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Old 11-03-2009, 05:21   #1
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Anchoring Techniques for Storms, Hurricanes and Cyclones

Note: Mark asked that some posts on anchoring techniques be moved over from the "Who Ordered the Frikkin Cyclone" thread. Well, my good intentions went awry. Without going into the gory details, Mark's new thread was inadvertently erased. I was, however, able to resurrect the content of the posts so far, but the individual post structure couldn't be maintained.

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INITIAL POST BY MARKJ

There doesn’t seem to be a good recent thread on techniques for anchoring in severe storms, hurricanes and cyclones.

I sure wasn't sleeping comfortably in the cyclone that just missed us!!!!!!

I need to learn some ways that have been tried and tested by cruiser and also some new innovative ideas even if they haven’t been tried yet. Someone else may have or help with ideas.

If a storm hits and you are not at sea how do you use ground tackle to stop your boat being smashed to pieces on the rocks?

Mark

PS I am asking the mods to move some great posts from another thread into here
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POST BY BASH

here's my plan:

Two to Tandem: Maximizing Holding Power by Tandem Anchoring
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POST BY MV

Originally Posted by Bash



That is a very rich sailing link.

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POST BY KANANI

Mark

If you put down 2 anchors, it's best to put them down 180 degrees apart IMO. If you have a good big swivel, use it to link the 2 anchor chains.

The chains don't have to be tight, they just have to be connected, same thing for the "Y" set-up. The idea is to be able to fall back on 1 or 2 well set anchors without getting them sideways when the wind and/or tide shifts, resulting in an anchor pulling out. If you want to know where the anchors are, buoy them. In extreme conditions put a buoy next to each anchor also, in the mud. That way you can tell exactly what's going on with the anchor by comparing the 2 buoys. This is a little harder to do in a crowded anchorage but remember, you'd rather have your neighbor be secure than to give him grief about having buoys in the water.

If you put the anchors 90 degrees apart, you will turn them both over and possibly drag them in a wind shift.

For setting the 3 anchors on 50' chains, just disconnect your main anchor and attach that chain to the 50' chain & anchor. Set the anchor with 10:1 scope then motor up and disconnect and buoy the end of the 1st chain. Do the same with #2 & #3. Then connect them all to one swivel with shackle (seize all shackles of course). It's harder to do, but possible, with a breeze blowing. In a breeze, it may be necessary to lay 2 or 2 of the anchors with your dingy. You can tie a line to #1 chain and tie it amidships to control the boat from blowing down while setting #2. Then run a line form #1 & #2 to each side of the stern to allow you to back straight into the wind to set #3 while taking up on #1 & #2.

I know what you are saying about having a twisted up mess of anchor lines. I learned that lesson early on, in American Samoa. It's always blowing like a hurricane in that place. That's when I finally decided to get myself a good quality 1/2" swivel dedicated for storm and tidal anchoring so that I have only 1 line coming up to the boat.

POST BY AMGINE
Ooo! I actually know this one!

You can lay out the 'Y' anchors, but you need to lay out the complete rode, which is why it's usually only used when setting up a semi-permanent mooring complete with buoy. So, literally, you'd lay out the whole rode, attached to a big swivel which is, in turn, attached to the boat. Then lay out (at 120 degrees to the first anchor) the full rode of the second, and attach it to the swivel. Then the third... then attach the cement bucket to the swivel, with a spare safety line, and chuck the whole mess off your bow.

You now have two lines off the bow - one to the swivel and a safety line to the cement bucket. Plus the snubber if required (likely).

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Old 11-03-2009, 05:24   #2
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Gezz , I had wrote a long reply and was ready to post it and poof it was gone !
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Old 11-03-2009, 05:44   #3
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OK one more time- Ive lived through 6-8 hurricanes in S. Florida and in 4 of them I had a vessel I had to prep for the storm-

the best thing if at all possable is get out of the way of the storm, todays weather reports you have a very good idea on where it will land most of the time with in 4-5 days and you can travel a very long way in that time-
just being 3-400 miles away from most storm center makes all the difference-

If you have to stay put - get the boat on the hard- if you cant do that find a mangrove or a small canal where you can get your boat in- ive done all of these things and have come out with little to no damage-

Once you have your boat in the canel/mangrove I put 2-3 lines on every cleat in every direction possable along with all anchors out

Proprer Chaf protectin is important- do not use plastic hose to protect your lines- these have failed a lot- what happens is the violent movement of the line heats up inside the hose because no water is able to get in and keep the line cool and the line fails- what has been found to work is old fire hose or simalar materal - the outer shell of the fire hose is peeled off and wraped around your line it lets water in to keep the line cool
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Old 11-03-2009, 14:36   #4
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Quote:
Originally Posted by Ram View Post
the best thing if at all possable is get out of the way of the storm,
I fully agree with RAM:

« The best thing if at all possible is get out of the way of the storm, »

Then talking about the TANDEM SET technique:

- If your single anchor isn't working on its own or you don't feel you can trust it in average to strong conditions then maybe it is time to consider replacing it rather than chucking various complicated arrangements of ironmongery at the problem.

