Photos of Anchors Setting

[twohapence]

Originally Posted by hoppy

I knew a Swedish engineer who at one point was involved in modifying the design of a bruce like anchor. His task was to also make it glide. Very handy in Sweden where the like to tie bow first to islands and use a stern anchor with a rope or tape rode

What was the result?

[JPA Cate]

Re: Post #2442:

Nice pix, hoppy. Thanks for the explanation about the swivel.

Ann

[hoppy]

Originally Posted by twohapence

What was the result?

I don't know how successful they were. At the time I knew him I didn't have a yacht and was not interested in anchors

[hoppy]

Originally Posted by skipgundlach

That explains the silver bar in the pic. And it's a nice self-righting tool.

But I'd still be nervous about side loading...

I have little choice. The bow roller setup on my bowsprit is a bit narrow, so the shackle I bought with suitable strength for my G70 chain would not fit. I had another high strength swivel last year but bought the Ultra over winter as it's stronger

[noelex 77]

I love watching anchors set. It is a great way to assess anchor performance.

In the lovely clear waters around here, this is quite easy. Unfortunately, it is a bit more difficult to photograph, as I need to be reasonably close. Diving around a boat with spinning props and bow thrusters when the skipper might not be able to see you or even know that your there needs to be done with some caution.

However, I thought you might want to see how an anchor behaves on smooth rock. This Delta was dropped by a private boat. They managed to drag the anchor a considerable distance (about 75m), before it finally found a crevice. They stayed the night despite our warning. The anchor started in about 5m of water with a scope of a bit over 3:1, but where the anchor came to rest was deeper and the scope had dropped to less than 3:1.

You can see what is happening in the photos, but a few things I would like to point out:

• The drag speed in this smooth rock was very rapid, at about one knot. At this stage many boats do not have a snubber in place and with all chain there is very little elasticity. If the anchor catches some solid rock, the stop is going to be very abrupt. Something is likely to break. Personally I always put the snubber on before I back down on the anchor, but I am in the minority.
• Notice how in a couple of the photos the toe is nowhere near the bottom. The anchor has no hope of setting even in a good substrate when this happens. The hydrodynamic force of the moving water seems to force the tip up (at least sometimes) reducing the effective toe weight. I think this is one aspect of anchor design that could be studied more. It would be helpful to have an anchor design where water pressure forced the toe down if the anchor was moving ie dragging it would be nice to get more pressure on the tip not less. Danforth and convex plow anchors seem particularly poor in this regard
• Learn how long your anchor takes to set. If it is taking longer something is wrong with the substrate or debris etc. The Delta can take a very long distance to set which makes this judgment harder, but it still should have been obvious there was a problem.
• The depth used for the scope measurement should be taken where the anchor is located. If your anchor takes a long distance to set the depth may not be the same as the spot where you dropped.
  

[kas_1611]

Could I be mistaken but it looks like their anchor float/buoy/tripping line isn't helping matters there. It appears to have a fair amount of tension on it but that could be an artefact of the anchor dragging rapidly through the water.

You'd be surprised at how many boats we see going several dozen meters backwards, into deeper water, in anchorages and often at quite rapid speeds who then wonder why they drag. Or worse who then think they are set. The only thing worse are those that drop all their chain while going forwards then just stop then wonder why they drag or swing into someone when the wind changes. Muppets.

Keiron

[double u]

"...but I am in the minority..."
most unfortunately also in your general attitude that anchoring in general is among the most important things while crusing...most unfortunate!!! (I don't care about the boats of the "chuck-in-the-hook-in-&-hop-in-the-dink-&-leave" fraternity - but they are andangering other people's boats!!!)

[hoppy]

Originally Posted by noelex 77

I love watching anchors set. It is a great way to assess anchor performance.

I'm waiting for the day when you solo drop your Mantus whilst SWL is in the water documenting the whole process

[noelex 77]

We did one a few years ago. It is amazing to see it gradually "snuggle" its way under the sand without otherwise moving. I should download it in a higher quality version. It was recorded in HD but YouTube seems to have downloaded it in a very low resolution format.

Mantus Anchor setting - YouTube

Edit this is a little better:

https://Vimeo.com/178320321

[hoppy]

This is yesterdays anchorage. A grassy bottom and the Vulcan dug in nice and quickly. I backed down at 2500rpm or so and it held fine.

Later in the day I guy (could be Finnish) who owned a motor boat on a mooring ball came up to all yachts anchored warning about the evening conditions where the wind swung to the west and picks up resulting in yachts dragging. After sunset a second guy came up to me as I was closest to the lee shore and also near the other guy motor boat. By this time the wind had swung 45 degrees.

I dropped another 10m of chain taking me to 6 or 7 to 1 and backed up again. This time it felt like I wasn't digging in. Maybe it was the darkness making judgement harder and I gave up whilst I was still taking up the slack, but I decided to abandon the anchorage. I decided to move to an anchorage that was only a short distance away but a 5 mile motor around an island to get to it. So in the dark I anchored 0.37 nm away. No lee shore until Crete so I could sleep soundly with the anchor alarms

I guess that with the grassy surface there is perhaps only a small difference between being dug in and dragging fast? A bit like divots on a golf course.








https://www.google.com/maps/@36.8608.../data=!3m1!1e3

[noelex 77]

This was the finish point of the Delta in post #2450:

[skipgundlach]

It appears that not very many anchors you dive on use shackles or a chain interval before their swivel attaches to the anchor.

Have you found any anchors which could have failed under those circumstances?

[sanibel sailor]

yes, pics have been posted of a few

[hoppy]

I spent the day lazy onboard after my night time relocation. Then in the late afternoon I grabbed my camera and went for a swim. When I got to the bow and looked at the chain I saw the horror of all horrors, a massive but clenching moment

The sight was so bad that rather than taking a photo, I immediately followed the chain to see what horrors awaited me. Thankfully there was nothing really bad further on. On my return to the boat I took some quick snaps as I was not in the mood to make an effort with the photos.


This is what held me last night..


no big deal


This could cause a problem


OMG I think I'm going to die


Overnight the wind stayed in one direction and if I had left by lunch time there would have been no issues I think. Later I swung around a few times and it ended like this.

A lot of different scenarios went through my head during the swim back to the boat.....

[sanibel sailor]

That's a convincer for all chain rode.