Anchoring sea in high wind

[Fuss]

Originally Posted by boatpoker

Surprised you haven't had a pile of chain wrapped around your anchor.

Water is not air, if you dump it fast enough it will glide forwards.
I always anchor as if I’m just about to go on the rocks, that means no care for paying out slowly, nothing done carefully. Strong winds is easier. Just dump fast, let the winch scream until the required meters are out, snub it and give it some astern. I’ve never once had a pile of chain on the anchor.

[noelex 77]

Originally Posted by NYSail

Drop almost the wanted scope and let the boat settle back letting wind do all the work.

When setting the anchor the best technique is to deploy the chain at approximately the same rate as the boat is drifting backwards. It is important not to put any force on the anchor before you have deployed a reasonable scope because you will drag the anchor backwards and collect debris. At the same time you don’t want to dump the chain in a pile, as some are advocating (although this has nothing to do with whether or not you use the clutch).

If you rapidly dump the chain it will look something like this on the seabed:



There is a risk that the chain can foul the anchor (especially if you going slightly forward when dropping) but even if this does not happen, when the boat moves backwards it will create a sudden snatch load on an anchor that is completely unset. An unset anchor prefers a nice progressive increase in force to start to dig into the substrate. An anchor that is moving at any speed has a very difficult time attaining the initial bite into the substrate.

In a good substrate anchors (especially modern designs) are incredibly forgiving and will set no matter what you do (the Bruce in the above photo set very nicely despite the poor technique, see photo below) so it is possible to use these practices and believe they are working well. However, in poor substrates deploying the anchor with the best techniques will produce significantly better results. As we never truly know the quality of the substrate,` routinely dropping with the best technique is sound seamanship.

[/QUOTE]

[boatpoker]

For those that like to anchor with the dump it all method ...

[carstenb]

When we find our spot we starttje anchor down while putting the boat in low reverse unless of course there is wind or current making this unnecessary

We have never had a chain around the anchor problem when we set the engine lightly in reverse

[Lodesman]

Originally Posted by Fuss

Water is not air, if you dump it fast enough it will glide forwards.

Interesting theory. In practice, I don't notice much of a glide with the Rocna - and I dump it as fast as it can pull chain out of the locker. I think the direction of any "glide" would be highly dependent on the design of the anchor, and whether or not its orientation changes on the way down. In other words, it's just as likely to glide aft.

[Panope]

Originally Posted by Lodesman

Interesting theory. In practice, I don't notice much of a glide with the Rocna - and I dump it as fast as it can pull chain out of the locker. I think the direction of any "glide" would be highly dependent on the design of the anchor, and whether or not its orientation changes on the way down. In other words, it's just as likely to glide aft.

I have often used a "dump and yank" deployment technique in my 8 years of anchor testing of almost every relevant anchor design. Result: as long as the anchor is "let go" with little resistance from the windlass or any other part of the system, they almost all "fly" just as Fuss indicated. The direction of travel changes little from the initial orientation.

One exception to this is the aluminum Fortress anchor when heavy chain is used. In the initial part of the drop, the anchor will begin "flying" in one direction, then it will change directions as a result of the chain "overtaking" the anchor (chain goes deeper)

I suppose any anchor could experience this "chain overtake" given enough depth and an extremely low friction chain deployment system, like a nicely flaked pile on deck.

On the other hand, there are likely many anchor systems that have too much "built in" friction to be able to "fly the anchor" at all.

Steve

[Naughty Cat]

If you don't know how long it takes you to drop 5m and 10m of chain, find out.

As helm, you will get over the intended spot, your crew will start to drop the chain, and the anchor will hit the sea bed a while later. Knowing what that while will be will be the point at which you can start to drift back.

I see many a boat start the drift when the anchor starts to drip. 15 seconds later the anchor glances the sea bed whilst being dragged backwards. Some time later there is enough chain to enable it to set.

As a helm, start counting when the drop starts and just taking the power off when the anchor is due to.meet the sea bed. You can even turn off the wind to let the wind do the drifting for you (but sounds as though this happens naturally in any event).

As an example I am 7 seconds for every 5 metres off the windows, and I have 2m fretboard, so it is normal 10 seconds plus before the helm starts to drift backwards.

In France, you will.often see them dropping.anchor whilst appearing to be moving forwards. Actually, it is what happens when the anchor hits the sea bed a few seconds later that counts.

[Lodesman]

Steve, I believe the anchors might assume a stable orientation, but don't buy that they would generate enough forward "thrust" to fly more than a couple inches, especially pulling chain. Maybe with a rope rode and enough depth.
The previous picture with the chain piled up by the anchor would support that.

Just thumbing through a couple of your videos, I got a screencap that shows the moment of 'touchdown' with the anchor chain coming up a few inches along the shank, suggesting the anchor maybe "flew" a couple inches backwards:



In your test video #99, around the 8 min mark, where you see the anchor descend with the camera opposite the chain. When it hits, you can see the chain briefly pile up before straightening out with the movement of the boat. If the anchor was 'gliding' both the camera and chain should have been on the same side - don't you think?

[Lodesman]

Originally Posted by Naughty Cat

I see many a boat start the drift when the anchor starts to drip. 15 seconds later the anchor glances the sea bed whilst being dragged backwards. Some time later there is enough chain to enable it to set.

What depth of water are you anchoring in, if it takes 15 seconds to hit bottom? And how fast do you accelerate in a drift?

[s/v Jedi]

Again, all these problems are caused by not using the clutch. I also notice an obsession with knowing exactly how much chain is out.

If you anchor on your comfortable scope a couple times and set the anchor with the engine, you can tell if you have enough chain out just by looking at the angle of the chain while pulling in reverse.

