is the PBO chain to rope splice sound?

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pcatterall

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I want to add rope to my anchor chain. On my last boat I used octoplait and spliced according to some PBO instructions. It looked sound and I was confident with the result.
This time I have spare 3 strand on board and would like to use that. Flying out to boat in France and no decent chandlers where the boat is moored.
I see that the recent PBO method( July 2013) shows the rope sort of 'back spliced' through the last link of the chain. Does this not subject the strands through the link to a lot of wear where they 'bend' back on themselves?
There seem only to be two strands of the rope through the link, is this not a weak point?
 
Yes - a very weak point. One ought to engage all three strands, and have each of them bend over a manufacturer-specified minimum radius. That's what a hard eye is intended to achieve.

That's not readily compatible with most rope/chain gypsies.

Could you consider a 'soft' eye spice through the last link of the chain - or through a suitable shackle - with a tough wear sleeve fitted onto the loop of the eye splice? That would be much stronger than the very-suspect PBO notion.
 
I learned to sail dinghies at the Emmsworth Sailing School, run by Crab Searle. That dates me, doesn't it? The anchors on the dinghies had traditional splices rope to chain as demonstrated in PBO, but I remember the instructor's comment that the rode was larger than required to make handling easier so the loss of strength was acceptable. Similarly the old style moorings where the bouy rope was used to haul the chain up from the seabed used that type of splice, again not to be fully loaded.

I use a hard eye splice and shackle on the rope rode if it is to attached to extend the chain rode and I accept that it won't ride over the windlass. Mind you, it won't pass through the pipe into the chain locker either!

Rob.
 
There is another kind of rope to chain splice where the rope is interwoven with the chain for some distance, rather than just looping through the first link. This seems more secure to me.

Pete
 
Not seen the PBO method but I used the rope chain splice shown on the Jimy Green marine website - where rope sided along the length of the chain
I doubled the length of the splice "for luck", and tapered the rope strands for the last few tucks to make a bit more streamlined

Haven't yet lain to the splice in a full gale (comes after 55m chain) but in that event I would want something that was as chafe resistant as possible as betting the boat
 
dunedin said:
"......I would want something that was as chafe resistant as possible as betting the boat."
Click to expand...

I still advocate slipping a length of very chafe-resistant timex'd firehose over that position, and tying it on to protect the rope strands from chafe.That's a 'zero cost' option - except it takes a few seconds of precious time. Me, I'd rather take all reasonable precautions to secure the boat.... then have my Mojito, or Sunbury Stinger, or whatever the latest poncey potion on offer is now.
 
oldbilbo said:
I still advocate slipping a length of very chafe-resistant timex'd firehose over that position, and tying it on to protect the rope strands from chafe.That's a 'zero cost' option - except it takes a few seconds of precious time. Me, I'd rather take all reasonable precautions to secure the boat.... then have my Mojito, or Sunbury Stinger, or whatever the latest poncey potion on offer is now.
Click to expand...

Sounds eminently sensible, although I'd want to eyeball the splice at the start of every season so the tying on would be zip ties or some lashing I could get a knife through.
 
oldbilbo said:
I still advocate slipping a length of very chafe-resistant timex'd firehose over that position, and tying it on to protect the rope strands from chafe.That's a 'zero cost' option - except it takes a few seconds of precious time. Me, I'd rather take all reasonable precautions to secure the boat.... then have my Mojito, or Sunbury Stinger, or whatever the latest poncey potion on offer is now.
Click to expand...

Sounds eminently sensible, although I'd want to eyeball the splice at the start of every season so the tying on would be zip ties or some lashing I could get a knife through.
 
dunedin said:
Not seen the PBO method but I used the rope chain splice shown on the Jimy Green marine website - where rope sided along the length of the chain
I doubled the length of the splice "for luck", and tapered the rope strands for the last few tucks to make a bit more streamlined

Haven't yet lain to the splice in a full gale (comes after 55m chain) but in that event I would want something that was as chafe resistant as possible as betting the boat
Click to expand...


Tapering the strands of a splice is a good idea for strength, as well. If you don't, you have a sharp change in diameter of the rope which acts as a stress concentrator. Tapering the splice (after the usual full 3-4 tucks) will make it stronger as well as smoother.

Of course, splices should be served as a matter of course - but I get lazy about that!

I must admit I've often wondered about chain to rope splices. I've never needed to do one, but I agree with OldBilbo that the usual splice (which is effectively an eye-splice with a vanishingly small eye) must be prone to wear, as well as stressing the strands of the rope excessively. It is noteworthy that Ashley states that the "Chain Splice" - which looks like the one described - is suitable for attaching hemp tails to chain rigging, not for anchor rodes. A Hemp tail would presumably only be used for hauling, with all real stress taken by the chain. I'd have thought that with octoplait you could do an effective splice over several links of the chain, weaving the 4-plait lay-up of the octoplait between the links (2 strands crossing through one link, then the other two through the next, and so on), turning the ends back over a couple of links, and then serving over the lot. That would spread the transfer of load from the rope to the chain over several links, and also ensure that any chafing was minimized. I think the splice would also be less bulky than the usual one.

I haven't had eny bright ideas about 3-strand rope!
 
Well, PBO's description of the chain splice splice is just as it appears in my 1968 seamanship manual, so I guess it's been around as a method for a while. With two strands each side of the link, and long splicing one strand, it's probably more efficient than a short eye splice - who will do the tests to find out?
 
I queried PBO on this having just installed a windlass and so far no reply. I also posted on here about it a few weeks back http://www.ybw.com/forums/showthread.php?362286-Rope-to-chain-splice&highlight= as my first splice was rubbish! I have now done another normal 'short' splice through the last link using 14mm 3 strand onto 8mm chain. To get it to 'seat' nicely I had to thread one strand through the link in the opposite direction to the other two. About 4 or 5 tucks with another 2 tapering off. This goes through the windlass very nicely. As the rope has 3 times the strength of chain a bit of wear is ok. My last rope to chain splice was over 2 links as the rope was 22mm 3 strand. 14mm looks like string!
As I now need calibrated chain for it to work hassel free, I will be redoing the splice again shortly unless I also change to octoplait.
 
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prv said:
There is another kind of rope to chain splice where the rope is interwoven with the chain for some distance, rather than just looping through the first link. This seems more secure to me.
Click to expand...

That's what I've done on my boat. It's been fine for several years.
 
The problem with rope-to-chain splice that weaves the rope along the length of the chain is that the chain rusts badly. With my kedge warp I have spliced a couple of metres of stainless chain on he end. My backup warp for the bower anchor now has an eye splice and shackle, though in 25 years and thousands of miles I've never used it.
 
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I have a mooring buoy strop made up of two lengths of 14 mm three strand rope with about 2 metres of 8 mm chain between them. On each end of the chain are back splices with all three strands of the crown knot passing through the final link. The splice does thicken the joint but would be perfectly OK if not required to pass through a gypsy, and might well do so in some cases.
 
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