The following is a set of recommendations from the PS crew who tested many types of jacklines. What is your experience? Do you agree with theirs?


Jackline Installation Tips

Posted by Darrell Nicholson with Drew Frye at 07:45AM - Comments: (0)

September 30, 2015


Whether you are clipped into a jackline or not, the safety rule still stands: one hand for the ship, one hand for yourself. A crewmember aboard Amro One, ducks under white water during the 2006 Volvo Ocean Race.

The “to-do” list begins to swell in October, a month when many northern hemisphere sailors start preparing their boats for offshore passages to warmer climates. High on many lists is the job of installing jacklines—the lines running along the deck to which we attach our safety tethers. Jacklines have been in use aboard ships for centuries, and materials have evolved from traditional woven hemp to braided Dyneema, a strong, stiff (high modulus) fiber that is pound-for-pound stronger than steel.

In the upcoming November issue, we try revisit the ideal materials for jacklines—webbing, rope, wire, or a combination. We carried out a similar comparison in 2007, but this time around we 're looking more closely at how elasticity can have a dramatic impact on the jackline 's effectiveness. One of the most startling conclusions of our current test was that despite the International Sailing Federation’s (ISAF) generalized approach to jackline standards, the best material for a jackline varies as boat length increases.

Material selection is just one of many details regarding jacklines that deserves careful thought. If you are re-installing your jacklines or installing for them for the first time, be sure to read our upcoming test report. In the meantime, you can read our 2007 report and review some of the following tips that came out of our ongoing jackline research.

Although you can use existing hardware for anchoring jacklines to your deck, finding adequate anchors on light boats can be difficult, since the deck and fittings might not be very strong. Whatever hardware you use must be strongly reinforced and capable of supporting the anticipated loads.
Confirm that the entire system is of known minimum strength. ISAF standards recommend 4,500 pounds minimum breaking strength for webbing, although we recommend more for boats greater than 40 feet in order to provide an adequate safety factor. The minimum safety factor is 2.4:1, based on dynamic loads. This means that whatever gear you use should be capable of supporting 2.4 times the amount df force generated by a falling body (or bodies), or by a person who is dragging in the water at maximum boat speed.
Nylon stretches a great deal when it is wet, so nylon jacklines should be tensioned when wet.
Webbing jacklines should be twisted—not laid flat. This way they are easier to clip into when wet and they won’t flap in the wind.
Outboard-powered boats should never have jacklines or tethers so long that a sailor who has fallen overboard could be towed behind the boat near the prop.
Jacklines should stop well short of the bow. Fast boats, multihulls in particular, can hurl a person forward when the bow stuffs into a wave.
The cockpit should have at least one dedicated fixed point for clipping into. Consider installing dedicated clip-in points (padeyes) at other work stations—i.e. at the mast, or at the bow.
Rope jacklines can be acceptable on boats with higher coachroofs that allow the lines to be routed off the deck where they won’t fall underfoot. Rope is more durable that most other choices, it is also easier to clip on and off with carabiners.
When Dyneema or stainless cable are used on the deck, sheathing them in tubular webbing can reduce the chance that the jackline will roll under foot. However, some of our testers preferred exposed Dyneema because the carabineers slipped along the jackline more easily.
Jacklines must be clearly distinguishable from running rigging, so that there is no chance of clipping into the wrong line. Color is not enough, as the typical side deck is littered with similar control lines and colors are indistinguishable in the dark.
Jacklines should be permanently rigged during a passage. It takes time to become accustomed to their use, and sailors have often gone overboard in benign conditions.
Jacklines should be rigged under sheets and over deck-routed control lines so that a sudden tack or jibe does not grab the tether.
If you rely on stainless steel hardware, use only the highest quality. (Wichard is one company whose hardware has consistently done well in our tests.) During our field research we came across a 46-foot boat with very tight 3/16-inch stainless jacklines attached with 3/16-inch stainless shackles. Our tester grabbed the jackline at the centerpoint with gloved hands, gave it a maximum effort jerk, and one of the shackles exploded, the cable whipping about. Stainless-steel jacklines must be very conservatively sized to account for hidden corrosion.

For more on jacklines see our eBook Man Overboard Prevention and Recovery.

http://www.practical-sailor.com/blog/Jackline-Installation-Tips-11829-1.html?ET=practicalsailor:e30525:125771a:&st=email&s=p_waypoints093015

Vice Commodore, OCC 

Daria,

This is an advertisement for an up-coming report, due to be published in November, and seems to contain just some points from their 2007 report.

They mention "elasticity", but don 't say whether they found it to be good or bad, and we 'll have to wait for the full report. In the meantime, my opinion is "not too much or too little". I would consider nylon to have too much, and stainless steel wire or Dyneema to have too little. Too much, and you 'll be overside; too little, and the shock loadings become greater.

Way back in 1977, I think it was (half a lifetime ago), I designed the Gibb double-action safety hook, and witnessed the drop test that was called for in the British Standard for yachtsman 's safety harnesses. A 100kg wooden dummy was fitted with a harness, and dropped though a distance of 2 metres, the usual length of a tether. This resulted in a momentary load of about 750kg, and a real person would have suffered sever whiplash and/or cracked ribs. Ever since then, I 've used a tether of 1 metre length, and the hook remains within arm 's reach for easy disengagement and shifting to a new attachment point.

