Dyneema warps?

[oldvarnish]

Is this the way forward for us?

http://gcaptain.com/mooring-ropes-dyneema-show-minimal-wear-six-years-service-vlcc/

Or would it be too expensive?

I wonder what they sleeve it with to prevent chafe ( as mentioned in the item) and what might we use?

 

[dunedin]

Thought that some stretch was good for shock absorption. Might be a quick way to remove the mooring cleats though

 

[prv]

I certainly don't want non-stretch warps!

I know at least some ship mooring lines are Dyneema but with a springy section spliced in.

I wonder if large ships use active winches like some modern tugs?

Pete

 

[Tammany]

Always thought nylon was the best for warps and anchor rope?

 

[GHA]

Is this the way forward for us?

http://gcaptain.com/mooring-ropes-dyneema-show-minimal-wear-six-years-service-vlcc/

Or would it be too expensive?

I wonder what they sleeve it with to prevent chafe ( as mentioned in the item) and what might we use?

As mentioned in our world the complete lack of stretch would probably rip cleats out.
However I have a few short strops of dyneema connected to some nylon for extra mooring warps with the dyneema going over cleats / Samson post on the boat which keeps things much tidier through the fairleads and uses less locker space. The main springs and anything doing any work is still all nylon.
Even 5mm Marlow d12 is surprisingly tough on it's own with no cover.

 

[prv]

Always thought nylon was the best for warps and anchor rope?

Personally I like 3-strand or octoplait polyester for most warps - nylon (I have a couple) can be a bit too stretchy. But it depends on how you're using them.

(The construction of laid or plaited rope provides more stretch than tight braid.)

Pete

 

[ip485]

I suppose the advantage is that it makes the ropes very light and easy to handle. I find as the boat gets bigger (with a 50 footer, and 26 tons) mooring ropes can be lot for the girls to manage. I use quite light weight ropes for this reason most of the time, but they would need changing in a really good blow. With Dyneema that would not be a problem and I guess the stretch could be dealt with by incorporating the typical "rubber" or stainless shock absorber.

 

[Lucky Duck]

Last season I picked up a mooring buoy just off Torpoint and noticed the pick up buoy had been secured to the mooring strop by some multi-coloured dyneema

 

[knuterikt]

On the VLCC Dyneema replaced steel-wire rope, not much stretch lost there.

 

[laika]

Might not be much cop for mooring against a wall somewhere with a big tide

 

[sailorman]

I certainly don't want non-stretch warps!

I know at least some ship mooring lines are Dyneema but with a springy section spliced in.

I wonder if large ships use active winches like some modern tugs?

Pete

Can i come along side Cpt, then they get out all their old sheets :disgust:

 

[JohnGC]

It's been posted before, but this is a good illustration.
http://dmmclimbing.com/knowledge/how-to-break-nylon-dyneema-slings/

I can't think of a mooring condition that would lead to the equivalent of that 2:1 fall factor which breaks the Dyneema. But I agree with GHA, the increased strain of the fittings could be considerable. Any snatching would be more abrupt and uncomfortable as well.

 

[GHA]

It's been posted before, but this is a good illustration.
http://dmmclimbing.com/knowledge/how-to-break-nylon-dyneema-slings/

I can't think of a mooring condition that would lead to the equivalent of that 2:1 fall factor which breaks the Dyneema. But I agree with GHA, the increased strain of the fittings could be considerable. Any snatching would be more abrupt and uncomfortable as well.

Little Fred rift, but that video is also a good example of how important terminations are with dyneema, a good Splice in 12 strand should be on the way to 100%. Most of the sling failures wouldn't have happened with a good termination in the video, still doesn't mean it's a good idea for dynamic loads though.. but that dyneema ain't yer ordinary string.

 

[KINGFISHER 9]

My boat is on the end of a pontoon run and I use enough warps to strap down the Queen Mary - Liros braided dockline - bow to pontoon, mid cleat to pontoon, springs port side, two more starboard side back to the pontoon from mid and stern cleats and two more scissored across the stern - all except the springs stretch! ... guy inside me has the same model, 40 foot 10 tons motor boat with 3 Dyneema warps ... one mid cleat to the pontoon cleat and one each side at the stern, not crossed ... when the Tramontane is blowing a hooley mine's banging around all over the place and his doesn't budge ... no snatching to pull the cleats out (!) because it doesn't move at all! ... just as well because he's in Belgium whereas I check mine twice a week at this time of the year!

 

[JohnGC]

My boat is on the end of a pontoon run and I use enough warps to strap down the Queen Mary - Liros braided dockline - bow to pontoon, mid cleat to pontoon, springs port side, two more starboard side back to the pontoon from mid and stern cleats and two more scissored across the stern - all except the springs stretch! ... guy inside me has the same model, 40 foot 10 tons motor boat with 3 Dyneema warps ... one mid cleat to the pontoon cleat and one each side at the stern, not crossed ... when the Tramontane is blowing a hooley mine's banging around all over the place and his doesn't budge ... no snatching to pull the cleats out (!) because it doesn't move at all! ... just as well because he's in Belgium whereas I check mine twice a week at this time of the year!

Interesting. I guess his does move but only with the pontoon. Might be different against a harbour wall.

 

[oldvarnish]

Just thinking a bit - I've got a stack of springy mooring warps, but they're thick and heavy and take up a lot of space.

With a bit of imagination, couldn't we devise some kind of shock absorber (like a snubber but better) which attached at the boat end, then dyneema all the way to the shore?

Less weight, less space, stronger mooring.

 

[DaiB]

Ships moorings using wire or dyneema have to have a mooring tail to give stretch and take shock loads.

Off the web.
"also supply nylon and composite fibre mooring tails in order to provide elasticity in a mooring system. This helps to reduce damage to wire and ropes made with Dyneema® fibres by absorbing shock loads.

Grommet construction to give higher breaking strength on request.

All of the above comply with OCIMF (MEG3) guidelines. Synthetic tails should have an MBL of at least 25% higher than that of the mooring line to which they are attached. Polyamide tails should have a 37% higher MBL than the mooring line, to take account of loss of strength when wet."