Damaged anchor?

[Benz]

I saw an aluminum Spade shank bent into a corkscrew by being violently worked out from under a coral shelf, and a Rocna with a shaft bent sideways by a windshift in a Typhoon. Rocna was set deep in mud for a day or so of hard wind, then the wind shifted and blew hard again from another quarter. The water was shallow there (less than 2 fathoms), so the strain on the rode and snubber must have been fantastic to dig it in that deep.

[Panope]

Originally Posted by Benz

I saw an aluminum Spade shank bent into a corkscrew by being violently worked out from under a coral shelf, and a Rocna with a shaft bent sideways by a windshift in a Typhoon. Rocna was set deep in mud for a day or so of hard wind, then the wind shifted and blew hard again from another quarter. The water was shallow there (less than 2 fathoms), so the strain on the rode and snubber must have been fantastic to dig it in that deep.

Benz, the Rocna that you witnessed MIGHT have been from the batch that were manufactured with lower strength metals, as the higher strength shanks appear (to me, anyway) to be almost indestructible.

One of the Rocna Anchors that I have was manufactured with the shank misaligned with the fluke (the attach hole is 1 inch from center line) In an attempt better align the shank, I used an 18 foot long lever and all of my strength and body mass (running start). Although the shank was deflected at least 3 inches, it sprung right back to its original position. It acted like a leaf spring. I was never able to change the shape of this shank in a measurable amount.

Bomb proof Rocna 20kg:

[s/v Jedi]

Originally Posted by Panope

Benz, the Rocna that you witnessed MIGHT have been from the batch that were manufactured with lower strength metals, as the higher strength shanks appear (to me, anyway) to be almost indestructible.

One of the Rocna Anchors that I have was manufactured with the shank misaligned with the fluke (the attach hole is 1 inch from center line) In an attempt better align the shank, I used an 18 foot long lever and all of my strength and body mass (running start). Although the shank was deflected at least 3 inches, it sprung right back to its original position. It acted like a leaf spring. I was never able to change the shape of this shank in a measurable amount.

Bomb proof Rocna 20kg:

And you gave up before even getting the come along out? Hahaha

[Panope]

Originally Posted by s/v Jedi

And you gave up before even getting the come along out? Hahaha

The F-250 truck was lifting off the ground!

[s/v Jedi]

Originally Posted by Panope

The F-250 truck was lifting off the ground!

Definitely requires a Ram

[Benz]

Originally Posted by Panope

Benz, the Rocna that you witnessed MIGHT have been from the batch that were manufactured with lower strength metals, as the higher strength shanks appear (to me, anyway) to be almost indestructible.

One of the Rocna Anchors that I have was manufactured with the shank misaligned with the fluke (the attach hole is 1 inch from center line) In an attempt better align the shank, I used an 18 foot long lever and all of my strength and body mass (running start). Although the shank was deflected at least 3 inches, it sprung right back to its original position. It acted like a leaf spring. I was never able to change the shape of this shank in a measurable amount.

Bomb proof Rocna 20kg:

It's surely possible--it was on another boat we were in company with, so the provenance of the anchor was unknown. Still, even though it bent it held in the first Typhoon to go through the Bering Sea (Merbok, 2022) in time out of mind.

[thinwater]

I asked around at a local very large marina, and the staff that serviced the boats assured me that the vast majority were damaged while docking. If you looked at the rollers and railings, it was pretty obvious. They ran the anchor into the dock. This was at the big boat end of the marina, where there would be a LOT of momentum involved. Smaller boats, probably other causes.

[thinwater]

Originally Posted by Panope

6 anchors have bent during my anchor testing.

1) A Viking 20kg rollbar was bent backward during a straight line pull (5000lbs) in Sandy Mud. Rollbar required welding during the repair. (sorry, no picture).

2) A Mantus M1 17lb. rollbar was bent backward during a straight line pull (600lbs) in Soft Mud. Rollbar was pushed back into position by hand/foot.


3) A Mauntus Dinghy anchor rollbar was bent backward during a straight line pull (600lbs) in Sandy Mud. Rollbar was pushed back into position by hand.


4) A Fortress FX-16 shank was bent sideways during a highspeed reversal test in Sandy Mud. I am 99% sure that no objects other than mud and possibly clam shells were touching the anchor during the bending event. Shank was replaced under warranty by the Factory.


5) A Quickset 22 lb. (Stainless Steel) shank was bent sideways during a highspeed reversal test in Sandy Mud. I am 99% sure that no objects other than mud and possibly clam shells were touching the anchor during the bending event. Shank was bent back into place using a come-along winch.


6) A Viking 7kg. Fluke toe was bent downward during a straight line pull (1000lbs.) when lodged against an large, immobile boulder. Fluke was bent back into shape, however, the metal was severely compromised.

Interesting.


1. It is very unlikely a boat with a 20# anchor would ever see 5000#. 1000# would be unlikely and only during a huricane. Pretty amazing it held that much!

2 and 3. I bent several Mantus roll bars at high load. They are large and very light. Thankfully, easy to repair or replace. But I never bent one in regular use. Or any anchor.

6. A 7 kg Viking is unlikely to see more than 500-800 #, but a failure at 1000# is concerning. I'm surprised, based on construction.


I have one dock mate with a bent Delta. He told me he did it on a dock.

