Will Someone just Choose an Anchor for me? I'm Exhausted.

[Fortress]

Don,

I hear you loud and clear. Ideally, a cruiser should have more than one anchor aboard, preferably at least a few, each of which best suits the bottom conditions where they are anchoring.

Additionally, if a wind or tidal shift is anticipated, then for maximum safety two anchors should be deployed, as no one anchor will dependably reset 100% of the time.

However, I understand that both of the above suggestions are considered to be impractical for a variety of reasons, and so there is a desire for one single "all purpose anchor" that will perform reasonably well in every situation. What I am starting to see now with some cruisers is that they are buying a new generation anchor and massively over-sizing it, which might help compensate in bottoms like soft mud where it's holding power is likely to fall off considerably.

I have concerns about whether their sailboats have the engine power to back down hard enough to properly bury these huge anchors, we'll see and we'll probably read the stories here.


Regarding our testing, I hope to conduct off center pulls, but one thing to keep in mind is that if an anchor cannot handle much of a straight line pull, then there is no reason to believe it is going to perform any better when you simulate a wind or tidal shift with a hard or slow drifting side pull.

Concerning the performance of our product under that circumstance, the few times I have read in forums that a Fortress has broken free during a wind shift have been when it was undersized for the boat and conditions. We maintain that a properly sized and well buried Fortress anchor, with its two large precision-machined flukes, is not more likely to break free from a sea bottom during a wind or tidal shift than an anchor with only a single narrow fluke.

As I have posted before, the Sailing Foundation conducted straight line, 90° and 180° pulls on the test anchors. After they loaded up a 22 lb FX-37 to 4,000 lbs in the straight pull (the max they could pull), they recorded the same results at 90° and 180°. No other much heavier steel anchor came close, in any direction.

After this they commented in the test report about the great difficulty they had recovering the anchor with their 80,000 test boat and at a 1:1 scope, and we experienced the same thing during our testing after just a good steady straight pull.

We were directly above the Fortress anchors in 26 feet of water with 20 feet of 3/8" G4 chain and 15 feet of 5/16" wire rope payed out, and we were still having a hard time getting them to finally break free. Afterwards, the thought that one of these anchors would somehow break free more easily at a normal 5:1 scope from a wind shift is a bit impossible to imagine!


Below is a short video of the 10 lb FX-16 after we finally broke it free and got the anchor back on deck. The mud stuck to it probably weighed more than the anchor.

[downunder]

Originally Posted by Fortress

Depends completely on the bottom conditions. After 3 days of extensive and preliminary holding power tests in the soft mud bottoms of the Chesapeake Bay aboard an 81-ft research vessel in late May, it became crystal clear that the new generation anchors were designed for harder soils, and not soft mud.

Bob Taylor, a retired US Navy anchor design and soil mechanics expert who served as a consultant for us on this project, was not surprised by the results, as he stated that anchors designed for harder soils will typically have a holding ratio (holding power divided by anchor weight) of 10-15, which is almost exactly what we found for the 44-46 lbs new generation anchors that we tested.

The 45 lb CQR did better, with a holding ratio of about 20, as it clearly had a better trajectory and higher effective fluke angle when being pulled into this common soft mud type of bottom.

I would also expect that a non-roll bar anchor might perform better in less common grass, weeds, or rocks, given that it does not have the roll bar which could impede penetration.

We are planning on conducting the next series of tests with the boating media present for independent review, verification, and reporting of the results in late July.

Safe anchoring,
Brian

I do think you may have just identified one of weak links of the roll bar type of new generation anchors. Very few of the tests promoted have used the bottom type you are talking about.

How does the roll bar anchor type turn over if its drops upside down in soft mud?

Very interesting information. Good work. Thanks

[cwyckham]

Originally Posted by Fortress

Don,

I hear you loud and clear. Ideally, a cruiser should have more than one anchor aboard, preferably at least a few, each of which best suits the bottom conditions where they are anchoring.

Additionally, if a wind or tidal shift is anticipated, then for maximum safety two anchors should be deployed, as no one anchor will dependably reset 100% of the time.

However, I understand that both of the above suggestions are considered to be impractical for a variety of reasons, and so there is a desire for one single "all purpose anchor" that will perform reasonably well in every situation. What I am starting to see now with some cruisers is that they are buying a new generation anchor and massively over-sizing it, which might help compensate in bottoms like soft mud where it's holding power is likely to fall off considerably.

