The Sheepshank loop

[xarax]

   If we reeve the one bight of any TIB double loop through the other, we get a midline / TIB single loop. To be able to do this easily and quickly, we better choose one of the many available TIB double loops with "communicating" bights - the material of the shrinking second bight can feed the widening first bight, so the knot can be dressed without any further adjustments. 
   I have tried this trick in the case of the simplest Sheepshank knot ( which, in its turn, can also can be tied easily and quickly, by a "three-bights" method similar to the one explained at ABoK #1162/#2432/#2566 ). The result is the very interesting TIB eyeknot shown in the attached pictures. It can be used by anybody who is not satisfied with the less complex "pet loop".
 1.  Taking into account that there are two ways we can tie an "ordinary" Sheepshank, and that the first bight can pass through the one or the other side of the second bight, we see that there are four different Sheepshank loops tied this way.
 2.  If we reeve, through the second bight, not only the first bight, but the whole nub ( so that the second bight becomes a collar around the ends ), we get a Sheepshank bowline - a double collar bowline, very similar to the  Jug sling / "Coming and going" bowline :
http://igkt.net/sm/index.php?topic=4336.0
http://igkt.net/sm/index.php?topic=4412.0
 

[xarax]

  See pictures of the Sheepshank bowline I am talking about in the previous post. The bight through which we have reeved the whole knot becomes a collar around the Standing end and the Tail.
  For a knot tyer who is accustomed to tie the Sheepshank with ease, this is the easiest to remember how to tie secure double collar TIB bowline ( double collar = two collars, one around the pair of the legs and one around the pair of the eye legs ). Just one step away from the Sheepshank - there can be nothing closer than this ! 

[xarax]

   Another variation of the same theme. In fact, there is no need to pay much attention to the initial form of the Sheepshank ( although it may be preferable to start from the point-symmetric form, which can be inspected at a glance ), or to the particular side through which one reeves the one bight through the other - all the double collar TIB bowlines generated by the application of this method on the Sheepshank are similar very secure knots.