ANCHORING
This video goes through anchoring technique and has an in depth interview on anchor chain.
Our anchor chain comes from Germany: Ketten Waelder, Cromox anchor chain...
https://www.ketten-waelder.de/de/nautic
Some clarification of stainless steel grades
The hardest part of sorting out stainless steel is working your way through all the grades, understanding which is best at what, and deciphering the many codes that are given in different countries.
Here's an attempt and a simplified table of what's on offer:
Grade 2 - AISI 304 -- Not suitable for marine use.
Grade 4 - AISI 316 -- Standard 316 is marine grade and is what you will normally find on boats
It comes in 2 main variety’s - 316Ti (1.4571) and 316L(1.4404). 316L is the superior product in anything other than environments
with extreme heat, like cooking.
Duplex Stainless steel -- This is not an austenitic steel like 304 and 316. It is austenitic and ferritic, so magnets will stick to it. It doesn't work harden like
austenitic steels can can be made to be very strong.
PREN number -- The Pitting resistance equivalence number is very important for stainless steel that is going to be submerged. It is directly related
to the resistance the metal will have to corrosion at different temperatures.
Also metal corrosion is also dependent on what's in the water you are sailing. Salt water is not just brine, so some seas are more
corrosive than others both because of chemical and biological elements in the water. Yes bugs can eat your chain!
KEEP YOUR CHAIN AS CLEAN AS POSSIBLE WITH REGULAR FRESH WATER WASHES AND KEEP THE LIMBER HOLES CLEAR SO YOUR CHAIN DOESN'T SIT IN SALT WATER IN THE LOCKER. DON'T STORE METAL ITEMS IN THE LOCKER THAT MIGHT RUST.
If you have an electric windlass then make sure it is properly bonded and has no electrical faults. There have been instances of
electrical faults causing the gypsy to be at 12/24 volts. This will put the whole chain up at a high potential and turn it into one long
anode for electrolysis to happen!
USE CERTIFIED CHAIN
IF YOUR CHAIN IS NOT CERTIFIED (I.E. TESTED FOR STRENGTH ON EVERY LINK) THEN YOU LITERALLY HAVE NO IDEA WHAT BREAKING LOAD IT WILL TAKE WHEN NEW. ADD TO THIS THE FACT THAT UNCERTIFIED CHAINS OFTEN HAVE INFERIOR WELDING AND GALVANISING OR UNKNOWN MATERIAL COMPOSITION IN THE CASE OF STAINLESS STEEL CHAIN. AS IT AGES, AN INFERIOR QUALITY CHAIN MAY WEAKEN SIGNIFICANTLY.
CERTIFIED CHAINS WILL COME WITH A CERTIFICATE STATING THEIR QUALITY. CHECK MANUFACTURERS SPECS FOR THE RECOMMENDED CHAIN SIZE AND BREAKING STRAIN FOR YOUR SIZE AND WEIGHT OF BOAT. REMEMBER HIGH TEST CHAINS ARE SIGNIFICANTLY STRONGER THAN STANDARD CHAINS AND MAY ALLOW YOU TO WORK WITH A SMALLER DIAMETER CHAIN WITH A LARGE REDUCTION IN WEIGHT. SOMETHING THAT CAN BE VERY IMPORTANT TO THE PERFORMANCE OF YOUR BOAT AT SEA (TOO MUCH WEIGHT IN THE BOW CAN MAKE BOATS DIG IN WHEN BEATING, MAKING FOR WET DECKS AND IN SOME CASES DANGEROUS UNBALANCED STEERING, ESPECIALLY IN CATAMARANS)
BREAKING LOAD UNCERTIFIED CHAIN = UNKNOWN!
BREAKING LOAD TYPICAL 10mm 40 GRADE GALVANISED HIGH TEST CHAIN = 6 TONS
BREAKING LOAD TYPICAL 10mm DUPLEX STAINLESS STEEL CHAIN = 11 TONS
ESPECIALLY WHEN USING HIGH TEST CHAIN THE SHACKLE/SWIVEL IS OFTEN YOUR WEAKEST LINK SO MAKE SURE YOU USE SOMETHING OF EQUAL STRENGTH.
IT CAN BE DIFFICULT TO FIT LARGE ENOUGH SHACKLES IN SOME SITUATIONS. IF YOUR CHAIN DOESN'T HAVE AN OVERSIZED LINK AT THE END TO ACCEPT A LARGER SHACKLE THEN DONT BE TEMPTED TO FIT THE PIN THROUGH THE STOCK OF THE ANCHOR AS IN THE PICTURE BELOW. THE PRIZING LOADS BETWEEN SHACKLE AND ANCHOR CAN BE HUGE IN THIS SORT OF INSTALLATION. USE CERTIFIED STRONG SHACKLES AND FIT SEVERAL LINKS OF CHAIN BETWEEN THE SHACKLE AND THE ANCHOR IF YOU ARE UNABLE TO FIT THE SHACKLE THE RIGHT WAY AROUND BECAUSE YOU CANT PASS THE BODY OF THE SHACKLE THROUGH THE CHAIN.
