Reply
 
Thread Tools Display Modes
 
Old 05-06-2012, 07:35 AM   #21
Veteran Member
 
JanisK's Avatar
 
City: Melbourne
Country: Australia
Vessel Name: NightinGayle
Vessel Model: Tradewinds 42
Join Date: Aug 2011
Posts: 88
Back to the topic of anchor loads...

I just bought 100 Metres (330Ft) of 10mm chain rated at a WLL of 1 ton to connect to my 35Kg Super Sarca. The plan is to connect the Sarca to chain via a long 12mm (16mm pin) long D shackle due to anchor shank shape to 10mm bow shackle (rated 1.5 Ton) with no swivel. However I can't find a long D shackle of that size locally rated at greater than 0.6 Ton. Is that an issue in terms of realistic anchor loading? Gemma is 42' and 13.5 Tons
__________________
Advertisement

JanisK is offline   Reply With Quote
Old 05-06-2012, 08:49 AM   #22
TF Site Team
 
Peter B's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Lotus
Vessel Model: Clipper (CHB) 34 Sedan/Europa style
Join Date: Jun 2008
Posts: 6,671
Send a message via Skype™ to Peter B
Quote:
Originally Posted by Marin View Post
A trip line only trips the anchor when you pull on it. Attaching the rode to a shank slot can trip the anchor when the boat pulls on it. Like at 3am when the wind shifts. I prefer to retain control of when our anchor backs out of the bottom.
He he..I knew you'd say that. You are wrong, but I don't know what will ever convince you, so ...ok...I officially give up on that one...
__________________

Peter B is offline   Reply With Quote
Old 05-07-2012, 04:17 PM   #23
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Peter--- You don't have to convince me that I'm wrong. I'm wrong lots of times. You have to convince the people who've had this happen that they're wrong.
Marin is offline   Reply With Quote
Old 05-07-2012, 05:36 PM   #24
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,724
Gemma,
I do'nt know why you need a long D shackle. I looked at the Sarca site pics and can't imagine why a conventional wide D "anchor shackle" won't work. Does it have something to do w the slot? I use a trip line and put a galv bolt through the slot of my Manson Supreme thereby keeping the shackle at the end of the shank in the usual way.
It may be a long time before you put over 1.5 tons load on your rode but it may be next week. Can you call Rex at Anchor Right? Peter how about help'in your mate out here?
Nomad Willy is offline   Reply With Quote
Old 05-07-2012, 09:32 PM   #25
Guru
 
bobofthenorth's Avatar
 
City: Cowichan Bay, BC
Country: Canada
Vessel Name: Gray Hawk
Vessel Model: Defever 43 Offshore Cruiser
Join Date: Oct 2009
Posts: 570
Quote:
Originally Posted by manyboats View Post
Gemma,
I do'nt know why you need a long D shackle. I looked at the Sarca site pics and can't imagine why a conventional wide D "anchor shackle" won't work.
We use a conventional anchor shackle with our Super Sarca.
bobofthenorth is offline   Reply With Quote
Old 05-08-2012, 03:36 AM   #26
Veteran Member
 
JanisK's Avatar
 
City: Melbourne
Country: Australia
Vessel Name: NightinGayle
Vessel Model: Tradewinds 42
Join Date: Aug 2011
Posts: 88
Manyboats and Bobofthenorth, thanks for your replies. The reason for the long D shackle is that I happen to have one but it is rated at 0.6T which fits and I bought a normal D shackle with a 16mm pin rated at 2T but its not wide enough to slide over the Super Sarca shaft So I figured I would have to see if I could get a higher rated long D shackle. I didn't know they also make wider ones. I'll go and explore that. Thanks again.
JanisK is offline   Reply With Quote
Old 05-08-2012, 08:02 AM   #27
TF Site Team
 
