Photos of Anchors Setting

[GILow]

Originally Posted by noelex 77

This was a Delta in light weed. 7m @ 4:1.



They dropped several times and in each case the anchor failed to bite. On the final drop I think they realised that the anchor was not holding the reverse engine force and just let the anchor slowly come to a stop.



There was a long drag mark. The anchor has made some attempt to dig into the underlying substrate, but when feeling with my fingers the penetration was minimal.

This sort of weed problem, I am told, is very common here in South Australia. As a result the most favoured local anchor is the somewhat old fashioned stockless. I have been warned that my elderly sarca will give me grief here in the Gulf St Vincent. These photos seem to support that assertion.


Sent from my iPhone so apologies for weird autocorrect typos.

[noelex 77]

This was a fixed convex plow anchor. I think it was a genuine Delta.

The anchor was a little bent. The shank had a small but distinctive curve. The fluke was tipped down on one side so if the anchor was sat on a flat surface the shank would not sit upright.

It is important to realise that any anchor can bend. I have seen a lot of Delta anchors and this is a very rare problem. It is tough anchor overall.

The anchor was totally unset, but at this stage it had very little force placed on it. I did not see the drop, but it is likely the anchor was dropped with the boat going slightly forward. The anchor is facing the wrong way with a big loop of chain that ran around the weed then back to the boat.

Thick weed like this can provide quite a bit of grip on the chain alone (as this example shows) or on the anchor even when it has not penetrated into the substrate below. It is easy to mistakingly believe your anchor is good performer in weed because it consistently reliably holds the boat in light/moderate conditions. The reality in thick weed like this is that the chain and almost any heavy weight would provide enough grip to hold the the boat in light/moderate winds.

The real test comes in strong wind when the anchor needs to dig into the substrate below to provide enough grip.

[noelex 77]

The wind was forecast to increase to the low 30's. In practice, the average was a little less, about the high 20's (gusts of course will always be higher).

I have found that our setting technique of gradually building up to full reverse and holding this for 30 seconds is the equivelent of about 25-30 knots of wind (once again as an average, gusts will be higher). Less wind than this from the same direction and the anchor will sit unchanged, more wind and the anchor will bury more.

You can see in this case the Mantus has nicely buried a little more in response to the higher wind. It is always remarkable to me how the top anchors can dig down deeper while barely moving back at all. Before using the camera I often dropped rocks as landmarks. The concave rollbar anchors will typically bury significantly more while only moving back a couple of inches.

If you look closely at the photos there are some landmarks such as scrapes in sand that can be compared in the before and after pictures. Judge for yourself, but the movement to me looks only about an inch.

Some other designs will consistently move back many metres for the same extra depth of bury. I feel this is a bad characteristic that is not mentioned in anchor tests, or discussed on anchor threads.

The setting force is a means of testing the substrate where the anchor has buried, but an anchor that needs to move back a considerable distance from its initial setting position to dig deeper in response to stronger wind, is entering new ground. If hazards such as rocks, debris or even a thicker patch of weed exist in this path there is a risk of the anchor failing.

An anchor that can bury deeper in a short distance is less likely to encounter problems. Using an anchor model like this helps me sleep at night.

The distance required to bury deeper when exposed to stronger wind seems very closely related to the distance the anchor requires to set in the first place. This is one of the reasons why I am keen on anchor designs that routinely set in a short distance. This is easy judge for yourself from the photos. Holding power with a straight line pull as measured by conventional anchor tests is of course important, but there are many other characteristics that contribute to making an ideal anchor.

This is a reminder of how the anchor looked after just the setting force (see post #1967)




This was after the increase in wind, showing more bury with minimal movement back:

[noelex 77]

It is always nice to see other anchors respond to stronger wind. Unfortunately, everyone else left .

I don't think this was just a coincidence. The anchorage was not very well protected, only allowed for a shortish scope (we had 3:1) if you wanted to leave 360° swinging room, which was sensible given the thunderstorms predicted.

Looking at the other anchors I think the skippers made a wise choice to seek better shelter. However, we felt quite comfortable with the holding ability of our large Mantus and stayed. One of the major advantages of a top quality anchor, especially one that is oversized is the ability to safely stay in anchorages like this when it may be inconvenient to move.

Location is one of the key factors in determining if you are going to safe so It is important not to become overconfident. Even an oversized excellent anchor can and will drag in the wrong situation. However, you can significantly extend the range of conditions in terms of wind strength, substrate quality and scope ratio that can be safely utilised.

It is often thought that advantage of over specified anchoring gear lies in unusual situations such as when the wind is very strong, or when the forecasters have made a mistake or perhaps in an emergency situation such as when the rudder jams and you are drifting towards a lee shore. However, there are many simple common situations such as this where better anchoring gear simply saved us trouble and inconvenience.

