Videos of Anchors Setting

[eheffa]

Thank you Steve for some very interesting findings.

It strikes me that in this very soft semi-liquid mud that, if the anchor can dive, then its ultimate holding power will be dictated primarily by the surface area of the flukes and how closely they can be oriented to approach a right angle to the direction of pull. (Your observation that the thinner flukes work better would suggest that the thinner flukes will cut through the soup more readily and a little bit of angle off of 90 degrees would be necessary to promote diving?)

Thus, the relatively light Fortress holds well in this soupy substrate. It presents a very flat large surface area against the direction of pull and has just enough angle to dive. Or the fact that the Aluminum #5 Excel is equivalent to the significantly heavier steel Excel #5. It looks like surface area is key... so a bigger version of any given anchor should hold better in this sort of mud.

It would be very interesting to see how much difference it makes to simply up-size any given anchor design and how much that affects holding power e.g. how much better is a #6 Excel than a #5 Excel or a Spade 140 vs a 120 vs a 100 ? (The advantage of upsizing would probably have more to do with increased surface area than increased weight.)

I appreciate that finding a series of multiple sizes of the same anchor to test might be a major impediment but maybe some of the anchor manufacturers would be willing to sponsor a test like this?

Great work. It's much appreciated. I'm also looking at the 13 pound Fortress in my spare anchor setup with a lot more respect.

-evan

[Panope]

Originally Posted by eheffa

Thank you Steve for some very interesting findings.

It strikes me that in this very soft semi-liquid mud that, if the anchor can dive, then its ultimate holding power will be dictated primarily by the surface area of the flukes and how closely they can be oriented to approach a right angle to the direction of pull.........

Thanks for the comments, Evan

My take is that the DEGREE that an anchor dives is very very important, not simply 'will it dive or not'.

I believe that an anchor with smaller fluke area but dives more deeply, will generate more holding power than larger, less diving anchor.

For example, in my "soft mud shootout", the 55 lb. Vulcan had the largest fluke area of all the anchors yet it had the same holding power as 4 (smaller) anchors, and less holding power than 5 (smaller) anchors.

I believe the fortress won because it dove the deepest.

Steve

[rslifkin]

I'd be curious to at some point see a soft mud test of the 2 better performing groups of anchors again, but with longer scope (like 5:1 or 6:1). I'd be interested to see if the performance ranking changes, indicating that some designs' ability to dive in soft mud is more dependent on scope.

[LesCheneaux]

What a fantastic set of videos, Steve. Thank you for your contributions!

In thinking about eheffa and steve's comments, I imagine that "fluke area" could be separated into (1) total surface area of the embedded anchor and (2) projected area perpendicular to the direction of pull. The second area could better be converted to the mass of material opposing the pull force (i.e. a square inch of anchor a foot down would have more mud opposing it than a square inch of anchor one inch down). For soft mud, (2) might be much more important than (1), whereas that might be revered for sand, where the friction along the flukes could contribute more.

Considering how little information is out there, I imagine these areas are unavailable without measuring them by hand or with a projector/camera. For sand/mud, the values needed would be even hard to obtain since they'd need to be based on the amount of anchor buried at one pull force.

[Kelkara]

The Fortress probably demonstrated this, but it is worth remembering that mud compacts exponentially with depth below the seafloor, so the deeper the anchor can dive the more solid the substrate it will encounter ... and presumably the better holding it will generate.


Is it possible to measure how deep the anchor set. by measuring the length of rode at 1:1 scope just before retrieval? or would that be too difficult.



As always ... great videos Steve ... thanks

[Panope]

Originally Posted by rslifkin

I'd be curious to at some point see a soft mud test of the 2 better performing groups of anchors again, but with longer scope (like 5:1 or 6:1). I'd be interested to see if the performance ranking changes, indicating that some designs' ability to dive in soft mud is more dependent on scope.

Yes. This would be a fantastic and very revealing test.

Unfortunately, my boat does not have enough power.

It is almost certain that increasing the scope will cause the maximum holding power of the better performing anchors to exceed Panope's bollard pull.

I cannot afford to buy or build another boat.

Steve

[Panope]

Originally Posted by Kelkara

The Fortress probably demonstrated this, but it is worth remembering that mud compacts exponentially with depth below the seafloor, so the deeper the anchor can dive the more solid the substrate it will encounter ... and presumably the better holding it will generate.


