A Great Racing Shackle For Cruisers

Colin’s post about the failure of a snap shackle on Pèlerin and his recommendation to stick with shackles made by Wichard or Harken, which we heartily agree with, got me thinking about another type of shackle that we have found very useful on Morgan’s Cloud. A type that may surprise you since it is normally associated with racing boats.

Eight years ago, we replaced all our halyard shackles with J-Locks from Tylaska. The big advantage of these beautifully made and super-strong fittings is that once they are locked with a half-turn of the pin, they just simply can’t come undone, no matter how hard they thrash around, or what they hit or brush against whilst doing so. (Diagram showing how the J-Locks lock.) This is a big improvement on normal snap shackles that can and will, at the worst possible moment, open up unexpectedly, and this is only made worse if they have lanyards attached to facilitate opening.

We also find that J-Locks are a great replacement for standard screw pin shackles since they don’t need pliers to close and open, or wiring (mousing) to be safe.

Inspired by a comment from Paul Mills, I’m even thinking that the next time we replace our lifelines, we will replace the boarding gate portion with rope and J-Locks to get rid of the pelican hooks, all types of which, that we have seen, can open when brushed by a crew member or thrashing sheet—an extremely dangerous weakness.

The one down side to J-Locks, aside from their expense, is that you do need to splice the line around them really tightly to make sure they can’t pop off the splice when open. We have our favorite rigger, who incidentally recommended J-Locks to us in the first place, do this for us.


We paid the same price as anyone else would for our Tylaska shackles and have received no benefit of any type from Tylaska or their resellers.


Any thoughts? Please leave a comment.


Like what you just read? Get lots more:

Please Share

Meet the Author


John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 12 years, as co-editor/publisher of AAC.

19 comments… add one
  • Stuart Dec 11, 2012, 8:32 pm

    I know they seem like a good idea, but once fingers get wet and cold, they are a pain in the rear to twist and open up. After a few years, the spring will get harder to twist making that moment when you have to open them up that much more of a pain. I just had to use them on a J120 last month in a two day race around the San Juan Islands. Not quite the high latitude cruising, but quite a bit of sail changes non the less. Just an opinion from the bow….

    • John Dec 12, 2012, 8:37 am

      Hi Stuart,

      I can certainly see that as a problem on the bow of a racing boat where every second counts, but we have not really found it a problem in our more relaxed cruising environment.

      Also, after eight years of use, we have not noticed that they have got any harder to open.

  • Dick Stevenson Dec 12, 2012, 5:39 am

    It is really nice to see someone creatively go after a problem. And for lifeline gates they may be much safer. I would like others to weigh in with their experience in use when the wx is cold and wet and the shackles are salty. Stuart’s comments certainly crossed my mind.
    You mention the need to have the shackle spliced really tightly and suggest having professional riggers do so. One alternative is to use a buntline hitch to tie on the shackle. It is essentially a slip knot that locks itself tight and so will become very tight onto the shackle. This is a bulletproof knot not to be used when necessary to untie regularly or quickly. This method will also allow the halyard to be turned end for end when the need arises, something hard or impossible to do with re-splices as the rope gets older. I have been using the buntline hitch in place of splices in this and other applications for years and found it a very useful knot to have in one’s tool kit. The one down side, there is always a down side, is that it can be very hard to undo the knot after it is loaded up, although, over the years, with patience, I have never had to cut one off. Another consideration is the reduction in strength of line, especially high modulus line, with knots. So far that has not been a problem. Generally, the new lines are so much stronger than old that some reduction in strength at the knot has not been an issue.
    Using buntline hitches with modern shackles is wedding the new with the old, providing me the pleasure of a satisfying symmetry.
    My best, Dick Stevenson, s/v Alchemy

    • John Dec 12, 2012, 9:07 am

      Hi Dick,

      Yes, the buntline hitch is a great and useful knot. I guess I just like the neatness and strength of a professionally executed splice in braid, but your points are all valid.

      One caution, for those that may not be aware, there is no knot, not even the buntline hitch, that will hold reliably when tied in a rope made of spectra (dynema). Those materials, and some others, must be spliced. If in doubt consult a good rigger.

      Just to clarify, there is no reason that a cruiser can’t do their own splices, if they practice enough. We just get Jay to do them because he can do 10 beautiful and reliable splices in braid in the time it would take me to do one, even though back in the dim and distant past, when I was a sailmaker, I used to do them professionally. This is in keeping with our policy of delegating high skill jobs that we don’t do often. See https://www.morganscloud.com/2012/10/17/40-rules-for-a-reliable-sailboat/

      • Martin Dec 12, 2012, 9:13 pm

        John said ” .. there is no knot, not even the buntline hitch, that will hold reliably when tied in a rope made of spectra (dynema)”.

        John, can you clarify whether the ‘knot-will-slip’ also applies to the following dyneema variants?
        1) Dyneema core with a braided polyester jacket
        2) Core of Dyneema bulked out with polypropylene and then jacketed with polyester.