The advantages are not just a hypothetical increase in holding power, but a practical change to what you can accomplish. It is little like owning a lifting keel yacht - it opens up anchorages that would otherwise be unusable. Something worth considering if you are debating spending the extra money on one of the better anchors, and/or the extra weight of going to an anchor that is larger.

[noelex 77]

This a FOB-HP anchor. It is a slight variant of a Brittany anchor.

The Brittany anchor is popular with French sailors. It is a pivoting fluke anchor a bit like a Danforth, but with a slightly more tapered blade and without the stock.

In my opinion it is not a very roll stable anchor. This one has developed a high list and has one fluke totally above the substrate.

I think the Danforth style itself is prone to sometimes developing a high list like this, but mainly when the direction of pull changes. Sometimes the anchor will break out, or partially break out when this occurs. The Brittany style appears a bit better at changing direction than the Danforth, but it still a fluke style anchor and in my opinion it does not rotate as well as other anchor designs.

[noelex 77]

This was a Delta dropped by a charter boat in light/medium weed. 7m @ 5:1.

This was another example where the the crew made several attemps to get this anchor to hold without success. On the final try I think they knew that their transits were changing and the anchor was dragging, but they just let the yacht (and anchor) grind to a halt.

It is worth persisting to get a good set. Even if your anchor is a poor weed performer there are usually patches where the weed is lighter. Weed is a generally a very inconsistent substrate as I hope the photo show.

[noelex 77]

This was a Delta in light/medium weed near the transition zone between sand and weed.

This one is at least trying, but it is scraping at the substrate rather than the fluke tip digging down in a convincing manner. Most of the hold is the accumulation of weed in front of the fluke. Even thinnish weed like this is quite tenacious so the anchor will at least (probably) reliably hold up to 20-25 knots or so.

[SVNeko]

Why all the little floats on the anchors? The lines aren't long enough to reach the surface and if its to assist in pulling a stuck anchor out, with such a short line it would seem just as easy to dive all the way to the anchor than get to the float. A number of the pictures showed the float fouled on the anchor which could affect its ability to set.

[SailRedemption]

Originally Posted by SVNeko

Why all the little floats on the anchors? The lines aren't long enough to reach the surface and if its to assist in pulling a stuck anchor out, with such a short line it would seem just as easy to dive all the way to the anchor than get to the float. A number of the pictures showed the float fouled on the anchor which could affect its ability to set.

I believe it was said a long while back, but...

The little floats, at least for nolex, is so the can see the anchors location easier. You see with these new gen anchors like Mantus, Rocna, Manson they can bury themselves with much ease due to their efficient design. This is a good thing for the boat but if your trying to document it, you need a marker.

Sent from my VS986 using Tapatalk

[noelex 77]

Originally Posted by SVNeko

Why all the little floats on the anchors? The lines aren't long enough to reach the surface and if its to assist in pulling a stuck anchor out, with such a short line it would seem just as easy to dive all the way to the anchor than get to the float. A number of the pictures showed the float fouled on the anchor which could affect its ability to set.

As SailRedemption has pointed out, the float is mainly so you can find and inspect the set of the anchor underwater (where diving is possible). Some boats also use the rope to secure the crown of the anchor while sailing (although I do not).

A non roll bar anchor will disappear as soon as the fluke and shank are buried. A rollbar makes the anchor visible even when well buried, but in a soft or weedy substrate even a tall rollbar can disappear.

It is rare for an anchor to be fouled such that it has to be pulled out backwards, but if it does occur attaching a line to the anchor is not easy. The suitable attachment points may well be buried under the substrate and threading a line or shackle through a small hole can be a struggle.

An underwater float makes for an easier attachment (if you have a loop near the float) and reduces the diving depth by say 1.5m. The latter does not sound like much but diving to say 10 m is significantly harder than say 8.5 m for most part time free divers.

Most anchors drop straight down and the risk of catching the underwater anchor float is minimal. The Mantus is bit different. If dropped in free fall it tends to "fly" in a stable upright position. This had the advantage of ensuring it always lands the same way, but the forward momentum does occasional trap the float underneath the fluke. I doubt this has much practical effect, but I have been experimenting with a couple of simple systems that allow the anchor to be dropped in free fall without any risk of the float getting caught. So far they seem to working well, but I would like to give them a longer trial.

[noelex 77]

A new anchorage and a patch of lovely soft sand.

Soft sand is not a good test of anchor performance, as most anchors will set very well. Typically the fluke and shank will disapear with just the setting force.

