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  1. #11
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    Default mooring

    I gather from your post that you were surprised at the amount of wear, my club advises and if we could we would insist, that all groung tackle is examined annually. How long did you expect the gear to last, in most cases there is a lot of investment swinging from these little bits of quite inexpensive metal bits, I never understand not renewing annually, most harbour authorities round here require certification by a local mooring contractor.
    Time is of the moment.

  2. #12
    SAWDOC's Avatar
    SAWDOC is offline Registered User
    Location : Ireland West Coast
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    Quote Originally Posted by tabernacleman View Post
    I gather from your post that you were surprised at the amount of wear, my club advises and if we could we would insist, that all groung tackle is examined annually. How long did you expect the gear to last, in most cases there is a lot of investment swinging from these little bits of quite inexpensive metal bits, I never understand not renewing annually, most harbour authorities round here require certification by a local mooring contractor.
    Well, I started off by saying this was a newly laid mooring. It was also the first mooring I laid so I honestly didn't know. Five years on, I am of a mind to inspect annually with a view to replacing every three years. It is probably something that is user and location specific.

  3. #13
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    .
    Our riser lasted five years and was worn to about 8mm from 19mm when we replaced it. That sounds like its bad, but our anchor chain is 8mm!

    - W

  4. #14
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    Jun 2001
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    Quote Originally Posted by SAWDOC View Post
    I use galvanised chain and galvanised shackles. As Vyv mentions above, every winter it is gathered up and dropped to the bottom into the anaerobic mud of the bay. Thanks for illustrating the corrosion by abrasion issue Vyv - what was the seabed matreial in the area in which that chain was used?

    To compare the before and after shackle size, I am posting a pic of the replacement shackle which to the best of my knowledge is very simiar to the corroded shackle above.



    I agree with VicS that one has to be extremely wary of shackles of unknown origin from whatever source. The green pin shackle in the next pic come with a CE mark and I assume they are of a good standard. I would be interested if anyone has any comments on their performance.


    Green pin shackles are a trade mark of one of the better hardware companies and as they are extensively used in the offshore business and shipping they should be OK for you.



    http://www.vanbeest.nl/products/product_updates/item/22
    Eastern Scotland and beyond.

  5. #15
    SAWDOC's Avatar
    SAWDOC is offline Registered User
    Location : Ireland West Coast
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    Thanks for the link Bilgediver - must give their catalogue a look. Are all green pin shackles vanbeest?

  6. #16
    impact30's Avatar
    impact30 is offline Registered User
    Location : Limerick Ireland
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    Hi Tony
    On the Shannon estuary moorings are similar but all use riser chain. Rope can get caught on keel during change of tide as there can be strong currents. It is almost unthinkable here to put a boat on a mooring at the start of the season without first inspecting the mooring. Shackles are changed annually and riser chains every other year, sometimes they can last 3.
    Tested shackles (green pin) seem to fare better. PTFE tape on the threads can preserve them and aids removal. Dont even think of putting grease on anything down there!
    It is usual here to use uncoated ground chain with galvanised shackles, swivel and riser chain. Anodes for chain are usually magnesium/aluminium type but are seen as prohibitively expensive for their effectivness around here.
    Sin a Bhfuil
    Padraic

  7. #17
    William_H is offline Registered User
    Location : West Australia
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    Default Mooring hardware wear

    The stories and pictures are typical of wear of iron on moorings in Swan River except perhaps faster here in warmer water.

    I disagree re quality of shackles (and chain) the only thing you need is iron. So far better a bigger shackle of unknown origin than a high quality fully tested shackle that is smaller. In a mooring the gear needs to be so big that actual strength is not an issue. You need large size so large amount of wear still leaves a lot of metal.
    Some people have reverted to rope for mooring riser here with some success. You need a large diameter rope and the steel thimbles will still wear away. As will any shackles used.

