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Heidyg28 · 17-08-2014, 17:09

I bought a Maxwell HRC 10-8 windless. Ill be using 150 feet of 5/16 chain. My boat is a Horizon Nemo 39, 22,000lbs. I currently have a 44lb Rocna. I'd like a bigger anchor being as I'm using smaller chain due to this windless. Can it put a 55lb rocna? Is there a formula to figure out what anchor would be too heavy? Is 11lbs that much different when it comes to the windless? I feel likely will make a huge difference in my ability to sleep. We are leaving for Mexico in October. Thank you!!

**JPA Cate** · 17-08-2014, 17:14

Heidy,

If you PM DoubleWhisky, he can give you a formula he uses for determining anchor size. Or click on his name and get all his posts. This was all covered some months ago.

Good luck with it.

Ann

Stu Jackson · 17-08-2014, 17:16

Anchor System Sizing Tables (Reply #6) & Swivels Ground Tackle & Anchor System Sizing TABLES & Swivels

Check out the tables, pretty good basic info from real books.

Good luck, great question.

**Jim Cate** · 17-08-2014, 17:25

That small increment in anchor weight will make no difference whatsoever to your windlass. Don't worry about it... and the bigger anchor will serve you well.

Jim

model 10 · 17-08-2014, 17:45

These charts and tables do not know what your situation will be. You may not do a good job of setting your anchor, you may be anchored in a funky bottom. The variables are endless. The more junk you have on the bottom the better. How strong your chain is only comes into play after your anchor has stopped moving. You would not work it out the other way around because you could never know when an anchor will drag. 3/16 chain might be strong enough.

onestepcsy37 · 17-08-2014, 17:55

You won't regret getting a bigger anchor. The chain should be strong enough. If you are worried, get the high tensile version of 5/16 chain, which is much stronger than the BBB version. It might be necessary, or might not, to change the chain gypsy; check with maxwell.

Terra Nova · 17-08-2014, 22:38

Use the larger anchor. And double the length of chain, or add another 150' of rope rode.

**noelex 77** · 17-08-2014, 23:00

Welcome to the forum.

Most of the weight is in the chain so increasing anchor weight does not have as much impact on the windlass as might be imagined. The larger anchor is less difference than 10 foot of chain.

The windlass should have enough power to be able to recover the whole weight of the chain and anchor. In some parts of the world the anchorages get deep very quickly and rapid drag can result in sutuation. This would be 224 lb for a 44lb anchor and 235 lb. This is only a 5% increase. (This is using air not water weight)

People that cruise shallower waters point out that they will never drag into water deeper than their chain. In this case you can do similar calculations for the deepest water where you are likely to need to retrieve chain.

There are formular used by the windlass manufacturer to convert the working load of the windlass to a maximium chain+anchor weight. You are better to use such a formular from the manufacturer of the windless. Some over inflate the the working load of their models. If no guidelines are available this formular from Muir can be used. (See halfway down "DETERMINING THE CAPACITY OF THE WINDLASS TO SUIT MY REQUIREMENTS")

http://www.muir.com.au/shop/manuals/...0Selection.pdf