Another thing that upsets me is people using a GPS (!!!) while setting the anchor to see if it’s holding or not. Please, no!

The counting seconds for chain is useful after tightening the clutch, for fine tuning the scope. I often also visually follow a link from windlass to the water surface and know how much length that is.

[Panope]

Originally Posted by Lodesman

Steve, I believe the anchors might assume a stable orientation, but don't buy that they would generate enough forward "thrust" to fly more than a couple inches, especially pulling chain. Maybe with a rope rode and enough depth.
The previous picture with the chain piled up by the anchor would support that.

Just thumbing through a couple of your videos, I got a screencap that shows the moment of 'touchdown' with the anchor chain coming up a few inches along the shank, suggesting the anchor maybe "flew" a couple inches backwards:



In your test video #99, around the 8 min mark, where you see the anchor descend with the camera opposite the chain. When it hits, you can see the chain briefly pile up before straightening out with the movement of the boat. If the anchor was 'gliding' both the camera and chain should have been on the same side - don't you think?

Perhaps it was misleading of me to use the word "fly" when describing this phenomena because as you imply, the "glide angle" is very steep.

But, the point that I was making, is that the anchor can indeed move horizontally with enough distance to not have chain pile onto it (assuming the boat is stationary).

As to the video snapshots, the Rocna shown in video #85 is in only 6 or 8 feet of water (not enough depth to glide far), and we do not know if the boat was moving during the drop.

For video #99 at the 8 minute mark, it appears that the anchor (17 lb. Mantus) did indeed "fly" far enough to avoid having chain piled onto itself. But, again, we do not know the motion of the boat.

I am basing my thoughts about how anchors glide/fly by observing the behavior first hand during the deployments.

Disclaimer: In this discussion, I am not advocating for or against any particular anchoring technique. Am am only discussing a particular nuance (that anchors can descend at an angle sufficient to avoid having chain piled on them)

[noelex 77]

As Steve has indicated, the Mantus M1 with its large fluke area typically “flies” forward perhaps 3-4m in 10m of water. This can be annoying if trying to hit a small patch, but the stable "flying" geometry means it invariably lands upright and leaves the chain behind. This means it can then fall to the correct side, eliminating the chance of the anchor needing to roll completely from one side to the other in order to set. This is one factor that helps ensure consistently short setting distances.

The Rocna is much less predictable. It has a steeper fall, and sometimes lands on its side, but will typically land slightly forward of the drop point. The convex plow anchors tend to drop straight down and can land in a very awkward way, which probably accounts for the fouling problems reported with these models.

Note these results will obviously vary depending on chain size, speed of drop, depth of water etc etc, but do not expect anchors with a large fluke area to drop straight down.

[s/v Jedi]

Let me describe another problem I often see with boats that don’t use the clutch: in reasonably calm conditions, they manage to keep the boat stationary enough so that the slow feeding of chain is good enough. But now they are piling chain onto a heap as well, because they are focusing on chain markers to find the right marker that they have determined is the correct scope.

Once the boat starts moving back, there is nothing slowing it down and it gains momentum. Then, when the slack chain runs out, instead of digging the anchor in properly, it gets janked/twisted, flying after the boat and often not digging in correctly.

When you use the clutch, let the movement of the boat pull the chain out. It should stop paying out, then the first tuck feed a bunch more then stop again. Contrary to claims from those not using the clutch, this is how it works also with smaller anchors.

Then once you have 3:1 scope out, carefully tighten the clutch a bit more to start digging in the anchor in a controlled manner. Tighten more and more as you feel the anchor having a good bite and at some point movement of the boat stops and you will move forward again. Now start thinking about which scope you want to anchor at and use the electric up and down buttons to adjust scope, set the snubber, feed out enough chain to allow the snubber to stretch, then set the chain stopper. You do have a chain stopper, right? If not, make one from Dyneema.

[Lodesman]

Originally Posted by Panope

For video #99 at the 8 minute mark, it appears that the anchor (17 lb. Mantus) did indeed "fly" far enough to avoid having chain piled onto itself. But, again, we do not know the motion of the boat.

Again, if the anchor was "flying" forward, how did the camera stay ahead? My take is the boat was making very slight sternway, as was the anchor.

Originally Posted by Panope

I am basing my thoughts about how anchors glide/fly by observing the behavior first hand during the deployments.

Risk of observational bias. If your boat making any sternway, it will look like the anchor 'flies' forward, from your perspective. Maybe a controlled experiment is in order.

[noelex 77]

Using the windlass clutch and powering out the windlass are both valid options for letting out chain in a controlled manner when deploying the anchor. Rather than one technique being superior, they are both useful options.

The major advantage of using the clutch is that it can deploy chain rapidly. It is also a more automatic process. Adjusting the clutch to the desired force means chain will slip out whenever the force is sufficient.

The major drawback of the clutch is that if the chain becomes partially trapped in the locker the chain can stop paying out unless considerable force is exerted. This is not ideal in the early stages of deployment when the anchor has minimal scope and therefore minimal grip. Placing even a mild force on the anchor at this stage may drag the anchor backwards.

The chain can become partially trapped when chain pile falls over when sailing. This traps the links closer to the anchor near the bottom of the chain pile. The extent of this will vary depending on the design of of the chain locker and size of chain in relation to the anchor size.

Generally the best anchor deployment is achieved using both the clutch and powering down, depending on the conditions and stage of deployment. If you limit yourself to one technique you are missing out on some advantages. When the wind is strong and the drift rate of the boat exceeds the deployment rate of the windlass using the motor is a time when often the clutch method is particularly beneficial.