LIFELINE TENSION

[farkle48]

Hi all - I'm reinstalling lifelines removed to ease deckwork and toe-rail repair on the hard. Boat is a CAL 39 MkII. Any suggestions as to a proper tension/feel would be appreciated.


Thnx. Fair winds and relatively calm seas to all.

[GordMay]

I'd suggest as tight as you can reasonably get them.

[LakeSuperior]

Gord we will have to agree to disagree here. The resulting tension on taunt wire with a perpendicular force applied can be extra-ordinarily high. Some examples include a body on a harness attached to the lifeline going overboard or a sailor being thrown against the lifeline.


Consequently, I let my lifelines have a small amount of play in them. This will significantly reduce the peak tension in a case where a shock load is applied.


In essence, lifelines having a small amount of play is easier on the hardware giving a larger margin before failure.

[Alan Mighty]

I've seen a couple of different standards.

One is from the Pacific International Yachting Association, which (in 2013 and in earlier years) maintained the standard of:


"Lifelines (including lower and upper lines) shall not sag more than 4” under a 5lb. load applied halfway between the stanchions."

See: 3.16 (on page 3) of http://www.wvyc.ca/files/PIYACertificate2013.pdf

A second rule comes from the Offshore Special Regulations of WorldSailing, and has been modified over the years. Currently (2018-19) it is:

"As a guide, when a deflecting force of 4 kg is applied to a lifeline midway between supports, the lifeline should not deflect more than 50mm." (from 3.14.1 on page 12 of http://www.sailing.org/tools/documen...#91;23449].pdf)

A few years back the Offshore Special Regulations of World Sailing (aka ISAF) had a force of "5.1 kg". So now the force has been dropped to 4 kg for a lower tension. I don't know why the tension was lowered.

[Alan Mighty]

Originally Posted by Alan Mighty

I
A second rule comes from the Offshore Special Regulations of WorldSailing, and has been modified over the years. Currently (2018-19) it is:

"As a guide, when a deflecting force of 4 kg is applied to a lifeline midway between supports, the lifeline should not deflect more than 50mm." (from 3.14.1 on page 12 of http://www.sailing.org/tools/documen...#91;23449].pdf)

The format of the Offshore Special Regulations of WorldSailing made the job of copying and pasting difficult, so my workaround was to quote an earlier version. But that was subtly different. Here's a second try to get the wording of the 2018-19 OSR:

'When a deflecting force of 4 kg (8.8 #) is applied to a lifeline at the midpoint
of the longest span between supports that are aft of the mast, the
deflection shall not exceed:
i 50 mm (2”) for an upper or single lifeline
ii 120 mm (4 ¾”) for an intermediate lifeline'

Note the 2018-19 rules only specify (I think!) deflection for lifelines aft of the mast. My understanding from earlier years that it was for lifeline forward as well.

[a64pilot]

I’d say snug, not loose.
My reasoning is if I had it grab at the thing, I don’t want excess movement, that isn’t expected and can lead to a loss of balance.

I don’t understand why more boats don’t have higher railings myself. Cost I guess.

[-bliss-]

Quite tight!

I´d say hand tight + a couple of full turns. This means the stanchions will be under a little pressure, just enough they won´t vibrate while your engine is idling. This should be enough tension to make it feel safe leaning against the lifelines. (Don’t do this if you don’t know the condition of your lines!)

And while we´re at the topic of lifeline safety: Do not tie fender lines to the lifelines! Every time the boat is pushed into whatever you are tied up to, the fender lines will pull the lifelines down, causing wear where the lines penetrate the stanchions. Sooner or later one of those lines will break at one of these more or less invisible stress points. It might not happen in your home port, but it might happen if you lose your balance while under way and fall over the lines. Therefore, fenders should be attached to the toe rail, the bottom of the stanchions or some dedicated attachment point. If all of those options are absent, you should use the lover lifeline. The top one is there to save lifes.

The lines should be inspected at least annually, and all riggers should implement this in a full rig check.