Larry M's Avatar
 
City: JAX, FL
Country: USA
Vessel Name: Hobo
Vessel Model: Krogen 42-120
Join Date: Nov 2008
Posts: 5,750
Gemma: Here's a source for some specialized shackles:

Specialty Shackles
Larry M is offline   Reply With Quote
Old 05-08-2012, 08:04 AM   #28
TF Site Team
 
Peter B's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Lotus
Vessel Model: Clipper (CHB) 34 Sedan/Europa style
Join Date: Jun 2008
Posts: 6,671
Send a message via Skype™ to Peter B
Sure, no problem Eric. Jan you got yourself a pretty heavy anchor there, but as everyone seems to agree heavier is better than light when push comes to shove. Better still if it is a heavy version of a really good anchor.
You need a 12mm stainless long D shackle because you need a size above the chains gauge, and also dictated by the anchor size. The long D shape, and being stainless means the sliding slot mechanism works properly. A short or galvanised shackle might jam, and not work when needed. All info here.....
Super SARCA Anchor No 8 - Galvanised Anchors - anchorright.com.au
Peter B is offline   Reply With Quote
Old 05-08-2012, 08:20 AM   #29
TF Site Team
 
Peter B's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Lotus
Vessel Model: Clipper (CHB) 34 Sedan/Europa style
Join Date: Jun 2008
Posts: 6,671
Send a message via Skype™ to Peter B
Quote:
Originally Posted by Marin View Post
Peter--- You don't have to convince me that I'm wrong. I'm wrong lots of times. You have to convince the people who've had this happen that they're wrong.
Not really Marin, because what I really have to counter is the misinformation they have fed to you, and which unduly influenced you. Why I say that is they really could not possibly know why their anchor dragged - unless, that is, they were down there with tanks on watching as it happened. All they could report is they dragged, and they happened to be swinging on Manson Supreme slotted anchors. However, as we know there are many other factors which can cause an anchor to drag - many do all the time, and without slots in the shank. Poor holding bottom, poorly set, insufficient rode out, too light chain or rode for the weight of the boat, or even just conditions just too overwhelming for any anchor to cope - the list goes on.
So they dragged, and like many poor workmen, maybe found it convenient to blame their tool. What I do know is that if they were in a blow, (where dragging matters), then no matter how the tide changed or the wind shifted, there would always be too much tension on the rode for the trip mechanism to come into play. The shackle would be right at the end of the shank, just like any other anchor. Sorry, but I can't put it any clearer than that. Bottom line - there is no way they could know their anchor slot triggered - they just surmised it did, but in conditions which would make that impossible, insofar as it is possible to say anything is possible or impossible.
Peter B is offline   Reply With Quote
Old 05-08-2012, 12:45 PM   #30
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,724
Peter I can see why you are frustrated.

I'll try and present Marin's point of view that is basically my point of view as well.

When the wind changes 180 degrees many (but not most) anchors will revolve while rotating around to the new "heading" all the while staying buried or at least set. Even anchors that usually do this cannot be depended upon to do that all the time and most anchors will break out and reset. So if your anchor stayed buried ......fine but most wo'nt so will need to re-set.

But I think Marin feels his anchor will stay buried and his message to you is basically "why should I want an anchor that will positively break out when I HAVE an anchor that probably wo'nt". And I think he has a good point assuming that he has an anchor that will stay buried.

Since most anchors will break out anyway it makes no difference if they have the slot and break out because of that or break out because of anchor design or bottom conditions.

BUT whatever anchor we use if it dos'nt break out we are better off so why shoot ourselves in the foot and use an anchor with a slotted shank that is guaranteed to break out and insure that we need to depend on that anchor resetting when there's a good chance that's not necessary. Of course if you have an anchor that ALWAYS resets there would be no problem. But what Marin is saying (if I'm reading him right) is.......why ask for it. Why lower one's odds of staying hooked to the bottom.

