Strop strength

[Neeves]

Dear Neeves ...

Sadly - you assume that all modern materials improve or increase possibilities ... which unfortunately for you is not always true.
In the case of some super strength combos in cordage - some actually state you are advised not to splice as the material is too slick and does not 'bind' ........ I'll leave you to look that one up ...
As to your swipe at Anchors / Rodes and Catenary's - that certainly is way of the mark. Remind me not to anchor near you !!

For some reason you seem to have interpreted my post as some form of criticism of you - I apologise - that was the opposite to my intent.

Me thinks you are more sensitive that I would have thought. and are reading content that does not exist.

I'd withdraw the post - except it was not about you, at all.

Jonathan

 

[zoidberg]

What is sad is that much of sailing knowledge has not moved on and we seem stuck in some sort of intermediate era trying to impose old skills on new product (or worse - ignoring the new and sticking with the old).

..... I do become obsessed by the..... modern yachtsman's inability to accept modern developments. I'm also disappointed at the constant criticisms - we should be encouraging - we newbies have much to learn.

I understand, but come at this from a rather different direction.

I see 'modern yachtsmen' not much interested in a deep understanding of the problems their expensive 'new technology' is intended to resolve. 'Convenience is king', almost regardless of cost, and if a solution is mucky, sweaty or hard - it is rejected and 'help' called for.

It seems to me that most of the problems we face in our boating are ages-old, presented to us by the same winds and waves. In previous ages, those of our g'fathers working on the water invented solutions - often ingenious - to such problems using the materials that were readily available to them and affordable. For example, painting their hull bottoms with tar each season was preferred to sheathing with sheet copper.... Tools, materials and knowhow were carried to fix things that inevitably wore out or broke.

I'm much more interested in understanding the problems, and also understanding the solutions that were invented in past ages, to make better use of modern materials and designs. For example, understanding how traditional ropes became damaged and were protected by our g'fathers, and applying that knowhow - suitably modified - to high performance running rigging. Using repurposed firehose as 'sacrificial' chafe protection to anchor and mooring rodes instead of expensive manufactured anti-chafe sleeves from chandleries..... 'baggywrinkle' made from old braid halyards used on a high-tech trimaran to prevent shroud damage to the mylar mainsail.

I'm intrigued by top modern riggers using e.g. the likes of 'zero creep' Dyneema D20 for standing rigging on ultra-performance foiling catamarans, developing 'soft shackles', using torque ropes in furling spinnakers.... while being prepared to use older solutions and materials where they remain valid and economic, such as 'fishing' a broken carbon boom with splices and wedges.

Shrouds in Amsteel 1/10th the weight of the 1 x 19 stainless wire rope they replace.... Low Friction Rings replacing heavy, costly sheave blocks..... Engineering plastics used in rudder bearings and halyard sheaves....

The knowhow to construct a 'sheer legs' with sound lashings to lower/raise a mast or engine..... to suss out what the weather will do over the next few hours by observing the sky and the barometer rather than an app..... to mend or 'jury rig' a damaged mast and get home without calling for a lifeboat.... to sail onto/off a mooring reliably when the engine fails....

To me, there's value in knowing and using new products - and also knowing and using older solutions when warranted or just convenient.

'A larger toolbag, with many more tools in it....'

 

[Refueler]

For some reason you seem to have interpreted my post as some form of criticism of you - I apologise - that was the opposite to my intent.

Me thinks you are more sensitive that I would have thought. and are reading content that does not exist.

I'd withdraw the post - except it was not about you, at all.

Jonathan

Think a matter of both misreading posts .... but I wasn't thinking criticism of my post ... as we all have opinions ... My reply was as posted because just because a modern material does not automatically mean better product in all matters. Dyneema is well known for greater longitudinal strength - but also for its lesser factor in knots etc. Just clearing the point ...

Anchors etc. - well that's a subject that is always going to create opinion !! Me - I'm a KG + chain user ...

 

[Neeves]

Think a matter of both misreading posts .... but I wasn't thinking criticism of my post ... as we all have opinions ... My reply was as posted because just because a modern material does not automatically mean better product in all matters. Dyneema is well known for greater longitudinal strength - but also for its lesser factor in knots etc. Just clearing the point ...

Anchors etc. - well that's a subject that is always going to create opinion !! Me - I'm a KG + chain user ...

If you search, not very far, you will find that the slippage characteristics of Dyneema are well recognised and that splice and knot techniques are now widely available that will allow you to use the inherent strength qualities - with safety. Starzinger did a lot of work 15 years ago (its not new) and now you can google dyneema and splicing/soft shackles etc and have so many self help videos you will not know where to start. I recall the time, not so long ago, when dyneeema was not recommended, by the cordage manufacturers, for use without a braided cover - to protect the dyneema from UV. Once the tests were completed - that recommendation went out the window. But I still see the 'poor UV resistance of dyneema' quoted (in this forum). I still see mention of how abrasion resisting is dyneema - tests show that is also wrong, depends on the abrasion.

If you quote opinions you can be wrong and in the absence of data - it can be dangerous - quote technical data and you are on firmer ground. I'm the first to accept one cannot keep upto date on all technology - which is why I have something of a focus - and don't pretend to be all things to all men, and women. It is also why some of us restrict our comments to researched and tested advice and don't offer opinions. People do not research - and you might have seen a query on using dyneema to attach anchor to chain - do only a little research and the question is answered - the work has been done

Good luck with a reliance on catenary in tight anchorages with lots of fellow yachts. Most of us carry a finite length of chain. There are options - and being a kg and chain person to the exclusion of anything else is questionable. Snubbers are hardly new nor novel - but closing your mind to them seems perverse - a bit like leaving your phone at home but carrying a sextant when coastal cruising (in case the GPS goes down).

