There is a man living in my chain locker. His name is Marcel and he’s a second-row forward for the French national rugby team.
Marcel is a big lad – just over 20stone (that’s 130kg to the French – 286lbs if you’re American). But stocky: Marcel has very short legs. Second-row forwards don’t have to run.
I am fantasizing, of course – but the weight is real enough.
It’s all to do with replacing the anchor chain. The last time I wrote about this was in March 2021 – when I was enthusing at getting it re-galvanised for a fraction of the cost of a new one.
Well, now I’ve got a new one.
Periodically, I was supposed to take the stainless steel swivel off the end and measure the last link. This was 10mm chain and one day the last link would rust away to 8mm – at which point it would need cutting off so the swivel could get on with sacrificing the next link. However, the corrosion seemed to have stopped at a fraction below 9mm – and a 32ft boat doesn’t need even that much.
Like many things about Samsara, the chain is somewhat unusual: When she was built 51 years ago, it seems she started off with 30metres, and then one of the succession of previous owners decided to add another twenty. It was the last link of this 20metres that I had been measuring so conscientiously.
Then, a couple of weeks ago, on a whim, I decided to measure some of the links at the other end – the older end – the end that was (not to put too fine a point on it) fifty years old…
I found one that was down to 6mm.
And you know what they say about the weakest link…
So, a new chain was called for – and what did I say about a 32ft boat and 10mm chain?
The worst part is the way it gets jammed in the chain locker by its own weight. So, the new chain would be 8mm.
But then there is this thing called catenary – the weight of the chain providing a shock-absorbing effect. This would be reduced with a lighter chain, meaning that I would need a bigger scope. Up to now, I’ve worked on 3:1, which is very old-fashioned. Modern anchor manufacturers all seem to recommend 4:1 as a minimum.
Well, that was OK, because 50m of 8mm weighs only 70kg, compared to 115kg for 10mm.
Or I could get another 32 of length for the same weight. I would be able to anchor in 20metres – and still have 4:1 scope!
But who walks into a chandlery and asks for 82m of chain? I rounded it up to 85m – it was only another 4kg.
And this is where Marcel and his short legs came in. Instead of measuring all 85m, he cleverly paced out the remaining 15 to leave in the tub. In fact, he paced out 14, to be on the safe side – at least, that’s what he said he was doing. I was over on the other side, working out how many more chain markers I was going to need.
It turned out I didn’t buy enough.
When I loaded the new chain into the dinghy to row the half-mile back to the boat – and then, when I laid it out between two pieces of plastic tape stuck to the deck exactly five metres apart, it transpired that Marcel’s little legs hadn’t measured out 14metres to leave in the tub… but only seven.
Either that, or he’d forgotten to double it.
Either way, I’ve now got 93metres of 8mm chain, weighing a colossal 130kg or, as I say, just over 20stone (or 286lbs).
I could just cut off the excess – but who throws away brand new Vigouroux chain? Also, the extra eight metres only adds another 15kg…
But when you add it all up – with another 20kg for the anchor – that’s an awful lot of weight up front. It’s a whopping 150kg!
As I say, that’s the same as having a rugby player in your chain locker (instead of where he should be, on the weather rail.)
I can only hope that the Rival’s famously fat and buoyant bow will be able to cope…
Forgive me if I’m wrong, but I was under the impression that the length and weight of the chain added to the holding power of the anchor. I’d like to know if that is so.?
Oh dear, I fear you will have started another anchor war (or, in this case a chain war). Heavier is better obviously, but it’s all a trade off – the heavier your chain, the less length you can carry … and I would suggest that (providing you have the room) the more length, the better. Geoff Crowley (who is an anchor specialist) suggests that in a strong wind, heavier chain will go straight fairly soon anyway – which means the only benefit of it being heavier is that it is less likely to break – and how often do you hear of chain breaking? The anchor will pull out long before that happens.
Isn’t it just wonderful how the topic of anchor & chain keeps us pondering for years and years and never fails to fascinate. There must have been hundreds of thousands of words written on the subject yet it still finds us wanting more! Thanks John. Keep ‘em coming.
Best wishes, Nick.
This is the perfect post – for my 36 footer, I am going through the same arguments. Today planning to put big tub of water (150kg) on bow to see what the chain weight will do to the trim!
I have been considering doing all chain on my 27ft boat. After reading this I am more convinced it is a good idea. I can shorten my scope in busier anchorage’s around here with less worry.
I ‘chaperoned’ a friend’s Rival 34 for over a decade, which had something close to 300′ of 10mm galv chain, in two chunks – one in the chain locker with the notoriously delinquent navel pipe, and t’other in the port cockpit locker. “You can never have too much chain,” he would intone. The boat had a permanent list to port, and the spare length didn’t see daylight in a decade.
Nowadays, I’m fettling a similar-shaped boat, but 55% of the weight of the Rival. It came with 10mm chain. That’s now adorning a pallet, and I have >50m/160′ of Grade 8 high-test galv chain – in 6mm.
That’s less than 40% of the weight, and bulk, of the hefty stuff, and is as strong.
Sure, there’s a trade-off. On the balance of advantage, I’ll live with that.
Catenary only exists when you don’t need it. High rode force means an almost straight chain, from bow to anchor. No shock absorbing in that. Snubbers however (10m of stretchy nylon rope) do absorb shock loading on anchors.
Did you consider a mix of 2/3 chain and 1/3 rope to reduce the weight. It would probably still provide the catenary effect. Anyhow, brave on you to row all that weight back in your dinghy.
Rope is too liable to chafe.
I sailed along time with 8 mm chain and CQR on an Ohlson 38 and it pretty much always ripped when I needed it most regardless of healthy scope.What’s on he bottom is also a massive concern.Sold the Ohlson (a pig of a boat to hand steer in a breeze) and am now happily throwing in the Rocna and 10mm .
Incidentally bought your books for my island hopping in the Med. this summer. Now 68 ex marine reading your stuff is very inspiring.Keep it coming John.