floating anchor rope

[beau]

I am trying to keep the bow of my trimaran as light as possible.
I have a 45 lb plough anchor and 100ft of 8mm chain.
Most of the time I will try an anchor in less than 30ft of water (i have a 1ft draft Trimaran) with ALL chain.
I also have 200ft of 16mm rope to use for deeper anchorages.

I have noticed that I can purchase floating anchor line, which would keep the anchor rode off the bottom.(can't get fouled)

Any comments please

[rebel heart]

Unless I'm crazy, nylon sinks, and polypropelene(sp?) floats. I use a poly line for my dinghy painter because there's less chance it will wrap around stuff under water.

But the load capacity and stretch of the two lines are light years apart. Maybe someone else's input can clear it up, but three strand nylon is pretty much the only thing realistic for an anchor rode.

[maxingout]

When we were anchored in the Tuamotu Archipelago of French Polynesia, we had to float our anchor rode to keep it from wrapping around coral heads. We were inside an atoll called Apataki, and there were coral heads everywhere. The coral heads were deep enough that there was no problem with our keel hitting the coral heads. The problem was that our anchor chain would wrap around the coral heads, damaging the coral, chafing the chain and shortening the chain placing it at risk for breakage in a squall because there was no effective catenary to decrease shock loading on the chain. We didn't want to damage the coral, and we didn't want to risk breaking our chain. What to do?

Simple. We attached inflatable fenders along the length of the chain so that the chain no longer swept the bottom of the anchorage and interacted with the coral. It also created a reverse or upside down catenary, since the chain was being held off the bottom. If a squall came by, the chain would straighten and sink the floats that were holding the chain off the bottom. It actually worked! It was interesting to watch the floats attached to the chain. You could guage how much tension was on the anchor rode by how many of the floats sunk from view during a squall.

When you use this type of system, you need to be careful to maintain a safe scope between your last float and the actual anchor or you will pull the anchor out in a squall. Once again, you have to use your common sense to make the system work safely.

Anyway, you might be able to use a variation of such a system to good effect. If you could do it in a chafe free manner, it would keep your nylon rode off the bottom and decrease the risk of chafe. And there are lots of anchorages in Australia - some behind Fraser Island like Scotty's anchorage - where you wouldn't want to have a rope rode on the bottom because the bottom may be foul.

I personally would not use a floating anchor rode. There's too much traffic and too many props that would run over it and liberate my boat at the most inconvenient of times.

I have only floated my anchor rode one time for a week in Apataki, but it can be done.

Cheers,

[AnchorageGuy]

Using poly for an anchor line is a bad idea. It deteriorates quickly when exposed to UV and will fail quite suddenly. And it does not have the strength that nylon has.

[delmarrey]

Originally Posted by rebel heart

Maybe someone else's input can clear it up, but three strand nylon is pretty much the only thing realistic for an anchor rode.

http://www.yalecordage.com/html/industrial/index.html

See Nylon Brait (Multi-strand)

[GMac]

I'm with the do not go there team. No to Polyprop as an anchor warp or any serious load application actually. Under big cyclic loads it can heat up and melt, from the inside out.... Spooky. Common cause of boats coming off moorings in a blow, melting at the bow roller.

It would have to be a bloody big bit of PP to lift the chain anyway. Good in theory but not so in practice.

[craigsmith]

Originally Posted by beau

I am trying to keep the bow of my trimaran as light as possible.
I have a 45 lb plough anchor and 100ft of 8mm chain.
Most of the time I will try an anchor in less than 30ft of water (i have a 1ft draft Trimaran) with ALL chain.
I also have 200ft of 16mm rope to use for deeper anchorages.

I have noticed that I can purchase floating anchor line, which would keep the anchor rode off the bottom.(can't get fouled)

Any comments please

Replace your plough with a decent type that could be half the weight for the same or better performance.

I don't think the floating rode is a good idea. Under the remotest strain it will be pulled straight anyway, so it's pointless, and will just present an obstacle for your own boat, and others, when it is floating at the surface. The only way to adequately deal with the problem of fouling is to carry more chain. You could lower the size a bit and up the grade. Hopefully your low draft will allow you to avoid the 300' or so that is common on serious cruising boats.

Rebel Heart is wrong, 3-strand nylon is anything but ideal for anchor rodes, you should ideally be using multi-plait polyester (not to be confused with polyprop), or nylon for short lengths (but be aware of the disadvantages).