Wil >I work from a model which in the computer programming world is called, "Top-Down Design with Step-Wise Refinement." The term "penetration" was chosen with deliberate care. But it does no good to discuss the refinement until one grasps that there is a difference in the bottom and that difference will dictate much about his anchoring solution.< Might I suggest, that you didn't get to the top in model. I believe that if you are going to understand penetration you must first understand what it is that you are trying to penetrate. The Bottom. Grasping that there is a difference in the bottoms is not enough, if you are looking for understanding, you must dig deeper into those differences. That is where I started, and I have no problem understanding your results. Computer science is fine but not the universal solution. >Most who anchor are unable to really understand "pounds per square foot" in any meaningful way, < I think you underestimate your audience or at least MY audience. I am sure there are lots of people who want the easy way out. That's fine. But there are others who are not satisfied with that. They wish to use there intelligence to help them solve their problems. To some much of the fun of boating comes from problem resolution, whether it is anchoring or navigation or what ever. Others use their boat for a drinking platform and don't want to be bothered by anything cerebral. In between there are lots of other folks. All I am trying to do is offer a choice. Anchoring smarter isn't the easy way out but to some it can be more rewarding. >For example, they know that sand is "good bottom." They understand exactly what I am talking about< That is just my point saking that there are only four types of bottom material and that one anchor will solve all problems they will come to grief, sooner or later. Of course time is on there side and later may never come. If they want to take the chance, hey that's their decision. As I said I'm pro choice. >they understand that, they are eager to learn how to do the same thing on their boat.< And it will work for them as long as they anchor where you anchor with the equipment your using. There isn't an anchor that mother nature can pull. I have been down that road. >My objective is to teach people how to anchor with as few problems as possible.< Admirable so is mine. But you miss a major point. Solving a problem through testing has some major draw backs. First the results are only applicable to the test unless you have a theory to explain the results of the test, you can not extrapolate those results to the rest of the world. And of course you have repeatedly said that, these results are only for your boat and were done for your own information. Is there some risk here? True I have no hope of teaching soil mechanics in three paragraphs, but you can get a few solid principles in that length of time which will expand the boaters knowledge. It allows the good solid base to take their, my and your experience and make sense of it in places neither of us has been. I am not trying to give people a solution only trying to give them enough knowledge to use their own heads. If they want, a place to start searching on their own. I have a lot of faith in the human mind and spirit. >We have ample proof that the derived procedures from those tests give excellent results in our conditions. < I agree, I am not trying to downplay your work or ridicule it in any way. But as you have implied, the world is larger than the east coast of the US. >The problem exists long after the chain has removed all the catenary shape. < If you understood more about soil mechanics of soft soils you would also understand that the catenary shape can not be removed by gravity alone, it is a function of soil shear strength. >I think it is because the chain pulls the end of the shank down into the bottom, and this forces the tips of the flukes up. < That's one explanation, I see the problem you describe as being related to the shape of the fluke and crown and the soil strength. I get the same results as you do without resorting to changing a rode. You seem to hit on a solution that works for you, but because you can reduce 16/64 by canceling the 6's doesn't make it right. All I am trying to do here is suggest that some of what I have found might help you. You seem very resistent to my help and that's fine too. >In all these situations which I have observed, the anchor comes up clean and the chain comes up filthy. The chain is getting into more firm bottom than the anchor. If that were not so, the anchor would be filthy also.< Again, that is one possible explanation. I have also notice a tendency for anchors to clean themselves of soft, non sticky, material much better than chain. >In Danforth type anchors, the crown is intended to trip the tips of the flukes into the bottom. < Precisely the point I was making above. The material is too soft to position the flukes properly. The crown sinks down and the flukes point up. >I had hoped that just taking the chain off would solve all the anchoring problems -- wrong. < I think your search for a single solution to all anchor problems is simplistic and will lead to frustration. >>I can't explain it here, but anchors dig by several principles.<< >I'm glad you aren't sure you can explain it because that means there are two of us who can't. Second the bad news. I wish someone could.< Ah but I can explain it. Now you see why I can't explain it HERE. You missed the word >HERE.< My point was that email is not the easiest place to discuss involved subject matter. No tables, graphs, figures, even formatting to help understanding. Certainly not the best forum for controversial discussion. You have done some work on testing I have done some work on testing and theory. My theory does not disagree with your results as near as I can tell. On the other hand I find you results quite understandable. If you don't want my help. That's fine too. CplDon NPR