Anchors - Bigger is Better ?

[noelex 77]

Shackle strength is an important issue. There are many more boats that break shackles and swivels than ever bend anchors.
If the join between the anchor and chain parts the boat will drag very quickly. It is difficult to find and therefore recover the anchor with no chain attached.

If the anchor bends its likely not to noticed untill retreval. Many manufacturers will replace bent anchors under warranty.

For the small extra price it is worth getting good quality shackles and inspect/replace them regularly. They commonly corrode before the chain.

The biggest problem seems to be a number of poor quality shackles with inclusions etc that are sold. The problem is compounded by the move to lighter chain which also reduces the maximium shackle size that can be used. At the same time newer generation anchor creep less than the the older designs increasing the peak loads.

[downunder]

Originally Posted by noelex 77

Shackle strength is an important issue. There are many more boats that break shackles and swivels than ever bend anchors.
If the join between the anchor and chain parts the boat will drag very quickly. It is difficult to find and therefore recover the anchor with no chain attached.

If the anchor bends its likely not to noticed untill retreval. Many manufacturers will replace bent anchors under warranty.

For the small extra price it is worth getting good quality shackles and inspect/replace them regularly. They commonly corrode before the chain.

The biggest problem seems to be a number of poor quality shackles with inclusions etc that are sold. The problem is compounded by the move to lighter chain which also reduces the maximium shackle size that can be used. At the same time newer generation anchor creep less than the the older designs increasing the peak loads.

Agreed that using correct and adequate shackles is a given. A trap for the unwary and seeking cheap.

Still I would like to be convinced all new gen anchors particularly current ROCNA are using 690MPA steel in their shanks. We know the original NZ built ones were.

We know Manson and SARCA do. I think in saw a post by Mantus that they were also but can't find it on their website.

Cheers

[noelex 77]

Originally Posted by downunder

Agreed that using correct and adequate shackles is a given. A trap for the unwary and seeking cheap.

Still I would like to be convinced all new gen anchors particularly current ROCNA are using 690MPA steel in their shanks. We know the original NZ built ones were.

We know Manson and SARCA do.

The Sarca and Super Sarca are mild steel.

[DumnMad]

It is dead easy to design a grade 500MPa shank to be stronger than a grade 690MPa shank. Increase the thickness & depth each by 12% - its proportional to b x d x d or bending sideways; d x b x b.
The big thing is to make sure its welded right. Another thing is ductility - will it bend or break?? Higher strength steel is less bendy so more likely to break.
It's naive to harp on about steel grades when other factors need to be taken into account. Just sounds like sales talk.

[downunder]

Originally Posted by noelex 77

The Sarca and Super Sarca are mild steel.

Now I understand. I must have uttered a dirty word. Can't respond as a response may close down the thread.

[downunder]

Originally Posted by DumnMad

It is dead easy to design a grade 500MPa shank to be stronger than a grade 690MPa shank. Increase the thickness & depth each by 12% - its proportional to b x d x d or bending sideways; d x b x b.
The big thing is to make sure its welded right. Another thing is ductility - will it bend or break?? Higher strength steel is less bendy so more likely to break.
It's naive to harp on about steel grades when other factors need to be taken into account. Just sounds like sales talk.

Only issue there is that the thicker shank/blades may not penetrate as well.

[DumnMad]

Agreed downunder, heavier is not always better - it depends the weight being in the right place, having the correct angle between blade and rode, and sharpness of leading edge.
My Bruce copy is appalling. From a distance it looks like a Bruce but the blunt leading edge and heavy shank tells me its only good for mud.

[congo]

Down under wrote:

Still I would like to be convinced all new gen anchors particularly current ROCNA are using 690MPA steel in their shanks. We know the original NZ built ones were.

We know Manson and SARCA do.

Noelex wrote:

Sarca and Super Sarca are made of mild steel.

All Sarca threads are closed but it’s fine to reintroduce it by taking a line out of context every time someone says something positive about Anchor Right.

