Anchoring in Storm Conditions

25 - 30 knots in Upper Loch Carron with lots more to come overnight.

Sancerre rock solid in the gale at Upper Loch
Carron riding to the Bower with c 10.5 Kg on
the chain acting as a "Chum".

I have ridden to my bower anchor with no problems in well over 40 knots of wind in relatively calm waters and in somewhat less with some chop generated over a fetch of a few miles. However in the most extreme conditions I have always had a good bit of water behind me to give me time to sort things out if I dragged. 

Without that luxury or in a real storm like "Evert" that lashed the Isles of Scilly in July 2021 causing multiple boats to be driven ashore after their anchors or moorings dragged it would be prudent to be rather more pro active, also some precautions to help getting the anchor(s) up would be useful.

My post "Anchors, Drogues & Emergency Steering" describes the ground tackle I have on board so I will not repeat much of it here, one area that I will expand on is trip lines and there use.

And don't forget to secure everything on deck, get the dinghy onboard and deflated and take extra care of a furling headsail by putting multiple sail ties around it, 40 or 50 knots of wind could destroy a loose headsail before you have time to secure it. 

Many would argue you should also reduce windage by removing dodgers and dropping the spray hood, on Sancerre getting the dodgers off and back on would be tiresome and with the high cockpit coaming would not reduce windage by much and it would have to be seriously bad for me to drop the spray hood and risk getting the cabin wetter than necessary, fortunately with low freeboard she already has less windage than modern boats and normally rides well to the anchor.

Trip Lines.

I mentioned in the other piece that trip lines should be robust and easy to handle and recommended 6mm or preferably 8mm. In storm conditions it would be sensible to use a 12 mm line or more. Modern anchors are designed to dig in when under load which is good but, in sand or mud they can bury themselves very deep, I have always managed to get them out using the rode but others have not been so lucky and have had to get a diver to go down to dig them out. Patent devices to trip a fouled anchor are unlikely to work if the whole anchor is buried.

A strong trip line might enable the anchor to be pulled out backwards, to do that it might be necessary to take the line to the windlass or back to a serious winch, or to use the engine if the boat can be aligned correctly. A 12 mm line 20m long or more would be a lot easier to handle and has a 3.3 tonne breaking strain rather than 820 Kg for 6mm. It would also work on the windlass (tedious but possible) or a self tailing winch. I don't carry lines specifically for this, but a long dock line could be utilised.

The calm before the storm at Lindisfarne 2021 the anchor trip
buoy off the starboard bow. 

Backing up the anchor.

A quick fix is to back up the bower anchor (see "Anchors, Drogues & Emergency Steering") I use my 10 Kg folding stock anchor wired shut plus some chain. That helps the anchor by reducing tugging and may improve the catenary curve of the rode to pull on the anchor closer to horizontal; but make sure the sliding shackle or whatever can not go over the end of the anchor and jamb - that could be a big problem if you have to reset the anchor.  

My 10 Kg folding stock and 5m of 8mm chain
ready to go to back up the Bower.

In action together with the rubber shock absorber that as
well as further reducing shock loads stops the annoying 
“Grumbling “ of the chain moving on the roller.

Some recommend using 2 anchors in tandem, one anchor, usually the kedge, is linked from the normal attachment point to the trip point on a second anchor with a length of chain and the two laid out, hopefully with both digging in. It is reported to work well but is going to be very difficult to get back on board, if the water is deeper than the length of chain between the two anchors you would be underway with 2 anchors hanging off of the bow.

Two Anchors at an angle.

Short of a super heavy "Hurricane Hook" this is the traditional solution, but becomes problematic if there is a big change in wind direction (see below), the bower and kedge anchors are laid with an angle between them of about 45 degrees (less rather then more), the kedge, in my case probably the 24 Lb CQR, should have some chain to protect the rode from chafe where it is close to the sea bed, I would use 10 metres of 8mm, more would be better but that lot already weighs 24.4 Kg / 55 Lb plus the warp, as much as I would care to heave up. If laying the kedge from the dinghy I would probably use my 5 metre length to save weight.

Tip

If putting out 2 anchors forward establish which way the wind will turn as the system moves through (on the south coast a westerly will normally veer, but not always) and position the anchors to allow for this; with a veering wind the best bower goes on the starboard side to take the increased load as she swings. Also consider the possibility that you may have to change anchorage or your position in the anchorage as the wind or tide changes, getting underway in a gale, especially single handed, is difficult enough doing it with two anchors it may not be possible so you would have to cast off the kedge and come back for it later, if you have room behind it might be better to rig the kedge but not to drop it.

The kedge anchor is either laid from the dinghy or it may be possible to lay both from the boat by  manoeuvring under engine perhaps against the first one to be laid - it helps if there is spare cable on the Bower to give some space but care is needed to avoid getting one around the prop or rudder. If the Bower is on chain and the kedge on mainly rope then the latter will ideally be much longer than the used amount of Bower rode.

For strength I would probably use my 80m length of 14mm platted rope on the kedge rather than my 100m 12mm cable laid rope, but it does have the disadvantage of having a spliced in thimble at each end for the drogue so that it can not be fed through the windlass or blocks to a winch. A very expensive snatch block would help, my cheaper but still expensive one is not big enough or strong enough for the 14mm. A work round might be to haul the anchor up with the tripping line.

I would probably back up the bower with the 3.2Kg Grapnel or the folded 10Kg fisherman and some chain. The kedge would have to look after itself, the nylon rode is very stretchy so with the reduced snatch at the anchor end it should be OK. I would be loath to risk the chafe of running a weight down nylon.

Getting the two anchors up could be a challenge, it may be necessary to buoy the kedge rode with a fender, get the bower up then pick up the kedge or vice versa. Both anchors should have a heavy trip line, just in case.