BRAUN RICK CRANE SERVICE: Skyscraper Construction.
Braun Rick Crane Service issued the following announcement on Nov. 16.
Tower cranes are enormously tall and do not have a movable base. They are a very structurally sound type of crane that does not exist as a single unit, but is built according to job site specifications.
These cranes have a long, ladder-like base and a perpendicular boom, which suits their use in skyscraper construction.
Original source can be found here.
Source: Braun Rick Crane Service