Rope Rode - What Type (do you have)? What would you prefer?

[thinwater]

Originally Posted by Jim Cate

With all the talk of super long snubbers, do you not loose the benefit of the catenary weight and length for the portion of the rode between bow and snubber attachment point? If one has, say a 100 foot snubber on say, a 200 foot chain rode, you loose the energy absorbtion of half of the catenary, which as DH points out, is considerable. I wonder where the crossover between loss of catenary and gain of elasticity of snubber occurs?

Jim

No, the catenary is not reduced.

The weight is still there and it is still supported the same places. Generally, the snubber will have only enough slack so that the chain does not come tight in the greatest gust. So the angles and weights, during the greatest gust, have not actually changed significantly. Counter intuitive, perhaps, but testing supports it, even when 1/2 of the rode is snubber.

And a 100 snubber is a straw man anyway. 30-40 feet is typical.

Finally, I use a 36-foot snubber in as little as 5 feet of water, with only about 75 feet of rode out. BUT, I never said that the snubber was attached to the bow cleats. It is actually anchored to the midships cleats, so it only extends about 10 feet in front of the boat. The routing over the chocks is very carefully calculated to eliminate chafe and sharp turns.

[thinwater]

No, you do not need a snubber. The ABYC tables are based on not having one. The deeper the water and heavier the chain, the less the need.

FWIW, the real reason I spliced up my first nylon snubber was ride. The original snubber was polyester, and the chain would snatch in gusty winds and shallow water, starting at about 20 knots. I changed to nylon and the ride is smoother. That was enough reason.

[cortezsailor]

Corbin39 , 24 000 lbs unloaded , west coast of BC , some of my anchorages 20- 25 meters .
I went with Rocna 33kg as primary on 300 feet of 3/8 G40 chain with 25 feet of 8 Plait 3/4 inch line . Mainly to enable my ability to cut loose in an emergency .
I also have a Mantus 65 lb anchor as back up on 100 feet of 3/8 G40 chain followed by 250 feet of Maxwell 3/4 inch 8 plait. If I'm in a situation where I Loose my primary anchors ability in bad weather I want something just as good to put out.
Stern anchor is Fortress f-37 50 feet 5/16 G40 chain 200 feet of 8 plait .

I'm big on the 8 plait , easy to store , a pleasure to work with and great strength. All chain primary rode makes overall anchoring easier , safety wise . I sleep well most nights

[UNCIVILIZED]

Guys, thanks SO MUCH for all of the excellent contributions to this thread. It has, actually, turned into much of what I'd hoped for. A way for me (& likely others) to learn a "bleep" of a lot about different rode types, what works well when, & why. As well as the reverse. Including explaining the science behind why some rodes either fail, themselves, pull their anchor's free, or otherwise make things get FUBAR.

I really, appreciate it. Especially when coupled with some of the other knowledge along similar lines which has been posted of late about topics such as the rodes used for drogues.

And while my thanks goes out to everyone, as does my growing respect. Thinwater, thanks so much for (tirelessly) laying out the science behind so much of this stuff. And doing so in a manner which is easy to follow, & well communicates the key info which you're explaining. Honestly, you could, & perhaps should, pen a book on this stuff. It certainly would sell.

Also, for those new to the thread, who haven't had a chance to follow the whole thing (which I never dreamed would get this long - gracis on that), below are the original questions which I posed on rodes, ground tackle, drogue & shore lines (shore ties).

And thanks too for putting up with my verbosity, preternatural curiosity, & OCD
I hope that it's more helpful than it is painful most of the time.

Originally Posted by UNCIVILIZED

Yes, my curiosity is spiking again (what else is new). But hopefully to good outcome. Maybe to save some of us some money. Or perhaps our boats.

What I’m wondering is, what kind of rope do you use for your anchor rode, or have you used in the past, would you use it again or something else, why, etcetera? Be it for your primary anchor, secondary, or land lines (shore ties).
- Specifically, is/was it 3-strand, 8-plait, 12-plait, doublebraid? Why?
- Nylon, Polyester, Polypro, or other? Since Spectra’s been discussed a little bit in this application. Ditto some Polypro blends.
- Would you use it again, or switch to something else? And regardless of how you answer this, why would you make said choice?
- What size (diameter) & strength are your rodes, & how big is your boat (LOA, & Displacement)?
- Did you “discover” any techniques in using a specific rope type that were particularly helpful? That, or the reverse; meaning bad ideas?
- In a worst case scenario, like riding out a named storm or Hurricane, what rope would you ideally have? Why?
- Do you think that the ABYC rode recommendations are accurate? Too conservative? Or perhaps the reverse? Why?
- How much/how many rodes do you keep onboard? And of what length(s)? Where are they stored?
- Fiscally what do you consider to be the best choice when it comes to rope rodes? And where do you shop for them?
- Chain rodes aside, if cost isn’t part of the equation, what would you have in terms of rope rode?
- What rope rodes; types, or brands, & or, suppliers would you avoid?
- What kind of lifespan do you get with your rode(s)?
- Do you think that UV resistance is a big factor in rode lifespan?
- What else significantly lengthens or shortens rode lifespans in your experience?

