I am fortunate enough to have a great view of midtown manhattan from my office on fifth avenue and have, for the past year, watch the construction of the infamous conde nast tower. My question is how do they get that enormous crane down upon completion of the building. It seems to large to just disassemble. Please help me sleep better.
I'm not sure what specific type of crane you are referring to but if you are asking about a tower crane this site might help http://www.howstuffworks.com/tower-crane.htm
See also HOW DO THEY GET THOSE CRANES UP THERE?.