This video is all about anchors. It goes through the research we did in choosing the best anchor for our needs.
UPDATE OCT 2020
After a lot of research we went for the Ultra anchor. Since the video was made we've anchored in most substrates from very soft mud, rock & weed to soft and hard sand. We haven't dragged even on strong backdown when setting in marginal sea bed conditions where others have failed to set. The anchor so far has set first time every time. We haven't yet had winds at anchor over 45knots but we will continue to access the anchor as we sail around the world and report back here, so do check back from time to time.
Link to Ultra Anchors: https://www.ultramarinewest.com/
UPDATE SEPT 2021
The Ultra anchor remains completely reliable, anchoring every night with no problems. We have had one instance of dragging which was completely my fault, missing the spot that I wanted to anchor on and ending up on a steep underwater slope thee anchor can free when the wind picked up. I was waiting for it to happen, so no problem.
Resetting has been the most impressive thing, always staying down deep in the sea bed it has reset in every sea bed.
FOR MORE INFORMATION ON CROMOX CHAINS GO TO KETTEN WÅLDERS SITE
Some things that didn't get covered in the video
we will add to this as we go along, so check back.
Kedge Anchors
We didn't cover kedge anchors in the video. We have a Danforth anchor as the kedge, mounted on the pushpit rail. Fortress / Danforth type anchors make great kedge anchors as they stow flat, are good on short scopes (which you often end up with using your kedge) and they come in aluminium which is vital for a kedge which you will often be launching from the dinghy.
Some of these type anchors come with wider (mud flukes) that can be fitted for sloppy mud and some can have the set angle (between flukes and stock) changed for different conditions. But know their limitations. They are rubbish in thick weed and stone and sometimes struggle with hard sand.
The main use for the kedge for us is setting it as a stern anchor, or off the beam, to hold us more into the swell if we are lying off the swell as sometimes happens when you have little wind of some running current. Beware of using a kedge to pull you off line in strong wind / currents however as you are greatly increasing the load on the bower anchor.
By far the most common situation is the wind dying off at night and there being a left over swell coming in at a different angle, so for this the kedge is perfect.
To set it we most often lie the kedge in the dinghy, flake the required amount of rode (we have a reel of webbing) onto the top and row it out. Drop the anchor and winch in, or just haul it. To retrieve we just pull the dinghy out on the rode and haul it up. Then pull yourself back to the boat with the rode. That's how I do it anyway. Means you don't get in a tangle with the rode.
Kedge sent from the stern to hold the boat in position
On Fair Isle we have two bower anchors. This is useful not just as a spare but to use in other situations like the Bahamian moor. This is very useful in tidal situations. To set your anchors first motor into the current and drop the first anchor. Pay out twice the chain that you need and set the anchor.
Then turn the boat and drop the second anchor. Go astern along the same line towards the first anchor and set the second anchor with the correct amount of chain for the depth. Now pull in the extra chain from the first set so you are sitting nicely between the anchors. Now when the tide turns you will swing around onto a properly set anchor every time.
If you are using the kedge anchor as your second anchor just lead the rode over the bow with the bower anchor, tie the two together and if you're using rode not chain let the connected part drop down a few meters. This is a situation where a kellet type device might be a good idea to keep the rode down and away from the keel as you swing.
Extracting yourself from the set up may involve motoring in a circle or two to unwind yourself!
I don't tend to use to bower anchors together in a V as some people favour. As well as risks of serious tangles this setup can load each anchor in turn by more than you would have had straight to wind with one anchor and you can end up dragging one anchor then the other until they are together,
Bahamian Moor
Environment
We all want to protect the marine environment. One thing that I've mentioned before in our videos is that the marine industry should be moving away from Zinc Anodes to Aluminium.
Aluminium is just better all round. It's lighter (easier to ship) works more efficiently than zinc, you need less of it for the same effect, it wears away more evenly so lasts longer.
But it also is much better for the environment. Zinc contains cadmium which is poisonous and very harmful to marine life. So replacing zinc anodes is one thing we can do, another is not using galvanised chains. The surface area of an anchor chain is huge so there's a lot of zinc and cadmium going into the ocean every time you use one.
Huge thanks to Chris for his expert advice in the anchoring video.
If you should need a materials expert for anything to do with yachts you can reach him here HERE