Anchors and Anchoring
From sailingissues.com, Parts of an anchor:
* The shank is the stem of the anchor in which direction is pulled to set (bury) the anchor.
* The crown connects the various parts of the modern anchor.
* The stock turns the anchor into an attitude that enables the flukes to dig into the sea bed.
* The tripping ring is used for the optional tripping line: by pulling the tripping line, the anchor will break out.
* The flukes will be buried into the seabed. The very tip of a fluke is sometimes called the bill.
Information from the Baja Cruising Notes website:
The most over-rated anchor for the main anchor on a cruising boat is a Danforth.
They have tremendous holding power, once you get them set, and as long as you don’t swing you’ll be fine. Mostly though, they’re good for a Bahamian moor or a stern anchor. Danforths don’t like kelp, rocks, or hard bottoms. They don’t store well in a bow roller, and are not very strong. If one of the flukes gets bent, it’s useless. Do not use a Danforth as your primary anchor!
The Bruce never seems to do well in the various holding tests, but the majority of serious cruising boats carry the Bruce and the CQR.
The Bruce is a very strong anchor. You’ll never break it. It’s made in one piece, and is easy to store on a bow roller. The Bruce doesn’t really have a lot of fluke area for its weight, and it doesn’t like to penetrate a crusty surface. Many anchorages here have a crusty surface on the bottom, or shallow sand bottoms. Bruce doesn’t like these. When setting the Bruce it starts on its side, and then he rolls over and starts to dig in. If there isn’t very much sand down there, or it’s a hard surface, it stays on its side and just drags along. Bruce also loves to pick up large rocks in his flukes. If this happens, you’ll have to pull the anchor up and remove that rock. If you’re crazy enough to anchor in rocks, it’s the anchor of choice. One of the reasons the Bruce works well for a lot of people is that they also use all chain, and it’s the chain doing a lot of the holding. In all the anchoring tests they use a short chain leader with a nylon rode. This is not a very realistic test. If the Bruce breaks out because of a wind shift, he’ll try to dig back in if you can keep the boat from moving too fast. The patent on the Bruce has recently expired, and you’ll see a lot of imitations. These anchors are significantly cheaper.
Don’t ever buy an anchor just because it’s cheaper. Buy it because it works, and works well. Do not trust your boat, maybe even your life, to a cheap anchor.
In the past the genuine CQR has been the anchor of choice for long term cruisers.
It’s very strong and also stores well on a bow roller. It has a weighted tip, which helps it to penetrate crusty bottoms, and it doesn’t need all chain to help it hold. The hinged fluke on the CQR allows the shank to rotate from side to side without breaking the anchor out of the bottom. The wind will have to veer quite a bit before it breaks out. If it does break out, it will want to dig back in, but try to keep the boat from moving too fast. I feel that the CQR works best with chain and nylon rode. A rule of thumb would be to use two feet of chain per foot of boat, and the rest nylon. If you have to use all chain, use a snubber of at least 25 feet, and set the anchor with the snubber. The CQR doesn’t have a lot of fluke area for its weight. You need a heavier anchor to get the same holding power as the Max. I have only seen one plow anchor (custom made), that wasn’t a genuine CQR, that worked. If you want a plow, spend the extra money for a genuine CQR.
The Max anchor isn’t sold in marine stores, so you don’t hear much about it, but whenever you read anything about the Max, it’s always positive. One magazine, The Practical Sailor, gave it a big thumbs up. I did something very crazy last year. I sold both my 66# Bruce and 60# CQR, and bought two Max anchors. The 37# anchor has about the same fluke area as the 66# Bruce, and two to three times the holding power. The 56# anchor I use during the summer, when we are more likely to get the chubascos. The Max comes in two styles, fixed and adjustable.
I really didn’t need the adjustable anchor (you adjust it for mud bottoms), because except for Puerto Escondido all the bottoms in the Sea of Cortez are sand or a crushed coral and sand. I bought an adjustable Max in the larger size, so I could take it apart and store it easier. The anchor is made from high-test steel, the flukes have beveled edges, and have a much larger area than the CQR or the Bruce. The Max is a very strong anchor, and it doesn’t need a lot of chain to help it set or hold. The wind will have to veer quite a bit before it breaks out, and if it does break out, it will dig back in very fast. The shank is slightly shorter than the CQR or Bruce, and the flukes are longer. This makes it more difficult to store on a bow roller. It stores in the same style of roller as the CQR, but it’s really best if the roller sticks out from the bow slightly more. It’s the only anchor I know of that comes with instructions! The anchor is also ugly, but I’ll tell you one thing, it digs in fast and it holds!
