anchor chain lifespan/assessment/inspection

[jrevkin]

Hi,

My recently purchased Shannon 28 was built in 1981. Displacement 9,300 lbs. It came with a 28 lb. CQR with 100 feet of 5/16 inch galvanized chain with a 100 foot 5/8 inch nylon rode.

How can I assess if the chain is still suitable for use? Are there clues on inspection that would suggest that it needs to be replaced? I am thinking of replacing the anchor, having read that CQRs have fallen out of favor, thus also begging the question as to whether the chain may have reached end of life. Of note, Shannon still has faith in CQR anchors.

Please advise.

Thanks

Jim

[Reefmagnet]

Anchors depend to some extent on the substrate you anchor in. I've only ever had CQR's and I think that they're fine in most instances. I'd say soft mud and really hard packed sand are the two substrates where they don't set to well. Soft mud because they, well, plough through instead of setting and hard sand because they can have trouble digging in initially.

As for chain visual inspection should easily confirm if it's shot, assuming it's galvanized. If it's rusty enough that the links are bound together or it otherwise binds after sitting for a while it's probably due for replacement. Ditto if the links have worn or corroded considerably at the points they rub against each other under load.

[Redcoat]

I have faith in my CQR. Your chain if all used up might need replacement. Your rode is what I would focus on.

[boatman61]

Flake the chain out on the dock.. hose it down well then let it dry out properly.. give each 'flake' a real good shake to get rid of any rust flakes then give the ends of the links a quick look.. if they're wearing and look to be getting to 1/4 worn think about changing in the next 12mths.... the first 15 metres from the anchor usually see's the heaviest wear.. dragging over the bottom etc..

[GordMay]

All chains should be periodically inspected for wear, elongation, nicks, gouges, cracks, and suitability for the application.
Removal criteria for wear and damage have also been established for the chains covered under specification, and are listed in Table XIV *.
All chain should be removed from service if the material thickness at any location on the link is less than the listed minimum value
* Here ➥ http://www.nacm.info/Downloads/NACM%20_Welded_Specs.pdf

[roverhi]

Anchored with a CQR 24/7/365 for more than a year and never had a problem including a couple of days in a tropical depression with 50mph winds. They probably not as good an anchor as the new inverted plow types but they still work. Think most problems are caused by too small a CQR. See people using 35# CQR on 20,000# and 25# one on 14,000# displacement boats which is a recipe for problems. In our case, a 45# CQR for 20,000# did the job.

Thanks for the dimensions on allowable reduction of link diameter GordMay. You are a infinite source for all things on the Net. Carefully inspecting each link will tell you if the chain is suspect. Not hard to figure out that a rusty chain with significantly reduced link diameter is ready to be replaced. If you need an actual diameter, the last table at the link that GordMay posted gives the figure.