I use a trip line on my Manson and put a bolt in the slot that insures that the shackle on the rode stays at the end of the shank. My trip line goes UNDER the roll bar so it will pull back instead of basically straight up. I think that up's my chances of retrieval. And if I buy a Sarca I'll do the same w it.

I sincerely hope none of this offends either you or Rex.
Nomad Willy is offline   Reply With Quote
Old 05-08-2012, 01:01 PM   #31
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by Peter B View Post
Not really Marin, because what I really have to counter is the misinformation they have fed to you, and which unduly influenced you. Why I say that is they really could not possibly know why their anchor dragged - unless, that is, they were down there with tanks on watching as it happened.
We saw one instance where the reversal in the slot was actually videotaped in a test. The anchor (Manson) was set properly and then the boat was pushed off to the side by a fair size RIB. As soon as the angle of the boat to the shank was 120 degrees or so the shackle began to move down the slot under the pressure of the RIB pushing the boat. As the boat continued to be pushed farther around the shackle continued to move down the slot until it contacted the sand the fluke end of the anchor was buried in. But at that point there was enough pull in the direction of the fluke that the fluke began to loosen its set. And the more it loosened up, the more it began to emerge from the sand. Finally it came all the way out and the boat, still under pressure from the RIB, began to drag it along the bottom.

While I have read a good number of comments on T&T and in other publications over the years from boaters who have claimed that the same thing happened to them, including one I recall with a sailboat in shallow, clear water in the Caribbean or southwest Pacific who claimed to have watched this happen from his dinghy over the anchor, it was the video that convinced me that a slotted anchor shank is a really bad idea.

Unless you specifically want the ability to back the anchor out because you are moving the boat frequently. Like if you're bottom fishing where you are anchoring in kelp or over rocky bottoms and you want to change locations fairly often. Having the ability to back the anchor out from kelp or rocks or whatever using the slot instead of a trip line can be a major plus in this case.

You can defend that slot all you want, Peter, but after reading everything I've read and particularly seeing that video taped test there is no way in hell I would ever trust our boat to stay put with the rode fastened to the slot in a Manson or Sarca. Not with our often-strong currents that reverse directions four times a day. Perhaps in a place like Hawaii where reversing current is not much of an issue but strong winds and coral bottoms can be, a slot could be beneficial.

But not here. I suspect that this is why on every Manson anchor I've seen in our marina and in marinas up in BC, the rode is ALWAYS connected to the hole at the end of the shank, never the slot. Apparently, the owners of these boats don't trust the slot, either.

A rode shackled to the slot in a Sarca or Manson will absolutely, 100 % of the time never slide down the slot to the fluke end and back the anchor out until the day that it does. I prefer to eliminate that possibility altogether.
Marin is offline   Reply With Quote
Old 05-09-2012, 12:08 AM   #32
TF Site Team
 
Peter B's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Lotus
Vessel Model: Clipper (CHB) 34 Sedan/Europa style
Join Date: Jun 2008
Posts: 6,671
Send a message via Skype™ to Peter B
Ok...well I was gong to drop it, but both Eric and Marin have raised an important couple of points. Points which relate directly to the reason why the slot will not fail you in the sort of conditions when it matters, but might appear to in light conditions in a far from realistic test. But also why the advice to Gemma above re the correct shackle is crucial. Also, I am talking Sarca here, I can't speak for the Mansons, but it might just be their slot is different in shape enough to allow easier sliding. The Sarca slot is square-edged, which is really the reason why the advice given to Gemma above re the need for the long D shackle, stainless, and of the correct size, was important. But look, I'm not trying to convince anybody of anything. People have certain ideas, and life experiences and that's fine. We all have them. I'm just trying to explain the real situation, from my personal experience with this certain type of anchor, which is indeed a departure from the norm, because it is interesting in its own right, and others may well want to know more, as they are about to become available in the US very soon - and no I don't have shares in the thing either - wish I did.

So..to paraphrase Allo Allo, listen carefully...I weel say thees only warnce..(more that is)...

