Deploying anchors in preperation for Hurricane

[CharlesM]

Hello All

Since I am in the frame of mind regarding updating my anchor inventory, I have started thinking about the techniques for anchoring in preperation for a *REALY* serious blow - something like Hurricane force.

I have read in numerous places that many consider the fishermans as an excellent storm anchor. Why is this? - is it simply due to the weight of the anchor or what?

How would one go about deploying anchors for a hurricane. I imagine one of the problems is that the wind direction is not constant since once the hurricane passes, the wind direction could change by 180 degrees - so the anchor may break out...

My thoughts on anchoring are probably 2 heavy duty anchors in tandem. Main Bower (which will be either a Spade or a Rocna) and the fishermans. Which would be the first anchor to lay, and how long would the chain be between the first and the second.

Next, what are the dangers of the multiple anchors fouling each other when the wind direction changes?

I hope never to have to prepare for such a situation, but would like to have some tactic ready.

As an aside, it is alarming how many instances I have read about people in hurricanes talking about their furled sails comming loose!!!! Surely since they know the hurricane is on its way they should take all sails down and stow them down below??? I cannot believe that people leave them up. /forums/images/graemlins/confused.gif


Cheers
Charles

 

[tcm]

um, for a hurricane i would try the "be somewhere else" tactic if possible. I think a fair bit of surviving ginat wind whilst at anchor relies on luck: frinstance, loads of the problems could be caused by other boats.

I would try and be in a small almost entirely enclosed sandy bay, and nudging the sand on the windward side with anchor up the beach and one at the stern, perhaps. Then, when it subsided i'd go to the other side of this ficitious sandy bay and do the same again for when the wind reversed. There'd be a bar on both bits of the beach, of course, with laughing knowledgeable locals having a party.

 

[Salty John]

I certainly wouldn't consider tandem anchors for the very reason you mention - shifting wind direction. Ideally I'd lay three anchors from the bow, one to the north, one southwest and one southeast. Failing that, two about fifty degrees apart from the bow. I'd have a hundred and twenty feet of chain on each anchor, or eight times depth whichever is more. I'd have only the CQR because of the swivelling shank.
However, if a hurricane threatened in the Caribbean I'd be in the mangroves made off by lines in several directions and all my anchors out. Mangroves make for a soft landing if you drag.

 

[scarlett]

I have never experienced anything like a hurricane but have had a quite a bit of time on tandem anchors.

The percieved wisdom in that they should be 10 metres apart but I have only used them about two metres apart.

I had a Plastimo CQR that wouldn't set but was heavy enough when used behind a Fortress a sixth of the weight to form a good working partnership. The 3 Kilo Fortress held my 32 foot four tonner in Med. sand in a six. I would doubt that there could have been be a tangling situation when there is tension on the rode, even if the wind changed direction. The longer the intervening chain the more likely the tangle I would have thought. The reason for a distance between the anchors might be to give the furthest anchor a chance to find virgin ground in an uncontrolled dragging situation. I would be interested if someone else has a better reason.

Regarding your other post. This might be a reason for choosing a big Fortress as your second, light and easily handled anchor. They also easily dismantled and stowed away when not needed. Storage is maybe not a problem on a forty footer!

 

[homa]

When I was caught in a hurricane at the end of a 2 week Caribbean charter we were instructed by the company to take the boat to their preferred hurricane hole. This turned out to be a mangrove swamp protected on all sides by mangroves.
Due to the number of boats (roughly 80) we tied up in a long raft athwartships, 2 x huge 6 foot long fenders tied each side, n.b. the fender lashing went right under the boat to prevent the fenders riding up.
boats were secured bow to bow, stern to stern and 2 x spring lines each side.
2 x anchors from the bow and 2 x from the stern, these were motored out after the boats were tied up and the lines tightened afterwards by hand.
As far as I can remember, the only damage was to the dinghys, a lot were lost or stolen, no one thought to secure them properly.
Sails were left hanked on but lashed.
I saw quite a bit of damage in an adjacent marina.
Biggest problem seemed to be chafe and for this reason a lot of owners in the marina prefered to remain with their boats. As charteres were were put up in hotels all over the island.
I'd say the boats in the marina fared far worse than the boats in the mangrove swamp.
If it were my own boat would go for the mangrove if at all poss and run a couple of lines ahore (windward side) with anchors out astern.

 

[vyv_cox]

Nobody has ever persuaded me that tandem anchors, by which I mean one attached to the crown of the second, offers any additional holding power. I believe that all the holding would be done by one while the other contributed next to nothing. Two anchors laid about 30 degrees apart is another matter altogether but the problems that may occur if and when the wind changes direction are well documented. For this reason I believe it sensible to have two entirely separate anchors and warps so that one may be retrieved and relaid (hopefully) without the additional problems of trying to detach one half way up the rode.