And of course other relevant comments & discussion are more than welcomed. Ditto on any “categories”, or questions that I didn’t pose.

[UNCIVILIZED]

As a real world thanks for all I've learned in this thread, here are a couple of tips that may aid when it comes to keeping rode costs down. One's that have worked for me at least.

If you can, buy stuff by the spool, or at least half spool. Even if it means coercing your neighbor into being a "cordage enabler". Quite often there's at least a 10-15% discount if you buy line by the spool, sometimes more. Especially if you ask them nicely. And or buy several "big purchases" at once, like anchor rode, along with some cordage for running rigging.

Also, along with the above, if you can, find someone who can qualify/buy using a commercial account. The price differences between this & what you'd pay retail, or even with a "Port Supply" discount can be staggering.

Shop at sources outside of the recreational marine industry vendors. Whether that means an arborist, or climbing gear supply shop. Or via going to a cordage maker's website, & seeing what other industries besides sailing they sell say 'Sta Set" to. And querying the vendors for said industries for their prices on the exact same line. It's usually a good bit cheaper though them.

And there are others, which by all means, anyone & everyone's free to add.

[Dockhead]

Originally Posted by UNCIVILIZED

As a real world thanks for all I've learned in this thread, here are a couple of tips that may aid when it comes to keeping rode costs down. One's that have worked for me at least.

If you can, buy stuff by the spool, or at least half spool. Even if it means coercing your neighbor into being a "cordage enabler". Quite often there's at least a 10-15% discount if you buy line by the spool, sometimes more. Especially if you ask them nicely. And or buy several "big purchases" at once, like anchor rode, along with some cordage for running rigging.

Also, along with the above, if you can, find someone who can qualify/buy using a commercial account. The price differences between this & what you'd pay retail, or even with a "Port Supply" discount can be staggering.

Shop at sources outside of the recreational marine industry vendors. Whether that means an arborist, or climbing gear supply shop. Or via going to a cordage maker's website, & seeing what other industries besides sailing they sell say 'Sta Set" to. And querying the vendors for said industries for their prices on the exact same line. It's usually a good bit cheaper though them.

And there are others, which by all means, anyone & everyone's free to add.

Ha, ha. Love the phrase "cordage enabler"

My name is Dockhead, and I am a ropoholic. . .

Specifically, addicted to racing dyneema

I have a guy in Portsmouth who I have long referred to as my "rope pusher". He finds spool ends for me and finds other ropoholics to go in with me on spools, and we typically save 50% to 60% off the chandlery prices. I wish I had known him when I was spending thousands on 5x new dyneema halyards a few years ago

[UNCIVILIZED]

Originally Posted by Dockhead

Ha, ha. Love the phrase "cordage enabler"

My name is Dockhead, and I am a ropoholic. . .
Yep. Me, I'm not a "dope fiend", I'm a "rope fiend". AKA hooked on Liquid Crystal Polymer. Specifically, Vectran.

Specifically, addicted to racing dyneema

I have a guy in Portsmouth who I have long referred to as my "rope pusher". He finds spool ends for me and finds other ropoholics to go in with me on spools, and we typically save 50% to 60% off the chandlery prices. I wish I had known him when I was spending thousands on 5x new dyneema halyards a few years ago

Pass his business cards around!!! Guys like that are invaluable to know, or be acquainted with.

[UNCIVILIZED]

Originally Posted by UNCIVILIZED

While my thanks goes out to everyone, as does my growing respect. Thinwater, thanks so much for (tirelessly) laying out the science behind so much of this stuff. And doing so in a manner which is easy to follow, & well communicates the key info which you're explaining. Honestly, you could, & perhaps should, pen a book on this stuff. It certainly would sell.