In the situation where there is a reasonable force on the anchor, (ie when it matters), it will be dug in so far it would just rotate pretty much under the suface if gradually pulled sideways as the tide/wind shifted. That does not happen quickly, so the shackle would go nowhere near the fluke end of the slot. You would never in a sea-state be having the boat pulling at 120 degrees to the side, (ie somewhat forward of the beam, as in one example Marin quoted), and the anchor still in its original position - it would have started to follow the direction of pull as soon as reasonable force went on it. Sure in very light drifting conditions the boat might drift back over the anchor and end up exactly opposite and in line to the fluke end, but in those conditions, even if it was theoretically possible it might trip the mechanism, who cares..? You would not even know. In fact in those circumstances the anchor is not even taking any pull, a redundant loop of chain in the mud is holding the boat. You all know this for a fact, as most have had the experience of when a boat a safe distance away when downwind/tide vessel, suddenly with the full force of the tide change when it has become the up-tide boat, suddenly seems to come down much closer, often to the amazement of the skipper concerned. The redundant chain loop has suddenly come free, and they had more out than they thought, right?

Eric, the trip mechanism only works on the Sarca if pulled virtually exactly in line with the shank, towards the fluke, and from above. Any angle away from this, (such as the scenario Marin describes in the test they did pushing the boat sideways with a RIB), would just lock the shackle in place, (hence the importance of the correct type - the longer D gives a sideways leverage/jamming effect), and the whole anchor would be rotated sideways, probably without even breaking the surface, and so bottom substrate would help prevent the shackle moving anyway. Eric, it looks like you have the impression the slot trips the anchor out every time the tide turns. Certainly not so, (verified by underwater testing), but even if it did, it re-sets so fast you would not be aware of it. In strong wind/current conditions there is just no way the trip system can come into play. In the examples Marin reports, and I certainly do not question what you report Marin, the example of the RIB moved boat is hardly realistic, and the occasion where someone was able to watch it (the shackle sliding down the slot) happen in a clear coral lagoon would have to have been so calm for the ripples on the water to not blur everything completely, I can't see that as being realistic conditions either. A poor bottom set would be a more likely explanation if it happened in a blow.
I don't think there is much more one can say really.
Peter B is offline   Reply With Quote
Old 05-09-2012, 01:34 AM   #33
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,724
There certainly is but I want my bed.
Nomad Willy is offline   Reply With Quote
Old 05-09-2012, 01:58 AM   #34
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Peter--- I understand everything you are pointing out in your last post. And what you say makes absolute sense with regards to the shackle jamming in the slot and so forth. I don't know that I 'd want to trust my boat to stay put on the strength of something jamming against something else but I will concede your point.

But here's the deal.... I've had great luck with every machine I've been associated with all my life so far: cameras, cars, trucks, bulldozers, airplanes, sailplanes, boats, computers, snowmobiles, guns, and on and on and on. The one exception is a Bruce anchor. One of the reasons I believe I've had this kind of experience is that I follow a very basic philosophy: whatever can happen eventually will.

So I do everything in my power to short circuit negative "can happen" situations.

As this applies to slotted-shank anchors, the rode can slide down the slot and unset the anchor. And has. It might be rare, it might be almost impossible. There might be huge odds against it happening. But anything that can happen eventually will happen. If I don't have a slotted shank anchor, the rode will NEVER slide down the slot and unset the anchor. Ever. And that concern and uncertainty no longer even exist for me.

