Crane Development origin: history. Early 20th Century 25 t crane manufacturers in Europe began using the tower crane. Crane hoisting mechanism mainly run institutions, luffing mechanism, slewing mechanism and metal structure. Crane hoisting mechanism is the basic working mechanism 25-ton crane sales company, mostly by hanging system and winch composition, but also lift weights through the hydraulic system. Crane safety devices: from the weight indicator. From the weight indicator is set in the basic arm together side (ie, the right side of the cab), the operator sitting in the control room will be able to be clearly observed, it can accurately indicate the boom crane elevation and the corresponding conditions It permitted the rated capacity.