Visit our Popular Forums

gilligansail · 10-07-2017, 11:20

Why are safety tethers made from webbing ?
I've been a rock climber for years. I could easily put together a section of line with an auto-locking carabiner and a snapshackle. What makes the commercial safety tethers worth over hundred dollars?

ub1 · 10-07-2017, 11:45

If you step on the webbing your foot will not roll. On a wet slanted deck it tends to happen.

capt jgw · 10-07-2017, 11:47

When you step on a round line it will roll under your foot, possibly causing you to fall or turn your ankle. Webbing won't do that.

foreverfreedom · 10-07-2017, 11:53

Quote:

Originally Posted by capt jgw

When you step on a round line it will roll under your foot, possibly causing you to fall or turn your ankle. Webbing won't do that.

I think he's talking about lifejacket/harness tethers - you don't put your foot on those without some fairly acrobatic footwork!

gilligansail · 10-07-2017, 12:17

Yes I'm talking about the life jacket tether
My jack lines are webbing to prevent rolling underfoot
Are the life jacket tethers long enough that you get them caught underfoot?

foreverfreedom · 10-07-2017, 12:24

Quote:

Originally Posted by gilligansail

Yes I'm talking about the life jacket tether
My jack lines are webbing to prevent rolling underfoot
Are the life jacket tethers long enough that you get them caught underfoot?

If you get a good quality tether, they come with a failsafe hook for the harness and two tethers; a short one and a long one; you use whichever suits the moment - generally moving forward is with the long one attached to the jackstay, and the short one for working at the mast. Each should have a failsafe fastening. Don't know why they have webbing but assume that it is easier to connect webbing to the three failsafe hooks, and the attachment at the hooks is smaller and less intrusive than knots/splices would be.

sailorboy1 · 10-07-2017, 12:29

Quote:

Originally Posted by gilligansail

Yes I'm talking about the life jacket tether

Probably because it costs less to sew the ends than to braid rope

foreverfreedom · 10-07-2017, 12:34

Quote:

Originally Posted by sailorboy1

Probably because it costs less to sew the ends than to braid rope

Knots are easier to construct and inspect than sewn tape, and sewn tape is easier to do same than on a spliced rope. Consequently, I use knotted rope on my Jumar ascenders when climbing, and sewn tape on my deck gear.

Time2Go · 10-07-2017, 13:19

My tether is made from hollow webbing
because there is a section of shock cord sewn
inside which scrunches up the length of the tether.
It keeps it taught and out of the way
Good bit of kit
Cheers
Neil

thinwater · 10-07-2017, 13:34

It's complicated. I've written a bunch on my blog (below) and tested products for publication. In fact, surprisingly many commercial tethers fail the tests--they are tough to pass with webbing, because it has too little stretch.

8mm climbing rope. Far more energy absorption capacity than webbing, and a much soft impact on the ribs.

Autolocking climbing carabiners are prone to locking with corrosion if not carefully maintained. That said, the Kong Tango, show above, is used on may commercial tethers. A little waterproof grease and a regular freshwater rinse.
The autolocks should ones that can be operated with one hand, wet, in the dark, with gloves. Really, only the Kong Tango does this well (you can get them on Amazon). I get away with locking biners because I leave the tether on the jackline (I keep them on both sides).
Some people like quick release, some don't. Quick release makes sense for boats that can roll over and for people who sail with crew.
The CE standard contains a demanding drop test. You will not be able to pass the test with 1" climbing webbing, with knots, or with anything you can sew at home.
Climbing rope is a bugger to splice. I use sewn ends, but I have also pull-tested hundreds of sewn eyes. This is very difficult to do to full strength--you are better off with knots. Climbing ropes can pass drop tests with knots.

Personally, I like custom length tethers, because 3'/6' is wrong for many boats. But home construction of these to CE standards is very, very difficult.

Yeah, I think for many people they are worth $100. I did not make my own because of the money, I did it because I wanted something different (more stretch=softer catch, different lengths because a catamaran is wide).

I go into the engineering of tethers and jacklines in "Singlehanded Sailing for the Coastal Sailor," below.

Time2Go · 10-07-2017, 13:51

Quote:

Originally Posted by thinwater

It's complicated. I've written a bunch on my blog (below) and tested products for publication. In fact, surprisingly many commercial tethers fail the tests--they are tough to pass with webbing, because it has too little stretch.

8mm climbing rope. Far more energy absorption capacity than webbing, and a much soft impact on the ribs.

Autolocking climbing carabiners are prone to locking with corrosion if not carefully maintained. That said, the Kong Tango, show above, is used on may commercial tethers. A little waterproof grease and a regular freshwater rinse.
The autolocks should ones that can be operated with one hand, wet, in the dark, with gloves. Really, only the Kong Tango does this well (you can get them on Amazon). I get away with locking biners because I leave the tether on the jackline (I keep them on both sides).
Some people like quick release, some don't. Quick release makes sense for boats that can roll over and for people who sail with crew.
The CE standard contains a demanding drop test. You will not be able to pass the test with 1" climbing webbing, with knots, or with anything you can sew at home.
Climbing rope is a bugger to splice. I use sewn ends, but I have also pull-tested hundreds of sewn eyes. This is very difficult to do to full strength--you are better off with knots. Climbing ropes can pass drop tests with knots.

Personally, I like custom length tethers, because 3'/6' is wrong for many boats. But home construction of these to CE standards is very, very difficult.

Yeah, I think for many people they are worth $100. I did not make my own because of the money, I did it because I wanted something different (more stretch=softer catch, different lengths because a catamaran is wide).

I go into the engineering of tethers and jacklines in "Singlehanded Sailing for the Coastal Sailor," below.

Can't find the mentioned link but i think i have read it
before
My question is: Is the drop test a proper test for a tether, given the fact that the jack line will have
a certain amount of give and flex?
If attached to a hard point what is the likely hood
of a 6 foot dead fall?
Webbing should be bar stitched
the box with an X inside is a no go
Cheers
Neil

roland stockham · 11-07-2017, 08:12

I agree about the corrosion points, climbing crabs don't do well in salt water! But when looking at tethers you need to consider them as a system. There are a number of ways of doing this depending on the deck layout but you should be looking at overall strength and energy absorbtion. Also bear in mind that it is essential to prevent crew going over the rail and being dragged (leads to drowning).
The traditional solution of webbing has been around for some time and new products offer new possibilities. I am now converting to HMP lines surrounding the cabin top about 1ft above the deck so no trip hazard. Break load is way above anythin tape can do and similar to steel cable. Elasticity is very low so replacing harness tethers with climbing line to give shock absorbency. This also makes them cheaper and esyer to replace so can be done each season.
A word of caution. I am a very experienced climber and caver (used to do it for a living and manage equipment stores) but this is a complex business. If you don't know exactly what you are doing stick with 'established' practice until change is recommended.