All tower cranes consist of the same basic parts:
- The base is bolted to a large concrete pad that supports the crane.
- The base connects to the mast (or tower), which gives the tower crane its height.
- Attached to the top of the mast is the slewing unit -- the gear and motor -- that allows the crane to rotate:
On top of the slewing unit are three parts:
- The long horizontal jib (or working arm), which is the portion of the crane that carries the load. A trolley runs along the jib to move the load in and out from the crane's center:
- The shorter horizontal machinery arm, which contains the crane's motors and electronics as well as the large concrete counter weights:
- The operator's cab:
The machinery arm contains the motor that lifts the load, along with the control electronics that drive it and the cable drum, as shown here:
The motors that drive the slewing unit are located above the unit's large gear:
Now let's find out how much weight this equipment can handle.