If you can't drive wedges how do you fall something that is fairly even weighted the whole way up, needs to fall in certain direction and is missing a third of the barrel?
There was no option to install a pull line and we don't have tree jacks
Jacks is cheap, 25ton bottle jack from the local hardware warehouse store is all I use, got 2 of em, though I think one is frose up from hanging out in the backup crummy for over a year. Don't bother with anything under 20ton (metric or yank) they won't hold up and won't do much when you do need em. I've bent the handles on my 25t jacks just on 36" fir, not even leaning real hard just limb heavy. Doing pull ups and it don't move is a bad sign.
put a plate of steel on the top 3/8-1/2" thick (10mm-13mm? ******* metric *****) to spread the pressure out some, mine have about 3x5" 3/8 plate on em with a handy chunk of gas pipe welded on as a keeper, just happened to fit snugly over the ram so poof keeper. They are bent a bit and could be wider as they sink into the wood at times but they work.
Jacking snags is still a sketchy maneuver, its just safer then beating wedges in, go slow and be careful. Pump the jack a couple times and palm the wedge in a bit. Always use a wedge as back up when jacking. Jacks fail, anything with moving parts is going to break eventually, best not to rely on it.
Normally for jacking trees, I'll jack a little and then give the wedge a good smack, trading off the weight from one to the other as the tree lifts, makes a little less work. If you're using two bottle jacks you can pump one and then the other, for pretty much the same effect, but still keep a wedge or two in there. The cool thing is you will feel the weight come off the jack as the tree stands up and gets ready to go, gets to a balance point and will just sit there until the wind picks up or momentum takes over
CLEAR AT LEAST TWO ESCAPE PATHS, on every ******* tree, this is step one does not matter if its a snag or a perfect cone of delight, **** happens and you need to be ready for it. Its doubly more important on a snag because its going to blow up either when it starts to move or when it hits the ground or somewhere in between.
Also, the point of a face cut is A to direct a tree, and B to undermine the support of one side, therefor making standing weight into hanging weight, if its supposedly perfectly straight up and evenly balanced, putting a deep face in one side will change that equation fairly fast, by then palming a wedge into the back cut side it will prevent the trees from sitting back due to wind etc then the only way it can go is towards the face.
Folks have been know to say **** like "you didn't need a wedge in that" yeah well if I didn't wedge it then what? it has a chance to sit back... so take the time at least palm a wedge in and go.