CORRECTION: It appears that Thinwater already HAS written a book on anchoring. But publication is yet pending
Sail Delmarva: The Book Store

[Snowpetrel]

One thing that hasn't been discussed much regarding anchoring is damping of some sort of artificial shock absorption system. Eg a cars suspension uses springs and a shock absorber to control bounce and to act as a damper, prehaps it could be argued that the boat floating in water provides the damping? But anyone who has sat on a long nylon warp in gusty conditions has experianced the bungy cord effect, which can place pretty high shock loads on the system itself.

A few years ago I saw an interesting system for moorings at a boatshow that incorporated a spring loaded ram system much like the reverse of a car suspension that was built into the bouy. Seawater was used as a damping fluid for the ram.

http://www.seagrassmooring.com.au/mooring-systems

I was not so impressed by the use of stainless underwater like that with no sign of any anodes, but other than that it was smartly made.

The whole system seems a bit too complex for our anchoring, but prehaps another method of absorbing the shock loads other than stretching the rope could be developed?

A few random ideas, say for example with a dyneema warp with almost no inherent stretch. There is the old standby of attaching fenders to the warp and using the drag and bouyancy of them to reduce shock. Other possibilities might be putting rubber tube or rods inside the dyneema and compressing the rubber, rather than stretching the warp to get some elasticity. The rubber could be made slightly porous so that it has to force water out slowly to compress, providing some damping, and heat dissipation.

I don't know what the ultimate answer is, prehaps nylon is as good as it gets, but it seems like the balance between stretch and working load limits is always going to be tough to solve with nylon for stronger winds.

I remeber pulling a 65 foot schooner off the beach with a couple of fishing boats. The warp in use was 25mm polypropylene or similar, hopelessly undersized, and sure enough the first pull snapped it easily. The fishermen then added an old car tyre tied loosely to the warp near the middle, not even giving any stretch. But it's inertia in the water cushioned the shock load enough to prevent the line breaking again, and we towed her off.

[UNCIVILIZED]

There are purpose built "shock absorbers" for mooring lines, both for commercial vessels of most sizes, & to some degree for recreational vessels. Some of them consisting of progessive rate springs which get compressed as loads cycle onto the lines. It's been quite a while since I've seen one, but then I've not much looked either.

The car tire is a tool advocated by Jim Brown & some of the early multihull guys for use as a drogue. Way back before drogues were popular, let alone commercially available. And they're easy enough to source so that if you have to sacrafice it...
Note that they advocated using them with bridles as drogues, & that such rigs could also be used to steer the vessel should she lose her rudder.

But when you first mentioned tires, the thought which immediatedly ran through my mind, even before I finished reading the sentence, was kellets. Another tool who's efficacy is wrapped in controversies & mostly scientifically unmeasured results. With most folks now advocating putting the weight that you'd use for the kellet, into a yet bigger anchor.

[Snowpetrel]

Yeah UC, Jims dis-spare tire is another good use for the things, and they make pretty good fenders. None of the current shock absorbers for mooring lines really look strong enough or elastic enough in my eyes. And they all look inefficient. But the concept is a starting point prehaps.

The downsides and advantages of kellets are well known. But prehaps they still have a place in extreme winds? Especially as we go lighter and lighter chain these days? But possibly also using something bouyant near the boat could help. And even some neutrally bouyant weight and drag near the middle of the rode might help. Ive even wondered if a series drogue used as an anchor warp might help?

It seems to me that a lot of the shock loads when at anchor are caused by the boat moving sideways when sailing at anchor, rather than straight forward and backwards as might happen in bigger waves.

[UNCIVILIZED]

Originally Posted by Snowpetrel

Yeah UC, Jims dis-spare tire is another good use for the things, and they make pretty good fenders. None of the current shock absorbers for mooring lines really look strong enough or elastic enough in my eyes. And they all look inefficient. But the concept is a starting point prehaps.

The downsides and advantages of kellets are well known. But prehaps they still have a place in extreme winds? Especially as we go lighter and lighter chain these days? But possibly also using something bouyant near the boat could help. And even some neutrally bouyant weight and drag near the middle of the rode might help. Ive even wondered if a series drogue used as an anchor warp might help?

It seems to me that a lot of the shock loads when at anchor are caused by the boat moving sideways when sailing at anchor, rather than straight forward and backwards as might happen in bigger waves.

At least under normal circumstances, I've always been a big advocate of hanging a small drogue type parachute under the bow, or even a stout bucket. If not an anchor under foot. Usually in order to slow a boat's wanderings on the hook. Or if on a mooring, to hang a drogue or bucket off of the transom to avoid bumping the mooring ball. Ditto the dink's transom, so that she doesn't bump the mother ship.
Might be worth trying in moderate winds, whether a car tire, or some other type of drogue.

