The Math and Physics of Anchoring
Ref. http://trimaran-san.de/die-kettenkurve-oder-wie-ein-mathematiker-ankert/ In a nutshell, the main results are : The guidance of using a fixed scope like use 3 times or 5 times the water depth as length of chain, etc., is not adequate. It is not enough in shallow water, and it may be too much in very deep water. And it does not depend on the wind strength at all, which is rather odd. We consider this guidance to be dangerous, at least for the novice. Our results do depend – among other parameters – also on the wind strength. Neglecting swell and waves, the result is very simple, based on the catenary equation: Minimum required chain length is L = square_root( Y ( Y + 2 a )), where the parameter a depends on the wind strength, on A eff , which is the effective cross section of the vessel towards the wind – i.e., the windage area – as well as on the mass m of the chain per meter. Y is the water depth at the anchor (and not the vessel!). This simple non-linear catenar...
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