knot used to form a loop in the middle of a line or to shorten a line.
sheepshank (Wikipedia)
A shank is a type of knot that is used to shorten a rope or take up slack, such as the sheepshank. The sheepshank knot is not stable. It will fall apart under too much load or too little load.
| Sheepshank | |
|---|---|
 An unloaded sheepshank tied in nylon rope | |
| Category | Shortening |
| Origin | 1627[1] |
| Related | Catshank, Dogshank, Bell-ringer's knot |
| Releasing | Non-jamming |
| Typical use | Provides loops, shortens or removes slack from a rope, bypasses a frayed section of rope |
| Caveat | Spills if not under tension |
| ABoK | #1152, #1153, #1154, #1158, #1159, #1160 |
| Instructions | [1] |
The knot has several features which allow a rope to be shortened:
- It provides two loops, one at each end of the knot which can be used to pass another rope through
- The knot remains somewhat secure under tension; the coarser the rope the more secure it is (see Disadvantages, below)
- The knot falls apart easily when tension is removed