I see no benefit in using a fisherman anchor unless there are specific reasons for doing so, i.e. rock or heavy weed. In this case, the anchorage is certainly not one that should be considered for riding out a hurricane. Much better to use two modern high power anchors that will have high holding power and good ability to re-set.

The Fortress holds very well in the right bottom and I would be happy to use mine in the right circumstances. It does not re-bed well and I would be very wary when the wind direction changed.

 

[webcraft]

Re: Tandem anchors holding power

I have never yet had to use anything other than our single trusty Spade,but I do have two more anchors on board. The plan has long been to lay two in tandem if a really big blow is forecast . . . Spade first, with a big CQR behind it on 7m of chain.

I don't see how this can fail to help, even if it is only acting as an angel.

Of course, in a 180 degree turnaround (eye of the hurricane or maybe just the tide changing) then sod's law says any number of foul-up situations are possible. In this case though I would trust the Spade to reset if it wasn't totaly fouled by the chain. I wouldn't trust the CQR to reset, but it would still act as an angel and help the catenary.

Anchors laid 45 deg apart off the bow sound great in theory, but if you swing 180 deg then the rodes will indubitably become tangled.

It's a black art, innit?

- Nick

 

[machurley22]

Thought you might be interested in this account from an old pal whose boat survived IVAN in Grenada. It was written a couple of days after the experience and he's understandably still a bit emotional!

Unfortunately I don't know all the details of exactly how the anchors were deployed. His best bower is a 65lb CQR and he also refers to a fisherman but I don't know what the other "main anchors" are. They dragged a long way back and forth in any event and presumably eventually caught on something immovable by pure luck. I do know that the CQR had to be dug out of the seabed after the event which is hardly surprising given 150 knot winds.

I think the main point is that you can prepare as much as you like but the only preparation that doesn't rely on a large dollop of luck is to be somewhere else. I know they'd ground her in the mangroves if there was to be a next time.




Move Maverick round to Clarkes Court Bay put as much stuff on the seabed as possible .This was quite a lot

T ues early IVAN coming straight in and intensifying;what an interesting word when you already have a forcast for 105 knots with gusts of 130; intensifying to what for [--word removed--] sake