[Panope]

Originally Posted by thinwater

..........

1. It is very unlikely a boat with a 20# anchor would ever see 5000#. 1000# would be unlikely and only during a huricane. Pretty amazing it held that much!

............

That was a Viking 20 KILOGRAM (not pounds), so perhaps not quite so far fetched.

Looking at the Viking sizing chart, they indicate it is good for a boat up to 60 feet and 60,000 pounds. I'm guessing a hurricane might reach the 5000lbs pull with a boat that size. But, I would guess that very few people with a 60,000lb boat would actually select this small of an anchor. I sure wouldn't.

[thinwater]

I miss read #1.


Still, if held 5000# and only suffered a bent roll bar, you'd probably kiss it!


---


The conclusion remains that you really don't want to get caught in the open in a worst case. So many failure points at those high loads. Gear can only take you so far.


I recorded > 60 knots a few times, but the anchor load was 500-800 pounds (35# anchor on a 34' cat). I used a long snubber and was not caught in breaking waves. If the load had been 4000-5000 pounds, many things could break.

[Panope]

There are different philosophies about this topic and I am certainly not advocating one or the other by posting my incidents of bent anchors.

On the one hand, a lightly constructed, performance oriented boat can only stand so much before stuff breaks. Keels and rudders break off when pounding on reefs. Rigs come off when the mast goes under water, and yes, bow cleats rip out when anchored in hurricanes. To me, it makes perfect sense to put a lightweight, high performing anchor (that may not be the strongest) on this type of boat. Have a good insurance policy and never look back.

On the other hand, a heavily constructed boat might be designed to survive all manner horrific conditions in a remote area where a credit card and an Amazon Delivery cannot help you. For these people, a bomb proof anchor is probably a smart choice.

I personally lean toward the latter camp, and have a perfect solution when using anchor designs that have less than awesome strength: Oversizing. For example, this season I intend to use a 55lb. Mantus M1 on Panope's bow. This is at least 2 sizes "oversize" and will be very unlikely to bend even in an extreme event. Even crashing into a dock will be less likely to bend it.

Again, no right or wrong answer here. My hope is that people use the anchor data that I present to help make their own decisions.

[Benz]

Originally Posted by Panope

There are different philosophies about this topic and I am certainly not advocating one or the other by posting my incidents of bent anchors.

On the one hand, a lightly constructed, performance oriented boat can only stand so much before stuff breaks. Keels and rudders break off when pounding on reefs. Rigs come off when the mast goes under water, and yes, bow cleats rip out when anchored in hurricanes. To me, it makes perfect sense to put a lightweight, high performing anchor (that may not be the strongest) on this type of boat. Have a good insurance policy and never look back.

On the other hand, a heavily constructed boat might be designed to survive all manner horrific conditions in a remote area where a credit card and an Amazon Delivery cannot help you. For these people, a bomb proof anchor is probably a smart choice.

I personally lean toward the latter camp, and have a perfect solution when using anchor designs that have less than awesome strength: Oversizing. For example, this season I intend to use a 55lb. Mantus M1 on Panope's bow. This is at least 2 sizes "oversize" and will be very unlikely to bend even in an extreme event. Even crashing into a dock will be less likely to bend it.

Again, no right or wrong answer here. My hope is that people use the anchor data that I present to help make their own decisions.

Your anchor data is super-helpful and much appreciated. I agree with your assessment above: I carry a 45lb Manson Supreme on my 31' cutter because everything else on it is built to handle insane loads--not because I push beyond what is reasonable, but because I cruise in places remote enough that any weak link eliminated is worth a litttle weight gained.

[Kettlewell]

I recorded > 60 knots a few times, but the anchor load was 500-800 pounds (35# anchor on a 34' cat). I used a long snubber and was not caught in breaking waves. If the load had been 4000-5000 pounds, many things could break.

After Hurricanes Bob and Gloria, and after numerous gales over decades, I have had the opportunity to check out boats on the beach or on the rocks to see if I could learn anything. Interestingly, in my observations I have noted that in many cases after really big blows it was as simple as the anchor or mooring dragging. After the hurricanes there were many boats ashore sitting right next to their moorings, still attached. I've also observed many parted mooring pendants and anchor rodes, though I have never seen a broken anchor chain. I don't recall ever seeing broken or pulled out bow cleats, though I have seen a few broken bow rollers. My conclusion is that the anchoring gear, even on ordinary production boats, is strong enough for most conditions, and even extreme conditions. The failure points are more likely to be somewhere within the anchor rode and anchor or mooring system, plus the bow roller.

[rslifkin]

Originally Posted by Kettlewell

My conclusion is that the anchoring gear, even on ordinary production boats, is strong enough for most conditions, and even extreme conditions. The failure points are more likely to be somewhere within the anchor rode and anchor or mooring system, plus the bow roller.

That's probably the case, but at the same time, it's hard to know if the cleats and such are truly strong enough. If the anchor dragged before the cleats failed, all that says is that the cleats were stronger than the available holding power. But given a bigger anchor, it's unknown whether the cleats would have survived the same conditions without issue.

[Kettlewell]

If the anchor dragged before the cleats failed, all that says is that the cleats were stronger than the available holding power. But given a bigger anchor, it's unknown whether the cleats would have survived the same conditions without issue.

Good point, but have you ever seen a boat ashore because its cleats broke?