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Old 01-01-2016, 08:31 PM   #81
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The turbidity is unfortunate but the essentials are there to see. Combined with the observations recorded by Panope, it is a well documented "real life" test procedure. We are fortunate to have an objective assessment of an assuredly current factory supplied version of the Sarca Excel, conducted according to Panope`s well established protocol.
I`d like to see a Super Sarca tested too, it`s what I have, for now this will have to suffice.
And Eric, please stop lifting heavy anchors.
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Old 01-01-2016, 08:46 PM   #82
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On another forum, someone was questioning the validity of the 'Anchor Right claim' that the "Ex-cel" cut-out aided in keeping the anchor clean. The person even theorized that the cut-outs might actually cause seabed to cling to the anchor. It was a reasonable question.

Here is a screen shot of the anchor form the final frames of my last Video. Only a small blob of seabed remains on the toe. This was consistent for the three retrievals that I have conducted so far.

It would appear that the positive cleaning action of the cut-outs has been verified.

Steve

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Old 01-02-2016, 01:40 PM   #83
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Originally Posted by rochepoint View Post
Great video!! Love all the anchoring videos but this one especially.

I was going to offer you our 48 pound SARCA Excel No. 5 for testing if you ever got over to Sidney BC but it was very nice of Rex at Anchor Right Australia to supply you with one. He is a fantastic person to deal with and makes a beautiful anchor.

We only have used ours a few times last year so I was remaining quiet about its performance but what I saw is what we have experienced. Next year we plan on using it a lot now that we are free to go boating whenever we like, so I will report back on our experiences....
The test also bears out my experience. Having not anchored with it in challenging conditions, I was waiting for more experience to report. Also in the shallow waters around Florida's east coast, I usually anchor at a 5 to 1 scope. It will now be shortened to a 3 1/2 to 1 scope.
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Old 01-02-2016, 02:32 PM   #84
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Don:


Why would you shorten to 3.5:1 from 5:1. The latter holds better, resets better.


I was somewhat surprised by the good performance of the modern anchors at that shortened scope that was shown in this test series. But I wouldn't do it unless I had to because of swing considerations, and if I expected a blow, then I would anchor someplace else where I could get to 6:1 scope.


Conventional wisdom (yeah, I understand its limitations) is that anchors perform better on an asymptotically diminishing basis, the longer the scope. At about 8:1 you are at the practical limit. It would take some heavy pulling gear to confirm this wisdom.


Let me offer a guess as to how the scope vs holding curve looks:


8:1 100%
6:1 90%
5:1 75%
3.5:1 40%
2:1 15%


David
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Old 01-02-2016, 03:11 PM   #85
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Quote:
Originally Posted by djmarchand View Post
Let me offer a guess as to how the scope vs holding curve looks:


8:1 100%
6:1 90%
5:1 75%
3.5:1 40%
2:1 15%
But...

That might be true for a traditional anchor, such as a navy anchor, yes?

Super high holding power anchors would deserve their own tests to determine loss of holding power as scope is reduced. Apples to oranges.

A mushroom anchor for example would perform even worse as scope is reduced, so why use traditional anchor test results on SHHP anchors?
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Old 01-02-2016, 03:15 PM   #86
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Here' an illustrated article on anchor scope...pretty easy to image how SHH anchors would perform better as scope decreases, especially if set first with more scope;

Anchor Scope Illustrated Photo Gallery by Compass Marine How To at pbase.com
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Old 01-02-2016, 03:40 PM   #87
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Chain Catenary will be pulled out much easier in shallow water compared to deep water (at the same scope).

For example: Say you are in 5 feet of water with a 5 foot bow roller. 3 to 1 scope would only require 30 feet of chain. A strong man could probably lift this chain off the bottom with bare hands.

Now image anchoring in 45 feet of water with a 5 foot roller. 3 to 1 scope would require 150 feet of chain. I don't have the exact math but I am gonna guess that it will require 5 times the pull to lift the chain off the bottom.

Often a Scope argument will rage between two persons where one of them is a shallow water boater and the other a deep water boater. The deep water boater will talk about years of trouble free anchoring using 3 to 1 scope often without even bothering to use a snubber (like me). The shallow water boater will say that if they did the same it would rip their mooring bits from the deck. Both boaters are correct.

