ahhh, good times with the tall rig...

If I recall correctly, the wind was switching around and we still had a chinese gybe when we had it sheeted in a bit. It was at that point we "let her fly".

Gotcha, makes sense. No purchase until you get past 2:1, even then, it wouldn't help if tied to the bottom of the mast. Hard to wrap my head around this today for some reason. Way too much blood in my alcohol system (and yes, I'm Irish)...

Mike

Actually, sheeting and/or traveling in increases the angle of attack. The goal being to increase the angle of attack to the point that the flow separates from the lee side of the sail and causing it to stall- resulting in a large decrease in power. The problem with this technique is that if the wind direction moves forward or the boat heads up to the point that the flow "re-connects" you will experience a large, rapid power increase.

If you bear off too far, the airflow will switch to clew first- i.e. sailing by the lee. It's doable, but not stable, so the potential for a flying gybe is pretty high.

After all depowering that can be done through tuning is done, reducing sail area is the safest and most effective next step towards depowering.

sm

Flattening certainly extends the usable range of a sail plan, but there always exists a wind speed where reefing becomes the only solution to keep sailing. Boats capsize with their crews in the wire, sails feathered and flattened.

I like the self-standing telescoping mast that Rob Denney devised. The mast top lowers with the sail, leaving no draggy mast tip up. The retracted mast also becomes stiffer, though, like in any telescope.

Not that I'm an expert, but if you were pointing into the breeze, couldn't you also drop the main?

What type of boat are you sailing.

I sailed in a Tornado regatta that blew 36 average, gusting 42 (confirmed). We ran very deep under kite, keeping both hulls in the water, crew on trap as far back as possible and myself leaning over the rear beam. Kite was eased a long way, main was sheeted reasonably tight with only a slight twist.

Gybes were ugly though. Only moving a few degrees through them and battling to keep the windward hull down after the gybes.

When you talk about depowering, I assume you mean, as far as the main is concerned, maximum downhaul and minimum outhaul. How about mastrotation - fully in? Reducing sail area is on modern F18s not an option since we don't have self-furlings jibs anymore ...

bingo! Ballistic guidance... good thing we never ran out of water.

I have the answer on how to handle survival conditions -- go out on a Wave and enjoy the hell out of it.
I remember a while back we were racing Waves in gusts to 45 mph at Lake Eustis. Downwind I was wishing for a longer bow.

Normally downwind you aim the Wave for the leeward mark. But, in those conditions you tacked downwind, sail all the way out. When a big puff hit, instead of heading down, like in a high-tech cat, you headed up to dump the air entirely. And when jibing, try to wait of a lull, and after coming about, instead of heading down for stability, do the same thing by heading up and dumping all the wind.
Upwind was just plain fun.
Rick

Yes, tension the sail to be as flat as possible- max outhaul & downhaul. In a true survival situation, drop the main and go downwind under jib alone. I saw one of the top H16 sailors in our area do this once a few years ago. We had to get to a tiny beach dead downwind that was situated in an area surrounded by pilings, bulkheads, and docks. Downwind under jib alone is no big deal. Its only when you have to try to go back upwind that it is an issue.

sm

when the wind was too strong for the first day of midwinters last weekend in pensacola we did some round robins on the waves Kirk had on his beach. Crazy fun. Wish I had the knowledge to tack a little downwind (I confirmed with Kirk beforehand about the DDW approach). I clocked 11kn downwind. I tried to get forward once but was soon corrected by the bows. Upwind it was fun- had to stay on top of things. You should have seen the waves on a downwind start in a 35kn puff!

I respectfully disagree with this analysis. Unless the combined force of the halyard and the cunningham are additively greater than cunningham alone, the compressive force on the mast proper seems identical. However, the distribution of the load is across *both* the halyard and bolt rope/luff rather than the luff/bolt rope alone (i.e. Cunningham and hook). The consequence of having a halyard distributing a portion the load would be probable loss of mast curvature and consequent increased chord on the main. (i.e. force distributed along the main halyard and the mainsail luff, vs only mainsail). Additionally, given the impressive shaping curvature of modern cat masts, the main halyard force could wedge the halyard into the boltrope channel, possibly jamming the bolt rope and placing an uneven load on the mast near its maximal point of flex. (I'm thinking that would be a bad thing in a big breeze.)

