Why Is My Anchor Chain Crackling?

[demonboy]

I suspect I have a short somewhere but I'm hoping this is a phenomenon that's quite normal that I've never come across before!

I have lifted the 90m chain from its anchor locker and onto the pontoon. The anchor is still connected and the chain is still around the windlass and touching the bow roller. The chain has not been used for 18 months and had a lot of surface rust that has been cleaned off. It is still crackling, however. No shocks have been received and it is not hot.

I had a problem with one of my solar panels shorting the other week, and that is connected to the pullpit that is in turn connected to the bow-roller, albeit indirectly. However I thought I had isolated this short so I remain unconvinced this is the cause of the crackling.

If this is a short what is the solution? How can I identify where it is coming from?

 

[vyv_cox]

It's a new one for me. I find it difficult to imagine that electricity could have anything to do with it.

 

[Twister_Ken]

It's a new one for me. I find it difficult to imagine that electricity could have anything to do with it.

Unless it's picking up static from something. Not parked near overhead power lines are you?

 

[guernseyman]

If you have an electric windlass, that would be a prime candidate.

Apart from that I would get a bit scientific and see if you can measure the potential difference on the chain with a meter. Then you can disconnect the equipment connected to the pulpit or the life lines, one by one, until the potential difference falls to zero. Then you will know.

 

[jordanbasset]

Just a hunch, is there any chance the electrical connections on the pontoon itself are faulty

 

[ALPHORA]

could be that the chain is drying out and the surface films are shrinking and crackling

 

[webcraft]

.
Shrimps?

- W

 

[demonboy]

If you have an electric windlass, that would be a prime candidate.... measure the potential difference on the chain with a meter

That was my initial thought but the windlass has an isolator switch which I disconnected. How do I do I 'measure the potential difference' of the chain?

Just a hunch, is there any chance the electrical connections on the pontoon itself are faulty

No, they're definitely fine.

Not parked near overhead power lines are you?

No, and I'm furthest away from any power lines in the marina.

could be that the chain is drying out and the surface films are shrinking and crackling

This seems like the most likely culprit though I'm not sure I understand what exactly is happening scientifically. The chain is not in great condition with quite a bit of rust. Could certainly do with some galvanising if they did the waterproof version here (that's a standing joke here in India: a yottie got his chain galvanised locally but was told not to put it anywhere near water otherwise it would come off).

Shrimps?

We don't get snapping shrimp here.

BTW - since this appears to have no identifiable explanation, at least so far, I am naming this 'FURLONG'S PHENOMENON". You read it here first

 

[ostell]

the windlass has an isolator switch which I disconnected.

But does it isolate BOTH sides of the supply?

Take a long lead back to the negative of the battery, plug it into a meter and use the other connection of the meter to check for voltage on the chain and anything metallic in the area. (assuming common negative).

If you are plugged into mains supply is the ground and neutral correct? There can be a significant voltage difference between ground and neutral.

 

[pcatterall]

Disconect chain from boat. Does it still crackle. I would have thought that there would be significant discharge from batteries to make a great lump of chain crackle?

 

[demonboy]

Hi all, thanks for your replies. I had to put the chain back in the locker as the person helping me was about to leave (SWMBO has done her back in) so I did not have time to try the suggested tests. However I will have it out again in a couple of weeks.

For the record I disconnected the windlass completely and the solar panels too, which I thought might be a problem. Not much changed, though, over time, as the chain was washed and dried in the sun, the crackling lessened slightly. I'm still of the opinion that it was something on the chain reacting in the strong sunlight.

Like I said, I'll try Guernseyman and ostell's test next. Thank you for your time.