About seventy vessels more or less in the anchorage a big storm and a muddy bottom. A night of mayhem ending with bruised and battered boats. In the cruising community there are still things to learn about anchoring. I can safely say we are not experts and we did increase our knowledge from what we learnt that night.
The Sail Indonesia rally fleets joined others who had sailed and motored in from different parts of Indonesia, Singapore and Malaysia to be part of the marine festival celebrations. We were all anchored in the Tanjung Pinang anchorage and by our calculations we estimated there was about seventy vessels more or less in the anchorage on the final evening. The vessels ranged in size from something that looked like a floating block of flats to small sixteen foot cabin cruisers. This is a well-protected anchorage for anything other than weather coming in from the west. So after the day’s hectic social events we were enjoying a drink and winding down prior to heading back out to the boat. At around midnight we noticed the lightning on the horizon to the west getting closer and knew from recent experiences a storm front was on the way. Oh great that’s all we needed was the cry as drinks were left unfinished. There was a scramble to the tender dock and before the last boat had left the dock the waves were already quite choppy and it was hard to board our tenders. We were lucky enough to get back to the boat relatively dry and tied the tender up tight off the stern in case we needed to do any manoeuvring later.
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| Stormfront on the way out of the West. |
Then it was on, it started with an icy cold breeze and large claps of thunder as nature unleashed her fury, the heavens opened up, rain poured down as the wind rose to a crescendo and the rigging whistled as the wind strength exceeded forty knots. As the storm progressed so did the wave height, it wasn’t long before there was surf rolling through the anchorage. Boats rose on the wave peaks straining on their anchor chains, the wave would pass and the boats surfed slightly down the back of the wave before the next wave lifted their nose pushing them back to strain on their anchor chains again. The VHF crackled with different boats communicating with neighbour's or warning others they were not holding, then there were the boats trying to untangle anchor chains and what to do next.
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| The storm is increasing looking west over to the ferry terminal, |
Seventy five percent of the boats in the anchorage dragged.
For the next three hours about seventy five percent of the boats in the anchorage dragged. Some of the dragging vessels smashed into others and took out or dislodged the anchors of vessels that were not moving so as you can imagine it was mayhem on the water. We had several vessels anchored around us and it was nerve wracking trying to raise the sleeping occupants as their vessels were on collision course with us or other vessels. I remember one comment a friend told us when they rose from bed disorientated and looked out the porthole of their vessel as it was dragging backwards through the anchorage. She commented to her husband that all the boats are hastily leaving the anchorage dear, so please get up quick and have a look. A look out the port hole was all he needed before urgently crying get up on deck they aren’t leaving we are going backwards, let’s start the engine or words to that effect!
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| Just about past waves and wind have died down |
There was a lot of damage to vessels
In the morning once things had settled down we went out and had a drive around the anchorage in the tender. We wanted to see how our friends went during the storm and did they require any more assistance. The rally fleet participants were very concerned because there was a lot of damage to vessels that night. One local vessel sunk not far from us and one of the participants on our rally had their vessel end up perched on the stairs of the local ferry jetty. It’s funny but not the ha ha type of funny, but the peculiar funny, it’s how you notice things in a different light the morning after a night of chaos. The one thing we did notice in the tender ride around the anchorage was the lack of snubbers or the incorrect use of snubbers on a large percentage of the vessels in the anchorage. However this wasn’t the first time we have notice it, we have seen it time and time again when we are in Moreton Bay with boats going every which way (usually with the wind) during a storm or a bit of a blow.
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| The local fishing village, several boat sunk including a large tug tied up at one of the docks. |
While the owners were on shore their vessel was re - anchored
Once you get a group of yachties together for a couple of months, if you take a little notice patterns start to emerge. Throughout the rally one vessel always moved when the wind came up, and the morning before the big storm while the owners were on shore their vessel was re - anchored after it was found moving backward through the anchorage again about to collect another vessel. The person who re-anchored it was another catamaran owner and noticed their bridle wasn’t set right nor was there enough chain out for the conditions. So he anchored the vessel as he would his own cat, and possibly for the first time, during a storm this vessel didn’t move. The owner was so impressed he actually asked for hints and tips, because in his words “this is the first time we didn’t drag in a storm” he didn’t think it was possible not to move. No wonder he was always a nervous wreck as soon as the wind rose above ten knots.