I have concerns about whether their sailboats have the engine power to back down hard enough to properly bury these huge anchors, we'll see and we'll probably read the stories here.

Regarding our testing, I hope to conduct off center pulls, but one thing to keep in mind is that if an anchor cannot handle much of a straight line pull, then there is no reason to believe it is going to perform any better when you simulate a wind or tidal shift with a hard or slow drifting side pull.

Concerning the performance of our product under that circumstance, the few times I have read in forums that a Fortress has broken free during a wind shift have been when it was undersized for the boat and conditions. We maintain that a properly sized and well buried Fortress anchor, with its two large precision-machined flukes, is not more likely to break free from a sea bottom during a wind or tidal shift than an anchor with only a single narrow fluke.

As I have posted before, the Sailing Foundation conducted straight line, 90° and 180° pulls on the test anchors. After they loaded up a 22 lb FX-37 to 4,000 lbs in the straight pull (the max they could pull), they recorded the same results at 90° and 180°. No other much heavier steel anchor came close, in any direction.

After this they commented in the test report about the great difficulty they had recovering the anchor with their 80,000 test boat and at a 1:1 scope, and we experienced the same thing during our testing after just a good steady straight pull.

We were directly above the Fortress anchors in 26 feet of water with 20 feet of 3/8" G4 chain and 15 feet of 5/16" wire rope payed out, and we were still having a hard time getting them to finally break free. Afterwards, the thought that one of these anchors would somehow break free more easily at a normal 5:1 scope from a wind shift is a bit impossible to imagine!

Below is a short video of the 10 lb FX-16 after we finally broke it free and got the anchor back on deck. The mud stuck to it probably weighed more than the anchor.

Since none of us can apply 4000 pounds to set our anchors, I would hope your comments on holding in a shift would be based on an anchor with a realistic set.

In my mind, the weakness of a Danforth style anchor in a shift is the rode getting caught on the hinge bar (called the stock I think? ) or in between one of the flukes and the shaft so the home jams.

This isn't hypothetical, it has happened to me

[sailorchic34]

Originally Posted by cwyckham

Since none of us can apply 4000 pounds to set our anchors, I would hope your comments on holding in a shift would be based on an anchor with a realistic set.

^^THIS.

It's all well and good to use a large fishing trawler to do anchor testing to 4000#. But the average 30-50 foot boat will be hard pressed to do more then a few hundred pounds. Plus real 180 swing tests are needed, as this happens all the time. Everyone knows fortress is great straight line. No need to test that again.

Gee I've 10 years of mostly tidal anchoring with 180 degree swing every 6 hours. My cheap POS knock off 44# Bruce design has never once dragged in repeated tide shifts and winds of 40 gusting to 50 knots and 4-5 foot waves. I don't even worry about it in winds less then 30 knots.

I've maybe had three times when it did not set the first try, mainly due to a fouled bottom. Most times the bow will dip a foot or so when it starts to dig in. I've been in soft mud, hard mud and sand.

Tests that only test an anchor in a single bottom and/or straight line only, with a big a$$ boat generating 4000# pulls, makes great marketing copy, but tells little about how it sets and veers in the real world, in a boat that only generates 200-400# of pull.

The problem with using a smaller boat for testing is pretty much every anchor will work and have the same set on a smaller boat. Be real nice to see the tests, set measure load then veer 180 and back to 0 and measure set again.

[Fortress]

Originally Posted by downunder

How does the roll bar anchor type turn over if its drops upside down in soft mud?

That's a fair question and we'd need a diver to find out for sure. I don't know what testing the manufacturers of these anchors have done in soft mud, and once again, our assessment is that they were designed and optimized for harder soils.

The above points out an obvious advantage of the Danforth-type anchor, in that there is no "right side up."

Originally Posted by cwyckham

Since none of us can apply 4000 pounds to set our anchors, I would hope your comments on holding in a shift would be based on an anchor with a realistic set.

In my mind, the weakness of a Danforth style anchor in a shift is the rode getting caught on the hinge bar (called the stock I think? ) or in between one of the flukes and the shaft so the home jams.

This isn't hypothetical, it has happened to me

I understand, and I won't dispute the event that happened to you. If the anchor is well buried, then it should be difficult for the chain to ever sink below the stock or in between one of the flukes, but obviously not impossible.