Take the foresails off Pull out an old fisherman and attach approx 58 miles of all the the rope we possess This I arrange so if the boat drags her main anchors to ratshit maybe it would delay things So anc hored in CCB opposite the new ish marina the skies lower and the wind starts time has run out..Do what has been decided ,that is leave Maverick and seek shelter ashore.Easy to say difficult to do ,eight years for us to build and IVAN is looking for bird Bid her hasta luego touch wood and leave with heavy heavy heart.Get to the house of a friend of a friend as the wind picks up more.We ,in the house,are looking down on the anchorage and acrossto Hog Island and the marina.Wind is at about 80 knots and the boats are coping so can relax a little.Stop looking out the window at Maverick,sit on the bed---ears pop wind screams ,bang and the [--word removed--] windows blow in glass flying across the room .Itssafe to look out the window no glass ,its bad movie time.Initially branches then. tree s become airborne ,big shudder and bang—alarge baulk of timber scud missile like pierces the roof and ceilingand lands in the next room.Outsideroofs aremastering the art of flight.Now the sound effects kick in a low low frequency roar.More windows in the house go ,the basement beckons but it would be suicide to even step outsideCower incorners whilst the women and child go under the bed covered withcushions and other mattresses.Edge along and look out the window-this seems to be a very basic level necessity to at least know the bad news as it comes in.Cant see Maver ick ,complete whiteout at sea level ,can see however a small local house achieve escape velocity momentarilyintact before separating into the bits that fly past the window.Fear in very large amounts arrives,we are like every Granadian in threat of our lives and there is not a lot we can do to help ourselves.Down below the whiteout fades replaced by huge gusts that tear the surfaceoff the sea shredding it into mini tornadoes.I can see Maverick almost lying on her side knocked down by these blasts,Icannot believe she can possibly stand up to this .Thie wind notches up more.The barometer has dropped 45mb in the last hour yes that figure is right 45.Owen ,Phil and Idont look at each other much ,Ive started smoking again.Maverick sliowly starts togive to the hurricane ,dragging slowly to the S .Other boat succumb riding up onto the rocks to the south,but the main drama is across from us the marina is migrating ,going south with her contingent of maybe 40 fledglings.The wind from a numbing roar stops just like that;it’s the eye no it’s the EYE we hurriedly take water , mattresses and stumble down to the basement ,we barely make it. The hurricane which had been from the NE then almost nothing powered back from the SE going to 120 knots in afew minutes we were in the bit the text books say to avoid the NW quadrant. Ihad alast vision of Maverick on her side trying to turn180 degrees before the surface whited out and visibility was reduced toa few 100 yards.This pleasant state of affairs lasted for afew hours with us alternativelt cowering in corners andtrying to safely to look out the windows .On the water couldnt see anything ,trees bit of buildings and so on were still flying past the house only in the opposite direction tothat earlier After a few hours of this,stomachs twisted into pretzels the wind(what a little [--word removed--] word)veered alittle so we could see across the bay .Main priority is still afloat ,dragged up the bay ,cannot believeshe is still there .That is more than can be said for the marina which has changed its mind and is migrating north.shedding her 40 or so boats onto the shore and mangroves as it goes.The wind (I have come to dislike this word) screams more and the seas build driving over the reef protecting the entranceto the bay.We now have serious waves in the anchorage along with the wind which we are told later is a sustained 145 knots gusting 165 category 4 hurricane and another whiteout stops us seeing more,just as well wind up more and the base ment windows go.More abject terror and cowering in protected corners-not even a bottle of rum.Then the rain.Isuppose you think you know what rain is. No you don’t .This was bits of water propelled by a pissed off category4 hurricane-- stun a stoat at 100 yards .I stuck my head out ttying to see what the [--word removed--] going on instantly blinded I swear I was beaten to my knees more like a waterfall-Another mistake.I,a few days ago foolishly thought I knew what high winds were after all we havestorm force winds on the west coast of Scotland but for [--word removed--] sake 145knots sustained and lord knows what in the gusts has changed my mind somewhat no lotswhat Occasional breaks in the sea level white out sees Maverick slowly dragging back towards the wreckage that was the marina and 40 or so boats then the wind notches up again the sea shreds visibility goes and Maverick vanishes in a white cloud lying once again on her side.Six oclock another break shows me Maverick leaping up and down as wave after wave bears down onher as she veers away the wind pins her down on her side .Idont see how she is surviving but she is and more importantly no longer dragging the wind screams and once again she disappears Six thirty another break just before dark and I cannot see Maverick near her last position ,actually I cant see her atall.Darkness falls the wind continues the rain increases deep depression and fatigue but no sleep .During the night the wind slowly subsides but the rain continues how can the sky hold so much water.By 5-30 the rain had lessened and the wind was bearable and as it became light Imade my way down to the dock through Woburn Most of the village was destroyed.The wooden houses were gone ,strewn over the hillside ,concrete houses windowless and roofs gone.Theverdant tropical island leafless and almost treeless .All amenities out..Still no sign of Maverick,climbed a wall to look up the head of the bay and there she was ,afloat 15 feet away from allthe boats from the marinapiled on the shore.Couldnt believe it ,don’t understand how the anchors withstood 145 knots sustained and gusts of165 plus after the eye passed through the waves. Quickly got the dinghy and went out.She had lost wind gen,solar panel,spray hood flooded down below,but basicly intact.Iwill stop as I might have a chance to send

 

[Salty John]

Re: Tandem anchors holding power

I've used two off the bow on numerous occasions and have never had a serious tangle. In Caribbean anchorages it is quite common to use two anchors this way. The rodes get crossed over from time to time but usually each turn of the tide unwraps them. You sometimes see people pushing their boat round using the dinghy as a tug when they have left it too long to unwrap the turns. I would never, ever, use tandem anchors, I've seen too many unholy tangles with them.

 

[Blueboatman]