Tests are conducted in a controlled environment
You may find it doesn’t hold as tested
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| The wrong place for a mooring springer, in reality this isn't going to do much and with loss of tension the chain hook will fall off, there is nothing holding it on. |
Points for having a snubber
I would say most of us have heard it suggested that when using all chain rode the catenary effect of the chain sagging because of its weight will provide sufficient shock absorption. While this might be true for larger ships with anchor chain links the size of cars and anchor in deep water, the catenary effect from the chain on the average size cruising vessel anchoring in shallower water will not provide any significant shock absorption, just look at the chain shape in a breeze > 25 knots you see that the catenary effect is no longer a factor because the chain is pulled tight in a straight line. So simply put, the use of a snubber ensures that your anchor has the highest chance of staying put where you placed it.
I will add a disclaimer here, this lack of catenary effect is mostly due to the depth we as cruising yachts like to anchor in, the shallower the depth the less likely catenary it is going to come into effect. Deeper water will certainly help due to the weight of chain hanging in a loop, gravity will be doing its work. The shallower the vessel anchors the less likely catenary effect will come into play. So with this lack of catenary effect the shock loads are certainly increased on the anchor and this is why a snubber is so important in shallower anchorages. A springer is still important in deep anchorages but comes into it own in shallow(er) anchorages. Also keep in mind chain weight, high tensile chain may save weight but also lessens the catenary effect, is more brittle and is likely to snap rather than elongate.
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| Just on 25 Knots chain is pulled straight beyond the snubber Dyneema loop in use |
Naively the owners drop the pawl onto the gypsy / capstan
Look around some more and you will see that there are vessels straining at the anchor (anchor chain in a straight line from snubber to anchor) and the small chain loop behind the attached snubber hook does not change. There is no shock reduction other than the load is removed from the anchor winch. This lack of elasticity is a problem that may be traced back to the length of the snubber, some are no more than 400-600 millimeters long while others are of the wrong rope type or the rope is too large a diameter to allow any stretch.
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| Heavy rope with a small loop wont do much good Hull damage due to chain scraping top sides during wind over tide |
Unfortunately, the majority of discount chandleries sell silver rope as an anchor rode because it’s cheap and then it starts to become the rope of choice for all things anchor on some vessels. This is a bad state of affairs, silver rope may be ok for the weekend power boat that is driven right on to the beach, but it is not the rope of choice for anchoring larger vessels in any weather.
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| Silver rope is furry when new and in most cases when its no longer furry it is getting too old and from my experience past its use by date |
We wanted a snubber system on our vessel that would work and was easy to use, as stated earlier it had to add sufficient elasticity to reduce shock loading on our all chain rode and remove the anchor chain load from the windless. Another requirement was to make sure it didn’t require additional consumables or an additional task other than removing the attachment during deployment or retrieval. We wanted the snubber to be long wearing, virtually maintenance free and we didn’t want any slipping on the chain. Furthermore, I didn’t want any dissimilar metal contact for example a stainless steel hook on a galvanized chain. Due to vessel design, I needed it to run over the bow roller when deploying and or retrieving the anchor chain with out causing damage to the roller cheeks.
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| Not a very good setup, this arrangement wont do much to help with holding, I am not 100% sure but it looks like a shackle holding the rope to the chain, could be difficult to remove in a hurry. |
Traditionally snubbers have been attached to the anchor chain with a variety of snap shackles, quick release hooks, steel chain hooks and purpose made chain attachment plates. All are proven to work, however some are better than others, but they can also have some downsides as we found out. Large snap shackles and quick release hooks can straighten out or become badly distorted if put under too much load. Exceeding the SWL (safe working load) if certified can lead to total failure or distortion of the hook. We have had the steel chain hooks wedge onto the chain after being anchored in a decent blow. The other pitfall with chain hooks is they can fall off the chain due to a multitude of reasons, for example, when you are running the chain out and loose tension, or the wind dies and the chain goes slack when it rests on the bottom, the tide turns or you experience wind over tide; there are tricks to minimize the hook falling off. We did use insulation tape to hold our hook on, but it is a constant problem and adds another task to do when deploying or retrieving the anchor and then you need to keep hold of the used tape so it doesn’t go over the side and become another piece of plastic in the sea. Friends purchased a fancy purpose built anchor chain hook and found that the plastic keeper to stop the chain from accidental disconnection would wear off or break when anchored in shallow water and the snubber ran along the bottom.
