Got too wondering about this slippage on the Figure 9s.
Noticed that the slippage seems to occur when the line around the tree is pulled slack because of the line catching on the bark.
Took out some small diameter guy line and a small Figure 9 and set it up and then secured the line around the tree so that it wouldn't pull around the tree like when it catches on the bark.
Thus, when I pull the free end to pull the line from the load tight, the line from the Figure 9 to the tree slackens and the Figure 9 slips.
Then I remembered the Hitchcraft directions for their rope tie.
You are supposed to give the line a twist when anchoring on the rope tie. Their animation doesn't show the twist, but the printed directions I got with the rope tie does specify the twist. (Edit: looked at the hitchcraft site again and the animation, the animation does show the twist)
Did some experiments using the twist on the Figure 9 when securing the line through the "eye" and around the Figure 9 stem. There are 2 ways to execute the twist on the Figure 9 (on the Hitchcraft rope tie it doesn't make any difference):
- load line on the bottom
- load line on top
where by load line I mean the line coming from the tarp or whatever you are trying to secure.
With the first method, the line still slips.
With the second method, the line doesn't slip. This makes sense since for the second method the load line sits on top of the line and secures it in place. It doesn't do that for the first method, hence the slip.
So, by simply introducing the twist when anchoring the line through "eye" of the Figure 9, the slippage problem can probably be eliminated.