Photos of Anchors Setting

[Don C L]

Well, I know they have a loyal following, but the only anchor I ever saw drag was a CQR. By the way, on one particularly windy day I had my Columbia 24 anchored (I know, it is a small boat but...) and I thought I'd dive down and check to see how my Danforth was doing. I had about 50' of chain and then nylon rode, maybe 100' of that out in 20 ft of water or so. The anchor was laying patiently to be buried in the sand but the chain had fallen over some rocks and one link was jammed in the rocks. That was it, that was all it took to hold the 5000# boat in about 15 knots at least for the afternoon. Naturally I moved the boat back to better holding ground, but I slept even better after that.

Don

[JPA Cate]

Thanks, NB, it's really neat to see all the pics!

Ann

[noelex 77]

Sorry, there have not been any other boats in the anchorage till this one. It was dropped by a private boat that stayed overnight, 5m @ 7:1.

It is only a Delta, but it is interesting in that it shows the effect of the Delta rotating. This was only a slight change in wind direction of perhaps 30 degrees.

Unfortunately I did not get to see the Delta before the rotation, so this is the after shot only. From the third photo you can, however, see the original angle of the drag and corresponding mark of the chain. The Delta is very good at setting level and it is a reasonably safe assumption that it would have been level before the rotation. You can see it has developed a very high list despite the the slight change in the direction of pull.

The anchor will very likely just dig in and once again rotate nice and level with a bit more force in the new wind direction. However this high list does make the anchor more prone to breaking out during the rotation. A sudden gust at the wrong time when the anchor has got one fluke high in the "air" can break the anchor out completely. Once an anchor starts moving and sliding backwards it is reluctant to dig in, although with this nice soft substrate it would need to moving at some speed for this to happen.

Rotation is a very underrated aspect of anchor performance. A lot of anchors break out during a wind shift and these sort of results show why. Some anchors frequently rotate like this. In most cases the anchor resets and the owner never realises there is problem.






You can see the original chain mark in this photo illustrating the change in direction of pull:

[noelex 77]

The wind has been shifting around. It has moved about 120 degrees.

The Mantus has rotated about 15 degrees at this stage. The fluke has scraped away some of the sand as it has moved. When the chain is leading off at 90 degrees like this the anchor tends to develop its maximum list. The Mantus has only a very slight list and it is very close to how it looked when originally set.

Ideally you want an anchor to shuffle around with a minimum list staying buried without sticking one side of the fluke high up in the "air". The Mantus is only in the early stages of rotation here, but is doing well.

[downunder]

Originally Posted by noelex 77

The wind has been shifting around. It has moved about 120 degrees.

The Mantus has rotated about 15 degrees at this stage. The fluke has scraped away some of the sand as it has moved. When the chain is leading off at 90 degrees like this the anchor tends to develop its maximum list. The Mantus has only a very slight list and it is very close to how it looked when originally set.

Ideally you want an anchor to shuffle around with a minimum list staying buried without sticking one side of the fluke high up in the "air". The Mantus is only in the early stages of rotation here, but is doing well.

Great photos again.

I guess rotating wind is a situation that will test an anchor and if the flute is jammed in a rock is when the strength of the shank will be tested. Do you recall the situation when you bent the lower grade shank?

Cheers

[noelex 77]

Like nearly all shank bends, it was during retrieval. The Mantus had set very deeply in response to some strong wind (about 45 knots over two days). There was wave action (onshore breeze) during the retrieval which unfortunately created snatch loads.

The new ATSM 514 shank is supposed to be almost three times stronger. We are coming up to the season for big winds so I am sure it will get a good workout.

[ImaginaryNumber]

Originally Posted by noelex 77

I picked up the new shank today. It arrived quite a while ago, but I anticipated a much longer delivery time so I was some distance from the nominated island.

Anyway, the ATSM 514 shank is now bolted on. It looks identical to the previous shank. It is welded both top and bottom on the foot (unlike the top only welded shanks on many anchors). Hi tensile steel is a bit harder to galvanise than mild steel, but the galvanising looks just as good as on the old mild steel shank.

The new shank should be almost 3x stronger than the previous shank.

Noelex,
How long was your old shank in service before you changed it for the stronger version? Was it difficult to remove the bolts, or to otherwise disassemble the shank? Was there any rust either between the shank and blade, or between the bolts and internal threads? Did you use any sealant when re-assembling the anchor to prevent rust? Is any special technique used to prevent the bolts from coming loose (loc-tite, wire-ties, jam-nuts, lock-washers)?

[noelex 77]

Mantus supply some grease and lock washers for the bolts. The bolts are galvanised as is the underside of the shank. There was no rust. They all came off easily, but it was only four months. (Although the anchor was used everyday during that time)

[NornaBiron]

Bit of thread drift here but it demonstrates the importance of digging your anchor in adequately.