We could load up the anchors minimally and then turn the research vessel around to simulate a wind shift, but with this soft mud it is hard to imagine any anchor breaking free, and not simply turning and re-pivoting.

Originally Posted by sailorchic34

It's all well and good to use a large fishing trawler to do anchor testing to 4000#. But the average 30-50 foot boat will be hard pressed to do more then a few hundred pounds. Plus real 180 swing tests are needed, as this happens all the time. Everyone knows fortress is great straight line. No need to test that again.

Gee I've 10 years of mostly tidal anchoring with 180 degree swing every 6 hours. My cheap POS knock off 44# Bruce design has never once dragged in repeated tide shifts and winds of 40 gusting to 50 knots and 4-5 foot waves. I don't even worry about it in winds less then 30 knots.

I've maybe had three times when it did not set the first try, mainly due to a fouled bottom. Most times the bow will dip a foot or so when it starts to dig in. I've been in soft mud, hard mud and sand.

Tests that only test an anchor in a single bottom and/or straight line only, with a big a$$ boat generating 4000# pulls, makes great marketing copy, but tells little about how it sets and veers in the real world, in a boat that only generates 200-400# of pull.

The problem with using a smaller boat for testing is pretty much every anchor will work and have the same set on a smaller boat. Be real nice to see the tests, set measure load then veer 180 and back to 0 and measure set again.

I appreciate the input, and glad to hear that you have had great success with your Bruce knock off.

We were actually using the winch aboard this research vessel to do the pulling, since the boat is too big, the bottoms are too soft, and the anchors are too small to conduct controllable and repeatable tests for each anchor. The boat had a "Dynamic Positioning System" which kept it in place, and the winch and wire rope were connected to a running line tensiometer which allowed us to very accurately measure time, payout length, tension, pull speed, etc.

I agree that most tests are focused on "holding capacity" which is obviously an important measurement if you are stuck (or about to be) in a serious blow, and more testing should be done in less frightful "real world" conditions.

That said, I think that most anchors, if properly set and with the right amount of scope, will work reasonably well in common bottoms and real world situations. We cannot leave technique out of the equation, as that can be the beginning and the end of many anchor performance issues.

[boatman61]

Originally Posted by onestepcsy37

in spite of my love for my 45lb manson and 3/8" all chain rode, i'll admit that sometimes you just never know.

my 66lb bruce dragged all over the bahamas; i finally changed it out for the 45lb cqr i had as a spare. worked everywhere. at the same time, our cruising friends were anchoring their 45 foot bob perry cutter, which probably weighed 35000 lbs, with the same 66 lb bruce and all chain and never had a problem. go figure.

Its not what ya got... its how ya use it...

[Alan Mighty]

Originally Posted by Fortress

I have concerns about whether their sailboats have the engine power to back down hard enough to properly bury these huge anchors, we'll see and we'll probably read the stories here.

I'd be very happy if you could explore that a little deeper with your testing.

As I've pointed out in an earlier thread (http://www.cruisersforum.com/forums/...or-123565.html) many sailing boats with conventional fixed propellers barely have enough engine power to back down hard enough to properly bury, in a hard quartz sand, the anchor rated to suit the boat.

Soft mud is less of a problem, of course. Technique and soak time seem more important in unconsolidated soils.

Fortress, do you know of, or can you do, any testing along the lines of testing whether a proper bury that might be gained in a particular soil by (say, for the sake of argument) running my engine at full emergency throttle (3,600 rpm, producing about 381 pounds.force) for 1 minute and 42 seconds could also be gained by running at 3,000 rpm (when force is about 57% of the 381 pounds.force) for 2 minutes or 2,000 rpm (when force is about 17% of the 381 pounds.force) for 6 minutes?

In other words, in a given soil, can proper bury be gained by the product of bollard pull astern x time?

Meaning that within reason, I can power set at a lower rpm but for longer, so as not to thermally stress my engine.

And so if I had a bigger anchor that I know needed a stronger power set than my engine can produce in, say 30 seconds, can I compensate by setting for longer?

Al

[boatman61]

Originally Posted by sailorchic34

^^THIS.

