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Melissa & Dave - Adventures at Sea

A new anchor chain

July 8, 2013

Dave upgraded Apsaras before we left Seattle with a Manson galvanized supreme Anchor.  He was super happy about this.  Self righting because of the big loop on the top, and because its a plow style anchor it always digs in.  Anchors are controversial, but side by side pull tests where they measured how much force it took to pull up an anchor were performed on various styles and this particular style did best under most conditions.  The competition to Manson has been reputed to have quality issues because they switched to manufacturing in a different country and this has raised controversy over the type of steel used in construction.  So Dave settled on Manson instead.

But the anchor is only half the story.  The other half is what the anchor is attached to.  You wouldn't think anchor chain would be a very interesting topic.  But boaters have an opinion on virtually everything.  We suspect this comes from the fact that you have to be pretty independent minded to be willing to set off in a tin can across an ocean.  Doesn't matter if you are on a cruise ship sized boat, its still a tin can relative to the size of the ocean.  And while in theory the Coast Guard can rescue you, the reality is that you are armed with your knowledge and your wits and are pretty much on your own.

Back to the anchor chain... The boat came with 50 feet of anchor chain (5/16th galvanized) attached to 100 feet of rope (known as rode).  Dave felt this was totally insufficient.  We've been asking every marine store along the way whether they had at least 150 feet of 5/16th inch high test chain so we could replace it.  The problem with the anchor chain we had was that it was the wrong size and not very strong.  The link size of the high test is longer than the galvanized.  Hence the galvanized would occasionally jump off the anchor winch (known as a windlass) because it didn't really fit properly on the cogs of the winch correctly.  The risk being that if it jumped off while deploying, it might dump the whole chain in the water - which means you have to reel the whole thing back in and start over.  So having the right type of chain is critical - and there is no debate over this amongst boaters. 

What there is debate over is how much chain vs. how much rode you should have.  One faction says you should have lots of rode because it will flex and stretch, which means you put less force on the anchor when the wind blows and the seas kick up while you are anchored.  This meaning that you are less likely to pull up anchor and drag.  Dragging an anchor is a bad thing because, of course, only happens at night when its dark and you've no idea its happening, and even if you did, its not clear how you would re-anchor in a storm anyway.  Dragging an anchor means you are probably headed for the rocks, because, well, that's just the way it goes.  You never drag towards a nice soft sandy beach.

The other boating faction believes that you should have lots of chain because (1) it adds weight to the anchor which helps hold the anchor in place, and (2) because its heavy it means the chain hangs lower than rope would, and hence you are pulling on the anchor more horizontally than vertically.  So the anchor "digs in" to the sand as the boat pulls on it.  This second point has been technically debated though because as the boat gets hit by strong seas and winds on the surface, some people believe the weight of the chain becomes irrelevant and the chain and rope still pull on the anchor at a roughly the same angle.

Dave decided to have the best of both worlds with 200 feet of chain + 100 feet of rope.  So if we find ourselves anchoring in storm conditions, he can let out 300 feet from the anchor and hope that the chain lies on the ocean floor while the rope takes some of the strain off.

The old chain and rode are now attached to the old anchor - making for a great back up anchor should we ever be so unfortunate as to lose our primary, or need to put down a secondary stern anchor.  This in addition to the third Danforth lunch anchor that used to be Apsaras's secondary anchor before Dave replaced the primary.

Only time will tell if we ever drag anchor.  Fingers crossed.  In any case, the new anchor chain should help Dave sleep a bit better whenever we are anchored in strong winds.

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