Another interesting advatange of tower cranes is that they can grow/shrink themselves by using a special jig; that's how they're able to negotiate 200 story sky

Another interesting advatange of tower cranes is that they can grow/shrink themselves by using a special jig; that's how they're able to negotiate 200 story skyscrapers. That jigs tends to be too convulted to use for smaller projects, in which case they use a mobile crane as seen here.