Climbing rope for traveller control line

[thinwater]

Originally Posted by TMarvin

... Correct me if I'm wrong but don't most climbing ropes get replaced after a set amount of falls? ...

Yes, this is incorrect.

Rope condition, even in climbing gyms with strict insurance requirements, is evaluated in much the same way it is for running rigging. Overall chafe and bad spots. This is because the max gym fall is at most 1/3 of a UIAA test fall (the geometry prevents it), and most are many times less than that.

Internet myth. Ask any experienced climber.
---
And yes, it is always better to control the jibe. I do not believe anyone has said or implied otherwise. It's not either or.

[thinwater]

Originally Posted by wingssail

There is no point, I just like telling a good story.

And it is a good story, well told!

[thinwater]

Originally Posted by TMarvin

... It may work fine in small boats under 30ft but it would scare me continually on a 45ft catamaran. Do you have a spinnaker? If running long distances down wind you can use that and drop the main, problem solved.

Lets do the math on this. My cat was 34 feet, but I was also using 7 mm ice climbing rope, which is only 40% of the strength of heavy duty 11 mm climbing rope. The larger boat will almost certainly be 4:1 purchase instead of 3:1 purchase, so an 11 mm, 4:1 tackle will be about 3.3 times stronger than mine. The sail area will be as the square of LWL, so about double, but run in a bit more wind. About 3.3 times the pressure. So the working load factor is the same, and never exceeded a few percent of breaking strnegth at the reef point (measured, not guessing).



Climbing rope, if used will be very nearly the same breaking strength as the polyester line but with a longer fatigue life. If you use larger than 11 mm (7/16-inch) then climbing rope will be too small. Done. This is the upper limit of the exercise based on available rope sizes. Likewise boats smaller than 30 feet may be better served by small nylon double braid, since 7 mm is the minimum size. It is too big for my 24-foot trimaran, which uses 6 mm line.



Is the line hand tensioned or winched? If it is hand tensioned, climbing rope is almost certainly enough, or it would need more purchase.


And controlling the jibe is always better.

[wingssail]

Originally Posted by Nooka

This thread is really interesting (hello btw. - I don’t post very often because the levels of knowledge on here can be a bit intimidating, but I’ll stick my neck out this time).

I had never considered the possibility of using the preventer as a sort of ad hoc boom brake, and don’t really understand the forces enough to try it in anger without checking, but it sounds promising. We are centre cockpit, 40m2 main, main sheet led to boom end on a cockpit width traveler immediately aft of the cockpit coaming. I can manage the traveller by hand but there is a fair bit of friction and my thoughts have been how to reduce this. But am I coming at it the wrong way? Should I perhaps be thinking about selectively introducing a bit more friction in the leeward system, perhaps by looping the line round a winch, or just playing with the angle of the line exit, then leaving the leeward end uncleated so it would act like a rudimentary boom brake. It sounds so simple it must be a stupid idea but perhaps someone can confirm that and I can put it to bed.

This technique will probably work, we sometimes do this (leave a couple of turns on the mainsheet, uncleated and let it run when the main jibes over) However you will be surprised at how hard it is to predict the amount of turns which would be needed to do it the way you want. One time there will be too much friction and it won't run out at all, the next time it will fly all the way to the stops.

[limte]

We use polyester line for the traveler, and 1/2" nylon climbing line for the gybe preventers. The preventers use a four part tackle. The traveler line is allowed to have a bit of slack in it, so that it is not taking any strain. One of the preventers keeps strain off of the traveler, and the other one prevents the boom from swinging across in the event of a gybe. We've used this system for years, with no problems. In the event of an unintended gybe, the nylon line absorbs some of the force, while the boom stays virtually immobile until the preventer is eased.


Regards,
Limte

[Brian Renwick]

Originally Posted by wingssail

We have never intentionally used a stretchy line on our traveller. It is a five to one tackle and we use small diameter polyester double braid.

We have no boom brake. Generally we control the jibe with the mainsheet. If the wind is moderate we "barn door" the mainsail, meaning we pull it in by hand and let it fly. The shock is absorbed by the multipart line in the traveller and the mainsheet. We have a big mainsail and occasionally it has jibed accidentally even in heavier winds. The sound is awesome but the system has held. (once however it caught the mainsheet trimmer in the back and launched him head first onto a winch (ouch) another time it caught me by my ankle and hung me upside down which resulted in a lot of rope burns).

So basically I am saying the putting stretchy line on the traveller to soften the shock of an accidental jibe is nonsense. I just do not believe in taking extra precautions to mitigate rare events which don't need mitigation. It isn't needed.

It seems to me that the 2 accidents are wake-up calls, which you are choosing to ignore.
The idea of a traveler that will absorb heavy shock loads has merit, as it reduces severity of damage or even prevents it altogether, and reduces the risk of injury to crew. Having a safer rig though, does not mean you should up the ante by taking risks you otherwise wouldn’t.

[Brian Renwick]

Originally Posted by TxCoastSailor

We have done it as well. Used a dynamic climbing rope, don’t remember the exact product but it was purchased from Amazon. Didn’t put eye splices where the rope attaches to the traveler. Simply pass the rope through the eye and tied a stopper knot. We have had this line on the boat for two years or so without any issues.

Have you checked that where your stopper knot is placed, there is no significant side-loading for which the hardware to which it is attached is not designed?

[Brian Renwick]

Originally Posted by wingssail

There is no point, I just like telling a good story.

And a bungee situation would have had even those stern-faced Colombian officers break out in smiles 😏

[Brian Renwick]

The more sailing and mountaineering literature I read, the more examples I find of men and women who indulge in both activities, which have a lot in common. Much of the gear and knowledge from one activity is transferable to the other…

[thinwater]

Originally Posted by Brian Renwick

Have you checked that where your stopper knot is placed, there is no significant side-loading for which the hardware to which it is attached is not designed?

I doubt the load is that high, but yes, a compact knot like a halyard hitch would be better. I used a sewn eye for compactness, but that requires some technique.

[malbert73]

Thinwater- I appreciate the engineering and validation- my traveler line is vintage polyester and I like the idea of reducing shock loads during uncontrolled jibes- which are best to prevent but also will happen from time to time. It is good to reduce the chance of exploding shackles and gear…

[TMarvin]

I am in a catamaran too though so jibing is easier. I pull traveler to the center and ease over the few feet with preventer by hand before letting traveler back out. Seems to work pretty good for me.