Because I threw this out for analysis by the collective, I thought that I should look at it a little more closely myself.
First of all I mis-stated the weight of the ½" chain above. It is actually 2.6 lb/ft.
The weight of the 5/16" chain is 1 lb/ft, and the weight of the anchor is 33 lbs.
I do not mean to speak for Craig, but I believe that the source of his info is here; Kellets or Anchor Angels / Sentinels: Uses and Applications
and here; Catenary & Scope In Anchor Rode: Anchor Systems For Small Boats
. Craig - please feel free to correct.
The conclusion of both papers is that rather than increasing weight of the rode, it makes more sense to increase the size of the anchor. I'll tell you now, that the 33lb anchor is as big an anchor as I am going to haul up; so that ain't happening.
Peter does allow the following regarding Kellets;
The ideal placement of the kellet is different according to the application. This is an unfortunate fact, as it means the desired benefit must be selected – the best of all worlds cannot be had.
To achieve the supposed increased anchor performance already dismissed, the kellet should be placed as close to the anchor as possible. This is so its weight exerts the maximum leverage on the rode. It pays to note that a kellet is not a point on a graph, but a physical object which hangs below the rode. Therefore, it cannot be placed directly next to the anchor, otherwise it will simply rest on the bottom and its weight will have no effect.
I believe that this is the point that Craig is referencing. Again, Craig, set me straight if necessary.
My counterpoint is that by adding the heavier chain, it is not the same as a kellet, which hangs beneath the rode, but becomes a (heavier) part of the rode. By spacing the heavier load away from the anchor, it has more leverage, and should help keep the load on the anchor horizontal, rather than vertical.
Continuing the quote from Peter;
To provide the best shock absorption, the kellet should be placed halfway along the rode. (Shock absorption is a point not elaborated on above, as it is closely related to the idea of increasing anchor performance). Since one may wish to both increase one’s holding power and benefit from shock absorption, one could compromise and place the kellet one quarter along the rode from the anchor. Neither is ideal, as, like the lowered pull angle, this quasi “spring” disappears in bad conditions when it is most needed.
To minimize swinging radius, the kellet should be positioned down the rode from the boat a distance equal to that of the vertical distance to the seabed (depth plus height to bow-roller). This allows the gravitational potential of the kellet to work to its full potential. (Nb. while effective in light conditions, this technique is questionable in any case; if the anchorage is empty, swing radius is unlikely to be important, whereas if it is crowded, it is desirable to swing similarly with the other boats).
I believe that my technique is a good compromise to both of these points.
Further, consider the weight of hauling the damn thing aboard. If I were to anchor in 20' of water, allowing 5' of freeboard;
- As illustrated above I am lifting 15' * 1lb/ft (15lbs) + 10' * 2.6lb/ft (26lbs) = 41lbs of ground tackle when hauling chain, and then 25' * 1lb/ft (25lbs) + 33lbs (anchor) = 58lbs max as I haul the anchor itself.
- Putting the heavier chain next to the anchor would increase the max load (20' of water, plus 5' of freeboard) to; 33lbs (anchor) + 10' * 2.6lb/ft (26lbs) + 15' * 1lb/ft (15lbs) = 74lbs