The Tandem set technique seems to be a very good one!

- I began to have doubts while seeing tandem set anchored boats dragging.
I thus carried out a series of measurements of traction with a motor boat. Almost all the tests gave the same results: one needed 200 rpm less to drag 2 tandem set anchors (CQR or Fluke anchors) than only one of these anchors alone. I thus checked what occurred, with small anchors, pulled by hand.

First problem with the CQR: it doesn’t have any fixation hole to attach the second anchor (that should have been a sufficient reason for not using this technique); I thus tested the bar, the trip line hole, the elbow of the shank. On these 3 points. the effect is the same one: the articulation plays badly, the plow cannot dig in. Remain the extremity of the shank, but it is not better. Almost each time, the chain comes to obstruct the plow The whole system does hold only on the most distant anchor. If this one is smaller, it holds less than only the large anchor one.

I noted too that an anchor holds very badly in the furrow of another.

With the “Fluke” anchors: this is again the same problem of devoted fixation, and it does not have there anything which can be used except sometimes the trip line rings which are usually not strong enough. However, from time to time y obtained results comparable with the holding of only one anchor.

I thus concluded from it, that I had sufficiently poisoned my life by re-installed useless scrap heap to definitively give up the tandem set technique.

Joăo
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Old 11-03-2009, 15:50   #5
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Location, location, location,- more important for anchoring in bad weather than in real estate! Nobody mentioned number one yet; that is, if you are actually going to be anchored in bad weather and not escaping the weather or being hauled out. Number one is to reduce the fetch! There is no bad weather if you can have the wind coming at you from only a hundred yards of water or so. 'Lots more to consider, but wouldn't all agree that that's number one? 'take care and joy, Aythya crew
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Old 11-03-2009, 19:16   #6
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In a reply that was lost, someone posted the following article on tandem anchoring ... which I was reading this morning:

Two to Tandem: Maximizing Holding Power by Tandem Anchoring

? A last resort, having run out of options on:
[1] Avoid
[2] Run
[3] Hide in the tightest nook & cranny to be found
[4] Find a humungous mooring block ?

The article covers anchoring very well, but could say a little more about spreading the load across fittings, minimising snubbing (covered) and managing internal friction on any ropes being used e.g. for extra scope or to reduce shock loading, etc. I.e. the top end of the anchor system.

I remember an interesting story in "Rascals of the South Pacific" (Rascal of the South Pacific by Athol Rusden - Books, Calendars, Magazines - Products from New Zealand) where a schooner (?) captain survived by setting up a spiders web of warps, chain, etc to chain & steel cable wrapped around coral heads (as well as using anchors). The skippers was quoted as saying something like "I put out everything I had, because if it did'nt work I would'nt be using it any more". The book is a very amusing read (I am not a marketer, relative, etc)
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Old 11-03-2009, 21:03   #7
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If you can't get out of the way, which is the best option(!), I believe it depends very much where you are as the storm approaches.

We have had 2 experiences.
The first was as Emily approached Tobago. We sailed overnight to Trinidad, hopefully further from the centre of the storm. Found a sheltered cove surrounded by mangroves and dug the nose of the boat as far in to the undergrowth as possible. Forward anchor deployed into mangroves and two off the stern quarters. Every bit of rope was utilized to tie ourselves into any substantial object. Wind 'only' reached 60k but it was pretty wild for longer than I would like.

Once as a tropical storm approached we were fortunate to have an empty bay to ourselves. This time we deployed tandem anchors, 2 CQR's 45lbs and 65lbs. Attached by chain and then on 200 feet ss anchor chain. Held like a dream. Definitely the way we will go in the future, provided there is sufficient space of course.
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Old 11-03-2009, 22:04   #8
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Huh?

Quote:
Originally Posted by Ancora Latina View Post
I thus carried out a series of measurements of traction with a motor boat. Almost all the tests gave the same results: one needed 200 rpm less to drag 2 tandem set anchors (CQR or Fluke anchors) than only one of these anchors alone. I thus checked what occurred, with small anchors, pulled by hand.
I'm having trouble putting faith in this test. Regardless, some anchors are not designed for tandem use. Rocna anchors specifically have an attachment point just for the tandem anchor. Of course, they recommend that the second anchor be a Rocna as well, and I'm not certain that makes any sense since identical anchors will generate identical furrows. For my setup, I'll use a Rocna primary backed up by a Fortress in tandem.
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Old 11-03-2009, 22:34   #9
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As well as increasing holding power & improving rodes, the other ways of improving your chances are to minimise strain on the anchor. Ways I have used or heard of (fortunately not in a full cyclone) are:

[1] Minimising windage, e.g. run halyards up mast on 3mm nylon twine, running backstays, lowering boom, biminis, etc. (This can also reduce reverberation effects.)
[2] Reducing 'sailing' (boats vary on best approach)
[3] Having the engine running in gear (e.g. anchor watch as max winds approach).

