Mooring weight guidelines

rajjes

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I'm all set to lay a permanent mooring, 2 actually as it is an area with fore and aft moorings, silty bottom, about 7m depth for a 26' heavy boat.

As I have easy access to a concrete plant, I'm planning of using concrete formed as a cube with an embedded heavy chain and a few iron bars throw in.

The reason for using a cube is that the concrete plant has a variety of steel moulds for making concrete blocks, however I am really at a loss at what size/weight to go for.

Are there some guidelines on this? What would you consider a siutable size for each mooring?
 

oldsaltoz

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a 1.5 Tonne (1,500kg) block will give you about half a Tonne (500kg) holding at around 3 to 1 scope, also note each mooring should be capable of holding in the event the other fails. A 2 Tonne block will give you closer to one Tonne holding.

Stick a few extra loops into the concrete for use later, protect them with a suitable coating.

Andavagoodweekend......
 

Bajansailor

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You could consider using two efficient anchors instead - eg two Danforth type anchors, each around 20 or perhaps 30 kgs even, with proper scope, would be much easier to set - and retrieve when the need arises.
 

Allan

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I've heard of people making concrete weights with concave undersides to give it some suction in the mud/silt.
Allan
 

rajjes

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Thanks for your reply, does this mean that if the boat weighs around 2 tonnes I need a 4 tonne block??
 

GMac

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No it means concrete is usually only half it's on-land weight when it's underwater.

The holding power of the weight will depend on it's shape and seabed type.
 
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