Hi Guys,
Is anyone running this stuff as anchor rope I was thinking of 120m/5mm Hi Spec 3000 with a top shot of 30m/8mm Double Braid Nylon then 8m chain. should be good for 1500kg breaking strain
I considered 190m/4mm Hi spec 3000 but then looked at 4mm on a ruler
Alternatively I was looking at 180m/5mm Spectra with a top shot of 8m/6mm Double Braid Nylon which would be good for 1000kg breaking strain
Its a 7.5m ali boat and Ive been using 10mm silver rope for 5 years with a breaking strain of 930kg with no problem.
The idea with the longer top shot with the Hi Spec 3000 was that it wasn't sheathed with polyester like the Spectre and most of my anchoring will be in 15-20m of water so it would only get a work out when I anchor out deep
Breaking strains
Hi Spec 3000
4mm 1500kg
5mm 2000kg
Spectre
5mm 1000kg
6mm 1700kg
Double Braid Nylon
6mm 1000kg
8mm 1500kg
http://www.bellmarine.com.au/boating...0kg-bstrain-2/
http://www.whittamropes.com.au/produ...rial-products/
Just make sure there are no sharp edges, nicks cuts or burrs on any of your bowsprit gear. We use dyneema tow lines and winch lines at times on the tugs. If adequate care isn't taken, the stuff will pick up on a snag and pull threads quick as look at you.
Also consider that stuff has very little stretch in it and would be shock loading when at anchor.
Democracy: Simply a system that allows the 51% to steal from the other 49%.
Also you would probably need to replace your bow rollers especially if they are the soft red ones it will cut through them, I had some made up in a local workshop from oil injected nylon after it happened to me. Bronze would be best but rather expensive and SS not recommended as pin is SS and it will bind unless you constantly lubricate it, alum will do in a pinch.
As Scottar says it will pull threads too easily, go the double braid, i had it on my trailer winch and always had to be careful not to let it touch the trailer as too many bolts etc wound to foul it, the deep blue dyneema worked better there. The top shot of nylon even though 8mm is your safety net as it will break before the braid or chain,and as always carry spare chain and anchor and enjoy your boating.
Just reread your post, go with 160m of double braid nylon, 8mm simgle ply nylon then chain. Do not go thinner than 6mm as you will then have tolerance issues with your bow roller as well.
You pulling it up with a winch? No way I would try to pull it by hand.
#8 Jmolan
Registered User
Join Date: Dec 2007
Location: Mexico/Alaska/Oregon
Boat: 34' Searunner Tri
Posts: 712
Ideas
Dyneema and Dux as an anchor line is a great question.
First thing I think of is the situation where you have all chain, and in a big blow you loose the cantetary. At that point you have a serious snubbing problem. All chain will do this. The shock loads at that point can be damaging as you are punching through waves and have no "give" with all chain.
I bring this up because you have the same situation with Dyneema. Except the situation will arrise much sooner as it has no weight. It will not stretch. It will cause the same or similar damage as chain in that situation. I have seen this stuff crack drums on winches from shock loading. It is amazing stuff, but using it can cause a number of interesting new problems to figure out. Any sharp snubbing and you will be damaging your boat or pulling your anchor out. Not so good.
The natural thought is to attach a snubber of nylon. Well.....how to attach it...?...any knot in Dyneema will weaken it %50 or more. Perhaps a hitch. Not sure. On our multi hulls you can use a nylon bridle, but you still have to think how to attach it to the Dyneema. You could easily splice an thimbled eye in the Dyneema, but you are restricted to using just that length then. A cow hitch is used often on ourfishing boat
I have played with a shock cord buried inside the Dyneema as a "core". It makes for a very stretchy line with ultimate strength.
I would love to lighten up my boat with synthetics any place I can. 7mm Dynex Dux has a breaking strength of 15,000 lbs. My boat weighs 7k total. Would be great to us 7mm. I can see it being very hard on the hands though to pull. Just some random thoughts.
__________________
#8 Jmolan
Registered User
Join Date: Dec 2007
Location: Mexico/Alaska/Oregon
Boat: 34' Searunner Tri
Posts: 712
Ideas
Dyneema and Dux as an anchor line is a great question.
First thing I think of is the situation where you have all chain, and in a big blow you loose the cantetary. At that point you have a serious snubbing problem. All chain will do this. The shock loads at that point can be damaging as you are punching through waves and have no "give" with all chain.
I bring this up because you have the same situation with Dyneema. Except the situation will arrise much sooner as it has no weight. It will not stretch. It will cause the same or similar damage as chain in that situation. I have seen this stuff crack drums on winches from shock loading. It is amazing stuff, but using it can cause a number of interesting new problems to figure out. Any sharp snubbing and you will be damaging your boat or pulling your anchor out. Not so good.