End of story.
Marin is offline   Reply With Quote
Old 05-09-2012, 02:04 AM   #35
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,724
I think it's Peter's time to get the last word.
Nomad Willy is offline   Reply With Quote
Old 05-09-2012, 12:07 PM   #36
Guru
 
bobofthenorth's Avatar
 
City: Cowichan Bay, BC
Country: Canada
Vessel Name: Gray Hawk
Vessel Model: Defever 43 Offshore Cruiser
Join Date: Oct 2009
Posts: 570
Quote:
Originally Posted by manyboats View Post
I think it's Peter's time to get the last word.
Given the givens that's unlikly but the debate is informative nevertheless. I have the wrong shackle on my anchor & I didn't know that until now.
bobofthenorth is offline   Reply With Quote
Old 05-09-2012, 07:45 PM   #37
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,724
I've read Peter's post carefully and maybe I'm not too bright it seems to me he's say'in that when the anchor is buried the shackle, in the presence of light real world forces, will remain at the rode end of the shank wherever the light forces from the boat pull from. Well.......I do'nt think a completely buried anchor is anyway near the norm.

Also I think most anchors break out on a 180 degree reversal so what does it matter wether they break out because of a slot or as a matter of course? In a Practical Sailor test that tested only the ability of anchors to perform on a much different angle of pull more than half broke out and had to reset. This was in January 01. Sarca was one of the anchors that did not break out.

As to having the "correct" shackle and shackles jamming in the slot ......I'm not sold on the idea of marketing an anchor that requires a special shackle to make it work properly. Perhaps I do'nt understand the shackle/slot relationship. Anyway when the Sarca's come to the US I'll probably get one. But I'll put a bolt in the slot.
Nomad Willy is offline   Reply With Quote
Old 05-09-2012, 08:10 PM   #38
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by manyboats View Post

Also I think most anchors break out on a 180 degree reversal so what does it matter wether they break out because of a slot or as a matter of course?
Eric--- I think you're correct but the issue that concerns me and others is not what happens when the boat gets 180 degrees on the other side of the anchor but what happens when the boat gets 100 degrees or 120 degrees toward the other side of the anchor. Those are situations where an anchor may stay set and hold your boat if the pull on the anchor is reasonable.

But it's these situations with just a degree of "backwards pull" where people have experienced/witnessed the rode shackle start to move down the slot toward the fluke at which point the pulling and tugging of the boat on the rode starts working the fluke out of the bottom. The theory is that the shackle pin will jam in the slot with a side load on it and this jamming will prevent it from sliding down the slot. I can certainly see how that could occur and it may occur most of the time. But it's not something I want to depend on to work all the time, every time.
Marin is offline   Reply With Quote
Old 05-09-2012, 08:17 PM   #39
Guru
 
City: Hotel, CA
Country: Fried
Join Date: Sep 2011
Posts: 8,328
Quote:
Originally Posted by manyboats View Post
Also I think most anchors break out on a 180 degree reversal so what does it matter wether they break out because of a slot or as a matter of course?
I do not question the Practical Sailor tests results but I do wonder if the above statement holds true in light currents, easy chop, mild days. I have experienced 180 degree tidal changes of direction without the anchor breaking out and re-setting.

Of course the Ca Delta is not exactly the PNW or coast of Oz either. Plow design and several Danforth style anchors with 5 to 1 scope in soft mud. In retrieving the anchors they would only break free once the scope was removed. Basically a straight up and down pull was required.

I seldom post in an anchoring thread as I have more to learn than to share.
CPseudonym is offline   Reply With Quote
Old 05-09-2012, 08:39 PM   #40
Senior Member
 
Larry H's Avatar
 
City: Pacific Northwest
Country: USA
Vessel Name: Jacari Maru
Vessel Model: 2014 Ranger Tug R-27
Join Date: Nov 2010
Posts: 359
It seems to me that he slot anchor does have some value.

Here is the scenario: The rode shackle is held in the end of the slot with a bolt. Then a second shackle is placed in the slot (free to move) and connected to a trip line. The trip line is as long as the rode and is led to the bow with the rode.

If the anchor won't release upon recovery, the trip line is used to slide the second shackle to the fluke end of the anchor and pulled on to trip out the anchor.

Would this work? Is it worth doing?
__________________

__________________
Larry H
Cruising the Pacific Northwest
Larry H is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:13 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012