Design Concept for a Helical Anchor

  On the ICW and in the Bahamas there are literally millions of spots that are shallow, with soft bottoms, and with very limited swing room. The goal is to develop a method to 'park' the boat, securely, on a very short scope. 

  What's under consideration is a helical anchor that can be deployed and recovered from the boat's deck in water depths < 7'.  Here's an $18 helix found at a local hardware store.  

  Concept feasibility was tested by screwing the anchor in by hand and then pulling on it (@1500 rpm or about 25hp) with a tug.   This is the same RPM used to set a conventional anchor when a blow is expected.  We would have gone to higher RPMs but we're afraid the rope would break :-0

Two things were learned. The anchor was easily screwed into the sand/mud bottom, to within inches of its hilt, using only the 32" wide wood handle (pictured).  The helix's shaft bent a little but easily held the load. 

  As proposed, the helical anchor system is comprised of two parts: the helical anchor and a T-handle. 

Once the helix is set the T-handle is brought back aboard.  

Note:  Welding the handle to the helix is a possibility but keeping the boat from hitting the handle is problematic--think tide and wind changes.   An inelegant but feasible solution would be to set helixes fore and aft.  I prefer to focus on the removable T-handle solution. 

  In order to recover the helix, the T-handle must be positioned over,  and then aligned with the helix.  A daunting prospect unless the anchor rode is used to facilitate the coupling.   

  Imagine a hollow T-handle made of aluminum tube.   If the rode traveled through the tube than the rode could be used to guide the T-handle to the helix.  The success of this design rests on the interface between the T-handle and the helix's shaft, i.e. the coupling.  Here's an idea for a coupling.

After the rode emerges from the coupling it is tied to helix's shaft.  A potently fatal flaw in this design is the chafing that would occur where the anchor rode emerges from the coupling.  

There are advantages going with a square tube T-handle:  it simplifies the coupling design; nesting T-handle tubes could extend the operating depths; and, height of the handle (the part turned by hand) could be adjusted (think ergonomics).  Here's what the coupling could look like if square tube was used. 

The coupling is greatly simplified. Of course, getting the T-handle back on the helix would be harder. 

  Perhaps the ultimate solution is to use square tube but with a coupling that allows the rode to run through the tube.  The Achilles heel, and the problem I'm having trouble getting around, is how to do this without chafing the anchor rode.