Preventer -- and an accidental gybe

[fxykty]

Originally Posted by markxengineerin

How do you furl your jib in heavy weather, with no main up to blanket it? I have done this ok with the staysail (head up a little to reduce pressure, then furl w/ winch before the flapping gets too out of hand) but can't imagine doing similar with the much larger genoa and in the conditions of a surprise squall. The above is not a quick process. Contrast this to heading up (likely to have already happened by itself in these situations) and simply dropping the main halyard, much faster, lazy jacks to catch the mess no matter how it comes down. The additional controls I'm referring to are the preventers, the traveller, lazy jacks, the halyard. None available or practical with the jib. Some will say "not available and also not necessary", but I don't know, I like having options and haven't had the "main only, sail downwind" strategy fail me yet in winds of 20 30 knots, doing hull speed or greater, seemingly in good control. Natural and strong weather helm seems like a good thing when a squall pops up.

Why headsail only rather than mainsail only for stronger wind downwind sailing? Because downwind you cannot depower a mainsail instantly, while you can let a jib/genoa sheet fly to instantly relieve the wind pressure of a monster gust. And an inadvertent gybe with headsail only will not risk your life nor your boat’s rig.

You say rounding up is safe, but in 30 knots TWS your AWS dead downwind will be in the low 20s. Head up to 60* AWA and your AWS will be well over 30 knots. Doesn’t seem very safe or comfortable to me. A recent CF thread described how two people died while doing exactly that.

If you do sail downwind with mainsail only then you should know how and be capable of reefing your mainsail off the wind, as well as dropping the sail completely. If you don’t know how to do either of those two things then learn how and set your boat up for it ASAP.

With a furling headsail alone you should be able to furl the sail on any point of sail - a larger boat or stronger wind will mean using a winch on the furling line. And the gentlest way to furl a headsail in any strength of wind is to turn downwind so as to maximally reduce the AWS. It’s certainly not to turn up to a close reach and to let the sheet (and sail) flog while furling.

[Don C L]

Hmm perhaps the debate of main or no main has more to do with the boat, conditions and tolerance for gybe risk. In my own case I’ve grown more conservative so I am fine doing 6 kts under headsail alone vs. 7 with the main up. Some boats are more squirrely Ddw as things pipe up. I hate having round up and reef the main so I’m good with main furled at 20 kts with my little boat. But broad reach? Then I am less conservative. Some time back I had to run home in 20-25 kts and my daughter was sick in my lap the whole way. I didn’t even raise the main, just the jib to leave the anchorage, and it was easy, fast and undramatic… and I was doing 6+ kts. As with most things, it all depends.

[donradcliffe]

The solution is to reef early and reef often. Once you have the sail area small enough that an accidental gybe won't destroy things, head up a bit and put the autopilot back on.

Wing and wing is not an unstable sail configuration. It is more stable than main only. If the boat tends to round up, the poled out jib will help the autopilot bring it back downwind.

Even safer and more stable is no main at all, as the center of effort is further forward, and the boom position is controlled by a tight mainsheet.

[markxengineerin]

Yea I don't think it's a black and white issue, depends on the boat and the operator. Reefing early and often sounds fine, but what do you do when you're asleep at the wind goes from 20 to 50 knots in a matter of seconds? It's not realistic to predict and react to this in advance, better to have the boat set up in a way that it handles the situation by itself. With a reefed "main only", I believe my boat will heel immediately and head itself up into the wind. I have not tested this theory in 50 knots, but this is based on how it reacts to smaller gusts in this configuration. I don't know what would happen with the genoa only. With equivalent sail area, I expect it would be slower to round itself up(?). I'm not in the cockpit to release the sheets, that will be maybe 30 seconds later.

I have not tested my furling gear by trying to winch it without blocking the wind w/ main first, but based on the loads to do this with the much smaller staysail, I half expect to break something if I tried. I have pro-furl furlers and am less worried about those than the turning blocks/line, which are cantilevered on stanchions/bow rail. I'm sure someday I will have the opportunity to test this setup, but for now, I try to avoid.

If you do sail downwind with mainsail only then you should know how and be capable of reefing your mainsail off the wind, as well as dropping the sail completely. If you don’t know how to do either of those two things then learn how and set your boat up for it ASAP.

The lazy jacks can be an issue here- they can't be dropped if the main is pinching them against the shrouds, and if they are not dropped out of the way, they catch the battens @mast as the sail tries to come down. I don't know a good solution for this, as I generally want the stack pack "up" when there are any reefs, or when dropping the main is imminent, for containment. The solution I've used is to just head up enough that the main is not pressed against the shrouds, but this violates your stated requirement "any point of sail". Ideas?

[CarinaPDX]

Running dead down wind with main only is a black and white issue: it is necessarily unbalanced and subject to severe yawing with gusts. The boat will make a difference in the response to this situation but the forces are there. Since you appear to be an engineer work out the vector diagrams with CE and CLR for yourself or take a class in sail theory.

Wing and wing is not necessarily unbalanced but in practice it usually is. Again, if you work out the torque vector with the main's CE against the CLR, it is almost always much larger than the offsetting torque for the jib, even if the jib is larger (because the CE is well forward of CLR). It takes a really big foresail, like a spinnaker, to balance a full main. Of course it can be done by putting two or three reefs in the main with a typical full jib forward but the extra drive is minimal, and still has the issue of getting the main down when things pipe up. Next time you are out with wing and wing check your helm and see how much you are fighting the imbalance (and adding drag).

Greg

[Bali43Cat]

Multi-Hull guy here but perhaps the same applies...

