rigging is one aspect of this business that i love. the height of the buildings work for you some time. i always double up anchor points on fire escapes, i beams, bulk heads etc. on hundered year old buildings i trust nothing. working off fire escapes gives more options. a few months ago we were removing a dead atlantis that was questionable if it could be climbed. so we got up on the fire escape and with throwind a rope through crotch's and a power pruner we were able to get the top out. then i rigged a line off the roof for the climber to tie in as he went into the tree to chunk the wood down. as far as atlantis i guess were talking about the same tree(weed) i just never heard it called what you mentioned. they go to seed and pop up every where. i've seen them sprouting in oak and maple crotch's , cracks in the side of buildings, etc. there fine to work with when there alive but the dead ones really suck. they get so brittle. i've ripped croth's out of them a few times. we usually dont get to the dead ones until limbs start breaking out, its usually in the poorer nieghbor hoods so the yards are kind of crumby to begin with. so you just go as high as you feel comfortable and try to make educated cuts. you could some times peel the bark off on your way up to check for horizontal cracks. the tips usually just shatter when they hit a fence or roof, so you could get away with stuff that would not work with other tree's. if rigging is involved i will only do them with a rope man i could fully trust. some times i'll run my own ropes in them if i'm working with a crew i can not trust. just hold it long enough to clear the obsticle and let go of the rope and let it crash to the ground, i try not to trust the crotchs too much. they get real big by me, i've needed a 12 foot belt for some of the sticks.(there the tree that grows in brooklyn) the only time i went down with a tree was an atlantis, but i still did not drop the saw. they can get real week at the base. once i had to remove just a vine cover atlantis stick on a lean. so i threw a rope up in it, and slaped a notch about 6 feet to clear a fence so i could dump it in a nieghbors back yard. i had the guys on the pull rope as i was making the back cut and i felt the tree moving. it was breaking at the base. i was able to finsh my cut and clear the fence but it was a close one.