sbu22
Guru
- Joined
- Mar 16, 2011
- Messages
- 1,253
- Location
- US
- Vessel Name
- Panache
- Vessel Make
- Viking 43 Double Cabin '76
I’m thinking I may not be the only one who’s tried this – might save somebody else some trouble.
I set up my stern dock lines using 5/8” three strand nylon about 4 years ago. I thought I was pretty thorough in examining my lines, but clearly not thorough enough. Put replacement dock lines on the “to do” list for this summer, before the throat of hurricane season. Nothing visually bad, but they’re getting a little long of tooth.
When I initially installed the lines, I had 1’ eyes spliced in. In each eye I installed an appropriate size thimble, held in place with tie-wraps placed well clear of the thimble throat. So the line goes through two eyes screwed into the piling to keep the line at the correct elevation on the piling, The running (boat) end goes through the thimble to provide a low friction bearing surface.
Because I don’t know why, I wound up with galvanized thimbles. Knowing that galvanizing produces a pretty rough surface, I Dremel’d the interior (running side) thimble surfaces to a smooth to the touch finish.
TS Cindy came in last week while I was out of town. Sustained 30-35 for a day or so with gusts 40-45. No big deal. I routinely tie up with 8 lines – 2 bow, 2 stern, 2 aft springs, 2 forward springs. I was therefore perplexed when a marina buddy called me to advise he had retied my stern because one line had parted. Only did a little rub rail damage.
Examination showed that the thimble had finally worn through line and it finally had enough and parted. After recovering the line, discovered that the thimble, while for the most part polished by the friction of the line continually shifting, also had some newly revealed rough spots in the surface. If you look carefully at the thimble picture, you’ll see a few black spots – that’s actually black nylon deposits.
Here’s the question: Given that the slip is set up such that I need to wrap the line around the piling and it is a “permanent” line, how best to minimize friction at the running end to loop/thimble interface? I can make up some sort of chafing gear, but my experience looking at other peoples is that it doesn’t last well. There is an array of 316 stainless forged thimbles that appear ultra-smooth and low friction. Additionally, there are nylon and other synthetic thimbles out there.
Any suggestions appreciated. And if you have a thimble setup, you might wish to look hard at the condition of the line at/near the wear point with the thimble. Like I didn't.
I set up my stern dock lines using 5/8” three strand nylon about 4 years ago. I thought I was pretty thorough in examining my lines, but clearly not thorough enough. Put replacement dock lines on the “to do” list for this summer, before the throat of hurricane season. Nothing visually bad, but they’re getting a little long of tooth.
When I initially installed the lines, I had 1’ eyes spliced in. In each eye I installed an appropriate size thimble, held in place with tie-wraps placed well clear of the thimble throat. So the line goes through two eyes screwed into the piling to keep the line at the correct elevation on the piling, The running (boat) end goes through the thimble to provide a low friction bearing surface.
Because I don’t know why, I wound up with galvanized thimbles. Knowing that galvanizing produces a pretty rough surface, I Dremel’d the interior (running side) thimble surfaces to a smooth to the touch finish.
TS Cindy came in last week while I was out of town. Sustained 30-35 for a day or so with gusts 40-45. No big deal. I routinely tie up with 8 lines – 2 bow, 2 stern, 2 aft springs, 2 forward springs. I was therefore perplexed when a marina buddy called me to advise he had retied my stern because one line had parted. Only did a little rub rail damage.
Examination showed that the thimble had finally worn through line and it finally had enough and parted. After recovering the line, discovered that the thimble, while for the most part polished by the friction of the line continually shifting, also had some newly revealed rough spots in the surface. If you look carefully at the thimble picture, you’ll see a few black spots – that’s actually black nylon deposits.
Here’s the question: Given that the slip is set up such that I need to wrap the line around the piling and it is a “permanent” line, how best to minimize friction at the running end to loop/thimble interface? I can make up some sort of chafing gear, but my experience looking at other peoples is that it doesn’t last well. There is an array of 316 stainless forged thimbles that appear ultra-smooth and low friction. Additionally, there are nylon and other synthetic thimbles out there.
Any suggestions appreciated. And if you have a thimble setup, you might wish to look hard at the condition of the line at/near the wear point with the thimble. Like I didn't.