It's all well and good to use a large fishing trawler to do anchor testing to 4000#. But the average 30-50 foot boat will be hard pressed to do more then a few hundred pounds. Plus real 180 swing tests are needed, as this happens all the time. Everyone knows fortress is great straight line. No need to test that again.

Gee I've 10 years of mostly tidal anchoring with 180 degree swing every 6 hours. My cheap POS knock off 44# Bruce design has never once dragged in repeated tide shifts and winds of 40 gusting to 50 knots and 4-5 foot waves. I don't even worry about it in winds less then 30 knots.

I've maybe had three times when it did not set the first try, mainly due to a fouled bottom. Most times the bow will dip a foot or so when it starts to dig in. I've been in soft mud, hard mud and sand.

Tests that only test an anchor in a single bottom and/or straight line only, with a big a$$ boat generating 4000# pulls, makes great marketing copy, but tells little about how it sets and veers in the real world, in a boat that only generates 200-400# of pull.

The problem with using a smaller boat for testing is pretty much every anchor will work and have the same set on a smaller boat. Be real nice to see the tests, set measure load then veer 180 and back to 0 and measure set again.

Exactimo...
And lets face it.. who's gonna say I screwed up after spending X$'s on the latest and greatest published in Yachting Dorks...
I'll stay a happy Luddite and smile as they drift on past.. again..

[sailorchic34]

Originally Posted by Fortress

We were actually using the winch aboard this research vessel to do the pulling, since the boat is too big, the bottoms are too soft, and the anchors are too small to conduct controllable and repeatable tests for each anchor. The boat had a "Dynamic Positioning System" which kept it in place, and the winch and wire rope were connected to a running line tensiometer which allowed us to very accurately measure time, payout length, tension, pull speed, etc.
.

Ah, Dynamic Positioning. Any idea what the the average error circle diameter is of the positioning system on the boat you use for testing is. Seems systems range in position holding of about +- 75 meters down to +-20cm for the best ones. I'm betting it's a bit more then a few meters

The less accurate the positioning system is the more meaningless the payout length would be. At least to how it relates to anchor set distance. You can't tell if the winch is pulling the anchor forward or the boat back, within the error circle of the positioning system. Plus if the positioning system is using GPS, that is another error circle on top of the dynamic positioning error.


Yes at 2000# to 4000# set, one might not worry about veer too much. But the average cruiser will only set an anchor to maybe 300-500#, which would be a far shallower set and perhaps more prone to pull out in multiple 180 veer's. Which is after all a common 4x daily event.

Veer tests would be very informative to most cruising sailors, I'm thinking.

[Fortress]

Originally Posted by Alan Mighty

Fortress, do you know of, or can you do, any testing along the lines of testing whether a proper bury that might be gained in a particular soil by (say, for the sake of argument) running my engine at full emergency throttle (3,600 rpm, producing about 381 pounds.force) for 1 minute and 42 seconds could also be gained by running at 3,000 rpm (when force is about 57% of the 381 pounds.force) for 2 minutes or 2,000 rpm (when force is about 17% of the 381 pounds.force) for 6 minutes?

In other words, in a given soil, can proper bury be gained by the product of bollard pull astern x time?

Meaning that within reason, I can power set at a lower rpm but for longer, so as not to thermally stress my engine.

And so if I had a bigger anchor that I know needed a stronger power set than my engine can produce in, say 30 seconds, can I compensate by setting for longer?

Al

Al, excellent questions which I will pose them to Bob Taylor, the US Navy guy, and see if he can provide some insight. Below is a table from our Safe Anchoring Guide which will give you a rough estimate of the maximum load you can create with your engine, depending on the HP and boat type.

Originally Posted by sailorchic34

Ah, Dynamic Positioning. Any idea what the the average error circle diameter is of the positioning system on the boat you use for testing is. Seems systems range in position holding of about +- 75 meters down to +-20cm for the best ones. I'm betting it's a bit more then a few meters

The less accurate the positioning system is the more meaningless the payout length would be. At least to how it relates to anchor set distance. You can't tell if the winch is pulling the anchor forward or the boat back, within the error circle of the positioning system. Plus if the positioning system is using GPS, that is another error circle on top of the dynamic positioning error.


Yes at 2000# to 4000# set, one might not worry about veer too much. But the average cruiser will only set an anchor to maybe 300-500#, which would be a far shallower set and perhaps more prone to pull out in multiple 180 veer's. Which is after all a common 4x daily event.