A bit away from the main thread, but I read about a boat that abandoned its anchor inside a reef (can't remember why), and survived by motoring into the wind within the reef.
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Old 12-03-2009, 01:25   #10
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I think that there are a lot of "if's" for tandem configuration to work. Like, I think it works if you have a Rocna primary with it's engineered attachment point for the tandem anchor and if that tandem anchor is something like a big Fortress and if the wind doesn't turn 180 degrees like when the eye of the hurricane passes etc.

I don't mean to say that I believe only a Rocna works, it's about the if's and the rest is an example.

We actually survived hurricane Ivan in Grenada while at anchor (cat.4 storm 120 kts sustained etc.) We used a single anchor: a 176 pound Bruce (original Bruce that is). The idea with a super oversized anchor like that is simple: bigger is better and it's just as easy to use the storm anchor for everyday anchoring too: makes you sleep better. Also, saving weight here doesn't matter much for the total weight of the anchoring system: going down to 110 pound Bruce saves 66 pounds which is only a small part of the 110 pound anchor + chain (couple hundred pounds). After surviving that storm, we love our Bruce even more.

But, if possible (we were nowhere near the boat during Ivan), I would have changed the anchoring system, because I have more anchors. But I would not ever change it to a tandem. I would add my two Fortress anchors (FX85 and FX125). I would set them 120 degrees and say 100' apart thus the three anchors spanning the compass. I would attach chains to all three and lay them to the center of that circle and shackle these to a big and thick steel ring. I would shackle my rode to that same ring and set as much scope as possible. I think I read that in a book and it computes for me. I also think I would need to visit some hardware stores to get the parts needed ;-(

cheers,
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Old 12-03-2009, 03:36   #11
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There are so many variables and yacht compromises on this subject of TRS anchoring techniques that I can only give advice on “ideal” solutions and let the mariner adjust to his own actual situation.

My best advice is that your yacht should have its primary ground tackle, retrieval gear and strong points sized to handle the shock forces and strain of Hurricane force winds combined with about 5-8 ft waves on your displacement. You should not need to play with Tandem, kedges or double deployments!

In my opinion, if you can not trust this basic gear with your life in those conditions then I think you are putting a lot of pressure on yourself.

IF you are more of a racer/cruiser and weight prohibits that, then you should consider not being in an area of TRS during their season. However, I do not advocate leaving a potential safe haven 4 days before predicted arrival to try and create separation from a tropical revolving storm as tracks and speed can become very irregular, breakdowns can happen during transit and it takes time to properly prepare if the storm follows you.

Living aboard in the Philippines, where out of the approx 25 Typhoons each year in the Western Pacific.... we get about 8 a year down “Typhoon Alley”...so these comments illustrate the specific realities I have to live with.

Choosing a “location” is often wishful thinking as we can get a Typhoon in any month so wherever we are cruising I research the nearest typhoon hole’s reputation.

My biggest concern is how popular it is with local ships and ferries? If it is popular, can I put some very shallow water between them and my anchorage?

For example, if any of you know Puerto Galera, that beautiful anchorage will often have over 25 small Ro-Ro ferries/ships/barges crammed in. If the storm passes nearby, many end up being dragged aground and luckily where you see the yacht moorings near the bottom we have a finger reef to catch most of them. But I have experienced in 90 knot winds a 200 ft car ferry passing within 10 feet of me before running aground further in. (I no longer stay there anymore in a typhoon because of its popularity)

Next to protecting from local ships and having faith in my primary ground tackle, I try to drop it in a hole so that it needs to pull up in any direction. If I know how busy it will get, I would rather put up with more Fetch and discomfort rather than allow myself to be crammed in with too many other boats in the very best area. I like room to swing and have put up with too many last minute frightened arrivals who want to park on your hip.

Once the anchor has been given time to bury on initial set I then do a heavy test using full rpm and surge to try and break it out. I have made up a very heavy duty deck bridle to be used in these storm conditions rather than my normal snubber. As someone else said commercial heavy duty fire hose material works well for chafe protection and from my towing days, I soak the line in oil before covering with chafe gear.

MarkJ asked that I repost my previous notes on how I would use the second anchor:

Again, this is based very much on the actual circumstances so how you deploy depends a lot on neighbors, holding conditions, swing room, yachts tendency to sheer and anchorage topography.