Last night at 7.30pm the wind was gusting to 20 knots in Pethi on Symi, Greece. The anchorage is deep and the holding is not the best (it's a bit ploughed). A Turkish flagged yacht started to drag towards us so we called for someone on-board. A man popped his head up, the skipper had gone ashore for dinner, and the man (his uncle) was very inexperienced and completely oblivious, and spoke very little English. We fended off as the yacht hit our bow and slid away down our side, taking out our aft quarter solar panel as it went. We manage to throw a line and tie the boat to our stern thus holding him from blowing onto the rocks. We held him for an hour until the skipper returned from town.

We were very concerned about the extra strain on our 45kg Spade - we had set in 23m and had 80m of chain out, luckily it held well until the skipper returned.

The yacht was a Jeaneau 46 with a 25kg Delta and 50m of 10mm chain. He set in 17m of water with short bursts of full power astern, but when the wind shifted 180' he swung into 25m of water thus causing him to drag.

We know from experience that this anchorage is not good and that there are often fierce gusts into the bay, therefore a good anchoring technique is essential, even if only staying for a few hours.

Unfortunately we didn't get any photos of the anchors as my merman can't free dive 23m and it was dark :-)

[noelex 77]

Sorry to hear about your problems.

Dragging boats are a real menace. For the first five years of full time cruising we averaged over one hit a year by a dragging boat. This is despite taking all the precautions.

We have been cruising areas with predominantly private boats for the last few years. The quality and size of anchors is much better, as is the skill using them. Touch wood we have not been hit for over two years now, but luck obviously plays a roll.

Viewing other boats anchors underwater is a big help. With a little practice looking at how well the anchor is coping with the substrate and taking the size and scope into account you can take a reasonable stab at what wind speed is likely to cause them trouble.

[NornaBiron]

Originally Posted by noelex 77

Dragging boats are a real menace. For the first five years of full time cruising we averaged over one hit a year by a dragging boat. This is despite taking all the precautions..

Wow, you were unlucky, we've only been hit twice by dragging boats in six and a half years of full time cruising.

[noelex 77]

Originally Posted by NornaBiron

Wow, you were unlucky, we've only been hit twice by dragging boats in six and a half years of full time cruising.

No one wants to hit a steel boat

The worse experience was a demented single hander who hit our bow, but also tangled our anchor chain. He decided the best way to fix the problem was to motor around at full speed while tethered to our chain. In ever decreasing spirals he came closer and closer to hitting us for the second time. This pulled out our anchor and we both slowly dragged down wind.

[JPA Cate]

Originally Posted by noelex 77

No one wants to hit a steel boat

The worse experience was a demented single hander who hit our bow, but also tangled our anchor chain. He decided the best way to fix the problem was to motor around at full speed while tethered to our chain. In ever decreasing spirals he came closer and closer to hitting us for the second time. This pulled out our anchor and we both slowly dragged down wind.

Panic is a terrible thing! And keeping calm enough to calm someone else when your own boat is threatened----- well, I'd say pretty d--ned hard to do.

Yucky experience. What did you take away from it? Any ideas about how to handle it if it happened again?

Ann

[JPA Cate]

Originally Posted by NornaBiron

Bit of thread drift here but it demonstrates the importance of digging your anchor in adequately.

Last night at 7.30pm the wind was gusting to 20 knots in Pethi on Symi, Greece. The anchorage is deep and the holding is not the best (it's a bit ploughed). A Turkish flagged yacht started to drag towards us so we called for someone on-board. A man popped his head up, the skipper had gone ashore for dinner, and the man (his uncle) was very inexperienced and completely oblivious, and spoke very little English. We fended off as the yacht hit our bow and slid away down our side, taking out our aft quarter solar panel as it went. We manage to throw a line and tie the boat to our stern thus holding him from blowing onto the rocks. We held him for an hour until the skipper returned from town.

We were very concerned about the extra strain on our 45kg Spade - we had set in 23m and had 80m of chain out, luckily it held well until the skipper returned.

The yacht was a Jeaneau 46 with a 25kg Delta and 50m of 10mm chain. He set in 17m of water with short bursts of full power astern, but when the wind shifted 180' he swung into 25m of water thus causing him to drag.

We know from experience that this anchorage is not good and that there are often fierce gusts into the bay, therefore a good anchoring technique is essential, even if only staying for a few hours.

Unfortunately we didn't get any photos of the anchors as my merman can't free dive 23m and it was dark :-)

Norna B,

Did the skipper offer to repair the damage his vessel did to yours? He should be feeling EXTREMELY grateful to you.

It seems like you did everything right, and good on your Spade for holding both of you, that's always a worry.

[noelex 77]

Originally Posted by Ann T. Cate

Any ideas about how to handle it if it happened again?

Don't anchor downwind of demented sailors

The obvious solution was to ditch our anchor rode, but my wife and eye were busy running around trying to get fenders to whatever spot he was aiming for.

Eventually the other skipper saw sense (maybe our shouting helped) and we just rafted the boats up together and untangled the anchor chain, by slowly pulling up his anchor. The dragging stopped as soon as he stopped his full throttle manoeuvres.

He did not speak any English so I never got his story. There was no damage to our boat other than a tiny scratch and only a little damage to his where he hit our bow roller with the initial contact.