Lifeline size?

[Ed Schenck]

On a thread regarding my stanchions I had added this:

"Have a quote from Seco South for the lifelines but I am uncertain about the size(diameter). I asked for 3/8" as measured with my calipers. They quoted 5/16" which makes me think the right size studs cannot be fitted. I had planned to send mine to them anyway. The wire size would be 3/16" instead of 1/4" so there is both a strength issue and looseness in the stanchion holes."

The quote would be at least $120. less than 3/8". I wrote back to ask if they are unable to quote that size. I am keeping my original hooks so the stud size has to be correct. Would you settle for a smaller lifeline on your boat?

 

[dscribner]

Ed,

I only have a 25 footer and my sailing experience is limited, but my engineering experience is not. Figure the tensile strength of 3/8" stainless steel wire rope (around 12,000 lbs) and ask your self, "Do I need that?" Would 6000 lbs do? That's 1/4" cable. There may be other reasons to stick with 3/8, but IMHO, strength isn't one of them.

 

[Roger Long]

Sounds like you are going with plastic coated.

DON'T!

Plain stainless:

Looks great.

Feels fine, better IMO.

Is better metal underneath.

Lasts longer.

Is easier to inspect as it get old.

Is stronger for the same diameter.

Doesn't become scuzzy plastic after a few seasons.

I've never heard of anyone who switched to plain stainless wanting to go back.
Almost impossible to damage.

 

[Warren Milberg]

Roger has it right. When my current plastic coated lifelines are replaced, I'll go with uncoated ss wire. I think 5/16" wire is as strong as you would need, if it fits your current hardware. On that note, when I re-do my lifelines (probably next year) I plan to get a quote from Defender as they gave me a great price on a previous boat. Also, give some thought to using line lashings to connect to pulpits and/or toe railings instead of barrel toggles or similar metal connectors.

 

[Ed Schenck]

How did I know that either your or Maine Sail would tell me that?!
But still the problem of looseness in the stanchions. My 1979 lines, now hanging in the garage, really are not that bad. There are a few cracks and stains where they went through the stanchions. The stains are just since I moved to salt water but now I am back. I know that uncoated is best but thirty years is not bad for what I think looks better and feels better. And did I mention the fit in the holes?

 

[Ted]

Lifeline size

Ed, When fabricating life lines which have the plastic outer covering, the overall diameter of the lifeline is of no concern. It's the actual wire diameter that is important in order to get the correct swaged fitting. Different manufacturers may have more or less plastic covering their wire and that is where you are having a discrepancy with your rigger. By all means send them your fittings as they will be know and be responsible for the final lifeline assembly. If the new lifeline is a little smaller in diameter than your present ones, the extra clearance at the stanchion holes won't be a problem. Stay away from the plastic coated lifelines as they are more dangerous in the long run and tend to show their age prematurely. I replaced my coated lifelines last season with bare stainless steel. Prior to doing so I thought I wouldn't like the way they would look. Actually I like them better because they are not as noticeable. I used 3/16" dia. wire for the uppers on my 29 footer. Your boat may need something heftier.

 

[Ted]

Lifeline size

If you are really concerned about the fit between the lifelines and the holes in the stanchions, you can insert a short bushing into the stanchion. The bushing can be nylon or stainless steel. Mcmaster.com has lots of sizes and materials to choose from. This should be a simple fix once you know the sizes you're working with.

 

[bria46]

I just toured JSI in St. Petersburg FL. Our subject was lifelines. They suggested that I remove my current life lines and send them. They will duplicate them and suggest alternate approches. They also have a store in Bronx, NYC

 

[Ron20324]

The studs on the ends of the lifelines will obviously be bigger than the line, so remember that they have to go through the stanchions also. I found it a way to have the proper fit was to buy the parts and the crimping tool and made my lifelines. 3/16, uncoated. Where the lines pass through the stanchions I used as bushings short sections the split cover meant for the shrouds.

 

[Ed Schenck]

From some of the responses I think I wasn't clear with my original post. What I know is that my current lifelines are 3/8" coated. I also know that the uncoated wire is 1/4" and that the studs are 5/16". So if I did go with uncoated wire it would be 1/4" and I might use bushings, a good idea if the 1/8" slop is a problem.

Someone mentioned Defender. I have their catalog beside me. Their largest uncoated lifeline size(7x7) is 3/16" at $1.64. Strangely they show a 3/8" coated lifeline with 1/4" 7x7 wire. Of course there is always the 1x19 or 7x19 wire at two to three times the cost.

