Tower crane (tower crane) referred to as tower crane, also known as tower crane, originated in Western Rotating crane with a boom mounted on the upper part of a tall tower. Large working space, mainly used for vertical and horizontal transportation of materials and installation of building components in house construction. It is composed of three parts: metal structure, work and electrical system. The metal structure includes the tower body, boom and base, etc. The work has four parts: lifting, luffing, turning and walking. The electrical system includes motors, controllers, power distribution cabinets, connecting lines, signals and lighting devices, etc.