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| Snap shackles can straighten out in a blow |
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| The chain is to tight and may tear the bow sprit off if the wind comes up. The length of line for the springer is too short and not enough chain has been deployed |
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| Chain hooks will fall off easily or wedge on the chain after a blow and don't go through the bow roller easily. Shown here with the snubber rope removed. This was our setup and I was so glad to see it go, it was always when you needed it, that it had fallen off. I was always worried I would loose a finger getting it through the bow roller when hauling anchor in a pitching sea |
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| Soft shackle, connecting it is very similar to doing up a button |
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| Soft shackle connected to the chain. |
This table is the breaking strain not the safe working load limit which is a lot less.
Nylon Dyneema
How well does a Dyneema loop stay attached to the anchor chain? We have been caught in a couple of nasty storms during the season transitional period while sailing in Asia. This has meant we have been caught exposed to the full force of the wind, and large expanses of ocean as fetch. Most of the time we are able to get the anchor up and get around the corner or headland to hide or go with it until the storm has blown its self out. Unfortunately on a very memorable occasion we were caught in a bay with several obstacles that made our escape hazardous. We had to stay anchored longer than we would have liked with storm force wind and seas that became well developed (surf). The photos of the galvanized thimble I think display just how well the Dyneema loop can stay attached to the chain and thimble.
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| Fairly standard gal thimble, its easy to see the force the shackle was under during the storm |
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| Another angle of the thimble distortion |
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| Another angle showing the compressed distortion from the soft shackle |
Below is a table I used as a starting point for putting together my snubber. One important rule is that the lines must be nylon to afford the required stretch. I have also found that it’s not the best to deploy the full length of the snubber until I am anchoring in deeper water (>7Metres) or I know a blow is coming my way. Like nylon anchor rode the snubber can suffer abrasion if it is deployed onto an abrasive bottom. As a rule I work out my water depth when anchoring and set the snubber to just be above the bottom at low tide. So as an example with a two metre draft and two metres under the keel plus two metres from the cleat to the water line I will deploy a snubber length of six metres. With a short snubber of six metres ten percent stretch will give you over half a metre (0.6M) in moderate winds and as the wind increases fifteen percent stretch would be just under a metre (0.9M). The nylon will usually part (break) at twenty eight to thirty five percent stretch depending on the brand. I have used nylon rope one size down from the charted size e.g. 13M boat 12mm snubber at full ten metre length when anchoring in soft mud. If used regularly (daily) the snubber should be replaced annually due to consistent stretch and UV degradation. Chafe protection will be necessary as the snubber will come into contact with the anchor chain regularly. A length of plastic tube approximately one metre long with a three millimetre cord used to adjust position should suffice.
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| A heavy duty thimble spliced into the new springer, compare with a standard gal thimble bottom, there are even better thimbles with the tail welded and loops around the line to keep the thimble in place if the eye is under tension and stretched. . |
To make a snubber is relatively simple, get a length of good quality three core nylon to suit your vessel (see table below) and splice a thimble or have a thimble spliced into one end is all that is needed. If you want to use eight plait or climbing rope go ahead but it does take a little more work. However, while it does look good for the first month or so before it becomes camouflaged in the sea green if used regularly, make sure you purchase heavy duty thimbles, sorry to say you’re most likely not going to find these on the shelf of your local discount chandler. Head off to someone who sells rigging/lifting hardware, and for a few dollars more you will come away with rope thimbles that won’t collapse in a big blow.
Keep in mind that this table is a guide only, due to the various shapes and sizes of vessels. An older mono hull vessel where the decks are lower to the water line will have a lot less windage than some of the newer builds with voluminous interiors and high sides. The same is true with catamarans, the earlier builds were close to the water, and now the newer builds with palatial cabins below decks and lounge rooms above do offer a larger area to the wind.
