This week our sailing blogger Jonty Pearce talks anchors...
My mate, Simon, called me for advice on anchor chains. Perhaps stung by my accusation that he was anchor-shy, he and Sue have decided to update Navassa’s ground tackle. They already own a hefty Rocna anchor, but the 8mm chain and 3-ply nylon anchor rode had seen better days. Put off by the cost of re-galvanising his existing 30m of chain, he wanted to know what I carried aboard Aurial – our yachts are sister ships (35′ Southerly 105 ketches).
I have never felt the need to change the 16kg Kobra 2 with its 30m of chain and 45m of anchorplait, though we do sometimes need to dash below to topple the chain pyramid that builds up in the slightly under-sized anchor locker. In an perfect world, especially sailing in the Bristol Channel’s high tidal ranges, I would look to invest in 60m of 10mm chain, ideally in stainless steel. Unfortunately our sailing budget does not reach to afford this luxury tackle – the price of stainless makes me wonder if the chain is actually made of gold! However, the advantages are that stainless steel seems to be much more slippery than galvanised chain and therefore less likely to form a pyramid.
In addition, 60m of chain at a secure scope of 6:1 permits anchoring in a depth of 10m – and with a still safe scope of 4:1, a depth of 15m. Tie a bit of 3 ply nylon or anchorplait on the back and your tackle would be pretty bullet-proof in most conditions, especially when a anchor snubber is rigged. I’m a great believer in lots of weight on the sea bed with a more than adequate length of rode to prevent dragging. Furthermore, 60m of chain takes up less space than 30m of chain with 45m of 16mm anchorplait in a cramped anchor locker as rope coils less compactly than chain.
The disadvantages of such a quantity and size of chain is the cost and the weight. As mentioned, stainless steel chain is exorbitantly expensive, and I’d be very upset if I had to cut it loose and leave it on the bottom. 60m of galvanised chain costs twice that of 30m, and you may already have some nylon rode already thereby saving the cost of new. Finally, it is important to consider how you plan to lift the chain when weighing anchor – the more you put down, the more you have to pull up. Aboard Aurial the previous owner had installed a Lofrans Tigres anchor windlass which does the job admirably. Simon currently has a bad back and a dicky ticker which made me recommend that he upgrades his manual Simpson Lawrence windlass to an electric model as a core part of his update, though you do always have to have a reserve plan in case you run out of volts.
The other option is, of course, to use 8mm chain rather than 10mm. 8mm chain weighs 38% less than 10mm. While 60m of 10mm chain weighs 138kg, 30m weighs 69kg. By comparison, 60m of 8mm chain weighs 86kg with 30m a mere 43kg. By opting for 30m of 10mm chain rather that the full 60m you save the equivalent of a 11 stone crew member permanently sitting on the sharp end with all the plunging and hobby-horsing that would result. Maybe the best compromise would be to use 60m of 8mm chain, weighing only 17kg more than 30m of 10mm. Whatever your choice, remember to match your chain size to your windlass gypsy size, and check the calibration of the chain to ensure that it fits your chosen windlass – suppliers will be able to advise you.
At the end of the day, it all depends on how often and where you are going to anchor. Blue water cruising yachts might regard 60m of 10mm chain as a mere starting point, whilst some coastal port hoppers might think 10m of chain with 30m nylon adequate. My long term plan is to increase to 60m of 10mm galvanised chain – Aurial is hardly a racing greyhound, and we tend to anchor in more challenging places. I suspect Simon will follow suit, but the jury is still out.
– Jonty Pearce