Veer tests would be very informative to most cruising sailors, I'm thinking.

Sailorchic34, I will check with the Captain to see if he has an accuracy rating with his DP system, which they tout as "state of the art" per the link below:

The R/V Rachel Carson | The University of Maryland Center for Environmental Science

My assumption is that since this is a local university-owned research vessel and their excursions often depend on this system, it has to be relatively accurate.

All of that said, I don't think that we challenged the DP system aboard to any great degree, as there was minimal current and boat activity to kick up waves and jar the boat around during our testing. Additionally, very few of the anchors pulled more than 1,000 lbs, with most pulls in the 450-700 lb range, which was not much to move a boat of this size.

I understand that veer testing is important, and it would be interesting to see how well the anchors performed in this soft mud after a 300-500 lb load (as you mentioned) was applied. However, I think it might be more challenging and of greater interest to see how an anchor would perform under this circumstance in a harder soil, where it might be more difficult for it to bury deeply.

Brian

[avb3]

Originally Posted by downunder

I do think you may have just identified one of weak links of the roll bar type of new generation anchors. Very few of the tests promoted have used the bottom type you are talking about.

How does the roll bar anchor type turn over if its drops upside down in soft mud?

Very interesting information. Good work. Thanks

Can't speak for other rollbar anchors, but my Mantus has seen a lot of mud bottom. It is tip is balanced such that it has a preponderance of entering the substrate first.

[DoubleWhisky]

This table suggest that the boat can execute quite reasonable load on the chain. For mine it is about 3200 lbs.
For average charter boat in the Med it will be still about 1200 - 1600 lbs.
Not so bad.

It would be interesting to know, how much pull per kilogram (or pound) of anchor weight is necessary to reliably set an anchor of given design in different substrates, but I think such a data are not available yet.

So may be more simple "tug tests" are still worthwile, if we can obtain new kind of useful data from them

[sailorchic34]

Originally Posted by Fortress

Sailorchic34, I will check with the Captain to see if he has an accuracy rating with his DP system, which they tout as "state of the art" per the link below:

The R/V Rachel Carson | The University of Maryland Center for Environmental Science

My assumption is that since this is a local university-owned research vessel and their excursions often depend on this system, it has to be relatively accurate.

Ah class 1 Kongsburg Cpos DGPS (from the R/V website), good system. Looking at Kongburg site, the GPS Accuracy will vary depending on what DGPS head in receiver they are using. Could be a good as <= 1 meter or as much as 3 meters which is still quite good for that sort of thing.

Of course that's just the GPS accuracy and perhaps not overall system accuracy, what with hysteresis in the various servos and all. Still quite nice.

So say +-3 to 5 feet accuracy on the set distance, maybe a bit better, if your using just cable pull to measure anchor set distance. Specially at >1000# pulls.

Agree that hard sand surface would be nice to test too.

[downunder]

Originally Posted by sailorchic34

Ah class 1 Kongsburg Cpos DGPS (from the R/V website), good system. Looking at Kongburg site, the GPS Accuracy will vary depending on what DGPS head in receiver they are using. Could be a good as <= 1 meter or as much as 3 meters which is still quite good for that sort of thing.

Of course that's just the GPS accuracy and perhaps not overall system accuracy, what with hysteresis in the various servos and all. Still quite nice.

So say +-3 to 5 feet accuracy on the set distance, maybe a bit better, if your using just cable pull to measure anchor set distance. Specially at >1000# pulls.

Agree that hard sand surface would be nice to test too.

In agriculture with at base station tractors are getting the accuracy in centimeters to steer down rows of plants so a ship using a base station should get within meters if the control aspects are sorted.

[u4ea32]

Just BTDT, opinion based on experience.

Heavy anchors beat lighter anchors. Its just the dominant effect: a 50lb brand X beats a 30 lb brand Y.

All chain works great when you dont need it, and is a bad, bad idea when you need your anchor to stay put, in big wind and waves. But nylon is stretchy (so it chafes even internally) and is weak when wet, so use braided dacron after, say, 50 or 100 feet of chain. So you have chain on the coral, rope (in a tube to prevent chafe) on the bow, especially in heavy conditions.

Anchors with stuff sticking out, like fortress and other danforth styles, get fouled and bent and stuck and lost. I stopped replacing them.