Looks like a nice lil boom truck, we run a lil bigger set-up than that 18ton national no lmi either. Weights hard hard to be exact on even with green log weight charts because of the foliage, seasons change, and many other factors. So think heavy and pick light, according to your charts, and feelings. you said you've been on the tree end of that crane before so should an idea of what size pieces you have taken before, hope you were paying attention the how he set the crane up and positioned the hook around the tree. Im not an operator so i cant tell you much bout pre-tensioning other than its nice my boss (the crane op) is also a climber with plenty of exp. on both sides of the 'hook', and that if you have to much or to lil its not nice as the climber you can usually tell when theres to much or to lilttle when are making you cut, and correct before its ugly, which isnt always so bad but never good n smooth. Cuts is a whole nother story as well different cuts for different situations, personally i like to make only one cut straight up/down/through whenever possible. There is times though when you do like to make a snap cut or rarely you would make a notch. Communication is KEY we discuss everything. Dont ride on the hook and make SURE everyone is wearing their headgear. Climb with a rope bag if you dont already and minimize clutter on your saddle, i never ditch the hand saw though keep that. Split tail system with spliced eyes everywhere is most effective for me. Would be a great idea to have your buddy come out on a couple jobs and work with your guy thats running it now.
Think thats about it for now I am working with my first company that has a crane and i love it, i feel i have a good grasp on my end of it so far. As mentioned b4 an experienced op. is great to have. Sorry for the ramble. lol
One that should be in the 'tree guy sayings' thread.....My boss favorite line "Dont be a pig, you'll tip your rig."