Ship cranes as marine winch is widely used in the shipping industry

with the development of the hydraulic system and electro-hydraulic control technology

hydraulics crane design and R & D should be paid more attention.Hydraulic cranes as product of trinity of the mechanical

electrical and hydraulic

need to have some theoretical and practical basis for its maintenance and failure analysis.The hydraulic crane’s three main institutions:the lifting device

the rotary device

and the luffing device are discussed

and there’s structure and function of hydraulic control system and the principle of electro-hydraulic control are introduced.The common failure of the hydraulic and electrical part are analyzed and excluded

and making a prediction of the development and prospects for the crane.