I would be very skeptical of short scope anchoring in shallow water.

Steve
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Old 01-02-2016, 03:48 PM   #88
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I think anchors in general perform better at short scope than most think.

But anchors of differing designs perform differently at short scope. For example on one of the most comprehensive tests I've seen the Supreme held w over 4000lbs of tension on the rode at 3-1 scope but the testers said the Rocna did comparatively poor at 3-1 scope. But the Rocna did slightly better at longer scope. Other anchors do enough better at short scope to have a reputation of holding well at short scope. All anchors not only look different but perform different. I even recall that there was one anchor that did poorly at long scope.

It's my opinion that some anchors sacrafice holding power at long scope for holding power at short scope and more dependable setting performance. An anchor engineered in that way will have overall better performance and be a better choice. Anchor tests concentrate very heavily on maximum holding power and assume (w good reason) that that usually will be at 5-1 to 7-1 scope. So being on a budget they usually just test at long scope. If I had my choice of a bunch of SHHP anchors I'd choose the one that set best.

On long scopes like 10-1 submerged chain may reduce performance because the chain may limit penetration. An anchor will only penetrate as deep as the shackle end of the shank. If the shank end can penetrate 2" deeper then the whole anchor will be 2" deeper. Having the chain up off the bottom may allow the end of the shank to go a bit deeper.

Don re your change in what scope you use I went that route a long time ago. And in 50 knot gales I use 5-1.
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Old 01-02-2016, 07:34 PM   #89
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Quote:
Originally Posted by djmarchand View Post
Don:


Why would you shorten to 3.5:1 from 5:1. The latter holds better, resets better.


I was somewhat surprised by the good performance of the modern anchors at that shortened scope that was shown in this test series. But I wouldn't do it unless I had to because of swing considerations, and if I expected a blow, then I would anchor someplace else where I could get to 6:1 scope.


Conventional wisdom (yeah, I understand its limitations) is that anchors perform better on an asymptotically diminishing basis, the longer the scope. At about 8:1 you are at the practical limit. It would take some heavy pulling gear to confirm this wisdom.


Let me offer a guess as to how the scope vs holding curve looks:


8:1 100%
6:1 90%
5:1 75%
3.5:1 40%
2:1 15%


David
David, I just thought cutting down on swinging room would be a good thing. We usually anchor in 10 to 20' of depth. That would mean about 85 to 90' of rode. 5 to 1 would be about 125 to 130' of rode. Without applying Pythagoris to it would be about 40' less swinging room. We don't do a lot of crowded anchorages, so it is probably foolish to economize on swinging room. It is nice to know that I can do it without worrying much.
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Old 01-02-2016, 07:38 PM   #90
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Quote:
Originally Posted by Panope View Post
On another forum, someone was questioning the validity of the 'Anchor Right claim' that the "Ex-cel" cut-out aided in keeping the anchor clean. The person even theorized that the cut-outs might actually cause seabed to cling to the anchor. It was a reasonable question.

Here is a screen shot of the anchor form the final frames of my last Video. Only a small blob of seabed remains on the toe. This was consistent for the three retrievals that I have conducted so far.

It would appear that the positive cleaning action of the cut-outs has been verified.

Steve

Steve, dunk the anchor a couple of times it will usually come right off. Of course with sticky silt clay all bets are off.
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Old 01-02-2016, 08:00 PM   #91
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In a conversation I had with Rex he seemed to regard 3:1 as short scope, I regard it as minimum, but all chain, with Super Sarca, it normally works for us in normal conditions. We get a characteristic wind reversal from onshore to offshore overnight, never had a problem with that.
We always clean off on retrieval, our strong washdown pump is mains(240v) powered via the genset.
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Old 01-02-2016, 11:51 PM   #92
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.........I think anchors in general perform better at short scope than most think.
That is an absolutely crucial point. The customary scope length recommendations were originally based on the performance of much older style anchors, so can nowadays be regarded as traditional wisdom, certainly worth bearing in mind, but are unnecessarily conservative in anything less than fairly extreme conditions with these modern super high holding anchors. That's my take on it and experience anyway. I never use more than 5:1, (blowy weather), and usually only 3:1 scope, with my Super Sarca.
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Old 01-03-2016, 09:41 AM   #93
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Sorry but I do not understand people wanting to use as short a scope as they can get away with. I always use a minimum of 5 to 1 and if I have the room 10 to 1. It is only a matter of how long I hold the button down. Might be different if I had no windlass, but I do. Ground tackle and it's proper use is to me the greatest piece of safety equipment on a boat.
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Old 01-03-2016, 10:33 AM   #94
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Sorry but I do not understand people wanting to use as short a scope as they can get away with.
Channels over 300' deep, small bays with steep shores along their length going at a steep angle to 100' or more in depth, sediment outwash fans from rivers or creeks at the head of bays, intertidal water from river sediment extending over 100' feet from shore then dropping in off in steep steps to deep water, and finally, 20' tides. Sometimes there is not very much room to swing.
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Old 01-03-2016, 11:01 AM   #95
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In short .. When you're forced to use short scope you learn how well it works.