I strongly agree with this statement "Rope jacklines can be acceptable on boats with higher coachroofs that allow the lines to be routed off the deck where they won’t fall underfoot. Rope is more durable that most other choices, it is also easier to clip on and off with carabiners." But I would go further, and say "are much to be preferred", and I would strongly advocate rope jacklines rigged at a distance midway between deck edge and boat 's centreline, used in conjunction with a short tether. Read this link to see why. It 's a magazine article from 1980, immediately post-Fastnet disaster, and it makes it very clear that being towed through the water at 6 knots leads to drowning very quickly. The purpose of the harness and jackline is to prevent you from going overside and being towed through the water. If it allows that, it 's failed. But if you are to be towed through the water, it 's much better to be towed from a point of attachment between the shoulder blades. Industrial full-body harnesses have their tether attached here, and not only is it much safer in the event of a fall, it 's possible to do a job of work (such as winding a winch). It 's high time that there was a re-think on the whole subject of yachtsmen 's safety harnesses.

In the meantime, I use a waist belt only, with a short tether that can be moved around to be out of the way while I 'm working, attached to a jackline that 's well inboard.

Thanks for that, David. I couldn 't agree more that the entire situation needs to be re-thought. I think it may be another good topic for the best practices series.

As food for thought, Evans Starzinger wrote a paper on the subject a couple of years ago. He makes some very important points. http://www.bethandevans.com/pdf/jackline.pdf His idea of fixed work stations at points where MOB is most likely to occur based on analysis of actual events has merit. In those places, such as at the mast, the boat has a fixed tether available to anyone who finds themselves having to work there -- and it is exactly the right length and type for that location.

Vice Commodore, OCC 

The subject of jacklines continues to come up in accident investigations.
http://www.pbo.co.uk/news/clipper-race-responds-publication-report-fatal-accidents-52210#xhvCkvTQHdg55sKx.01

The PBO article on jacklines is worth reading. http://www.pbo.co.uk/seamanship/is-it-safe-to-use-a-tether-25125

Vice Commodore, OCC 

The subject of jacklines continues to come up in accident investigations.
http://www.pbo.co.uk/news/clipper-race-responds-publication-report-fatal-accidents-52210#xhvCkvTQHdg55sKx.01

The PBO article on jacklines is worth reading. http://www.pbo.co.uk/seamanship/is-it-safe-to-use-a-tether-25125

Vice Commodore, OCC 

Also:
MAIBInv4-2012.pdf
The skipper of the racing yacht Lion, remaining attached by a six foot tether to the weather side jackstay on the foredeck, goes overside while trying to recover a sail in the water and drowns in a matter of minutes. The remaining crew find it very difficult to recover him.

Thanks for this post Daria. It is an issue that focuses the attention of offshore sailors whose primary objective is to stay on the boat. Here are some comments:

I think that the best jackline is high quality white webbing that is folded and sewn lengthwise. The result is a strong, soft square line on which the carabiner slips easily. I can also imaging that a Dynema line would provide the same quality. The line should be attached at strongpoints as far forward and aft as possible.

Always go forward out of the cockpit on the high side so that if you lose your footing you will fall inside the boat.

As a single hander I worried that if I fell overboard forward of the mast I would be swept back along the boat until my tether came against the shrouds. If the boat was moving it would be very difficult to pull myself back on board. My solution, which I never had to use, was to run a light line over the side from the bow to the stern on both sides of the boat. This line was a water level along both sides of the boat. On my life harness I had a short 9" tether. My idea was that if I fell over forward of the mast I would use this short tether to attach to the permanently mounted water level line. I would then release the main tether and slide back along the water level line to the stern where I could climb back on board. As I said I never had to use this backup.

On a passage north from Staten Island to Buenos Aires in 1997 a rogue wave turned our boat upside down. My wife 's knees and head went through the headlining above her bunk. I was on deck. I had just detached my tether to step over the boomvang when the wave hit. I was thrown overboard and came up about 200 feet from the boat. When the boat righted the mast broke and this acted as a drogue so that the boat drifted down wind to me. If I had been attached to the boat by a tether I probably would have been caught in the rigging of the broken mast and drowned. Sometimes you can be very lucky.

[quote="DariaBlackwell" post=2443]Thanks for that, David. I couldn 't agree more that the entire situation needs to be re-thought. I think it may be another good topic for the best practices series.

As food for thought, Evans Starzinger wrote a paper on the subject a couple of years ago. He makes some very important points. http://www.bethandevans.com/pdf/jackline.pdf His idea of fixed work stations at points where MOB is most likely to occur based on analysis of actual events has merit. In those places, such as at the mast, the boat has a fixed tether available to anyone who finds themselves having to work there -- and it is exactly the right length and type for that location.[/quote]

Daria,
I just tried the link to Evans Starzinger 's paper, and got "error 404". Luckily, I then found that I 'd saved a copy on my computer. Should we have this stored somewhere safe on the OCC site?

[quote="David Tyler" post=3803]

Daria,
I just tried the link to Evans Starzinger 's paper, and got "error 404". Luckily, I then found that I 'd saved a copy on my computer. Should we have this stored somewhere safe on the OCC site?[/quote]


David, I see that many links there are broken. If you have the paper, could you please post it here as a pdf with attribution to Beth and Evans? I am certain they wouldn 't mind.

Vice Commodore, OCC 

Evans Starzinger 's paper on "Jacklines, Clip-in Points and Tethers - Improved designs and approaches" is attached.