On Ground Tackle:
Most boats of over 30,000 lbs displacement in size use all chain in their primary rode. Unless you are going to be anchoring in coral, I think this is a poor choice. You’re putting a lot of unnecessary weight in the bow of an already over-loaded boat. If you have a good anchor you don’t need the extra chain to help it hold. If your anchoring depth is 25 feet or less, it only takes 125 feet of chain to have a 5:1 scope. In heavy winds the chain will go bar tight, and put a tremendous load on the boat and anchor. The nylon line adds a tremendous amount of stretch in the system, which puts a lot less load on the anchor and the boat. It’s quiet because you don’t hear the chain dragging all over the bottom. Line is easier to handle and cleaner than chain. It’s also a lot easier to replace in those distant cruising grounds.
Nylon will chafe, so you’ll need to make good chafing gear. Our chafing gear consists of three layers; 1″ heater hose, 1 1/2″ head hose, and then fire hose about two feet long. I secure these to two 25-foot snubbers and two 50-foot snubbers that are made of 3/4″ three strand nylon. I use the 25-foot snubbers all year, except when I’m anchoring in preparation for a major storm, and then the fifty-footers come out. I use a rolling hitch to secure the snubbers to the chain or the nylon rode. The snubbers are then secured to two bollards, never through the bow roller. The main rode is sitting loose in the roller so there is no load on it. The only way the main rode would ever get a load on it at the bow roller would be if the snubber broke. The main rode also has heavy chafing gear which can slide along the rode where needed.
When setting up the ground tackle all the components have to be the same strength. The strength of the complete system is only as good as the weakest link, and the weakest links are usually the shackle and the swivel. We use 3/8″ high-test chain on our 34,000 lb displacement boat. The chain has a WLL (working load limit) of 5,400 pounds, which is one third of the breaking strength. You’ll then want every other component in the system to be as close to the same strength as the chain. You would then need at least 3/4″ three-strand nylon for the rode. The WLL of the three-strand nylon would be 33% of the breaking strength, which is 5,115 pounds. I think double-braided nylon is a better choice for the rode than three-strand nylon for many reasons. First of all, it’s stronger. The breaking strength of the same 3/4″ rode in braided nylon is 19,400 pounds, which makes the WLL 26% of the breaking strength. It doesn’t hockle, and is very easy to clean and to store. It doesn’t have the stretch of three-strand, but it will stretch more than enough, and remember that we are using three-strand for our snubbers, which will have plenty of stretch. I’m always amused at those who use all chain, and when they see that I’m using braided nylon say, “…but it doesn’t stretch as much as three-strand.” Well, they’re right, but it sure stretches a heck of a lot more than chain!
So now we have our chain and our line. How are we going to secure these together, and then to the anchor? On “Irish Mist” we use a rope to chain splice to connect the braided nylon to the chain, and a 5/8″ swivel to connect the chain to the anchor. There is no shackle in the system. We have just gotten rid of one of the weakest links! You would have to use at least a 1/2″ shackle, which only has a WLL of 4,000 pounds (this has a 6:1 safety factor). What we’ll use to connect the chain to the anchor is a 5/8″ swivel, which has a WLL of 5,200 pounds with a 5:1 safety factor. Now how do we put the 5/8″ pin through the chain where normally you could put only a 7/16″ shackle? We’ll have to use a 1/2″ connecting link, which has a WLL of 4,750 pounds, or order the chain with an oversized link at one end. They make a pear shaped one that’s perfect for that large swivel. If you used the 7/16″ shackle, which will just fit in the 3/8″ high-test chain, the WLL would be only 3,000 pounds, which is totally unacceptable for our system. I’ve seen large boats using 5/16″ high-test chain and 3/8″ shackles for their main anchor rode, connected to 60 pound anchors! At a 2,000 pound WLL the 3/8″ shackle is only half of the WLL of the chain.
The reason for using the rope to chain splice isn’t just to eliminate the shackle, but also another weak link in the system, the thimble. Under load they have a tendency to rotate, and the throat of the thimble will chafe the splice. Thimbles are quite large and impossible to get through the deck pipe. There are two types of splices you can use to complete the rope to chain splice. The one you’ll see the most is a back splice. Simpson Lawrence recommends this style for use in their windlasses. Theoretically the chain and line will feed below deck on the special wildcat furnished with their windlasses. In real life, line is not self-storing in a standard chain locker. If your boat has a foredeck locker, it’s very easy to store the line, but most boats have the chain locker below decks. Most of the time you have to run down below, or have a crewmember flake the line or use a boat hook through the deck pipe, and shove the line into the locker. Usually almost everyone pulls the line up by hand, an when they get to the chain they then put the chain on the wildcat. At this point the all chain fanatics are saying, “Oh, I don’t have those problems because my all chain rode is self-stowing”. Well, it is if you have a very deep locker, otherwise they have the same problems. You’ll see many boats with the husband pulling up the anchor, and the wife (who is usually at the wheel) running down below knocking down the chain.
