Port crane to facilitate multiple cranes to work side by side on the same ship, the gantry crane with rotating column connected to the vertical column, or the rolling bearing type bearing slewing device connected to the gantry through the large bearing, is generally used to reduce the tail diameter of the rotating part, and the gantry structure is used to reduce the pier cover surface (the projection of the gantry main body to the ground). In the process of development, gantry crane is also gradually popularized and applied to the shipyard and hydro power station construction site with similar operating conditions to the port. Port crane has lifting, slewing, luffing and running mechanisms, the first three mechanisms installed on the rotating part, every week to participate in the operation. The rotating part is also equipped with a tilt single boom or combination boom that can be pitched and the driver's cab. The operating mechanism is installed at the lower part of the gantry to adjust the working position of the crane. The port crane with brackets is also equipped with telescopic funnel, belt conveyor and other additional equipment to improve the productivity of the crane handling loose materials with the grab bucket. In addition to the electrical protection device, also equipped with lifting weight or lifting moment limiter, crane rail clamp and other safety devices. Floating cranes are installed on the vessel and are mainly used for cargo loading and unloading operations. The implementation of the norms for the CCS “ships and offshore installations lifting equipment code” (2007) and 2010 amendments to the circular. This machine is a floating crane with single jib balanced change wheel set compensating rack and pinion luffing. It mainly consists of hoisting mechanism, luffing mechanism, slewing mechanism, jib system, column, turntable, machine room, driver's room, supporting cylinder, ladder railing system, electrical control system and other auxiliary devices. The machine can be operated by hook or grab, and can be loaded for horizontal displacement amplitude and 3602 angle slewing, lifting and amplitude change, the slewing mechanism can be operated jointly, lifting, amplitude change, rotating with AC frequency conversion speed control, and all the institutions are set up with the necessary limit switches and interlocking protection devices.