The natural thought is to attach a snubber of nylon. Well.....how to attach it...?...any knot in Dyneema will weaken it %50 or more. Perhaps a hitch. Not sure. On our multi hulls you can use a nylon bridle, but you still have to think how to attach it to the Dyneema. You could easily splice an thimbled eye in the Dyneema, but you are restricted to using just that length then. A cow hitch is used often on ourfishing boat
I have played with a shock cord buried inside the Dyneema as a "core". It makes for a very stretchy line with ultimate strength.
I would love to lighten up my boat with synthetics any place I can. 7mm Dynex Dux has a breaking strength of 15,000 lbs. My boat weighs 7k total. Would be great to us 7mm. I can see it being very hard on the hands though to pull. Just some random thoughts.
__________________
the above is from a sail boat forum...not mine!
While this is written about bigger boats...new materials have different problems ...ie just how much say 8mm nylon rope will you need to provide the stretch to damp the shock load forces..which are much higher in the non stretch materials.
It reminds me of the mountain climbers problem....an 11mm kernmantle rope (double braid nylon) will hold the fall of a climber its entire length .The rope will lengthen by up to 50% at that time as it absorbs the energy of the fall and slows the climber down relatively slowly to avoid injury to his internal organs.(generally after such a fall the rope is useless..but its done its job) If he used spectra as a climbing rope then he could use a thinner diameter rope but because of the lack of stretch the shock load is almost instantaneously exerted on the climbers body and he would be killed as his heart brains etc would be smashed.
Paradoxically the highest load factors on the ROPE occur during falls when there is not so much rope out...
Nylon is good in these situations because it can remain elastic , stretch and recover with no internal damage at moderate loads for the diameter...
Let us know what you decide.....
I thought of the same thing years ago...then went to nylon rope. My boat is 7.6 m and i like to anchor in deep water on the shelf. My rope is nylon 3strand 6mm. Importantly it has 30% stretch which makes for a smooth soft ride. I have anchored up to 500m deep but usual anchoring is 300 to 400 m. Another important feature of nylon...it sinks. This means i use a siily little anchor and some really light chain...5mm link but quite long...10 metres. Using this combo for 4 years... i am yet to break the rope or lose an anchor. Finish the package off with a float and ring to retrieve. I happily anchor and retrieve it in 400 m by myself. I carry about 600 m of rope which will all fit in a single 50 litre tub. Good luck
500m!!!! As soon as I'm in 3 figures it's all drift fishing with a parachute for me.
Democracy: Simply a system that allows the 51% to steal from the other 49%.
That's a lot of rope to coil, even after the boats done all the hard work.
500 m sounds deep but it is just 5 to 10 pulls to get it all up...dont make the mistake i did firstvtime in the deep and use float in a single pull.....the anchor was on top bot 800 m of rope had sunk😥 now that was hard!!!! And why anchor in 500m...it opens up a whole lot of options..... and coiling up a lot of rope.... nylon is very limp and it packs down best just dropping it into the bin loose and free. Dont coil it.
was thinking further on this overnight!
Assuming your using an anchor winch...I think you might have trouble when winding in the thin spectra/dyneema rope at sea ....the rope might tend to get pulled into the coils already on the winch and then tightened....this happens on the boat trailer winch with dyneema of reasonable diameter because of the variation in tension on the rope when winding in.With the larger diameter and the relatively short length of rope its not difficult to manage .
Yeah going to be running a anchor winch.
That's true but the way the line is tensioned is in reverse on a trailer winch where it gets tighter (more load on the line) the further up the trailer the boat gets. I would imagine there would be load on the rope up till the line is verticle with the anchore under the boat thene a short moment of higher tension to release the anchor and it should then be light tension so it shouldnt dig into the spool.
What Im thinking is winching in during a swell will mean you have varying tension on the drum until the anchor is lifted...will that be enough for the small diameter line to cut in ? Its one of those things that only time will tell..you may be fine....just post us how it goes....Id give Malki at Lone Star winches a bell in any case..they are manufacturers and very helpful with this sort of question.
bear in mind the retrieval rate. winches are really slow up and down.... but that is not all bad, cos it gives you time to make a cuppa
As mentioned above the unforgiving nature of this sort of rope can be harsh on mechanisms. It would be interesting to have feedback from anyone who has used this rope for an anchor.
Another aspect touched on above is - the spooling of dyneema style rope.
My only experience with dyneema is on the winch in my 4x4.
It's commonly known dyneema can and does bind on itself when wound onto a which spool under heavy load if there are loose spots on the spool. I've had it happen a few times and there's no way anyone can unspool it once bound. You have to attach the rope end to a solid object ie a tree for example and allow the weight of the car to unspool the bound up dyneema and free spool it out. So when spooling in ideally it's done under a continuous load. Loose spooling only encourages the bind up if there is heavy load onto a loose spool.
Depending on the size of your boat the snubbing might allow bind to happen.
I'm definitely no boat expert but it's an idea, anyone used the dyneema for anchor rope ?
Jamie
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