We use a long splice to connect the braided nylon rode to the chain. The line is woven through the chain for about fourteen inches. You don’t see this too often because not very much has been written about it, it’s a little more bulky and rigid than the back splice, and it won’t feed through the windlass automatically. As we can see, in the real world of cruising nothing is automatic. This splice is stronger than the back splice, and there is no chafe on the links. The backsplice has the entire load transmitted to where it connects to that last link on the chain, and then it makes a 180 degree turn back onto itself. There is chafe here, and the fibers of the nylon get compressed and weaken. If I was going to use this splice, I would put tape or heat shrink tubing on that last link before I started the splice, and then I would re-do the splice at least two times per season, depending upon the amount of times you’re anchoring. The long splice is stronger, and when whipped (with waxed twine) and tarred (liquid rope dip) has little or no chafe. The completed splice is finished off with leather to prevent any chafing of the whipping twine.
Although the long splice will feed through the deckpipe without any problems, we don’t store the anchor rode below deck. We use a bag made of Sunbrella, which holds the anchor rode, two snubbers and a small float on a six-foot line. The bitter end of the nylon goes through a small hole in the bag to a secure point on-deck. If we have to leave an anchorage quickly, all I have to do is throw the bag over board, and we’re out of there! We could then return to retrieve the bag, which is very easy to find because it has the small float six feet above it.
Naturally you’ll through bolt a Bollard or two (with back up plates), or two of the largest cleats you can buy, to secure the snubbers. For a boat larger than thirty feet or 12,000 pounds, I would recommend an electric windlass. They make anchoring so much easier. If you end up anchoring a little too close to another boat or not in exactly the place you want to be, it’s easy to pick up the anchor and move. Never secure the snubber or the chain to the windlass, use the bollard. When weighing anchor, motor up to it slowly while cranking up the chain. Let the momentum of the boat break the anchor out. If the anchor is really dug in (this is a good thing), shorten the scope so you’re directly over the anchor, and wait a while. Go tell your crew what a great job they’re doing, then motor slowly forward and the anchor should break out. If it’s really dug in you may have to repeat the process a few times. There have been many articles written on hand signals for anchoring. Another good solution is walkie-talkies. They are inexpensive, and leave both hands free. At night or when conditions are perilous, they are a tremendous asset. When anchoring you should be able to communicate with the helmsperson without having to say a word. Nothing is worse or distinguishes a novice more than yelling at the helmsperson while anchoring.
Setting the anchor
We now have our anchoring system sized properly for the boat, and now we have to set that anchor for the night. There is no doubt that the best entertainment for the fleet is watching the various boats and their anchoring techniques. No one will ever say anything if you do a good job, but don’t do it right, and you’ll have plenty of advice on what you’re doing wrong! Two techniques that won’t work are:
- first, to dump all the chain in one spot and then back up at 2-3 knots to set the anchor,
- second, to drop the anchor and back up too quickly without putting out sufficient scope.
The technique that works for us is to drop the anchor, and as it reaches the bottom, slowly back up until there’s a scope of about 7:1 out. At that point secure the line if you’re using nylon, or connect a snubber if you’re using chain. Put the engine in reverse, and slowly raise the rpms from idle until you reach the rpm cruising speed you normally motor at. For our boat this is 1600 -1800 rpms. Stop at each 200-rpm increment to determine that you are not dragging. I do this until we are at about 1600 rpms, and then we just sit there in reverse for about a minute or so, and then increase the speed to 1800 rpms. Watch that line or snubber straighten out. Put your foot on the line, and if you can feel the line jumping, the anchor is not holding and you should back off to 200 less rpms, and let it pull at that speed for a while. If it’s still not holding, don’t waste your time…pick up the anchor and drop it in a different place. Sometimes it’ll work if you back down 180 degrees in the opposite direction.
After the anchor is set, then you can pull in the extra rode, and anchor with a minimum 5:1 scope. If there are other boats in the anchorage, ask them how much scope they have out if you’ll be anchoring near them. Ask what direction the wind blew from the night before, maybe they can tell you about a local condition that would affect the way you would anchor.
After anchoring, if you think that maybe you’re a little too close to another boat, ask them how they feel, and if they say that they also think you’re too close, then re-anchor. It’s better to do it then than if the wind picks up in the middle of the night, and you have to re-anchor in the dark. Above all, never anchor up wind of another boat which would put your boat over their anchor. No matter which way the wind shifts you never want to be over another boat’s anchor. Sometimes you’ll run into a guy who thinks that if you’re within 1,000 feet of his boat, you’re too close. Try to find out exactly where he thinks his anchor is, and how much scope he has out. You’ll then be able to determine if you’re too close to his anchor. If you feel there’s no problem, politely tell him so, and offer to re-anchor if you do get too close later, but remember it may be in the middle of a pitch black night, so get it right the first time.
Every one will have a system for anchoring that works well for them. After anchoring in the Sea of Cortez over the last thirteen years, I feel that I’ve come up with a good system. I’m always trying to improve it because the time when you need an efficient system is when the conditions are the worse. In normal conditions (anything up to 60 kts.) I know that my boat is secure, and I don’t worry if the ground tackle is strong enough. You owe it to yourself, crew and boat to have the ground tackle sized properly for your boat. You’ll never regret it, and if you’re ever in that real chubasco, you’ll wish it were twice as strong.