Re: Tandem anchors holding power

For what its worth.
The best anchor set up in the world may not be enough to get you through a hurricane.....
Don't be there, track the weather and get out. As has been said!
OK So you are staying.....If you have to be there get organised early,get well into and tie to(spiderweb to) the mangroves ,hurricane holes fillup ridiculously..The mangroves are your crumple zone and hidy hole out of the full force of it..
You are in as much danger from others drifting down on you as your own inadequate ground tackle,this has been proved time and time again.
Once things go wrong,you may not be able to do much-people CRAWL along decks wearing snorkels to check anchor gear ina really bad blow!
A Typical 'regular'hurricane area mooring is a giant screw wound into the seabed,mooring chain/rope attached to this.These can fair well.Borrow one?
Some of the new anchors are looking very good-you need to access the experience of eg Caribean sailors who have verified these,probably via 7seas cruising club,Blue water,Practical sailor and other US marine sites(Google)
Hurricane winds are not steady-you rely as much on nylon stretch as on conventional anchors themselves to avoid breaking out of the ground-which puts massive emphasis on the war of attrition to be waged against chaff where the anchor lines come onto the boat- often parcelling layers of towelling/ducktape/pvc/ducktape etc which in turn means good stemhead arrangement ,generous smooth cleats or capstan etc-especially if as the moment of truth comes close you and your crew decide sensibly to 'retire' to a land shelter..
Boats have come through with big engines and low enough waterintakes that they can ease the loads in gusts by full ahead,...until the debris clogs props.
In my own extremely limited experience.... I have come through the EDGE of 2 hurricanes to the tandem anchor set up that you question, I suppose-
I dug in the 35lb cqr on 90' 1/4''chain with the large fisherman slung halfway down the chain as an 'angel'as much as anything...BUT it was a 21' one ton boat with very canoelike lines and low freeboard,and I stripped the rif and dropped the mast,to minimise windage,and the stemhead and cleats were really overengineered-and well tested.The boat lay beautifully..and I was lucky.Wind never over 100,yet this was 1995,Luis and Marilyn,real killers that wiped out many fleets through St Martin and Virgin Islands,before veering sufficiently to only graze the north shore of Puerto Rico ,....
so as I said just don't be there is my advice! But you are absolutely right on to consider upgrading to the biggest and best anchor set up you can manage-if only for a sound nights sleep when the halliards start to rattle.

 

[ccscott49]

To be totally honest, I wouldnt be anchoring to sit out a hurricane, it's not sdo much your anchors evcen if they do hold, in a vee pattern, it' s the othewr boats in the anchorage, being driven down onto you, dragghing anchors, lines, hulls etc. etc. Only place is in a hurricane hole, rammed into mangroves etc. Or ashore with your keel in a hole, tied down. That kind of thing. If forced to, but I dont see why you would be forced to, I'd put a fisherman out, and two others at about 45 degrees, maybe even dive on the main anchor and make sure it's jammed in a reef or somewhere it wont move. IMHO

 

[craigsmith]

[ QUOTE ]
I have read in numerous places that many consider the fishermans as an excellent storm anchor. Why is this? - is it simply due to the weight of the anchor or what?

[/ QUOTE ]

A combination of weight and fairly reliable setting. Most people carrying Fishermans tend to have very heavy ones, heavier than their main anchors since they're rarely used and kept low in the boat. Their flukes are usually small, and while that's not good in the holding power equation, it means they will usually get through weed and grass etc.

This is not to say that an X Kg Fishermans will outperform an X Kg modern type design (Spade or Rocna). It's just a good addition to your set-up.

[ QUOTE ]
How would one go about deploying anchors for a hurricane. I imagine one of the problems is that the wind direction is not constant since once the hurricane passes, the wind direction could change by 180 degrees - so the anchor may break out...

My thoughts on anchoring are probably 2 heavy duty anchors in tandem. Main Bower (which will be either a Spade or a Rocna) and the fishermans. Which would be the first anchor to lay, and how long would the chain be between the first and the second.

[/ QUOTE ]

Tandem is good, dual (in a Y) is bad - debatable. There are pros and cons, but we favor the former, so you're thinking along the right lines.

With tandem anchors, there are a number of issues. Ideally you will be using two anchors of the same type, if not size. This is to ensure both have similar setting behaviors. If both anchors are to share the load, they need to both be set and the rode between them needs to be rigid. This scenario is not by any means guaranteed.

In any case you should put the heavier anchor down as the primary anchor, the lighter one being the tandem (at the front). The length between the two: generally about a boat-length. Use chain not rope, as you want the link to be as rigid as possible.

[ QUOTE ]
Next, what are the dangers of the multiple anchors fouling each other when the wind direction changes?

I hope never to have to prepare for such a situation, but would like to have some tactic ready.

[/ QUOTE ]

The primary anchor could of course drag over the tandem in a 180 degree shift. In theory the tandem anchor would always remain in the same location, with the primary anchor dragging around it until the system is stabalized again. So you could foul them, but you'd be very unlucky.

You would be more likely to have problems with other methods of multiple anchor rigs. Ultimately of course you're better off with one single big heavy hook and a ton of chain, but it's a case of compromising with the daily reality, which doesn't usually include hurricanes. /forums/images/graemlins/crazy.gif

We have an article from a cruising guide to Chile that discusses tandem anchor deployment. Worth reading. I will e-mail it to you upon request.

