Tuesday, June 10, 2014

Dynamic Travelers

Cross-fertilization between interests is a good thing. In fact, the most interesting things are usually discovered at the intersection between two fields rather than at depth in one.  Over at Sail Delmarva, Drew brings a fusion of sailing and climbing. And in this particular fusion, we learn that low stretch line is not the be all and end all...
Some lines cry out for low stretch; elastic halyards and genoa sheets both allow sails to become more full in gusts, exactly when flatter is better.  For other applications some give is in order; tethers and anchor lines come to mind. Travelers fall in this latter category.

We know the sound of a traveler screaming across, and we all cringe, waiting for the "bang" that follows an accidental jibe.  During a proper jibe we brake the traveler car's motion by controlling slack and easing it out, but mistakes happen.  Some times we're short handed and a flying jibe in light air is not a terrible thing, not if the car was at least brought to center first.  Why not use nylon--better yet, highly dynamic climbing rope--to absorb the energy?

The same 8mm line I use for tethers. Notice the sewn eyes covered in rigging tape for UV protection; a knot would do, but testing for an upcoming Practical Sailor article about stitched eyes and another about chafe protection started some time ago.

It has been suggested--by folks that haven't tried it--that nylon traveler line will stretch too much.  Nonsense, it's just a matter of selecting the correct size for the boat.  Yesterday I took my PDQ for a blast in 15 knots sustained, right at the edge of reefing and hence at maximum main sheet loading. Slamming waves and powering through gusts, the traveler car quietly working through a 1/2-inch range of motion.  For test purposes I have crash jibed in 15 knots (with a reef in) intentionally, just to see what would happen; 2-4 inches of give and harmless thud rather than sharp impact. Obviously the jibes that can cause damage and normal working pressures are much different.  Unlike easing a genoa sheet which often powers the sail up more, easing the traveler relieves pressure in the correct way, without affecting sail shape.

Yes, I can see and feel the line stretch in a breeze.  The traveler may be pushed an inch further with the same settings as compared to light air, but a traveler is meant to be adjusted frequently and I would never notice were the line not marked.  Why is it marked?  In order to assure jibe shock absorption on gusty days it is important to maintain a 3-4 inch cushion from the traveler end stop, and a whipped marking shows that position at a glance.

What line size?  For hand-tensioned travelers, 8mm should be about right for any size boat.  For larger boats 10-11mm climbing rope is available. Simply use the same size as appropriate for polyester.

Climbing rope is available by the foot from MEC.

1 comment:

  1. This is interesting and seeing as I am installed a triple block traveller on my steel cutter this spring, it's worth looking at more closely.


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