Under the impact of electric lifting equipment, the use and occurrence of chain hoists have gradually decreased, but their advantages can still be demonstrated in millimeter level lifting operations, including jacks. At the lifting operation site of a railway super large bridge steel crossbeam, technicians used four 10 ton hydraulic jacks to lift a single steel crossbeam weighing 276 tons, and the jacks successfully controlled the alignment accuracy of the steel crossbeam within 5 millimeters.

At the site of large-scale bridge hoisting operations, due to limitations such as terrain, power supply, and space, steel beam hoisting operations face greater difficulties and responsibilities. The construction site needs to first use a thousand ton crawler crane to lift the steel beam. When the boom rotates and is positioned directly above the Hanyuan Railway, four groups of cable wind rope workers adjust the lifting operation in a timely manner by retracting and extending the cables.

And when technicians use hydraulic jacks to lift and align steel crossbeam components, they are not blindly lifting. They need to rely on intelligent monitoring systems to quickly analyze lifting angle, speed, traction force and other data, ensuring that the initial alignment accuracy is controlled within 20 millimeters. Subsequently, relying on temporary sliding support devices and four 10 ton jacks, millimeter level distance micro control was carried out to achieve precise positioning of the steel crossbeam, followed by welding work.