Jackline webbing - color & strength?

[bstreep]

OK, time for some REAL jacklines for the boat. Most of the jacklines I've seen are blue - probably for easy identification on deck? Our boat colors are gray, white & black. Mamma says blue doesn't really go with the boat. White I'm sure could be more difficult to identify in a pinch. Are black ones ok?

Is the 1" 4200lb OK, or should we step up to 6100lb? The price difference isn't much - about $15.

TIA

[Pblais]

White I'm sure could be more difficult to identify in a pinch. Are black ones ok?

The rules of the admiralty apply here. You are the captain of your ship and make no mistake - The Admiral is always right. Basically webbing colors don't matter. They all deteriorate at the same rate being nylon. Nothing wrong going heavier though. At 4200 lbs it would kill you dead if it broke with that much energy to break it. Your neck would snap like a twig. 1 Inch is plenty but you do need to watch for chafe and other damage. None of this stuff lasts forever. I've hung off 5,000 ft cliffs on one inch (X2). Tie it with a water knot.

[bstreep]

Thanks Paul. I kind of thought the 4200lb would work, but...

[imagine2frolic]

Who goes forward on deck when it is snotty? The Captain, or the Admiral? If it is me I would pick out what is most easily seen, and to heck with what goes with the boat. It's your life not a fashion statement........BEST WISHES in getting that one through!!!!!!!!!!!!!!!!

[Roy M]

Mine are almost-electric hot pink! They're hard to miss in dark or light, and they engender (no pun intended) smiles when people see them for the first time. What's really important is that you have them and deploy them.

[nautical62]

I'll second everything Paul says. I also use webbing a fair bit for a variety of purposes. Also realize that while webbing has an incredible tensile stength it can easily be cut or burned through easily with friction, so watch for any places it may get pulled against anything sharp and beware of any set up where rope might wear against it. Better to use a carabiner or shackle. For a long time I had wondered how long it would take to wear through a piece of one inch tubular webbing with a piece of 5 mm (maybe it was 4) accessory cord, so finally I tried. The answer was 13 seconds.

White won't stay bright for long. One thing I like about deep colors is I feel the rate at which they fade gives me some reminder of their age and when it's time to replace them.

One other note about strength and forces. While a fall with a force of 4200 lbs would kill you long before it breaks the webbing one should realize the tension on a line and direction of pull against it can generate very large forces to the points at which a line is secured. This is exactly why they intentionally put a sag in phone and utility wires. This can apply directly to jack lines.

As an experiment, tie loops in two ends of line - better yet, webbing. (Say a figure 8 on a bight). Have two people who are heavier/stronger than you grab each end of the webbing and pull against each other as hard as they can causing tension in the line. Now you put a carabiner and short line on that line somewhere near the middle and pull. You will easily pull the two heavier/stronger people off their feet. This is exacly what you don't want in a Jack line. Imagine instead of people, those two ends are weak deck fittings fixed fore and aft and your jackline is tight between them and you fall sideways overboard....

[Pblais]

White won't stay bright for long. One thing I like about deep colors is I feel the rate at which they fade gives me some reminder of their age and when it's time to replace them.

I know at altitude from climbing if you leave a 1 inch piece of webbing outside the UV trashes it about two years to wear I would not hang my body weight on it. So after about 600 days of uses you could toss the webbing. Colors won't matter but the fading of some colors is quicker than others. That may not be related to the degree of UV damage. If it looks worn then toss it as well as any cuts.

If some wave knocks you down the force could be similar to a climber taking a fall. Checking the condition is just good sense if you want to depend on it. It also brings up the point about what the ends are attached to. If it does not have a substantial backing plate you don't need a life line.

[roverhi]

Color does make a difference in longevity. Black lasts way longer than white when exposed to UV. There is good reason to go with black if longevity is your goal. Don't know if blue will last almost as long as black but assume the lighter the color the more it is effected by UV. There is also the problem of showing dirt with lighter colors.

In any case, the argument is mute. The Admiral outranks you.