When we run DDW especially in high/Open Water seas - I set the autopilot to its max performance/sensitivity. During our crossing from Cape Verde to St. Lucia we had 2 weeks of DDW. Early in the trip we were getting a few close calls (not a huge deal with a German Rig)...then I upped the autopilot setting and wallah a noticeably more responsive, smooth, and safe experience.

If you have that option I strongly recommend.

[jt11791]

I just sailed 1000nm from St Lucia to Panama all DDW with a poled out genoa and the autopilot driving. We saw winds in the upper 30s and 4M seas at times, but mostly about 20kts and 2M. My autopilot (Raymarine Evolution) did best with the response level set to the lowest. Wing and wing is very stable for my boat, except for the rolling which does get tiresome. If your autopilot can't steer DDW well, either your sails are out of balance, or you need a better autopilot. The modern IMUs are amazingly good and can out-steer most humans.

[Smokeys Kitchen]

Originally Posted by Don C L

Hmm perhaps the debate of main or no main has more to do with the boat, conditions and tolerance for gybe risk. In my own case I’ve grown more conservative so I am fine doing 6 kts under headsail alone vs. 7 with the main up. Some boats are more squirrely Ddw as things pipe up. I hate having round up and reef the main so I’m good with main furled at 20 kts with my little boat. But broad reach? Then I am less conservative. Some time back I had to run home in 20-25 kts and my daughter was sick in my lap the whole way. I didn’t even raise the main, just the jib to leave the anchorage, and it was easy, fast and undramatic… and I was doing 6+ kts. As with most things, it all depends.

This echoes our point of view. We are out for a good time, not a hard time.

[fxykty]

Originally Posted by markxengineerin

…

The lazy jacks can be an issue here- they can't be dropped if the main is pinching them against the shrouds, and if they are not dropped out of the way, they catch the battens @mast as the sail tries to come down. I don't know a good solution for this, as I generally want the stack pack "up" when there are any reefs, or when dropping the main is imminent, for containment. The solution I've used is to just head up enough that the main is not pressed against the shrouds, but this violates your stated requirement "any point of sail". Ideas?

Change your lazy jacks so that they don’t catch your battens on the way down! I can’t imagine how the forward leg could catch battens at the mast end but if that’s happening, change it so it doesn’t. We have LFRs on our shrouds about 1m above the gooseneck to keep the down legs of the lazy jacks away from the back of the mast.

It’s not my requirement that you can reef on any point of sail - it’s basic seamanship for offshore sailing. If you’re not going offshore (no big swells) then do whatever you want, the consequences are much lower.

[markxengineerin]

I agree the lazy jacks need to be improved, it's on the list, but I haven't figured out a good way to do it yet. There are 2 issues that I think must be common (?)
1) Windward lazy jack catching the main sail cars as they slide down, since that line is pulled across the mast as the boom is fully to leeward when going downwind.


2) Not pictured, but easy to imagine: Leeward lazy jack is entirely pinched between the sail and lower leeward shroud, when the main is let out all the way. This prevents it from being lowered, if I wanted to, temporarily, to solve problem 1. Now that I'm typing this, I guess I could lower just the windward one, hadn't thought of that, but it would double the amount of lines I need to run back to the cockpit. Now I have one line that controls both sides (up) and another single line to pull them both down at once.

What are LFR's?

Both above problems are solved by having the lazy jacks in the stowed position while sailing, but that isn't helpful for the already noted reasons. I want them up when reefed, to contain the sail.

[fxykty]

LFR = low friction ring. They can be used instead of blocks for either short travel high load (such as adjusting a running backstay or backstay) or long travel low load (your lazy jacks for example).

If you can, move your upper turning blocks for your lazy jacks from the mast to your spreaders - half way out works well. And lead each down leg to the base of the mast via a LFR on your shroud. Both those things move the lazy jacks away from the mast and prevent them catching mast flakes. We have four-legged lazy jacks set up like that and have no trouble lowering our main for reefing or dropping on any point of sail.

People often lower and stow their lazy jacks to prevent them chafing their sail. Ours are from bare Dyneema, which is slippery and doesn’t chafe, so we keep them up all the time.

Your reefing/lowering technique needs to change to work off the wind, as your mainsail should not be tight against the rig. Use your traveller to move the boom to centreline or near to that (a bit less if close to DDW to prevent an unwanted gybe mid-manoeuvre). Then use alternate lowering of the halyard until the sail just lays back against the rig, then take in the reefing line to pull the mainsail clew down and the rest of the sail back off the rig. Repeat three or four times until the sail is reefed. It’s not hard, but probably different to what you’re doing now.

[markxengineerin]

The main is touching the aft lowers anytime I'm downwind, as I think is the case with most boats. It's enough to prevent the lazy jacks from being drop-able in a care-free guaranteed way, maybe it would work if I changed where I'm grabbing them with the "downhaul" line, not sure, but I don't imagine this problem is going to completely go away. The more robust solution seems to be to just head up on a closer reach until this isn't a pinch-point anymore rather than insisting on reefing dead downwind.

I don't love the idea of potentially putting a downward force in the middle of the spreader. It's not designed to take that type of load. Normally there would just be the small force to support the lazy jacks/stack pack, but since we are talking about unusual/worst case scenarios, what happens when the topping lift is broken or too loose, or maybe the main halyard breaks? I don't want the spreaders to slip, that would be even more disastrous than having to head up for reefing. I still don't think these are black and white issues, just playing devil's advocate because I haven't figured out my own preference yet.

[carstenb]

here's what can happen when a boom brake is fully tight

https://www.cruisersforum.com/forums...be-268555.html

fortunately we got out of this OK, but it cost us $4000 for a new traveler etc