NLH type electric hoist double girder crane adopt European FEM advanced standard design and manufacture. The whole technical level reach to international and domestic advanced leading level. The crane’s steel mechanism with professional design, structure optimization, complicated with specification and standard, meet the requirements of strength, rigidity and stability. During the design progress, take into account in the working environment, the design of steel structure considering the manufacture, inspection, transportation, installation and maintenance convenience and possibilities. In meeting the demand and the current specification and standard, through limited margin analysis etc optimization design, minimizing the weight of steel structure. The electric hoist trolley adopt ND type steel wire rope electric hoist trolley, the rated lifting load is 3.2～80t.