Length in Metres Feet Metres mm
Some people say that with the long snubber bridle the chain is lowered below the waterline so it affords better scope. I don’t believe this is true, just look at the snubber in use in 25 knots or more of breeze it can almost come clear of the water. For better scope you would need to lower the attachment point on the vessel. The reality is that the snubber connection to the chain should be well below the water, if it’s not your snubber is too short or it’s blowing really hard. I have found that at a minimum the chain/snubber connection should just be above the bottom at low tide except when anchored in soft mud deploy the full length snubber along with extra chain. Perhaps a lower snubber attachment point (cleat) to achieve better scope may work but it will be difficult to attach the snubber on a cleat near the water line from up on the deck of the vessel.
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| Just on 25 knots the anchor chain is in a straight line to the anchor. Springer line has got a fair amount of stretch at this point. |
In the season transitional storms mentioned earlier on, in one storm we lost two snubbers due to them becoming over worked. It’s hard to believe but the one snubber we were able to retrieve had the core melted, it had become so hot absorbing energy. On inspection I found it could not be unwound and had parted I believe due to heat. In hindsight, if I had let out more snubber length earlier in the storm the snubber would have been able to absorb the energy and would not have become over worked.
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| The remains of the snubber the strands can not be unwound due to being melted together in the core. |
What else in your anchoring system? Chain is without doubt the rode of choice for cruising boats. It’s hard wearing and hard working. If the bottom is abrasive it won’t wear through a chain easily where a nylon anchor rod can be damaged in the course of an evening in the right or should that be the wrong conditions. Get good quality marked chain from reputable manufactures. Cheap chain with no identification marks as to type or manufacturer has no place in the chain locker. When you purchase chain always ask for the proof certificate, this is a little bit of insurance your chain has been tested. Because you have the certificate you now know that firstly you’re dealing with a tested to failure product and secondly you know some quality inspections have been carried out during the manufacturing process.
Another thing that is worth a mention is that it’s usually a better option to purchase a chain from a manufacturer. Not from a dealer (supposed chain manufacturing company) who sources the chain manufacture out to another company, usually somewhere in China not that that’s always a bad thing. During my work we got into all sorts of problems with a manufacturing company who after years of dealing with them, decided to outsource their chain manufacturing. From time to time the supposed chain manufacturing company would source a new manufacturer and twice during the changeover period there was serious problems with chain quality. The down side for us was that it was causing thousands of dollars loss through down time and equipment damage when some chains failed. We had to find a new supplier who would audit the manufacturer on a regular basis to improve the product quality. For those of you who find this to be a bit farfetched, I seem to recall something about an anchor manufacturer out sourcing and having the odd bit of trouble.
So how much chain do you need is totally up to you really, having just completed a journey through SE Asia and anchoring in all sorts of conditions and bottoms and now ten metres is the new five. Depending on the boat and area of operation, I would say to start off with eighty metres but one hundred would be better. One of our friends has gone with eighty metres of chain and has fifty metres of nylon rope he attaches for the really deep anchorages. He doesn’t lay the rope on the bottom but deploys enough to keep it off the bottom at low tide, so he rarely goes anywhere because he can have eighty metres of chain on the bottom in deep anchorages. We are frequently anchoring in ten to fifteen metres and one evening we anchored in twenty eight, yes every last bit of our hundred and ten metres was out of the locker that night.
Chain size? While not going over the top it’s better to have more weight on the bottom rather than less. So if you think a high strength chain of a smaller diameter sounds like a good idea it may be false economy because you may find you need to let out more length to get the weight on the bottom. This will then increase your swing room and may be the difference of anchoring in a tight anchorage at the end of the day or sitting outside in the weather. The other factor no one appears to talk about is that the higher the chain tensile strength the more brittle it becomes, this may not matter where anchoring is concerned but it’s worth knowing about.
The most important item in your system that will make it easy to find the end of your chain is an anchor. So, how will you make the right choice when it comes to selecting the anchor design that suits you? It’s not quite as easy as you may have first thought and your research options are certainly limited. If you take all the claims and endorsements seriously and at face value you would really have a problem making a choice.