 

[ClassicPlastic]

Hmmm, though I've never sat out a hurricane at anchor, I do believe in considering the simple physics of the piece... Two anchors on one chain to the boat will help with more rapid re-setting in certain ground, two anchors at say twenty degrees to each other on two seperate chains will do nothing positive (saw this most recently in a very uncomfortable anchorage in the 'eastern Med' in horrid conditions which were beyond what almost all of us expected - August in Turkey? Must be gorgeous!), as one anchor simply enables the boat to swing repeatedly about the the anchor and break it out...

Consider survival too - and get ashore!

 

[ccscott49]

Three reefs in the courtesy flag!!! Tickled me that one!!! ROFL

 

[davidbains]

I have used two anchors at an angle many times. The main benefit seems to be reduced swinging. Also the second anchor can be set towards the expected wind shift. Obviously you can reset one anchor without disturbing the other. A tandem arrangement (although I've never done it) seems more awkward to arrange after initial deploymnet of a single anchor, and you've put all your eggs in one basket as least as far as the rode goes.
I frequently throw a Fortress off the stern although leading the rode back to the bow to maintain position in crowded anchorages. However on a multi I often anchor in shallow water inside other boats.The lightweight Fortress is a real boon in dinghy deployment.
Last year a large yacht dragged down on me in a modest onshore breeze. Fending off and then recovering my own ground tackle was real struggle singlehanded as sod's law dictated I was that morning. Although I have never visited the Carib, hurricane force winds are not unknown during Med thunderstorms.

 

[vyv_cox]

As ever with anchoring questions, one person's proven method is vehemently decried by someone else, who advocates a method that poster 1 says doesn't work! The answer has to be that luck plays a major part in the equation. In the right circumstances you might get away with almost any arrangement, provided it has sufficient weight and a very long scope.

The point about other boats dragging down on you is well made. In the only big blow that I had to ride out (a long way from a hurricane) this was our biggest concern. In the well documented hurricane in Pollensa, Mallorca a few years ago several boats were forced to abandon a well secured anchor when dragging boats collided with them.

 

[john_morris_uk]

Hmm. For what its worth I will add my two pennyworth.

The last time I had to shelter against a hurricane is was only a Cat 2 (only is a bit of a funny word in the context of hurricanes)

Mangroves are good. I dropped the main anchor (65lb CQR on as long a rode as I could from the stern) and then drove the bow of the boat into the mangrove. We used a variety of lines to secure the bow of the boat into the mangrove and then laid the kedge out sideways from the stern in nthe direction that the wind was forcast to come from. In the end the eye went right over us so I am not sure how much it mattered...

I destowed the upperdeck of everything loose. Took the sails off. Secured everything below and retired to a hotel.

If we had stayed on the boat, I do not honestly believe that it would have made any difference. It might have endangered our lives.

The boat survived intact. It took us a few attempts to pull the anchors up though!

Place: English Harbour, Antigua.

 

[CharlesM]

Thanks Everyone for the replies - keep them comming. I am learning /forums/images/graemlins/smile.gif

 

[Sgeir]

So which one did you choose in the end, and why?

 

[jimbaerselman]

[ QUOTE ]
As ever with anchoring questions, one person's proven method is vehemently decried by someone else, who advocates a method that poster 1 says doesn't work! The answer has to be that luck plays a major part in the equation.

[/ QUOTE ]
Perhaps circumstances (type of boat, waves) rather than luck. And for most people, their strong wind experience at anchor is a 'one off', so their survival (or otherwise) may be attributed to the wrong element.

Boat Type? Lighter fin keel yachts will sail vigorously from side to side on a single anchor, especially with a longer scope, putting heavy 'tacking' sideways strains on a well set anchor. Using two anchors set well apart 60 degrees or so, will reduce the tacking and keep the strains in line with the anchor doing the work.

Long keel yachts tack very little, and won't gain much from such an arrangement; nor will catamarans if they set up a suitable bridle to hold the chain. Some people use a small sail astern to reduce tacking; questionable if that's suitable once you're talking 50kts or more.

Waves? If there's more than a 1000m fetch, then the anchor strains induced by the boat's circular surge in those waves become the main issue. Adequate elasticity of the rode is what matters - loads of nylon.

Without these precautions to reduce rode peak strain, your anchor (whatever type) is not getting a fair chance.

Tandem? A last thought - if tandem anchors are your final choice, how much extra holding power do you expect the additional anchor to create? 50%? Whatever, you must be sure your rode is capable of matching that extra force, otherwise you'll have a beautifully set pair of anchors, but no connection to them!

And, of course, if you have that heavier, stronger rode, why not just go for a bigger anchor to match, rather than tandem anchors?

Having said all that, I guess I'm really talking of strong wind anchoring - up to 60kts. Above that, the appropriate solution (as many have said) is a spider web of string in a mangrove swamp.