    Our mooring authority suply and require the use of a large yellow buoy. Too heavy to lift on board. It comes with a stainless steel rod through the middle with a swivel built in. I think the metal about 16mm diameter.
    Originally they expected boats to use the swivel however the stainless rod failed on many occasions. (about 2000 in use) so replacements deleted the swivel so you had to connect under the buoy. Not necessarily better but gets them out of responsibility. Though many people still rely on the built in swivel.

    The stainless steel however caused accelerated wear/corrosion of the Galvanised Iron shackle. I have now gone for all stainless with home made swivel and chain. The chain a gift from a friend out of some furnace.
    Well it has been stainless now for a few years with no signs of wear. The smallest bolts in the swivel are about 10mm. I do have some GI connecting additional weights/ anchors but this is isolated by sections of rope so no GI to stainless connection.

    I did get a shock a few months back when the authority rang to say the buoy was found on the beach. the rod up the middle had failed. There was a nut on the threaded rod with a pin through it to stop the nut coming loose. The rod had failed at the hole and the nut unscrewed. Fortunately I had moved the boat connection to the riser so only the buoy escaped. They gave me a new rod for the buoy now 18mm stainless. That should last better than the original.

    As for attachment to the boat. I use a rope to a snap shackle on the winch out eye half way up the bow. This eliminates all chance of chafe. I then have a second line onto the standard cleat on the foredeck. I remove the bottom connection on arrival by dinghy and reconnect before leaving the boat. The top line is used to cast off and piuck up.

    So yes even with the best heaviest gear a mooring needs to be inspected every year. In shallow water I check mine visually by diving every few weeks. This may help olewill

  8. #18
    SAMYL is offline Registered User
    Location : Strangford/Belfast
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    Quote Originally Posted by SAWDOC View Post
    I use galvanised chain and galvanised shackles. As Vyv mentions above, every winter it is gathered up and dropped to the bottom into the anaerobic mud of the bay. Thanks for illustrating the corrosion by abrasion issue Vyv - what was the seabed matreial in the area in which that chain was used?

    To compare the before and after shackle size, I am posting a pic of the replacement shackle which to the best of my knowledge is very simiar to the corroded shackle above.



    I agree with VicS that one has to be extremely wary of shackles of unknown origin from whatever source. The green pin shackle in the next pic come with a CE mark and I assume they are of a good standard. I would be interested if anyone has any comments on their performance.

    In Belfast Lough and Strangford Lough it is prudent to change shackles every year as they seem to corrode very quickly as per the photos shown above in some of the postings.
    As for the green pin shackles; my son works in a chandlers and was advised by the traveller from a shackle company that the green pin shackles should never be used under water, they are supposed to be 'high tensile' or very tough, so corrode quickly in sea water.
    I know one of the sailing clubs here some years ago bought chain from a coal mine in England which was closing but the chain was 'high tensile' or whatever, thinking they had had a great deal but it lasted less than a year when used for moorings!!!

  9. #19
    William_H is offline Registered User
    Location : West Australia
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    Default A worn shackle

    here is a photo of one I keep as a reminder. It was in service for 3 or 4 years then i saw it was wearing and fitted another in parallel. They are a devil to remove when underwater so I left it there. Eventually nature freed it. All in about 5 years. yes it started as a 10mm shackle. olewillhttp://www.ybw.com/forums/attachment.php?attachmentid=3734&stc=1&d=126662781 1
    Last edited by William_H; 07-06-11 at 09:53.

  10. #20
    vyv_cox's Avatar
    vyv_cox is offline Registered User
    Location : North Wales, sailing Aegean Sea or Menai Strait
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    Quote Originally Posted by SAWDOC View Post
    Thanks for illustrating the corrosion by abrasion issue Vyv - what was the seabed matreial in the area in which that chain was used?
    The chain was recovered from the seabed at Pollensa, Mallorca, where the bottom was sand. The chain is only 8 or 10 mm, on a very small mooring close to the shore. From the surface there was no reason to suppose that there was anything wrong with it. We remained in the anchorage for more than a week, during which I dived on lots of other moorings, finding many which were in similar, although not so severe, condition

    Moral - be careful when picking up unkniown moorings!
    Answers to some technical queries at http://coxengineering.sharepoint.com

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