Anyway how right you are Noelex, it would also have been nice if you could have included Sarca Excel has a bisaloy steel shank and a cast filled base and bisaloy toe.

It’s a bit like a dog chasing its tail trying to explain an anchors concept.

The Super Sarca is purpose built of mild steel grade 350 for those of you in the know, shank thickness verses penetration is taken into consideration when one designs a concept as such.

The steel thickness are thicker to cope with proof testing to pass certification, the Excel is a different concept, no roll bar, it relies on ballast among other details to right itself, shank weight is kept to a minimum to help this process and further cope with the stringent proof load tests.

Bisaloy 80 is chosen because it is thinner the steel quality, has to be stronger, nothing to do with the shank burying itself, when designing an anchor you have to take into consideration if you are going to use a thick shank, if this is done correctly shank thickness regardless of size, will bury.

Dumad, yes mild steel is less prone to snapping as when compared to high tensile steel, difference being Bisaloy is spring steel, it will flex at least 35% and recoil without bending, during our proof testing we have had the bisaloy with excessive loads shanks bent at 90% for a matter of interest and still not snap, there’s another one for you Noelex when you see fit to use it.

Noelex regardless of your arm chair observations facts are facts, all of our designs are proof tested and certified to find any weakness whether it be mild steel or bisaloy, our steel grades are listed on our web site, proof testing methods for all to see, independent holding power testing by a licensed Authorized anchor tester,all field testing and method used, we saved lives in the Tsunami that hit Phuket and the following testament from the U.K long before any concave roll bar got of the ground.

So give just a bit of respect.

Regards Rex.


Updated on: Sep 21 2009
The following state of events that was recorded by Peter Hutchinson, skipper of Quo Vadis drives home the need for good reliable ground tackle, equally as important when purchasing an anchor make sure that it is of an a approved and tested design. The Anchor Right anchor that Peter relied upon was a Sarca, (Sand and Reef Combination anchor).

Please Note: the attached photos were taken by the RNLI sea rescue the next morning whilst hooking up and towing Quo Vadis to a safer anchorage, they do not depict the ferociousness of the storm that Peter experienced during the night.

Hi Rex,
When I built Quo Vadis, my own design upon the hull shape of a Roberts Mauritius 43, I looked very specifically for an anchoring system that would perform in an emergency. If the 20-ton boat had complete systems failure and was being blown on to a lee shore I wanted to know that I could use a strong hook to grab the sea bed. After careful consideration I opted for the Anchor right system with 100m of chain, operated from my own custom-designed bow roller by a substantial windlass. There are very few places in the world that this would not stop a drifting disabled vessel in an emergency. In particular I was attracted by the Anchor right self-correcting roll bar (and reverse-pull extraction for release if snagged) as an emergency anchoring wouldn’t necessarily take account of bottom conditions.

On September 3rd 2009 I had occasion to test the Anchor right in severe conditions when running from a storm latterly written up as Force 10 by the local media. Sea conditions in Liverpool Bay delayed my approach to the Mersey, and thus the tidal lock entrance to Liverpool Marina where I required to be by around midnight on the 2nd, leaving me looking for a suitable place to anchor and see out the forecast storm. Good navigational chart-plotting equipment allowed me to explore all the water off Liverpool at my leisure for suitable anchorages. Not a lot of choice. There are a couple of small craft moorings areas that are likely to be fouled with chains. The next location, other than out in the exposed Liverpool Bay, was off New Brighton where outside the shipping fairway there was an area of water with depth, clear sea bed and swinging room.

At 3am on Thursday 3rd September I dropped anchor at the identified location, between Brazil Light Float and Rock Gut. I had a charted depth of about 7m and enough sea room to swing well over 100m in any direction, still without risking obstructing the fairway. Importantly, also, the ground conditions suggested good bearing and no wrecks or underwater obstructions.