The holding power comes down mainly to the fluke area, although the fluke shape also influences the overall drag. The sophisticated design and geometry that is needed to penetrate hard and weedy substrates is not needed.

As you can see the Mantus has penetrated this substrate with the minimum of fuss. It has sliced through the soft sand so easily that the setting mark was difficult to make out. There is a complete absence of heaping up:

[noelex 77]

This was not only at the same anchorage, but quite close to our anchor.

In this anchorage there was soft sand, normal Med hard sand, weed and rocks all within a few boat lengths. Those that advocate carrying a multitude of specialised anchors would be very confused .

This was a Bugel. 8m @ 5:1. Despite the roll bar, the anchor has almost disappeared in the weed. The Bugel roll bar is only small, but it does illustrate that without an underwater float even a roll bar anchor can be hard to find on occasions regardless of how well it has set.

From the surface the anchor looks like it is doing very well, but when diving down you can see it is not quite as good as it appears. There is a reasonable list. In the thick weed I had some trouble feeling exactly what the tip was doing. There did appear to be some penetration of the tip which is always promising, but it was not much.

The Bugel is normally quite a good weed anchor, although it lacks some of the refinements of the later roll bar anchors. The anchor is missing the heavier tip and the skids or wings that are incorporated into the more modern variants. These refinements help anchors like the Mantus, Rocna and Manson Supreme penetrate the tip past the tough weed roots. On the other hand, the relatively small blade area of the Bugel that hurts the performance in soft sand/mud, is perhaps an advantage in weed, although the very thin profile of the fluke means the reduction in resistance is only slight.

The setting mark was only very short. It would have been good to see how the anchor performed with a bit more force applied.

Spot the anchor:

[JPA Cate]

^^^^Hi visibility paint on the roll bar, maybe? [Probably would eventually get scraped off. At least, we've buried our roll bar sometimes (Manson Supreme).]

Ann

[noelex 77]

This was the chain from the Bugel, just a short distance from the anchor.

I think many people imagine the bottom of an anchorage to be like a nicely ploughed and prepared farmer's field. While anchorages like this do exist, there are many more with all sort of rocks, bumps and hollows (like this photo) and unfortunately, man made junk. If you dive down, what looks flat from the surface is often anything but.

The best defence is too keep the anchor in one spot. The spot that has at least been tested with setting force. Keeping an anchor stationary is a revolutionary idea I know . Many anchor designs move around on the bottom more than people realise. Some models will commonly move several metres when they need to dig down deeper in response to stronger wind. Others rotate poorly and on occasions break out. Anchors with this sort of behaviour will often reset, but of course not in the same position. Relying on the substrate for a large distance around the anchor to be suitable and free of debris is a gamble that you are likely to lose at some stage.

Traditional anchor tests are conducted in areas with a very uniform substrate for obvious reasons, so this sort of behaviour has little effect on the result. I think we should give some consideration to selecting designs that can set quickly, dig down in a short distance and rotate, or "shuffle" with the lowest chance of breaking out.

[noelex 77]

Originally Posted by Ann T. Cate

Hi visibility paint on the roll bar, maybe?

Hi visibility paint is a good idea for lots of reasons. The only proviso is some galvanisers will not re-galvanise parts with lots of paint.

I like Spade's idea of painting the fluke area. The amount of fluke area buried has a good relationship to the holding power. Anchors often look like they are doing much better from directly above and anything to highlight the amount of fluke buried is a help. Unfortunately, it does not assist much in distinguishing between a fluke that has actually buried under the substrate and one that has just scraped along loose substrate and piled this material on top of the fluke. A fluke that has managed to dig under the substrate will have much better holding power than one that is just covered by loose substrate, even if they look very similar until you get down closer to the seabed.

Roll bar anchors have the advantage that even when the fluke or shank is completely buried the roll bar will only just be starting its bury, so painting the roll bar can really help visibility, but this is more for just finding the anchor.

Stainless steel anchors like the Bugel are quite a bit easier to see underwater. The stainless will often catch the sun and glint. Of course stainless steel does not need to be re-galvanised but it is hard to get paint to stick. I also cannot see any owner painting a beautiful anchor like the Ultra .

If you ever have to cut away your anchor it can be be surprisingly difficult to find. Many years ago I helped a friend who dragged in a horrific storm. He dragged, collided with another small boat (that sank) then dragged some more and collided with another boat when he cut away his anchor. We had the location of the sunk boat as a starting point. The anchor was large and stainless steel, and was attached to 100m of stainless steel chain. I thought finding it would be easy. With two of us searching with scuba gear we only just found the anchor before our air ran out. One complicating factor was the storm had reduced the normally excellent visibility down to only a few feet.