Dyneema (or similar) lifeline advice needed

[pmbuck]

I am getting ready to order all the parts and pieces to replace the lifelines on our C&C 39 with HMPE (Dyneema, Amsteel, etc) line instead of steel. I'm excited to practice my splicing, prestretch the line, etc. etc. And I'm happy to have found a lot of great videos and posts sharing what others have learned.

here's what I'm stuck on: Our gate opening is small, say, 30" or less. I'm not at the boat, so I don't have exact #s. To build the gate with a synthetic line and a splice at either end (the forward end into a clasp with an eye, the aft end into an eye near the stanchion), I run out of space for the length of each splice.

A Brummel splice calls for 72 x (diameter of line), so that's >14" for a 5 mm line.

One alternative is to run the gate line all the way from the pushpit stanchion to the gate clasp. But then when the gate is open, the entire upper aft lifeline would be loose. I don't love it.

Anyone have a better idea? Can I risk each splice being a little shorter given the relative shortness of the gate?!? I'm scratching my head.

Thanks for your tips!

 

[Captain Larry-DH]

Can I risk each splice being a little shorter given the relative shortness of the gate?!

Yes - stitch it with waxed thread to make sure it doesn't slip. It's a good idea anyway, with something that will be frequently left hanging loose, such as a gate. It's the tension that helps lock it (think of the straw-tube finger traps you played with as a kid).

 

[Joe]

You need a "gate stop" .... for dyneema. Here's a pic showing a wire version... a simple collar that locks around the line to keep the rest of the line taut when the gate is open. I'll see if I can find a rope application.... perhaps there's a splice that can be used.

 

[heritage]

I agree with capt. Larry, a shortened Brummel splice and stitching backup will be plenty strong. I used a fittings
from csjohnson that are designed for lifelines for a gate stop and other attachments.

 

[jssailem]

I used pelican gate hook, did buried splices on each end, and lock stitched the buried splice. The buried splice nearly meet in the middle of the gate space. That had to happen to get the needed length for Dyneema. I then tensioned it with the threaded portion of the pelican hook. I have 2 gates on my boat one each - Port and Starboard.

They have been up for 3 years. Still look and feel great. There has been no need to adjust the tension. There is still room if necessary. Getting more dyneema would be a cheap fix when I need to retie. As far as the rest of my lifelines they are stainless cable. Looking great.

 

[pmbuck]

Yes - stitch it with waxed thread to make sure it doesn't slip. It's a good idea anyway, with something that will be frequently left hanging loose, such as a gate. It's the tension that helps lock it (think of the straw-tube finger traps you played with as a kid).

Captain Larry, thanks so much! This is my plan now. I'm relieved and I really appreciate your expertise!

 

[pmbuck]

yes! this is some of the hardware I'm planning to use, after going down a rabbit hole of looking at gorgeous Colligo hardware, lashings, and more, I fell back to the modest CS Johnson route.

Thanks for your advice!

I agree with capt. Larry, a shortened Brummel splice and stitching backup will be plenty strong. I used a fittings
from csjohnson that are designed for lifelines for a gate stop and other attachments.

View attachment 187963

 

[pmbuck]

Ah, so you only replaced your gate. What you describe about your splices meeting almost in the middle is exactly. what's going to happen to me, plus they'll be a tad short. So whipping them sounds best. I'm grateful. Thank you!

I used pelican gate hook, did buried splices on each end, and lock stitched the buried splice. The buried splice nearly meet in the middle of the gate space. That had to happen to get the needed length for Dyneema. I then tensioned it with the threaded portion of the pelican hook. I have 2 gates on my boat one each - Port and Starboard.

They have been up for 3 years. Still look and feel great. There has been no need to adjust the tension. There is still room if necessary. Getting more dyneema would be a cheap fix when I need to retie. As far as the rest of my lifelines they are stainless cable. Looking great.

 

[WayneH]

Did all of my lifelines in '16. Mis-measured the starboard gate splice so it sagged a bit. But on the old lifelines when you opened the gate, the aft top line sagged nearly to the deck. Plus the vinyl was cracking and the wire was rusting.

Where the dyneema goes through the stanchions, we use a wrap of sunbrella that we stitched to the lifeline to prevent chafing inside the stanchion. Not sure if that was necessary as the sunbrella does not show any wear after 4 years.

 

[thinwater]

Did all of my lifelines in '16. Mis-measured the starboard gate splice so it sagged a bit. But on the old lifelines when you opened the gate, the aft top line sagged nearly to the deck. Plus the vinyl was cracking and the wire was rusting.

Where the dyneema goes through the stanchions, we use a wrap of sunbrella that we stitched to the lifeline to prevent chafing inside the stanchion. Not sure if that was necessary as the sunbrella does not show any wear after 4 years.

View attachment 187967

A whoopie sling splice would make it easy to adjust. I think Colligo has a post on this. I've done this on one gate that requires a large range of adjustment (boat specific problem not worth explaining, but there are two modes that differ in length by about 4 inches).

 

[pmbuck]

yes - I liked that post on the whoopie sling! Also can recommend. We decided not to do it since I'll have a turnbuckle on that section. I'll also prestretch the line.

A whoopie sling splice would make it easy to adjust. I think Colligo has a post on this. I've done this on one gate that requires a large range of adjustment (boat specific problem not worth explaining, but there are two modes that differ in length by about 4 inches).

 

[pmbuck]

Similar to your sunbrella solution, I am buying a dyneema sleeve to put over each eye splice. My stanchions have some sort of coating or nylon protector on the drilled holes, so less worried about them.

Did all of my lifelines in '16. Mis-measured the starboard gate splice so it sagged a bit. But on the old lifelines when you opened the gate, the aft top line sagged nearly to the deck. Plus the vinyl was cracking and the wire was rusting.

Where the dyneema goes through the stanchions, we use a wrap of sunbrella that we stitched to the lifeline to prevent chafing inside the stanchion. Not sure if that was necessary as the sunbrella does not show any wear after 4 years.

View attachment 187967

 

[jssailem]

My stanchions have some sort of coating or nylon protector on the drilled holes, so less worried about them.

Just be certain that they are smooth and no chance of chafing the line as it is pulled through then when in use. Not difficult to sand then buff the steel smooth.

 

[thinwater]

Similar to your sunbrella solution, I am buying a dyneema sleeve to put over each eye splice. My stanchions have some sort of coating or nylon protector on the drilled holes, so less worried about them.

Remember that as the lines stretch and you retention, the covers will move if they are spliced in place. Dyneema sleeve tends to fray a lot if not spliced, even if melted. 9/16" tubular webbing might work better.