Tower Cranes
The Tower Crane is a modern form of balance crane. Fixed to the ground (and sometimes attached to the sides of structures as well), tower cranes often give the best combination of height and lifting capacity and are used in the construction of tall buildings.
These cranes are often seen in the skylines of cities undergoing a lot of construction. One building, especially a skyscraper, may be surrounded by 4 or 5 Tower Cranes at one time. You may have seen these in pictures of Dubai, rumored to have the largest number of Tower Cranes currently operating at one time.
