Slinging an unstayed aluminium mast

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  • 20 Jun 2022 03:51
    Reply # 12822134 on 12817106
    Further to Graeme's comment about the mast sticking: I suggest you avoid a stretchy rope like nylon.  We used it once when taking out the foremast on Badger.  The mast was slightly stuck and the crane driver kept on pulling.  The mast suddenly released and shot up into the air.  We were fortunate that the rope had stretched so much that even when the mast came back down again, it was above the deck, otherwise it could have unched a hole in it. Theoretically, you should be able to take off the coat, remove the wedges or equivalent and move the mast back and forth in the step, unless it has a polyurethane collar.  Good luck!
  • 19 Jun 2022 18:26
    Reply # 12821761 on 12817106

    For the load-carrying element of the sling you might like to consider the Icicle Hitch, see photo of instructions page below.  Steps 4 and 5 call for slipping a loop over the end of the "foundation", which in this case would be the top of the mast, so you would need to figure out how to lead the working end round the mast and through the previous turns.  The write-up recommends it as being effective on a slippery surface with reducing taper, so should fit the bill.  I have not used it to sling a mast, but tying it round my mizzen supported my 75kg person with ease. 

    Under load some of the loops of the hitch slip initially, opening up a gap between two groups of turns, which effectively tensions the interconnecting lines (which pass in opposite directions round the mast), creating the grip, and preventing further slippage.

    I think you may struggle to persuade the boat yard to adopt the hitch, largely perhaps due to its unfortunate name, which, like the name "junk rig", creates an inaccurate preconception of its efficacy in the mind of a third party.

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  • 16 Jun 2022 23:16
    Reply # 12819345 on 12817106

    I've stepped and unstepped masts constructed of alloy and of carbon fibre, painted with glossy polyurethane. The weight of the mast was taken with rolling hitches. I was uncertain to begin with and used a series of 3 hitches. There was never any sign of slippage and on one occasion, the crane began lifting the boat, which was held by a vacuum between the hemispherical heel of the mast and the greased glassfibre socket into which it fitted precisely. It makes sense to use rope of a size commensurate with the size of the mast. For Branwen's 20cm diameter masts, I used a 16mm, 3 strand mooring warp. One further point: neither of the masts I lifted like this was tapered low down near the partners.

  • 15 Jun 2022 23:24
    Reply # 12817986 on 12817106

    Well, I can't tell you how much I appreciate you guys taking interest to my request.
    All of your advices make sense and are comforting my thoughts.

    Two things for me to do now:
    1) adapt a clamp or collar at the bottom of the mast, big/strong enough to do the job without risk of crushing the mast,
    2) convince the yard boss that the job can safely be done.

    I don't know what kind of resistance to expect when lifting the mast from its partners, I have no idea of when it has last been done.

    Anyway, the job will have to wait until China Blue returns from the AGM!

    Thanks again,


  • 15 Jun 2022 22:46
    Reply # 12817956 on 12817106
    Anonymous member (Administrator)

    Darren: Make sure the webbing sling is ABOVE the balance point of the mast!

    Yes. Darren beat me to the post while I was busy trying to prepare a diagram, as Darren's sequence of photographs doesn't show it very clearly.

    I used to operate a Hiab crane truck and over a period of time got a bit casual about making sure the loop is clearly above the centre of gravity of the mast and its rigging. One day, a mast flipped upside down, slipped out of the sling, landed on its head and flopped full length. (That only happened once! But I suppose it proves you don't want to rely too heavily on the "skill" of the operator) 

    I never used a loop which pulls tight at the top, finding it more convenient for the arrangement to be simple and for the loop to be not too loose, but able to slide up or down (especially at the end of the reverse operation, installing a mast). [Edit - I just realised, David has already made the same suggestion].

    And anyway, if the mast is tapered I don't think a tightened loop can be relied on to carry weight.  Regardless, loop tightened or not, the attachment point at the bottom should be assumed to be carrying the full weight of the mast.

    (I have lifted with the loop close to, or a little below, the centre of gravity, by having a reliable person with the strength and weight to hold the base of the mast and restrain it from flipping. But that’s a bit dangerous and not recommended. I don’t like depending on the skill of other people. Better to get a high enough crane, and keep that loop sling plenty high enough if you can. You need a little safety margin too, because when the mast is out it will lean a little, and the weight of halyards or anything else hanging straight down from the mast head also wants to help the mast to flip).

    Another little point to be aware of - if the mast is raked it might want to jam a little at the partners - or maybe that synthetic rubber collar which some people cast into the partners might stick (not sure about that as I never lifted a mast with that detail) - anyway, if the mast sticks a bit, the power of a hiab crane will build up tension in the arm - like a bow - and in that case when the mast finally unsticks it can jump up and out of the partners - like an arrow. (A slight exaggeration, but you get what I mean - I have seen that happen and it can give you a surprise. So much for holding the base of the mast).

    As Darren says, its no big deal, and easier than you might expect. Just - be methodical and careful.

    Last modified: 21 Jun 2022 02:03 | Anonymous member (Administrator)
  • 15 Jun 2022 22:01
    Reply # 12817896 on 12817106

    Yes, that's right Patrick.  Also, the webbing sling tightens on the mast so the line running down only holds part of the masts weight (no idea what proportion).  Make sure the webbing sling is ABOVE the balance point of the mast!

  • 15 Jun 2022 17:57
    Reply # 12817550 on 12817106

    Thanks Darren, very interesting!

    On picture  2/5, I suppose the line that goes down from the textile sling is the one that takes up all the weight and is tied to the collar on picture 3/5.

    Then the other line that goes up would merely be there to lift the sling at the right place?

    Correct me if I'm wrong!


  • 15 Jun 2022 17:27
    Reply # 12817511 on 12817106

    I made an album with some pics of our mast removal if that helps (click photo below).  We had a collar lower on the mast for turning the lines to the pilothouse that we could use as an anchor, but otherwise as David describes.  This is one of those jobs that turned out much easier than I thought it was going to be (in part due to the skill of the crane operator).

  • 15 Jun 2022 16:38
    Reply # 12817411 on 12817106

    OK David I think  I understand.

    Still using as a loop, then it would look like on attached picture.

    Correct me if I'm wrong, and thanks again for taking the time to help!


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  • 15 Jun 2022 16:01
    Reply # 12817375 on 12817106

    Better to tie a loose bowline around the mast, so that it slides easily up the mast when hoisted on the crane hook before unstepping, and drops down easily after stepping again.


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