Barely had I got 40m of chain out and secured to the anchoring cleat on the bow when the storm struck. The rain whipped across with such force that exposure was painful. But by this point not only was Quo Vadis attached to the seabed, but also I had a waypoint on my chart-plotter showing exactly where my Anchor right had come in contact with the world. I put a second waypoint when QV reached the end of her 40m of anchor chain, and a 3rd when she had swung through a couple of arcs showing the extremity of the swing.

For an hour I sat by the plotter monitor watching for any sign of drag as the storm’s intensity had QV bucking about like a rodeo ride. Not an inch. We were hooked fast. After a cup of tea and still no sign of drag I went to my bed in the aft cabin. All the bounce was at the front and my cabin hardly moved.

At 11 the morning the wind still howled and the sea coming over Rock Gut was still boisterous. The bow rose an fell through quite an angle, but I could sit and work in the aft cabin with a cup of tea. Imagine my surprise when I looked out the porthole and saw a lifeboat man outside. The RNLI (British Lifeboats) had a Rib returning from helping kids endangered on a beach and they saw Quo Vadis looking like a fairground ride. They had no idea we’d been there all night. The Coastguard did know because I’d advised them when I anchored. From the perspective of the men in the Rib there was a danger my anchor wouldn’t hold and I would be blown out of control into the fairway, or onto Rock Gut. Upon their advice I agreed to relocate to the marina as it now had water level suitable for the sea lock.

Agreeing to relocate is one thing. Taking a perfectly safe boat off a secure anchor in a major storm is another. I was all for sitting out the storm, so the RNLI offered a line onto their bigger lifeboat so I could safely raise my anchor. For this I was very grateful. My original plan had been to berth in the marina for 2 days anyway as I had friends to visit in Liverpool. With expert assistance from the RNLI the anchor was raised from the seabed and stowed in the bow roller, and Quo Vadis was escorted, still attached to the lifeboat as protection against high wind gusts until we got to the marina entrance, and tied up in the lock before a happy goodbye handshake.

Later, in the marina, I was visited by the coastguard. Of particular interest was the track on the chart plotter that showed Quo Vadis had sat out the storm at anchor, swinging entirely within the waypoints I had placed. This was proof that I had never been at risk, and that I had chosen my anchorage and ground tackle suitably.
All good stories have a twist. A local TV crew spotted the lifeboat and reported I had gone out in the storm against advice and needed rescue. I attach the apology from the BBC. The local newspaper, The Globe, also noted the incident. I took exception to Quo Vadis being described as stricken. As their report had emanated from the RNLI, though with no names, I asked the RNLI if they could help me also correct this. I pointed out to the RNLI that my Anchor right ground tackle should be acknowledged.

When I get back to QV I will try to photograph the chart-plotter with the track if you wish. In the meantime I attach a link to the report in The Globe. This might help. (The blogs added by people who know me make amusing reading. The ballooning quip is aimed at my uncle who build a balloon to go round the world, but which sank in the sea off Japan.)
http://www.wirralglobe.co.uk/news/4582181.Wirral_lifeboats_rescue_lone_sailor_strand ed_in_Force_10_gale/
Cheers.
Peter Hutchison
BC APOLOGY
Peter, thanks for your call.
I can confirm that the story we ran on September 3rd was wrong in a number of respects. I have spoken to the Liverpool coastguard and they tell me that
a) you were in no danger at any point..
b) you had not “ignored coastguards warnings and put out to sea” as was stated in our story.
c) you were lying at anchor at the correct location.
d) the RNLI were on their way back from another incident when they saw your boat. They offered an escort back to the marina if you required it…
We are still investigating the reason for the errors and I might have some more info later but in the meantime I am really sorry if our inaccuracy on this story has caused you any embarrassment.
JIM CLARKE
Newsgathering Editor
BBC Northwest Tonight

[sailorboy1]

I don't read the real long posts.