Is it possible to measure how deep the anchor set. by measuring the length of rode at 1:1 scope just before retrieval? or would that be too difficult.



As always ... great videos Steve ... thanks

Great idea about measuring at 1:1.

Probably need a diver.

Or perhaps my "side view camera" trained on highly visible markers.

Beach testing is easy. Just dig down with shovel.

Steve

[rslifkin]

Originally Posted by Panope

Yes. This would be a fantastic and very revealing test.

Unfortunately, my boat does not have enough power.

It is almost certain that increasing the scope will cause the maximum holding power of the better performing anchors to exceed Panope's bollard pull.

I cannot afford to buy or build another boat.

Steve

It's probably a terrible way to go about it, but could you side-tie the smaller boat to Panope and have a helper run the second boat to get more pulling power (given strong enough cleats, etc.)? If I weren't on the wrong side of the country, I'd offer up use of a boat with bigger engines for that test.

[Kelkara]

Originally Posted by Panope

Great idea about measuring at 1:1.

Probably need a diver.

Or perhaps my "side view camera" trained on highly visible markers.

Beach testing is easy. Just dig down with shovel.

Steve

Using the chain might be problematic since you will have to determine how hard to pull to get the chain vertical, but without rotating the shank. I guess it might work with a retrieval line attached to the crown, pulled tight to measure the length at the water-line when buried, and then once the anchor has released drop it onto the seabed and measure again to get the true depth of the water. Although that sounds like a lot of additional work to add to the tests.

[Panope]

Originally Posted by rslifkin

It's probably a terrible way to go about it, but could you side-tie the smaller boat to Panope and have a helper run the second boat to get more pulling power (given strong enough cleats, etc.)? If I weren't on the wrong side of the country, I'd offer up use of a boat with bigger engines for that test.

I have given this a lot of thought.

Would probably need a bridal. One leg on each boat. Perfectly sized legs to prevent a sideways drift (vectored thrust of the outboard motor may mitigate this).

Tandem pulling (small boat pulling directly on Panope's stern) might be easier.

Ultimately, it comes down to not having another able bodied seaman available for long days on the water.

My father (the owner of the small test boat) is certainly qualified for the job, but he is now in his 80's and has been weakened by years of ongoing cancer treatment.

Steve.

[eheffa]

Hmmm.

Maybe when the pandemic is over, I could scoot over there from Victoria for a weekend or two of testing.

I’m guessing that my Nordic Tug 37 with its 380 HP diesel & 24” prop could generate enough thrust to expand the testing range?

[Jahwork]

Steve,

I am potentially able to provide assistance either topside as a deck hand, boat operator or even as a diver. I have full face mask capabilities with full communications between divers or from topside to diver. You have my number so give me a call and we can chat up a plan.

Thanks for all your efforts!!

Safe Journeys,
~Jake

[Panope]

Originally Posted by eheffa

Hmmm.

Maybe when the pandemic is over, I could scoot over there from Victoria for a weekend or two of testing.

I’m guessing that my Nordic Tug 37 with its 380 HP diesel & 24” prop could generate enough thrust to expand the testing range?

Yes, pulling in fwd gear should be good for several thousand pounds of pull.

The BIG hurdle will be transferring an all chain rode to the stern of the vessel. Easiest way that I can imagine would be to make up a rode of 105 feet of chain plus a rope leader. Using the bow roller/windlass, dump the anchor and all chain to the bottom. Then, transfer the rope leader to the stern and manually lift the first 26 feet of chain off the bottom and fix to the bollard/bridal. Reverse process to retrieve.

Does your windlass accommodate 3/8" chain?

Does your vessel have a strong STRONG attach point(s) aft?

Steve

[Panope]

Originally Posted by Jahwork

Steve,

I am potentially able to provide assistance either topside as a deck hand, boat operator or even as a diver. I have full face mask capabilities with full communications between divers or from topside to diver. You have my number so give me a call and we can chat up a plan.

Thanks for all your efforts!!

Safe Journeys,
~Jake

Thanks for the offer, Jake.

I'll keep that in mind for next season.

Panope will be hauled out for the winter/spring tomorrow.

Steve

[Jahwork]

Good plan! Let’s wait for the water to warm up a little.

Safe Journeys,
~Jake