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| The old tyre is not much of a springer, softer perhaps but not much good to keep you anchored in place. |
You can read the manufacturers claims all day long and I am sure most will excite you. But always keep in the back of your mind that they are trying to sell you a new anchor made by them, the best bet is to talk with other cruisers but take into account that its part of human nature to defend even our worst purchasing decisions. I would consider that it’s remarkable to talk to anyone who has never ever dragged, as with the manufactures you can’t take every ones comments at face value either. I remember a people’s behaviours quote my father would tell me about there being two types of sailors in Moreton Bay, he would say that there are those who have run up on a sand bar and then there are those who lie about it. However if you ask enough people you may see patterns emerge especially if you ask about other boats/persons anchor performance.
The other way to consider a new anchor purchase is to look at the independent testing results, these are most likely a reasonable bet, but you do need to realize almost everyone has a schema. You will also need to look at as many test results done by different people as you can. This should help find the anchors that perform well just about every time, lack lustre performance and hit miss results should be enough to eliminate poor performers. I remember seeing anchor tests over the years testing the same anchor and one will say that it works fantastic in mud the next review states this anchor doesn’t work very well in mud. The other hitch that I think confuses the issue is the same or slightly changed press release doing the rounds year after year with no new tests, it worked in tests years ago so don’t retest just keep retelling the same great results, and where and who by its earned accreditation.
I have seen supposed true endorsement of anchors or accessories on line and due to the over enthusiasm of the review and the known holes in the story, I feel that somewhere or somehow money or goods have conceivably changed hands. I have even read one review where an anchor was blamed for electrolysis on the vessel due to a fault in the anchor winch, but that was only one grievance amongst a long list of others. Funnily enough the vessel never ever dragged again once the new anchor was in place, which must have been a relief for the captain because it had moved every time they anchored with the previous anchor. Somehow I just don’t believe it, knowing the reputation of the anchor they put on.
Without doubt the new generation anchors worked the best during the storm in question, but that said one brand didn’t work as well as the manufacture's would like us to believe. If the anchor is based on an old design with a few changes then really do your homework, if they just turn in a satisfactory or good all-rounder during anchor tests then think again and look for exceptional holding because that’s what we all want at three in the morning on a hot and windy night. But the thing we all need to keep in the back of our mind is the fact that like the weather the holding is only as good as what you are experiencing right here, right now in this small patch of the ocean. But if our vessels are set up to help keep us anchored to this small patch of ocean floor we may all be able to sleep better.
With a new anchor purchase you will find an anchor that is larger than the anchor manufacturer recommends is well worth while but it’s your call whether it can be fitted and carried safely. With anchors, bigger equals more surface area and more weight and both will help you stay put. I know the old guys who sprout the virtues of the old generation anchors are in most cases using an anchor a minimum of two, three or even more sizes up from what the manufactures originally recommended. There is nothing wrong with that mind you, however it is more expensive to fit the vessel out with a bigger anchor and sometimes anchor winch.
It is important to note there are several manufactures who promote under sized anchors. Why? basically so they can sell more anchors. Yacht manufactures look at ways to save money so if an anchor manufacturer specifies that a 40' yacht only needs a 16 Kg anchor and the opposition list a 20 Kg as being suitable my bet is that the manufacturer is going to be going for the lighter and cheaper option.
While all the advertising sprouts the certifications making it all sound wonderful to be classed as a high holding anchor, from our experience we believe the selection charts promote the fitment of undersized anchors. While these anchors are good for a lunch time stop in a peaceful bay they certainly will not allow you to sleep overnight during a stiff breeze, let alone a storm. I think the old guys had it right with upsizing their anchors, they had too, and I believe we need to continue with it and fit an anchor at least two sizes up from what is recommended.
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| Staged set up, hooking up the springer to the anchor chain |
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| Staged again, the loop shown is certainly not big enough but to give an idea of how it will look deployed |
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| Got it right the soft shackle is just on the bottom at low tide lots of chain loop for stretch. |
In conclusion, if your anchor dislodges during a storm you will have to make the call on whether to re anchor during a blow. I know several vessels tried and tried but due to the wind pushing them back and in some cases turning them side on to the wind the anchors would not set. One vessel close to us really had us worried because several times he almost collided with us as he tried in vain to get his anchor to set when re anchoring. During a storm if you have control of the vessel with the motor running now may be the time to hold her nose into the wind and tread water until the blow eases. Go for a drive as you wait, it’s got to be better than exhausting yourself and crew. As we have experienced time and time again voices get raised and fingers have sometimes been put in the wrong place at the wrong time due to the stress and anxiety of the situation when trying to anchor in difficult circumstances which doesn’t do anyone any good.
