Monday, April 5, 2010

More Anchor Talk

Steve Dashew makes an interesting case for mult-plait polyester instead of nylon. The 5/8 inch breaking strength is 12,200 and at 30% of breaking the working load limit is 3600 pounds. The polyester holds its full strength when wet, has more abrasion resistance and stretches less than nylon. The 8 plait in nylon is readily available but in polyester it cannot be found in diameters under one inch in the US. It looks like Yale used to make it but it is not on their website now.  Gleistein in Germany and Trem in Italy have it in 16mm.


The Fortress is a good option for a stern anchor. It's lightweight, stores easily and likes a short chain leader with the rest rode. The Fortress people suggest using a short 2 to 1 scope on initial set.  This holds up the shank up and allows the flukes to penetrate.

If I use HT G70 chain I will have to buy oversize links to fit a shackle of equal strength.  The chain gypsy will not accomodate 1/4 inch chain anyway so there is no reason to move up from G-4 to G-7 HT chain primary but it would make sense for a lightweight secondary.

ACCO 5/16” G40 chain has a safe working load (SWL) of 3900 and the Crosby 209A 5/16” shackle matches well with a WWL of about 4400 lb. The G70 1/4 inch can be used on the secondary and the stern anchor without any lose in breaking strength and combined with an aluminum Spade, or on the stern, a Fortress both of which can be handled without any help from the electric winch.  The Spade Model 100 in steel weighs 20 kg, in aluminum 9kg and the holding power is no different. I think the aluminum Spade is a better choice than the stowable Rocna for the secondary anchor especially if the second anchor will be stowed on the anchor roller.

From Morgan's Cloud, "Our thinking is that once you have a good type of heavy anchor (we like SPADE or Rocna), having plenty of rode length is the next biggest contributor to anchoring security. It also lets you get away from the bumper-cars games in some crowded anchorages, by allowing you to anchor in deeper water than most other boats can."

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