Short Partial Chain Anchor Cable. Worth it?

[Mark-1]

Danforth.

3m chain.

50m nylon.

Boat is a Corribee.

All anchor/cable handling is manual.

Substantial Angel deployed as deemed appropriate always about 2m or further from the bow roller, but never allowed to touch the bottom of the cable were straight down IYSWIM. Angel is mainly mainly to keep cable below the keels on change of tide but also to keep the cable below close passing boats. I'm also convinced the angel helps reduce snatch loads and helps maintain a pull from as low as possible but I'm happy to concede that has no value for the sake of my question. (Indeed, nylon cable is so elastic that shock loading would rarely be a problem.)

The weight and faff of managing the chain is getting on my nerves. (Take my word for it, I can't be bothered to explain why!) Managing the angel is a doddle because it comes up clean and while the boat is securely anchored, weight and faff that end is no problem.

My question is: What is the 3m of chain adding to the party here? Chafe resistance? It will slightly lower the pull on the anchor where not at max tension but if I put all that weight in the angel so would that. It also increases the likelihood that the cable will tangle with the anchor itself IMHO. (Or does it reduce it, I can't decide.)

My personal prejudice is towards lots and lots of lovely heavy chain but I'd rather take chances with my boat than my spine and I've already gone down the nylon route to a massive extent.

I won't be fitting a windlass. (I'd rather take chances with my spine than my wallet.)

I'd keep the chain in the locker anyway.

 

[Tranona]

Sounds OK - but the angel is probably a waste of time. If you are relying on a mainly rope rode then it is th stretch of the rope that is important. Despite traditional thought catenary has little effect on holding - that is the job of the anchor and the short length of chain is there for abrasion resistance and to help keep the shank down while the anchor is setting.

 

[noelex]

The chain will help, primarily adding some chafe resistance and assisting the initial set.

To explain: With all rope rode when the anchor is first dropped even a very slight force will raise the rope up to the angle corresponding to the scope (for example at 5:1 this will be about 12°). At this early stage the anchor will be totally unset. Anchors can still start to set in these circumstances, but they may struggle in some instances where the substrate is less favourable. Chain weight helps reduce this initial angle while the anchor has very little or no grip.

Once the anchor has started to set, the force will increase and catenary largely disappears. Here the advantage of chain is lost. Nevertheless, in the very early stages, as the anchor toe is just trying to bury, the anchor has little grip so there is little force to lift the chain.

If you remove the chain, look for a difference in ability of the anchor to develop initial bite in the very early stages of setting. With such a small amount of chain I doubt you will see much practical difference, but it helpful to know what effects to watch out for.

You don't mention the thickness of the chain, but if thinner chain is an option this may improve the handling while preserving the existing chafe resistance and some of the initial setting performance.

 

[zoidberg]

There are those who place their trust in the idea that Fortress anchors accommodate a steeper angle of pull ( i.e. so many degrees above horizontal ) than most others. If that's the case, then it supports the argument for an all-rope rode.

Why don't you try it?

As for the 'angel' or 'chum', as far as I'm concerned that's in 'chocolate teapot' territory.

 

[brainstorm]

Treat yourself to a 4 kg Rocna anchor ( as I have on my Corribee) and add a couple of meters chain for good measure and you should be safe anywhere. Chain very important to keep anchor at bottom and cope with abrasion on seabed

 

[Mark-1]

Thanks for all the comments, I think I'm going to try without the chain. (On reflection, I use the 2kg claw without any chain so it's not exaclty a leap into the unknown.)


PS: The angel is essential in calmer conditions for two reasons:

1) Without the angel on quiet nights I frequently get the anchor cable caught round my keels at change of tide and end up in the middle of the night sideways on to the tide in my pants trying to push the cable down with a boat hook. It's no joke. I haven't ever suffered the problem using the angel - it's a cure - but if it did happen letting a few feet of cable out would effortlessly drop the cable out of harm's way.

2) I sail in a busy part of the world, there's always someone passing close over my cable. The angel holds the line down under their prop on quiet weather days. (Of course it also gives a false impression of the angle the cable is lying at.)

2.5) On quiet weather days the angel limits my swinging diameter relative to all the other boats who all seem to (sensibly) use chain and don't swing as far or as fast as me. Which makes a big difference, at least as I perceive it.

 

[Neeves]

I have this embarrassing confession - I don't know a Corribee (and am too lazy to look via google).

But its the internet and what is good for many, I'll conform on this occasion

However as you use a 2kg claw then I assume she is not very big. You have omitted to mention chain size but I wonder why not use smaller chain, amazingly enough it will be lighter. I might also venture to suggest that you are actually not using a Danforth but a copy, of dubious origin?, which may actually not be very reliable.

Find a small second hand Fortress on eBay - I understand they appear with some regularity. Hang the Danforth off the bow such that it just rubs on the seabed - it will stop the Corribee wandering around like lamb looking for its mother. Its a recognised technique - the name of which I have forgotten.

Jonathan

I've remembered - a hammerlock

 

[Mark-1]

Good question re the Danforth. I call it a Danforth because it looks like the anchor style I've always called Danforth. (And because that way we can call it "Daddy Danforth" and the Claw "Baby Bruce" and have amusing alliterative names.) I actually have no idea what it is, but yes, I very much doubt it has any legitimate pedigree. Google suggests 'Stockless' would have been a more correct term. The 2kg Claw, which I typically refer to as a Bruce, is actually a Lewmar.

I've lusted after a Fortress since I inherited the Danforth.

 

[zoidberg]

The genuine Danforth anchor was quite effective, in suitable substrates. It spawned a score of cheap 'n nasty copies, which replicated in their hundreds. They were nowhere near as effective - but they were cheap!

American Inventor, Richard Danforth, created our lightweight, versatile, and high-efficiency fluke-style anchor in 1939 for use aboard World War II landing craft.

This video from the sainted Steve Goodwin should please the eyeballs of Mark-1... especially considering the capable but not-load carrying merits of the 22' Corribee.

Don't forget the considerable benefit, in a small boat such as the Corribee, of the Fortress' disassembly feature. It can be stored 'flat-pack' in a homebuilt polyprop carpeting bag. Should the little hex bolts be replaced with small eyebolts/eyenuts, then no tools are needed for re-assembly.

 

[vyv_cox]

I believe that Fortress state that no chain is necessary with their anchor, all rope is fine. I confess I have 5 metres of 8 mm on mine. Due to confusion over the markings on the Anchorplait we lay at 3:1 scope in about 6 metres with the Fortress in a full gale for several days. I doubt very much that any of the chain was on the seabed throughout this time.

Not sure that a Danforth copy would have done as well but worth investigating.

 

[Boathook]

I used my anchor angel last week when I ended up anchoring in 'deep' (by my standards) water. It kept the boat in roughly the same position in the light winds. I haven't used it for a few years but this time was right. I did try using it in strong winds a few years back but it made no difference to the rode until the wind went below 15 knots I seem to remember. I think that it has possibly had more use as a weight on a mooring line when alongside in a drying harbour.
I am now in the process of changing my mixed (chain / rope) rode to all chain and will reconsider the angel in due course.