I think Ashley intended the difference between 1852 and 1725.
I concur; actually, there should be no doubt about it --Ashley's
text confirms his drawing (so, both are either right or wrong)!
First 1852 is shown attached to a ring, something one would be close to when attaching the rope probably whereas 1725 is attached to a bar. 1725 can be tied by passing a single bight and this is useful if either the bar is too high to reach or is in an awkward place to get at.
Quite so. In the first case, the point would be to take
some of the load off of the locking 2HHs
, and to keep
them spaced from the ring, easy to untie.
But one should question the value of the doubled rope in
the latter's pass around the object given the finish --i.e., is
the load well distributed on the two parts around the obect?
--otherwise, why not pass a single strand ... ?!
It occurs to me to try to tie the 2HHs
so that they capture
the passed bight --eh, so-so, IMO. Or, better, to turn this into
essentially a twin-eye knot, casting a turn/HH of the SPart
around the bight AND tail, then using the tail to wrap
around SPart and through bight tip; set the knot by drawing
down the bight-tip snug on the tail-wraps (equalizing load
on the eye legs. .:. This results in a bowinesque
knot with 3 diameters through the central nipping loop,
which should suffice for the implied applications (mooring).
For that matter, one could suggest dispensing with even this
much novel knotting, and just tie a bowline
with the bight
tip qua tail, and use the single-strand tail to put in some
final securing (and easily untied) component --perhaps just
make a sheet bend
to the bight tip, or 2HHs
That said the couple of times I've seen this the knot it was finished with a bowline (ABOK #1726) not 2 half hitches (which would slide up to the attachment point and could be difficult to reach to undo). The bowline finish uses more rope but this is be worth it for the convenience. Is the knot is less likely to collapse with both ends equally loaded?
NB: #1726 IS WRONG --SPart & tail are swapped : this knot
cannot be tied as the text states, as the illustration shows
the SPart (rather than the tail) passing through the bight.
Ashley should've copied #1853. (Yes, in the working of the
finished knot, it's a wash --the eye-knot loading legs equally--;
but in the tying, it's a matter of the 1 vs 2 passes.)
This is numbered among our collected Errata for ABOK