Don’t mean to scare you. Just a piece of advice for your own safety.

Safe sailing,
-kjetil-

[Stu Jackson]

Originally Posted by -bliss-

>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>If all of those options are absent, you should use the lower lifeline. The top one is there to save lives.

>>>>>>>>>>>>>>>>>>>>>>>>>>

Good advice, answered the question right there.

[thinwater]

The lower lifeline tip for fenders is good.

The problem with very tight lifelines is that they will gradually bend the stanchions inward. I've seen this many times. They are there to serve as a net, not a hand rail. In fact, since the cable does not stretch, all of the "give" you are seeing is the stanchions bending.

But if you are going to use them as a rail, pull UPWARDS. Don't push down or to the side. Not only are those methods more likely to bend or loosen the stanchions, they are not as effective at pressing the feet into the deck, where they will provide traction. Pushing down is just plain unstable. A jackline in one hand and a top lifeline in the other can be good, depending on the geometry. But always pull UP.

If you are pulling up, a little give won't be noticeable.

[Flagman101]

I'm french and maybe I don't understand well this subject but we are talking about lifelines and not jack lines.
Lifelines like those 1 or 2 wires that go from Bow to stern on the stanchions?
If so, I have always been told to NEVER clip yourself to them. ALWAYS clip to a jack line.
Lifelines are not designed to take the load of a falling body. Also with a 6 foot Lanyard you end up like a big Rapala fish bait dragged on the side of the boat.
Life line will prevent you from going over board when properly installed.
My 2 cents

[dkenny64]

A64,
you bring up a great point..
why are the life lines so LOW...in almost all cases they are knee height..
why not 3ft high..waist height for most people..if you're going to want something to fall against and help keep you from going over..knee height isn't it..


-dkenny64
just think about how to make my boat safer when we travel..

[Flagman101]

First thing that comes to mind is high stanchions will impede the foresail.
You will have to have a much higher cut so it won't get stuck on the lifelines.

I race a lot and I have been saved from going overboard twice by life lines.
In both cases I slipped and fell on the heeling foredeck to slide and end up caught in the life lines. The boat I was on was a C&C 30 and the lifelines are about 19 inches high.

Hurts like hell!!!.
You stop right there.

[thinwater]

Originally Posted by dkenny64

A64,
you bring up a great point..
why are the life lines so LOW...in almost all cases they are knee height..
why not 3ft high..waist height for most people..if you're going to want something to fall against and help keep you from going over..knee height isn't it..


-dkenny64
just think about how to make my boat safer when we travel..

The answers are simple:
a. Use jacklines.
b. Don't stand tall when it is rough. Either crouch, crawl, or scoot.


If you feel yourself falling... get low! There is no reason to walk tall when it's rough.


Not that I disagree with the sentiment, particularly on otherwise conservative cruising boats. But the reasons for low rails are also obvious:
a. Sail clearance up front.
b. Boarding everywhere else. You really can't step over anything higher with any agility. I've always been surprised at the lack of gates on cruising boats.


Another solution, seldom discussed, is rigging higher lifelines. MANY boats have shrouds or arches that would allow for high lines aft, but they are not installed. I did on my last boat. I also added additional gates.


The bottom line is you are on your own. I doubt the market will ever force it.

[rognvald]

"And while we´re at the topic of lifeline safety: Do not tie fender lines to the lifelines! Every time the boat is pushed into whatever you are tied up to, the fender lines will pull the lifelines down, causing wear where the lines penetrate the stanchions. Sooner or later one of those lines will break at one of these more or less invisible stress points." Bliss


Bliss,
I've had only one lifeline fail in the last 30 years. We were leaving Nassau heading back to the States and had a catastrophic failure at the swage fitting. The failure was internal and could not have been seen visually upon inspection. In your above example, inspection would reveal a problem by simply loosening the lifeline tension and inspecting the wire. So, in most lifelines, strand failure would be very evident and give ample time to replace the lifelines due to the strength of the average 1X19 wire strand. Good luck and safe sailing.