Pete7
Well-known member
Look at the comments made by anyone about any anchor with a very high degree of scepticism. The author may not know what he is talking about, is massaging reality.
Wise words indeed.
Look at the comments made by anyone about any anchor with a very high degree of scepticism. The author may not know what he is talking about, is massaging reality.
Pete, If you are trying to imply that I don't know what I am talking g about and I am massaging reality
Umm...should you really be anchoring on coral? This is an extremely destructive practiceAn interesting video but in my experience with my Rocna it has never failed to set on first attempt, in all substrates apart from coral, has been tested up to 50 knots gusts and high swell,
I can only go with what I experienced .
And Im no expert in the anchoring , I just do it right.
Apart from coral. Kinda gives it away.Umm...should you really be anchoring on coral? This is an extremely destructive practice
Jonathan, what do you think about the yaw of the boat, and how much it affects the catenary angles?I'll be picky.
NormanS made the comment, on a different thread that I could not find, that under the tensions being generated he would have thought the tree would move, or bend. Toward the end of the video Steve is applying a fair amount of tension and in addition to the tree possibly moving I might imagine the nylon strop he mentions (to protect the tree) might also stretch. He also uses a web of rope (not mentioned but in view when he mentions the nylon strop) to secure the strop to the chain. He is making measurements of very small amounts at these high tensions - when his datum point might be moving with greater influence from stretch in the textiles than actual change in the catenary.
I'd suggest the numbers are too low for tension and angles and the distances moved too high.
I've done the same sort of test and with 30m of 8mm chain at a 5:1 scope in air the last link lifts off the horizontal at 84kg which is about the same tension I measure with a similar scope to wind of 17 knots - beyond which all the chain is off the seabed.
In other tests this is the data I recorded. Sadly my testing does not have the excitement of a video - just dry words. If you don't like the words - cut to the graphs. If the script is behind a paywall, for you, let me know (by pm)
Anchor Testing and Rode Loads - Practical Sailor
Jonathan
Jonathan, what do you think about the yaw of the boat, and how much it affects the catenary angles?
I guess that in certain frequencies the yaw effect will change the resoults.
We were cruising in the Bahamas three years ago in company with friends who have a Rocna. We were anchored close to each other, with them up wind of us. It was a lovely sunny day with light winds. We had been anchored in the same spot for three days. Our friends were down below when I noticed they seem to be dragging. I jumped in the dinghy a whizzed over to inform them by which time they were clearly dragging towards us. I was alongside their yacht when they lifted their Rocna. It was encased in a ball of hard sticky grey mud. Our friends couldn’t believe it. The conditions were benign and they had been in the same spot with stronger winds for three days.
It wasn't a tide issue or blowing 55kts. More like 10kts