Anyone recognize this line?

[sanibel sailor]

This line was on a 26 foot sailboat I bought about 25 years ago and I am trying to figure out what it is. Looks about 120 to 150 feet long. Given the size of the boat and length of line, I assumed it was for a multipart tackle for going up the mast. Did not match anything else aboard. I am thinking climbing rope. Knobbly hand to double braid cover. Not slippery like polypropylene. Parallel core. Melts so not Kevlar core. Too old for Dyneema type fiber.
Anyone recognize it?

[Orion Jim]

Looks like floating tow rope.

[thinwater]

Originally Posted by Orion Jim

Looks like floating tow rope.

Does the core float (probably polypropylene)? Tow rope.
Does it melt in battery acid (probably nylon)?

[mickt243]

Looks like ‘kernmantle’ climbing rope.

[BrianGJS]

Likely floating tow rope as suggested. Being of age it likely is not trustworthy to tow a dinghy as the sun is its enemy. The comment about battery acid not bothering is is interesting. While purchasing a batter at distributers the chap carrying the battery had on nylon shorts. I suggest that he might end up with holes in his pants. He told me that the acid does not bother nylon so no worries.

[Mike Banks]

It looks like the kind of rope rock climbers use. It is similar to marine rope but the outer layers are more closely woven and the rope is very soft to handle and knots easily.

I do not see any reason it could not be used successfully on board a vessel if it is climbers rope...

[thinwater]

Originally Posted by BrianGJS

... While purchasing a batter at distributers the chap carrying the battery had on nylon shorts. I suggest that he might end up with holes in his pants. He told me that the acid does not bother nylon so no worries.

He was wrong about nylon. Concentrated acid goes through nylon like lava. I've seen it eat through nylon pipe fittings that were mistaken for PVC (which can handle acid). My first experience was burning a hole through a nylon backpack in college (organic chemistry), 40 years ago.



However, I suggested that because acid will NOT harm any other common rope fiber, such as polyester or Dyneema. Cause tic on the other hand, will damamge polyester but not nylon.


You can Google these under "plastic chemical compatibility."


--


I would not guess based on appearance. Does it float?

[KP44]

Climbing ropes are "dynamic". They sacrifice themselves to absorb energy during a fall. When a climber falls, the rope stretches so the falling climber is not stopped with a jerk; but with a hard, long pull. The rope will be permanently damaged when it saves a climber and ropes can not usually take more than a couple hard falls.
Since it will stretch under load and is more plastic than elastic, it is not suitable for halyards or sheets.

[BrianGJS]

Thanks thin water. Likely was polyester shorts.

[sanibel sailor]

Thanks to all contestants.
The winner is...

Dinghy tow rope. Hadn’t thought of that as I rarely tow and it seemed too heavy, that is until I cut off a bit.

[sanibel sailor]

Nylon’s poor acid resistance is why battery box straps are commonly made of polypropylene. BTDT when I used seat belt webbing once.

[thinwater]

Originally Posted by KP44

Climbing ropes are "dynamic". They sacrifice themselves to absorb energy during a fall....

As an engineer, 40-year climber, and lab rope tester, this is utterly false and is a mythology I wish would die. Climbing ropes actually have a far better fatigue life than standard DB.


A climbing rope can take far more hard falls than any comparable rope. In fact, few comparable strength nylon ropes can withstand more than 1-2 test falls and few polyester ropes can survive one. A Dyneema rope fails the first time. This has been tested many times. In this sense, they are far more durable than other ropes.



The implication is that they function in someway like a crumple zone. Complete non-sense. They are simply more elastic due to differences in the weave (the core is twisted parallel construction, not braided or laid).



I'm not implying climbing rope is built for marine application. Horses for courses and that would be a long discussion. But they are not, in any way, designed to be sacrificial or fragile. Just different.

[Boatguy30]

New England makes a tow rope that's the same color. That is not that product. I'd have to guess it was made by Marlow based on the stranded core and the plait of the cover.

[sanibel sailor]

This does seem to have a twisted parallel core, which I have not seen before in a yachting rope.

Off topic, but... What is the difference between static and dynamic climbing ropes? I doubt this is a dynamic rope as I assume they are nylon which sinks, but I can also imagine light weight is beneficial for climbing.

[Orion Jim]

Originally Posted by sanibel sailor

Thanks to all contestants.
The winner is...

Dinghy tow rope. Hadn’t thought of that as I rarely tow and it seemed too heavy, that is until I cut off a bit.