My advice? Make sure your hook works easily, Take down the main (if you can), roll it, stow it, and sail with your jib and your mast. I have found that in a 35kt breeze an infusion mast is a respectable storm sail...

The original analysis is correct- the compression on the mast doubles if you support your mainsail by using a halyard that runs up the mast and is then secured at the bottom. Instead of thinking of the halyard and luff of the main independently, think of them as one continuous line. Negating the friction of the sheave at the mast head, the tension in the line would be equal throughout the length of the line. So, since the line travels up the mast and back down, there are essentially two falls. Pull on the downhaul with 400lb and that equates to 800lb of force on the axle of the mast head sheeve compressing the mast.

It is the same as having a block and tackle with a 2:1 purchase.

sm

That makes more sense to me now. Thanks.

So, in truly tough conditions, is it best to round up, drop the main, and then continue w jib vs trying to manage the mainsail?

Not as much fun though and not nearly as fast!

Here is some stuff I wrote here a while back. If you use the 'search feature" you will find more. Bon Chance. Chris

Have you ever seen a plane fly backwards? or stalled?
Sailing stalled out (falling in an airplane) with managed projected area (twist or travel) is the key to reducing the excess of wind power you are experiencing. Every notice how slow it is when the crew oversheets the jib, he is depowering/STALLING the sails.
Have you ever seen a plane fly backwards? Sailing stalled out with managed projected area is the key to reducing the excess of wind power you are experiencing.

I addition to getting your weight back, pull your main traveller (& jib) near the center of the boat with minimal twist(sheet in tight), steering ALMOST Dead Down Wind. The closer the mainsail is to the centerline the smaller the projected sail area to the wind reducing wind force and pitchpoling. This sail configuration puts the sail in a STALL, like an airplane falling through the air NEGATING lift.

For steering DDW try using the following (3)three indicators,
that kind of 'check and balance' each other.
First, the bow wind indicator.
Second, pay attention to the feel on helm.
You can maintain a very slight weather to neutral helm with the sails stalled out.
If the helm goes a lee you WILL eventually jibe,
so push the helm away from you to get back to neutral helm.
If the weather helm helm increases pull the stick to get back/close to neutral helm.
Finally, with the jib strapped in (stalled) watch which side the jib FAVORS, as it oscillates
back and forth (how it behaves) out of the corner of your eye, and react accordingly.
This is useful when it is raining so hard you can not see the bridal fly.

Looking behind you, often helps, as you can sheet in before the puff (dark water)
hits you. Its fun watching the other boats go over next to you, as they let OUT their sails.

when the sail stalls and the effective shape looks like a big fat wedge whose lee side isn't bending the wind near as much as you'd like, so the lift (component of the force at right angles to the apparent wind) is much less and the drag (component of the force parallel to the apparent wind) is excessive. The combination of the two is smaller and points aft, robbing the boat of the drive.

The above has kept me upright in registered 40kn wind in the "Round the Island" Florida race on a H20.

**************************************
So downwind try sheeting in the jib in the puffs to stall out.
To depower more travel in the main to reduce projected sail.
To depower more and stall out reduce twist(sheet in)
and enter the 'Stalled Out Zone'.
(CAUTION sailing stalled in winds under 20nt is SLOW)
**************************************

All the above goes out the window with nuclear, gusting shifting winds which arbo was talking about. The winds were very unpredictable because they were shifting so much. We traveled in but had a surprise gybe which nearly took us down. If your wind is from a constant direction, it would work but not when you have gusty shifty winds.

Our situation was also made worse because we had the tall rig (6' taller than stock). With the buoyant bows of the Supercat, I was more concerned about unexpected gybes than pitchpoling which we came really close to once. While the strategy worked with my boat does not mean it would work with every boat. Part of sailing is to know the characteristics of the vessel you are sailing. Our strategy worked because we made it to Key Largo with no flips, failures or broken parts.

Exactly, when the wind is blowing steadily from the same direction with a constant speed - more or less like the relative wind speed in an airplane - it becomes feasible to manage a larger sail area.

About mast compression, just see the picture:

Did anybody manage to retrieve the main sail on the water in heavy wind? I imagine it being very difficult to keep the boat head to the wind (heavy wind = high waves) sufficently. We can't furl the jib and the crew will be too busy to get the main down to hold the jib backwards.