I have prices from Rigging Only, 1/4" bare is $1.68 and coated is $1.84. For some reason Seco South quoted 3/16" wire when I asked for 1/4". So having read all the above posts I think one more call to JSI is warranted. And you have me leaning to bare wire. Whatever I do the company will have my current wires to match up. Thanks for all the ideas.

 

[Ross]

They fence livestock pastures with number 10 galvanized wire pulled tight as banjo strings and I have never see a cow break it.

 

[Ed Schenck]

Is that a reference to my size and weight? Who told you?

I know enough about engineering to believe that the wire strength is a minor issue. The stanchions are the weak link. On the other hand Hunter saw fit to install 1/4" wire back in 1979.

 

[dscribner]

One place that I was checking out had clear plastic coated wire. It might be a good compromise between uncoated and white plastic. It would allow inspection and protection. (Wow! That could be somebody's jingle.)

 

[Roger Long]

It would allow inspection and protection. (Wow! That could be somebody's jingle.)

For a couple years until it turns cloudy.

Bare wire is going to last much longer than plastic coated. Being able to inspect the plastic coated would just let you watch your money going down the drain.

 

[Ron20324]

I see (per the West catalog) the rating for a web jack line is 6000 pounds; for a tether 4500 pounds, and the "safety flag" stitching pops at 900 pounds, and means it is time to replace the tether. 3/16 lifeline is rated 4000 pounds, just a little less than a tether. Perhaps Main Sail needs to get out his load block and see just how much load is there when a person is dropped through the gallows trap door?

If 3/16 is not strong enough for a larger boat, why is it strong enough for a smaller (30-40) boat??? Larger people? Nothing personal, Ed

 

[Ed Schenck]

This is getting old. I have decided on white plastic clothesline. Should look just as good. I'll just tell people not to touch it.

Most of the shops I talk to can only make 1/4" wire lifelines as a very expensive special order. One quoted $285. for 5/16" coated wire(3/16") and $480. for 1/4" uncoated wire. I also have a quote for 5/16" coated at $245. And the first quote from another company for exactly what I have, 3/8" coated wire(1/4"), at $385. I thought that was high until I checked with two others. Seems that not only do they not stock 1/4" wire but the left-handed studs that size must be rare. One company told me they only use 3/8" lifelines on boats over sixty feet. I am down to two choices, 5/16" coated with wire size of 3/16"($245) or 1/4" bare wire at around $350. Anybody know if the wire construction, 7x7 for the 3/16" and 1x19 for the 1/4", will make a difference?

 

[LuzSD]

I am going to jump in here very untechnically and just tell you what we did/ what we have and how happy we are with it. We changed our coated lifelines out for steel and from what I remember and understand, we have the same size but it is all steel so the 3/16 that we have is much stronger and larger than the coated that we replaced. We had all new swivel gates etc. and absolutely love the change. Everything is tight, looks great, feels good, and everything is visible and inspectable each time we wipe down the boat, no hidden deterioration. We had West Marine do our work and were very happy with their rigging shop.

 

[RichH]

Simple - go with the largest dia wire that will fit through the stancheon leads.

Then dont make the life lines as tight as a violin string but leave a noticeable slack - this will allow greater IMPACT strength and will reduce the important loads at the connections of the lifelines to the boat/railing/whatever. The reason is that perpendicular side forces applied to ropes, lifelines, can generate MAGNITUDES greater forces in the 'connection points' ,,,, the 'tighter' the cable, rope when the side occurs, the exponentially higher the resultant load in the 'connections'. With 'very tight' lines, cables, etc. low 'side forces' can generate 'instantaneous' forces that can approach 'infinity'.
IMPACT is VERY difficult to predict in such situations and IMPACT doesnt always follow the 'classic' rules of 'strength'.

Use the largest that can fit, that you can afford, leave it BARE ... and leave it a bit 'slack' ... and never ever touch it, grab it, or 'use' it - its there only if "all else fails". Ditto for jacklines, etc.

 

[Ed Schenck]

Rich wrote: "Simple - go with the largest dia wire that will fit through the stancheon leads." Not that simple because the holes are 3/8" and even 1/4" bare wire is twice the cost of 3/16" coated to 5/16". And 3/8" wire, if even available, wouldn't work because the studs would be too big for my hooks which I am keeping. Nothing is simple when you are related to Murphy.

 

[RichH]

Another 'simplistic' offering: Dont 'chintz' on lifelines.