I too think he must mean separate constrictors.
Anything else would be inefficient, since you need to pull both ends of the string to really tighten a constrictor.
Not entirely so, but it is a challenge.
There are two ways I can think of to tie some
kind of "series" of
constrictors --and here I'll
note that one might be better off using some
version of a
strangle knot as its tails run
parallel to the bound object.
Long ago a fellow told me about tying a 2nd
constrictoron back of an initial one, but wasn't clear --and maybe
I didn't press for details enough-- about how ... .
Not so long ago, I've found that one can do this by
making a tucked turn (half-hitch?) with one tail,
placing the tuck opposite the initial knot's crossing
area, and then bring the other tail through this just
as making a
c. --ta-da! And, of course, one might
critique this as being imbalanced --the one tail making
the full turn to the other's mere tucking through to
finish ...-- and have both make full turns (and so get
two overcrossings and a
double c.) !
Now, yes, you'll be putting these extra wraps around
/atop the initial knot's parts, but ... work it out as best
you can.
Otherwise, one can lead away from the initial knot
and tie the 2nd
c. and just tighten it with pull on
the leading-away tail, depending upon mere resistance
of the leading-into one for achieving the "pull on both
ends" tensioning --which might be sub-optimal, but
still effective (YMMV w/materials --the more frictive,
the more difficult this will be).
Frankly, my favorite and best-looking whipping comes
from a
multiple strangle knot in which there are e.g.
5 overwraps of mason line around a 3/8" rope (sizing the
materials here, for the example), and 1 extra crossing
beneath these (in mason line, this dbl'd inner part is
nicely just covered by 5 overwraps; in nylon fishline,
it seems to take 7ish overwraps to do the same).
And I often stopper the starting tail with end pointing
to whipped-rope's end, make the overwraps, then
tuck in a
bight from the finishing end (which might
be with a lot of whipping line to be cut off), then work
a sort of
sailor's/common whipping structure of
this bight (requires access to either end of whipped rope
--not a big issue on short, "play rope" pieces-- or brought
around the batch of whipping material to be cut off)
and so finish with both tails pointing out the tail end
of the whipped rope.
(I use pliers to squeeze the whipping
in hopes of better equalizing tension throughout --it's
delivered by setting to the end/initial overwraps, and
so needs some help to work into the center wraps.)
--dl*
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