Check and grease your electrical connections on the winch regularly, don’t use Vaseline or a lanoline based grease for this job due to the low melt point, it will just become liquid and run off the terminals the first day in the sun. Use a heavy duty marine grease and smear it on after making clean dry electrical connections. This will stop moist air entering the good clean connections creating corrosion. A small note: marine wheel bearing grease works a treat because it’s made to get hot and not turn to liquid.
Get yourself a spare hand controller if your winch is set up that way, the failure rate of the plugs, cables and buttons is high enough to warrant an easily plug in hot spare. Make sure the plug and sockets of the hand controller are water tight, some are just splash proof, and that just doesn’t cut it on the front deck or in the anchor locker of a cruising boat in a storm. All plugs and hand pieces should have an IP number, this rating will be an indication to how water tight the connection will be. The IP guide states that IP67: No ingress of dust; complete protection. Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water up to 1 m of submersion. However this will mean the housing and the plug have been assembled as per the instructions, that is the wire going into the plug back shell and the case/buttons must have all the rubbers/O-rings etc to attain water resistance.
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| A sad sight unprotected anchor winch relays removed from the chain locker |
Get under the deck or inside the winch cover to check solenoid connections, these should be assessed on a regular basis, this doesn’t take a lot of time, a quick inspection and jiggle the wires and connectors should spot any corrosion or water ingress that will then require repair. If the vessel is new to you or you have had work done make sure the forward/reversing solenoid is wired correctly. One vessel had a miss-wired solenoid block and while it still worked it didn’t work very well. Unfortunately this work was carried out by a paid professional who was either colour blind in a hurry for the next job or just wanted to get home. A note: if you’re on an extended voyage offshore get a spare set of anchor winch solenoid(s) in the spares kit, due to the variations in solenoid(s) they are not available everywhere off the shelf.
The large foot operated winch control buttons installed in the fore deck can also fail if the installer uses too much sealant causing a blockage of the drain holes. Without drainage any water/condensation remains trapped and will quickly cause enough corrosion to stop the switch working.
As far as I can see, most of the catamaran owners have this snubber/bridle thing down pat due to necessity, but without the same necessity unfortunately a lot of mono owners both sail and power are missing the point. While some catamaran owners do from time to time use the wrong type of rope on the snubber or perhaps tie off a little too short it’s usually the mono-hulls that don’t have long enough or the right type of snubbers or in some cases don’t have an effective snubber at all.
A week after writing the majority of this, we were anchored in a reasonably crowded anchorage. Although crowded there was a fair amount of room, and the bottom was good holding sticky mud in six metres of water. Because I have snubbers and anchoring techniques on the brain at the moment I took a little more notice of the vessels around us. I am sorry to say that of the thirty or so vessels in the anchorage only a few had anything that looked remotely like an effective snubber anchoring system. One vessel was using what looked like an old dock line rubber mooring springer. Very few had enough of a chain loop to allow the snubber to stretch effectively, so I can only surmise the short rope in use didn’t have much stretch in the first place. I also noticed two vessels had very short lines (300mm) in use that would only be good to take the strain off the anchor winch. Two vessels were using silver rode, after watching them anchoring I would guess they laid out about 8 to 10 metres of eight millimetre chain then a lot of rope. I could go on but it would be much of the same with small changes in snubber rope diameter etc. After a particularly nasty storm several vessels were not where they were before the storm. I observed the usual suspects, plows, deltas and claws were retrieved from the bottom when they pulled their gear up to re-anchor. Luckily there was no collisions but I watched two vessel take notice when there old neighbors re-anchored in front of them, funnily enough they then hauled anchor and moved a safe distance away.
Oh yeah, so what’s my schema? Hopefully to make a people stop and think, can I anchor a little safer than what I am doing now? And in doing so remove the grief that comes from being blown backwards through a crowded anchorage at three in the morning, with your wife waking you up to ask you why everyone is leaving the anchorage yah better get up and have a look!
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