Squall Strategy?

[Bash]

Originally Posted by maersi

Obviously, the rudder was losing effectiveness, but can't be sure why. Being partially out of the water seems the most logical reason.

When the rudder starts losing effectiveness like that, it often means that the boat is getting close to broaching.

[CapnBrown]

That's a no brainer that a broach is coming because you can no longer control the angle of the boat to the wind right? Through what's been said here I think the answer is most likely that the rudder is being lifted out of the water as the rig is pushing the bow down (while running down hill as well). I would think coming nearly to a stop in the trough could allow the vessel to lose steerage as well. I would think staying out of the trough would be a good tactic and possibly ensuring any sail area up is as low on the rigging as possible (which is typical anyway) and maybe less on the mast and more on the fore stay would be preferable?

Is there a way to set the fore stay storm sail in a way that would lift the bow? Just thinking of the physics and how to take advantage of the high winds to keep the rudder in the water instead of out...

If there are other dissenting views of the belief this loss of control is from the rudder being lifted please feel free to chime in... So far we have one alternative being that the water flow from astern running in the same direction as the boat catches the rudder and effectively kills the flow traveling from the bow aft due to forward boat speed. Has anyone else experienced such a thing.

I can't imagine being in the situation that it's very clear what all the dynamics are and all your focus is on where to steer to prevent it from happening again...

[barnakiel]

No HUHs here.

A squall will bash a hobo and the family guy just the same. A hobo can only survive while an army of family men exists. A squall can only be dangerous, if there are ANY boats on the water.

Thinking inside the box is just as valuable as thinking outside of one. And everybody is capable of both.

b.

[Hudson Force]

Originally Posted by barnakiel

No HUHs here.

A squall will bash a hobo and the family guy just the same. A hobo can only survive while an army of family men exists. A squall can only be dangerous, if there are ANY boats on the water.

Thinking inside the box is just as valuable as thinking outside of one. And everybody is capable of both.

b.

Help me inderstand this. I usually find your posts very clear, but I'm asking, "HUH?" Hobos & family men in and out of the box with squalls that are harmless with nobody there? Help me understand, please.

[Bash]

Originally Posted by CapnBrown

That's a no brainer that a broach is coming because you can no longer control the angle of the boat to the wind right? Through what's been said here I think the answer is most likely that the rudder is being lifted out of the water as the rig is pushing the bow down (while running down hill as well). I would think coming nearly to a stop in the trough could allow the vessel to lose steerage as well. I would think staying out of the trough would be a good tactic and possibly ensuring any sail area up is as low on the rigging as possible (which is typical anyway) and maybe less on the mast and more on the fore stay would be preferable?

You're complicating a fairly simple phenomenon. A downwind broach happens when the the bow suddenly doesn't want to go as fast as the stern does. Yes, moving weight to the stern helps, as do such strategies as towing a drogue. However, these are not really squall strategies. A squall is a short-lived, localized phenomenon. It's unlikely to build significant seas of its own. One does not need storm tactics for a squall, nor would one normally switch to storm sails prior to a squall.

Like the man said, when you see a squall, break out the shampoo.

[Paul Elliott]

I've experienced difficulty steering in three situations:

Breaking waves on the stern -- Entering San Francisco bay, sailing over the entrance shoals with small breaking waves. These were perhaps three or four feet, and due to the current and shallow water the tops were breaking and plunging. Whenever a wave would hit us the rudder feel became very light and had little steering effectivity. If anything, the rudder was steering us in the opposite direction. I believe this was due to reversed flow over the rudder, caused by the breaking wave. We were sailing pretty slowly, and if we had been going faster we probably would have retained steering ability. Fortunately we had sufficient directional stability that we stayed on course.

Downwind in big quartering seas -- Here, gravity was the culprit. As the swells would lift our stern before lifting the bow, gravity would try to force the stern to slide down the face of the swell. In this case the side-force on our large unbalanced rudder became huge. It took a lot of force at the helm to keep the boat from turning broadside to the swells. The helm-feel was completely opposite from the flow-reversal situation. Our rudder was effective, it just took some muscle.

Downwind in strong wind with the symmetrical spinnaker flying. This sail is intrinsically unstable, and requires quick and careful reactions to "keep the boat under the sail". When it gets out of control, the spinnaker ends up on one side of the boat, heeling us over and trying to spin us around until the wind is on the beam. Here, we have an extremely heavy helm, and in the worst case, the rudder is lifted significantly. In our case the rudder is still in the water, but the normal turning force is now being directed in a mostly downward direction and so becomes ineffective in steering the boat. If we have jibed during this fiasco, the prevented boom is keeping the mainsail up in the air, which is also keeping us pinned down on our side. Once we lose most forward motion the helm becomes light, but by this time we are frantically trying to get the spinnaker down and carefully bring the boom across.