3-1 isn't short scope to me ... It's the norm. Short scope is 2-1 and I've anchored at 2-1. In a gale though I use 5-1.

Now that I think about it if you enter an anchorage in benine weather and anchor at 5-1 it may be rude. One shouldn't take up more space than one needs.
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Old 01-03-2016, 05:40 PM   #96
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Channels over 300' deep, small bays with steep shores along their length going at a steep angle to 100' or more in depth, sediment outwash fans from rivers or creeks at the head of bays, intertidal water from river sediment extending over 100' feet from shore then dropping in off in steep steps to deep water, and finally, 20' tides. Sometimes there is not very much room to swing.
That is understandable, but not the norm for gulf coast, Florida or Bahamas. If you are anchoring in !00' of water at 3 to 1 you have 300' of chain which is a lot of weight besides the anchor. I think a short scope would work better in deep water than shallow water.
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Old 01-03-2016, 05:55 PM   #97
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READY2GO,
Most people don't have all chain. And for good reason .. mainly the one you just mentioned .. weight.
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Old 01-03-2016, 07:34 PM   #98
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Sorry but I do not understand people wanting to use as short a scope as they can get away with. I always use a minimum of 5 to 1 and if I have the room 10 to 1. It is only a matter of how long I hold the button down. Might be different if I had no windlass, but I do. Ground tackle and it's proper use is to me the greatest piece of safety equipment on a boat.
I think MainSail/Compass Marine did a rough test that showed where more than 7:1 really did little to improve anchoring...I tend to agree....unless riding out a hurricane....95% of my anchoring is in protected waters and winds less than 20 knots. The East Coast of the US isn't exactly Patagonia.

http://www.pbase.com/mainecruising/anchor_scope&page=2
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Old 01-06-2016, 10:15 PM   #99
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Here is the Excel undergoing my "Decreasing Scope" test.

I have already executed this test with the Manson Supreme, Spade, and Genuine Bruce. All did very well but the Manson reined supreme for this test. As you may recall from video #24, the Manson somehow held the boat at 3000 RPM with a scope of only 1.3 to 1.

The Excel takes second place. It held 2750 RPM with a scope of 1.5 to 1. The Excel got an unlucky break at the 1:35 minute mark of the test when the boat drifted about 15 or 20 degrees out of alignment with the anchor. This caused a small pivoting of the anchor that may have worked against it's final outcome.

The Bruce comes in third as it also held the boat at 1.5 to 1. (video #25) However, it got a lucky break when I cut the power just as it was releasing at 1.7 to 1 scope.

The Spade held 2500 RPM at 1.7 to 1 scope. (video #24, second half).

The reality is that there are no "losers" here. All these scopes are ridiculously short and in no way represent any sort of normal anchoring.

Steve

Video #32 Excel Reducing Scope:
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Old 01-15-2016, 03:48 AM   #100
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Engine thrust tested.

Panope has a Yanmar 3JH3E, 40 HP engine. The propeller is a fixed, 18 inch diameter X 10.5 inch pitch. The gear reduction box has a ratio of 2.61 in forward gear and a ratio of 3.16 in reverse.

The boat makes 3 times more thrust in forward as it does in reverse at the same ENGINE rpm. I believe that much of this discrepancy is due to the propeller being much less efficient in reverse. Another factor is the higher gear reduction ratio of the reverse gear compared to forward.

Here is a table showing the results:


And here is the video:

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