Aloha
Peter O.
Pearson 35

[nautical62]

Paul, if you are still following this I'd love to hear a bit more about your thoughts on webbing color. My dislike for white comes from the fact it doesn't fade the way deep color does, so it can be easy to think it hasn't had as much exposure as it has. I'm not saying fading should be the best judge of of a webbing's strength or need to replace it, but I also don't think it's bad to have the bright color begin to fade as an additional reminder that it's probably time to to replace that webbing (or past time). I know myself, when I climbed, I dated all my webbing and retired it conservatively, but on a boat, I'm not quite as precise...

As to color darkness and wear. Common sense tells me darker colors will get warmer, but I've seen nothing to indicate that has anything to do with the breakdown of the plastic polymers. Have you? I'd imagine if there was any notable proven difference, you'd never see the faster deteriorating option in climbing sales.

Good point on the fittings, - that's kind of what I was getting at with the forces. I don't know the exact math, but I should guess a 200 lb sailor going over the side could generate a fall force of 400 lbs which if pulled at right angles to a taught jackline might create a force of 800 or more lbs against a fitting. That's still nowhere close to the webbing rating, but on in poorly backed fitting or undersized worn shackle...

[Pblais]

Paul, if you are still following this I'd love to hear a bit more about your thoughts on webbing color.

I find no reason to differentiate by color. That is based on 40 years using the stuff. Pigment does effect materials UV resistance but it is not transferable between materials. If there really is a difference I sure have never seen it. When I wear my glasses I can see as well as any or at least most these days. As far as visibility goes if you can't see it in the dark you may have had too much to drink. You should be able to clip in based on the attach points. If you are attaching in the middle it means you forgot to clip in and you should have gone overboard already.

The forces get pretty high when you take a wave pushing someone 180 pounds (I'm a little more). F = ma (force equals mass times acceleration). If you get hit by a wave you are accelerating more than gravity by a lot. The backing plate is maybe the difference. I'm hoping more like a 4 inch by 4 inch square plate or better in a no coring area. That is just a gut feeling. Sort of depends on how big you are. The wave transfers force by your square area times your weight times the acceleration. If the webbing fails you probably died before you left the boat. Not a lot of data on something like that. Dead is sort of the same no matter how.

[witzgall]

Anyone using amsteel for jacklines?

[Pblais]

Why the need? Amsteel is so far over the top of requirements why bother.

[MidLandOne]

Pigments may protect plastics against UV deterioration. Carbon black is commonly used in black plastics (and it is black that many associate UV protected plastics with eg cable ties) and it protects the plastic by absorbing the UV and converting it to heat. But there again some white pigments are very good at doing the same thing.

I have no idea what pigments are used in the webbing used for jack stays (aka jack lines depending where you are) though.

Don't know if anyone has mentioned the telltale threads longitudinally through the webbing to be monitored for any excessive load having been applied.

[nautical62]

Originally Posted by Pblais

I.

...The forces get pretty high when you take a wave pushing someone 180 pounds (I'm a little more). F = ma (force equals mass times acceleration)... I.

The reminds me of another regarding fall forces and associated issues I've often wondered about concerning jack lines. I've seen some rigged where the the tether is too long to stop a person short of going over the side (at least up towards the bow) but too short to allow the person to hit the water. The combination of the force you mentioned being suddenly stopped by a static line and chest harness before the person hits the water, just can't be good. (all commercial jack lines and tethers I've seen are static) It seems much better to me to have that initial force stopped by a more forgiving sea hitting a good portion of the body than by a static stop on a chest harness. Dynamic lead falls in a sit harness are enough for me thank you.

(Not to mention if you get through that uninjured, it seems to me hanging over the edge of a boat with all you weight in a chest harness isn't a fun position either. I'd rather be swimming, but attached.)

[Paul Elliott]

Originally Posted by nautical62

(Not to mention if you get through that uninjured, it seems to me hanging over the edge of a boat with all you weight in a chest harness isn't a fun position either. I'd rather be swimming, but attached.)

The problem is that if you end up in the water you may very well be towed until you drown -- it can happen in a few minutes. If you are singlehanding you definitely need a plan for getting back aboard. Depending on where you go over and the layout of your boat you may have few options, but given a choice it is probably best to stay out of the water.