Of course, the only part of this that is squall-related is perhaps the spinnaker crash, since tradewinds squalls usually bring a quick wind-shift and doubled windspeed (which can trigger the spinnaker crash).

My point is that the feel of the tiller or wheel can tell you what is happening to the rudder.

[Rakuflames]

Originally Posted by Bash

You're complicating a fairly simple phenomenon. A downwind broach happens when the the bow suddenly doesn't want to go as fast as the stern does. Yes, moving weight to the stern helps, as do such strategies as towing a drogue. However, these are not really squall strategies. A squall is a short-lived, localized phenomenon. It's unlikely to build significant seas of its own. One does not need storm tactics for a squall, nor would one normally switch to storm sails prior to a squall.

Like the man said, when you see a squall, break out the shampoo.

That's the best explanation I've ever seen of a broach.

However (I'm sure I'll get flamed again) it depends on the waters you're in. If you're in shallow enough water, the waves can build rapidly. Combine that with a relatively small boat (and a reefing system so inadequate that it's basically imaginary) ... and you CAN be broaching in a squall.

Boy I learned a lot that day ... shortly after I had started sailing.

[goboatingnow]

Stuffing the nose , situations where excessive speed down the face of a wave cause the bow to partly enter the face if the wave in front , as was said the stern is now trying to go faster then the bow = broach


There are situations where the water speed over the rudder is reduced , outside of boat speed, these are when you find yourself in a " jet " of water ( tops breaking , full or partial wave breaks etc )

Other times its usually boat speed related or rudder aerating

Dave

[Rakuflames]

Originally Posted by goboatingnow

Stuffing the nose , situations where excessive speed down the face of a wave cause the bow to partly enter the face if the wave in front , as was said the stern is now trying to go faster then the bow = broach


There are situations where the water speed over the rudder is reduced , outside of boat speed, these are when you find yourself in a " jet " of water ( tops breaking , full or partial wave breaks etc )

Other times its usually boat speed related or rudder aerating

Dave

Thank you. I'll try to make sure I never do that!

[Paul Elliott]

Good point about the rudder aerating. This happens when you are trying to turn hard and the water no longer flows smoothly across the rudder (it loses "laminar flow"). You may feel the rudder getting light, and you lose steering ability. The cure is to straighten out the rudder some, and let the flow re-attach, then start turning again. You usually end up "pumping" the rudder as you find the best compromise between too much and too little.

[barnakiel]

Originally Posted by CaptForce

Help me inderstand this. I usually find your posts very clear, but I'm asking, "HUH?" Hobos & family men in and out of the box with squalls that are harmless with nobody there? Help me understand, please.

Nothing. At #55 and above. My thoughts re that part of the thread (extended version):

Whatever sort of sailor we are, we can only get hurt if we are out there. And if we are out there, we may get hurt irrespective of our thinking habits.

Those who believe in luck (good&bad), call this factor luck, some others call it coincidence.

Sometimes it is our skills that get us thru a squall, sometimes it is our skills that may get us hurt in a squall.

The X factor. The fate. The quantum cat.

Doh,
b.

[Blue Crab]

Physicists build a “quantum cat” out of light

[CapnBrown]

Paul, fantastic descriptions. About the relation of rudder control (or lack thereof) to a squall discussion is that in an unexpected or ill prepared encounter it will leave you having to pick a tactic. The one I'd chose might suffer a broach while running and trying to douse the fore sail. So understanding whether short breaking waves can cause a reverse or stagnant flow at the rudder is important IMHO.

I guess I'd amend my tactic to resort to heading up if I felt the reduced pressure on the wheel and the threat of a broach was significant. (Note to self...)

[Hudson Force]

Originally Posted by barnakiel

.................. Sometimes it is our skills that get us thru a squall, sometimes it is our skills that may get us hurt in a squall. ...............
b.

Thanks for your clarification. I did interpret this as the pervasive quality of your post, but I did need the clear picture. I agree, but I also understand that we will all respond to such an event with a skill or strategy. Squalls are usually short-lived and I admit that I'm prone to head up and grab the shanpoo, but then I've had surprises too. My surprises have been those brief few minutes, or maybe one minute that seems like a few, when the wind screams and you lose the interface, - that time when you can't see the line that distinguishes the water from the air and everything looks like smoke. At this time there is no reference for strategy, but it's always been gone in a moment for me (a moment that seemed like a minute) and I'm back in the real world were the water is separate from the air. These are those times when strategy is what you did in the past and your chance for more strategy will be after the event. Maybe these are those rare times when you are within a waterspout. I don't know what they are, I don't see them coming and I've only had a couple, but they suspend my ability to act.

[barnakiel]

Yes. So many aspects.

Like being able to quickly drop or furl the canvass.

b.