SailNet Community - View Single Post - Anchor Setting Woes
View Single Post
  #38  
Old 06-28-2013
Maine Sail's Avatar
Maine Sail Maine Sail is offline
Senior Member
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,540
Thanks: 13
Thanked 150 Times in 116 Posts
Rep Power: 15
Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice
Re: Anchor Setting Woes

Quote:
Originally Posted by MedSailor View Post
I get the impression that the Chesapeake is soft mud in many places. I'm surprised that nobody here has yet mentioned the folly of using too much chain with a danforth style anchor in soft mud.

You heard right, there can be such thing as too much chain (in special circumstances).

If the mud is soft, and the chain heavy, the shank of the anchor can pivot BELOW the flukes. You drag with the shank buried and the flukes stay on the surface. This is especially problematic if you set your danforth style anchor with a lot of scope. I know this is counter-intuative to setting every other type of anchor, but I think it's your problem.

Quote from an email I got directly from Fortress anchors in 2008 on this very subject:
..."One downside of using more chain is that with any “pivoting fluke” type of anchor, such as the Fortress, Dan forth, etc. the extra weight of the chain can sink the flukes below the shank [he actually means sink the shank below the flukes--Med] if you are using a long scope in a very soft bottom, like soft mud. I have attached an image which may help you to visualize this.

To prevent this from happening, you simply need to permanently install the Mud Palms on the anchor, which are included with all Fortress anchors. The Mud Palms will lift the rear of the anchor up and force the flukes to take a more aggressive angle into the bottom. You should also use a shorter scope in a soft bottom when initially setting the anchor, which will keep the shank up so that the flukes will dig in first."...


From Fortress's website (see point #8):Fortress Safe Anchoring Guide


If you have a bunch of scope out, 30ft of chain and you're setting it slowly, odds are it won't work in soft mud. I've had this happen and confirmed what was happening with scuba gear. You are better off setting your danforth with short scope (fortress recommends 2:1), to ensure you are pulling up on the stock enough that it is not below the horizontal and only after it's set you can add your scope to 5-7:1 and back up on it hard.

There is nothing wrong with a danforth style anchor area for your bottom types. I have over a hundred nights at anchor on a Fortress and it worked, but setting it was tricky and required skill. Sometimes I had to try 4 times (but usually got it first time).

While I say there is nothing wrong with the fortress/danforth (I have 3 fortresses aboard) I STRONGY prefer the Mantus anchor or the genuine Bruce for their setting ability. If you get an Mantus, Rocna, or Mansun you'll never go back. Actually... now that I mention it, has anyone ever heard of anyone going back from a next-gen anchor?

Happy anchoring and thanks for the good question!

MedSailor
Even with the new gens I find they set very well when I snub at 2:1 and apply light pressure to get the initial bite and penetration through a soft top layer.. I then drop to 3:1 or so and apply slightly more pressure and then 4:1 and more and then 5:1 etc. By 5:1 it is usually able to hold our boat at 2600 - 2800 reverse RPM.

I have had our Mantus fully set at 2:1 and then hold full reverse wide open throttle.. I find the Mantus sets slightly faster than both the Manson and Rocna but at that point we are talking inches. I have actually gone back to the Rocna as primary just because it fits better on the bow roller than the MS or the Mantus and they all perform tremendously well..

I think my next toy may be an Ultra but I just can't bring myself to have a SS "bling" anchor, despite how well designed it may be... Unfortunately that anchor can not be built in galvanized due to design...
__________________
______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Reply With Quote Share with Facebook