In terms of rigging much connected to the anchor line, especially part way along it's length. Be it a series drogue, or a kellet, etc. The prospects of said drag device(s) getting fouled on something underwater is a bit of a concern. As it would definitely throw a wrench into how, & how well one's ground tackle was functioning. And if it's part of the rode, or midway down it, then you can't cut it away if things go awry. At least not like you can with a drag device fastened to the bow or stern.

Maybe a seperate, short series drogue hung there. One tailored in length so as to not be able to touch bottom, much, if at all? But then it's efficacy would suffer I'd thinkk.

The one kind of drogue that I'd want to try hanging from the bow most, other than a tire, to test this, would be the sort of drogue made of webbing, in a cone shaped basket pattern. Don't recall the name at the moment. Thoughts?

Off of the bow would work better than the transom from the perspective of controlling shearing/sailing better. But with either, if the line connecting it to the vessel has much length, then there's the risk of it fouling the keel, prop, or rudder, as it & the vessel move around. So it's connecting line would need to be fairly short. Enough so that it couldn't wrap a fin keel. But I'd think that that would keep it deep enough so as to let it work fairly well, especially if a bit of weight were hung off of it's trailing end.

The other catch would be that such a device would negate the ability to motor ahead in the heaviest gusts when anchored. At least not until you had it secured on deck anyway. Otherwise...

I'll look around the DDDB & see if there's any data or reports of doing such.

[UNCIVILIZED]

When it comes to the line used in one's drogue, as in Jordan Series Drogue, the concept of using a Spectra rode for it suddenly made a lot of sense when I compared the weight of the equivalent line strengths... Dry. And wet, the difference is geometrically greater. Like on the order of 10-15x or more. Which is a lot of extra weight to haul in, let alone tidy up & put away when you're already wiped out from deaing with a storm.
Spectra as compared to say Nylon is also but a fraction of the latter's bulk. On the order of 25% or so, sometimes less.

Yet another reason to keep one's eyes open for high modulus line on the cheap. But even if you purchased the two types of line of equivalent strength, the cost isn't all that different. Particularly when compared to the overall cost of the drogue.

Thoughts on the use of say Technora, Kevlar, or Vectran, etc. instead of Spectra/Dyneema, if one were to find it cheaply enough, for use as part of a series drogue?

[Dockhead]

Originally Posted by UNCIVILIZED

. . .

But when you first mentioned tires, the thought which immediatedly ran through my mind, even before I finished reading the sentence, was kellets. Another tool who's efficacy is wrapped in controversies & mostly scientifically unmeasured results. With most folks now advocating putting the weight that you'd use for the kellet, into a yet bigger anchor.

I think what kellets can and can't do is pretty self-evident. It's just extra catenary, isn't it?

There's a point when the force on the rode increases and energy aborption by catenary approaches nil -- a kellet, like additional catenary, will delay that moment. But not prevent it from coming. That is the same moment when catenary stops improving the angle of pull on the anchor to any significant degree.

I think x kilos of metal added to the anchor might very well be more effective than the same amount used as a kellet, but the thing is, is that there is no practical say to do that once you already have the anchor. So why not send another weight down the chain, if you have one handy and you need more catenary? Say, if you are forced to anchor on a short scope?

I don't think, personally, that kellets are as useless as some people claim -- with apologies to Peter Smith, whose work I greatly respect. On the other hand, they are certainly not a panacea for anchoring.

[Dockhead]

Originally Posted by UNCIVILIZED

. . . Thoughts on the use of say Technora, Kevlar, or Vectran, etc. instead of Spectra/Dyneema, if one were to find it cheaply enough, for use as part of a series drogue?

I'd be interested in YOUR thoughts about that. I have a lot of experience with dyneema (both SK75 and SK78) but none with cordage from other UHMWPE/Aramid/liquid crystal/etc. materials (although I have Technora and carbon in my sails and the outer skin of my boat hull is Kevlar), and I'm sure we'd all be interested to hear your views.


As to UHMWPE/Aramid/etc. cordage for drogues in general -- I think that one is a no-brainer. Less chafe, no unpredictable failure modes like nylon, less weight, less bulk, what's not to like? I don't even think it's more expensive than say polyester, if you use say dyneema single braid a couple of sizes down, which also greatly simplifies the splicing. I didn't even think of the weight-when-wet issue until you pointed it out.