Sunday, September 13, 2009

Anchor Windlass

The plan is to replace the teak sampson posts with deck mounted bronze sprit gammoning iron and sprit heel tie down by Port Townsend to open up chain locker access below decks. The ABI manual windlass will be replaced with a Muir Atlantic 1000 bronze vertical electric windlass with capstan and cockpit remote.

I am rethinking the third battery bank dedicated to windlass idea based on a West Marine advisory I recently read :
“Though some experts may disagree, we believe that the best way to power a windlass is from the existing house battery bank, rather than from a separate battery in the bow. We suggest you use your boat's "house" battery to power your windlass installation. To limit voltage drop and ensure that the windlass operates at full capacity, cabling for the power circuit must be of the correct size for the amperage draw of the windlass. Not only does a dedicated battery add to the already appreciable weight of the windlass, anchor and rode, it presents charging and maintenance difficulties. The weight and cost savings of using short cables between the battery and the windlass, instead of long ones from the windlass to the house battery bank (which is presumably far away), is offset by the weight and cost of cables necessary to charge a bow battery. Charging cables must be sized to handle any potential charging load. This is liable to be less than the maximum windlass draw, but could still be 50-100 amps, so the cable size would be almost as large as those required to power the windlass from the house bank. In addition, charging a battery over a long distance can involve large amounts of current flow for an extended period of time (assuming a heavily discharged battery), which in turn could lead to a voltage drop, heat build-up, and/or a large electromagnetic field. In contrast, a windlass draws current in short bursts, so the cables supplying it will not be under continuous use.”

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