But doesn't it seem unacceptable that there isn't clear testing of things as simple as chain etc. Or is it just for the boating chains etc that all the disagreement occurs. Afterall chain etc is well tested for lifting loads for rigging.

[boatman61]

Originally Posted by Don L

I don't read the real long posts.

But doesn't it seem unacceptable that there isn't clear testing of things as simple as chain etc. Or is it just for the boating chains etc that all the disagreement occurs. Afterall chain etc is well tested for lifting loads for rigging.

Ahh... but thats for static loads and lifts... it does not cover snatch loads... wobble effect... poor maintainance... crap attachment points... plus there'd be nothing to go on about nuttin..

[Cotemar]

Originally Posted by downunder

Still I would like to be convinced all new gen anchors particularly current ROCNA are using 690MPA steel in their shanks. We know the original NZ built ones were.

We know Manson and SARCA do. I think in saw a post by Mantus that they were also but can't find it on their website.

No convincing needed.
Here's the facts.

Rocna re-licensing & historical steel quality issues

[sailorboy1]

Originally Posted by boatman61

... plus there'd be nothing to go on about nuttin..

There is that! If we knew look at all the entertainment we would miss out on!

[congo]

Cotemar Wrote:

No convincing needed.
Here's the facts.

Rocna re-licensing & historical steel quality issues

Cotemar I really am blown away with the video on this link, who is responsible for the captions of Lloyds an Rhina, this proof test, I have never seen anything like it, surely this is a set up.

Proof test in lewd with Lloyds register is that the load is to be applied at no less than two thirds from the shank base, to the front of the fluke, my friend these chains are attached to a added welded section square to where the shank is welded, any proof test like this will produce a shank strength many times its strength than if proof tested as per DVNV, LOYDS N.M.S.C. THE LIST GOES ON, talk about controversy.

Certainly there is to be no welded sections to be applied to any part of the anchors construction.


Well Don L, you want entertainment this should keep you going for a while, as an example of how it is done I have uploaded a section from our web site, you will probaly kick it out, I would have uploaded pictures only but I dont know how to upload just the pictures, if some one wants to do it for me before pulling it from the thread I would appreciate it, if you look at how Ultra do it it is vertually the same as Robertson testing from the USL Code and Lloyds rules.

The below link shows you how the shank and the fluke plate are hooked up for proof testing, this is to gauge maximum strength of weld structure fluke toe and shank strength, massive leverage is apllied in this link as compared to the one above.

Regards Rex.


Proof and field testing of anchors | Anchor Right News and Updates

[Cotemar]

Originally Posted by congo

I really am blown away with the video on this link, who is responsible for the captions of Lloyds an Rhina, this proof test, I have never seen anything like it, surely this is a set up.

http://www.petersmith.net.nz/boat-an...cna-issues.php

These are just the facts.
No conspiracy theory here, as you guys so fondly refer to when the data does not meet your needs.

Isn’t (High tensile steel), yield strength 690 MPa min. better than Sarca and Super Sarca made of mild steel.

[congo]

Well Cotemar I dont remeber saying anything about a conspiracy,what put that in your mind, all Iam saying is we have been proof testing to meet all the required proof testing rules over many years- many times to destruction.

None of what I see on that video relates to correct procedure here in Australia at least. And certainly dosent comply with the various proof testing codes.

As you are aware Cotemar, whilst the super sarca is 350 grade mild steel and we have never tried to hide the fact, it is on our web site for all to see, you are also aware the shanks on Sarca, and Super Sarca are one and a half times thicker than on the Rocna, or the Excel for that matter to cater for the extra strength needed for proof testing.

If we were to fix, weld sections to the Super sarca and pull in more of a lateral test as the one you have posted, I wouldn't mind betting we would blow it away.

That video, I am sure that was around long before the take over of Rocna,I would be checking the date of when it entered You tube if I were you.

Sorry to upset your camp just commenting on what I see.

Regards Rex.