        • John Dec 12, 2012, 9:58 pm

          Hi Martin,

          I really don’t know. I’m not an expert on rope types and splicing by any stretch (ouch).

          My guess would be that even a spectra rope with a Dacron sheath should not be knotted, but only spliced. My thinking would be that the spectra core is so slippery that it would eventually snake out of the knot leaving the Dacron sheath holding the entire load.

          But the key issue is that there are now so many different ropes that the only way to be sure of the right protocol is to ask the manufacture or a reputable rigger who has asked the manufacturer.

          • Colin Speedie Dec 13, 2012, 11:41 am

            Hi John

            I’ve always used the simple fishermans knot for joining spectra line, either to form a lashing or to make a quick loop as a shackle. I was told that this was the only knot that would hold in spectra, and so far so good.

            Maybe I was misinformed, but I’ve never had one slip yet.

            Best wishes


  • Giancarlo Dec 12, 2012, 7:11 am

    ciao John,
    based on the same idea as the Tylaska, i like better the Equipelite connectors ,they are much lighter and have all the benefit of dyna loops.to avoid the ,too small radious of the splice you can do a regular splice eye and do some cross whipping to fill the gap.not sure if i can post a pic to show how i do that

    • John Dec 12, 2012, 8:52 am

      Hi Giancarlo,

      The Equipelite soft connectors look great: http://www.equiplite.eu/en/products_non-swiveling-connectors

      However, I would worry about their strength after the eight years of near continuous exposure to sun that our Tylaska snap shackles have endured without any sign of deterioration.

      Soft fittings are great, but I do worry that the average cruiser, including me, might not replace them as often as they should. And, without regular destruction testing, how can you know how often to replace soft fittings?

      Each to their own, but for me, who likes to solve each problem for as long as possible, the Tylaska represents the best combination of reliability, ease of use, and long life.

  • Dick Stevenson Dec 13, 2012, 7:07 am

    So far, knock on wood, my knots using HM lines have worked out. A few things may contribute: To have the lines be sized for human use (even downsizing as i have done), they may be overkill for strength on my 40 foot boat whereas a larger vessel may use lines closer to the load limits where creep may occur. I also whip lines with an eye to seizing core to shell, often with 2 whippings, one at the end and the other a couple inches in. I am not sure whether the whippings really do much, especially with parallel laid core, but they make me feel better. Finally, I leave a bit more tail on the knot and stitch it lightly to the knot to make it a bit neater. I suspect that the tail would show creeping and may give a bit of warning. In thinking about it, I believe I only use buntline hitches (or splices) with HM/spectra dyneema line as my only use for them so far is halyards.
    My best, Dick Stevenson, s/v Alchemy

    • Colin Speedie Dec 13, 2012, 11:43 am

      Hi Dick

      I second your practice of long tails and a few stitches – especially for uses where the the knot can be subjected to much flogging, such as storm jib sheets.

      Best wishes


  • Giancarlo Dec 13, 2012, 11:57 am

    in my opinion any knot should be avoided on dyneema ropes in 1:1 configuration(ex:sheets -halyard) you loose the 50 % of the breaking load ,multiple single hitch are ok when used in a multiple turns configuration just to finish the bitter end(ex lashing blocks ) almost no load on the knots.
    not really sure i made clear my point…..

    • John Dec 14, 2012, 9:39 am

      Hi Giancarlo,

      I think you sum it up very clearly. I would agree completely.

  • Dick Stevenson Dec 14, 2012, 7:35 am

    Colin, Do you have experience with undoing the double fisherman’s knot after it has been loaded up? Spectra or otherwise? Dick

    • Colin Speedie Dec 14, 2012, 1:35 pm

      Hi Dick

      Yes, it can be done, but it’s not easy (as you correctly imagine), and a spike is needed. This of course, after you’ve taken the load off. And I only use this knot for Spectra, either where it will not be removed unless absolutely necessary, or where I want to use the Spectra in case the shackle fails, in which case it tends not to be too heavily loaded up.

      Best wishes


      PS – I only use this knot on occasion – in all other uses I’ll make a spliced strop/loop

      • Martin Dec 14, 2012, 11:18 pm

        And to add pain to the job of undoing a double fisherman’s – you have to break the knot twice; there is a fig-8 knot on either side, and you have to undo each, and they are both typically (from my climbing days) …ss tight after load.

  • Dick Stevenson Dec 14, 2012, 7:37 am

    Colin, Or the fisherman’s knot to a shackle (used as a hitch and not a bend)? Dick

  • tim tylaska Jun 18, 2014, 10:45 pm

    Probably old news now as I see this last post was over a year ago. No, Tylaska is still in business. There was a storm and server glitch back in Feb 2013 which brought down the site that week and somehow our host service put the wrong IP address pointer for our domain. Thus, it routed people to some other domain site. Only was that way for a few days until they corrected it. Sorry about any issues (now over a year ago) but we are alive and well here at Tylaska Marine!

    • John Jun 19, 2014, 7:13 am

      Hi Tim,

      Good to hear, I will delete the comments that refer to your company’s demise.

Only logged in members may comment: