should reduce weight aloft by a bit. Does it change how the boat handles, rolls, or performs in any way?

[TrentePieds]

@ #57:

A joy to read — quintessential common sense :-)!

Cheers!

TrentePieds