Anchors should work by design not weight, I and thousands of others would rather a 15kg Spade than a 15kg CQR for a 40' yacht - but if you are comfortable with a 15kg, or 20kg or even 40kg CQR - go for it. The 40kg CQR and 100m of 10mm chain is going to do nothing for your sailing ability in a 40' yacht - and that is why we are here - to go sailing.

Take care, stay safe

Good luck

Jonathan

 

[Refueler]

Oh Dear ..... what a lot of supposition and insertion of things never said by me in your 'dissertation' on my point of view and posts.

Just to say one thing on chain catenary ........... I am not one who just chucks out chain as some do ... nor am I one who turns blind eye to evolution or developments. I do read tech - keep up generally with new - but like many - not to the point of being a bore or curing insomnia.

I have anchored at times and had others anchor nearby ... to avoid argument with them - have picked up and moved when their boats observed to be veering / playing on rope rodes putting myself and others at risk. Snubbers have their place - but are not a universal do-all answer ... place and means for all ... I prefer to utilise weight and holding of both anchor and chain and not just trust an anchor to 'set' .....

I shall go back to playing with my boats and you with yours ... Bye ...

 

[zoidberg]

There's a lot of hesitation, deviation and repetition going on in this thread.

I'm far more interested in the design, make-up and performance of multi-part strops - which I need for certain tasks on my wee boat. There are plenty of other threads for wittering on about anchoring....

F'r instance, would one make up a 'selvagee strop' from Dyneema cordage, then use it in a 'Spanish windlass' arrangement to assist the 'fishing'/support of a damaged boom?

When Jean-Luc Van Den Heede suffered a severe knockdown in the last Golden Globe Race, and his port lower shrouds tore a 10cm rip down his mast-wall, how exactly did he use Dyneema cord to 'beef up' the crippled components well enough to get him round Cape Horn and back to Les Sables D'Olonne without his mast going over the side?

That's the kind of seamanship knowhow I'm interested in hearing about....

 

[Refueler]

Typical of all forums for 'thread drift' ............

 

[thinwater]

There's a lot of hesitation, deviation and repetition going on in this thread.

I'm far more interested in the design, make-up and performance of multi-part strops - which I need for certain tasks on my wee boat. There are plenty of other threads for wittering on about anchoring....

F'r instance, would one make up a 'selvagee strop' from Dyneema cordage, then use it in a 'Spanish windlass' arrangement to assist the 'fishing'/support of a damaged boom?

When Jean-Luc Van Den Heede suffered a severe knockdown in the last Golden Globe Race, and his port lower shrouds tore a 10cm rip down his mast-wall, how exactly did he use Dyneema cord to 'beef up' the crippled components well enough to get him round Cape Horn and back to Les Sables D'Olonne without his mast going over the side?

That's the kind of seamanship knowhow I'm interested in hearing about....

This?

I think the picture tells the tale.

You would need enough cord to bb stronger than the mast wall is in shear, and then find something to tie it to. The lashing tie-off is what snuggs it. The tape was just to prevent shifting, but I don't know what is under the tape.

Ordinarily, a Spanish windlass is not used with Dyneema to get it tight because it does not stretch and thus does not need to be pulled very far. A tight tie off of the lashing is often enough. But you could.

That really looks like a knife edge between those plates, but maybe it was polished round.
----

If he used Dyneema, which was forbidden, how did he win the Golden Globe? That repair could have been done with polyester, but not as well. (Not taking anything away from the guy, I just though some of the rules were dangerous.)

 

[zoidberg]

This?

I think the picture tells the tale.

You would need enough cord to bb stronger than the mast wall is in shear, and then find something to tie it to. The lashing tie-off is what snuggs it. The tape was just to prevent shifting, but I don't know what is under the tape.

Ordinarily, a Spanish windlass is not used with Dyneema to get it tight because it does not stretch and thus does not need to be pulled very far. A tight tie off of the lashing is often enough. But you could.

That really looks like a knife edge between those plates, but maybe it was polished round.
----

If he used Dyneema, which was forbidden, how did he win the Golden Globe? That repair could have been done with polyester, but not as well. (Not taking anything away from the guy, I just though some of the rules were dangerous.)

Yes, Drew, that looks like the 'emergency repair', although I hadn't seen that pic. J-L had huge prior experience, and Robin K-J had tipped him as 'likely winner'. He'd replaced his original mast wih a shorter, tougher and beefed-up section. His wary prudence - and his seamanship - paid off. A masterclass in self-sufficiency, and 'zackly what I'm banging on about above.

As for the 'forbidden Dyneema', more than little ol' me suspected that the rules were honoured more in the breach than the observance. F'r example, how did some of those guys manage to shape a course accurately due east just a mile or three above the Limiting Ice Latitude, day after day, while using only astro.... and with skies near-permanently completely obscured by thick cloud so that celestial observations for latitude would be impossible....? What did they do to check for changing compass variation and deviation with large changes in latitude, then longitude...?

More than little ol' me suspected that marketing and sponsors' considerations trumped 'corinthian' ideals.... but the muggles who tuned into the website in their thousands didn't care.

Mor than little ol' me suspects the next one will be the same, only more so....

 

[fisherman]

Bit of drift: talking to a coal mine engineer about chain, he said you know it's been to the limit when it doesn't bend.