Once I lay out my primary anchor at maximum scope to keep me off anticipated dangers I make sure that the remaining chain can be run out easy and I put a lighter line on the bitter end so that it can break away easy if I need to let go due to a barge or ship dragging down on me. (Tip: I put a bright yellow named float on a line from the anchor so that it marks its position for others to see where I have dropped and hopefully keeps them well clear. Also helps monitor the shape of your anchor bight if wind goes 180)

Well before any real wind comes, I lower my secondary anchor to full extent replacing any faded marks, then retrieve it back while carefully laying the chain in the locker so that no snags can happen if I need to run it all out in the storm.

Then when the anticipated wind settles in, but before it builds too much, I lower the secondary anchor at my stretched out position so that it just drags the bottom.

The reason is that most Typhoon holes are in Mangrove areas and the shallow bottom can be muddy slurry.

My goal is to reduce and slow down the sheering tendency that could break out the primary anchor and if the topography is steep hills or cliffs around you, it will slow down the effects of rebound gusts.

If swing room is limited and the eye passes close by as the wind starts to go 180 I then deploy my second anchor using engine and clocking angles to lay it out at an angle away from the primary anchors bight.

I don’t believe in committing both anchors before the TRS shows its hand, since they can fool you, but I do like the second one in the water and ready to use for any scenario.

Some other on-board preparations tips not mentioned:

Fill water tanks in case you do go aground or the anchorage is too dirty to make water after storm.

As well as removing all sails and canvas, I unhook the toping lifts, lash boom aft ends to deck and use vang and extra lines to use boom as aft brace for Mast as well as a steady support if you need to be on deck.

Tension all halyards and topping lifts for additional support of masts and make sure no slapping against the masts can happen.

Safety Lines set up on deck.

For each of us, prepare mask / snorkel and bicycle helmet for emergency deck work. (I also have a thin diver’s hood to protect face and ears from wind pressure.) Fins are nearby in case we needed to abandon into the water.

Lash poly beach line on stern ready for deployment (I have actually used this to catch another yacht slowly dragging close by and help hold them…they had a Y set up that fouled)

A mechanical lock on the wheel to centre the rudder helps to slow down sheering during surges.

I personally don’t believe in using the engine blindly to relieve strain on the holding gear. There can be too much flotsam in the water from fish nets to poly line to foul the prop. Also if you get it wrong in a wind sheer you can over-run the chain and then come back very hard.

Hope some of this helps.
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Old 12-03-2009, 15:54   #12
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I am with Pelagic. Sound strategy and it's how we survived Ivan. I can only add:

bring your dinghy to shallow water close to shore and sink it using deflating, sand, rocks etc. Tie it to a tree or whatever so you can find it back.

If you trust your rigging to keep the mast up during the storm, tie big knots (so they can't slip into the mast) in all running rigging and pull the knot up to the masthead so that only the mast and standing rigging are left (this assumes running rigging goes through the mast). secure all at deck level.

Like another poster wrote: reduce windage. Keep removing stuff until time is up.

Don't join hurricane parties until you're 100% ready and wish to leave the boat and find better shelter ashore. That might well be safer for you.

About running away from the hurricane: yes, you get notice that one is coming days in advance. Same for Ivan. They reported it would hit the Virgins and many boats traveled south. But the reports changed any many other boats in the windwards came south too. In the end it struck in Grenada, where many of those boats ended up as they kept going further south and many of them were destroyed. Had they stayed where they were before moving out of "the predicted path" they would have been safe. This shows it's like a lottery and this was a normal storm track, not one that turns 180 degrees or hitting the same place three times etc.

cheers,
Nick.
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Old 12-03-2009, 16:18   #13
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Storm path forecasting has improved greatly in the last 3-4 years-since Ivan- Not sure what the accuracy is now for 3 days out but its very good
- not perfect but a lot better than when Ivan came through-
but you never know...
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Old 12-03-2009, 17:15   #14
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Ram: I am not aware of any new computer-models used for forecasting the storm tracks; I think they still use the same. But they add new storms to the database used basically just widening the area that the storm might wander about.

Lots of people only look at the line that is drawn but you should look at the grayed area around the line instead. (like on the weatherfax etc.)

cheers,
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Old 12-03-2009, 17:51   #15
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Very good material here.

I always remove the booms and stow them below, as apposed to lashing them. If the boom gets loose, which is all too common, it's a killer.

Not enough can be said about not motoring into wind gusts. Very dangerous. Having the motor running to avoid other vessels dragging by or getting out if something breaks, is a good idea. Putting the the engine in gear can cost you your last life-line to safety. I have seen several yachts abandon their ground tackle and opt for motoring back and forth in the harbor until the storm subsides. I've also seen that go bad but it's good to reserve that as your last option.
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