Most yarders have the potential to pull themselves inside out and then some if anchored well at the back end. What it will actually pull into the landing depends on a few things.
Mainly what does your slope profile look like - ie: what kinda deflection do have - your running lines in relation to the ground. No deflection - no payload. Do you have a nice concave slope that runs out at the back end or do you have an ugly little convex roll in the middle, in front of the yarder or at the backend? Deflection is the amount of sag in the cables and it increases with distance. If the cables sag low enough and touch the ground then you're into ground lead and you won't be pulling a whole lot into the yarder (other making a trench) The more you tightline the mainline / skyline to get the cables off the ground the more potential payload you use up (cables have a safe working load - the more you tighten them the more force on them).
How far are you yarding? 100m or 500m?
Can you drag the turn to the yarder (highlead / slackline) or do you need to partially suspend or even fully suspend the turn (skyline / carriage combo)?
Some ideas....
