How to install QU120 crane rail correctly?

Installing the QU120 crane rail-the heaviest profile in the Chinese standard series weighing 118.1 kg/m -is a highly technical engineering process that dictates the safety and efficiency of massive lifting equipment.

GNEE RAILWAY RAILWAY combines state-of-the-art production capabilities with profound engineering expertise to deliver flawlessly rolled QU120 rails. Our advanced manufacturing facilities ensure that every rail we produce features unparalleled dimensional accuracy and exceptional straightness, which are the fundamental prerequisites for a seamless installation.

Correctly Install QU120 Crane Rail 

1. Foundation Preparation and Inspection

The performance of a QU120 rail relies entirely on the quality of its foundation, whether it is a continuous concrete beam or a structural steel girder. Before any rail is lifted, the foundation must be thoroughly cleaned and inspected. Surveyors must check the elevation and alignment to ensure strict flatness tolerances. For steel girders, the surface must be free of rust, oil, and debris to ensure optimal adhesion for subsequent welding of the base plates. Any unevenness in the foundation will amplify dynamic impacts from the crane, leading to premature wear on both the rail head and the crane wheels.

2. Laying the Sole Plates and Continuous Rubber Pads

Given the extreme concentrated loads that QU120 rails handle (often exceeding 500 kN per wheel), they cannot be mounted directly onto hard concrete or bare steel. First, steel sole plates are positioned and leveled. Then, a steel-reinforced elastomeric continuous rubber pad is laid along the center of the track line. This specialized pad absorbs massive dynamic shocks, reduces noise and vibration, and distributes the wheel loads evenly across the foundation, significantly protecting the underlying infrastructure from structural fatigue.

3. Rail Lifting and Precise Positioning

Because a standard 12-meter QU120 rail weighs over 1.4 tons, specialized lifting equipment and synchronized spreader beams must be used to prevent the rail from bending under its own weight during handling. Once placed onto the rubber pads, engineers use laser alignment tools to position the rails. Achieving the precise track gauge (the distance between the two parallel rails) is critical. The tolerance for gauge deviation on heavy-duty crane tracks is incredibly tight-often within ±3mm to ±5mm depending on the crane span-to prevent wheel flange binding and derailment risks.

4. Welding the Rail Joints (Aluminothermic Welding)

For ultra-heavy applications using QU120, traditional bolted fishplates (joint bars) are generally not recommended due to the severe impact caused as wheels pass over the gap. Instead, the rails are joined using Aluminothermic (thermite) welding to create a Continuous Welded Rail (CWR). This process involves aligning the rail ends with a specific gap, clamping a refractory mold around the joint, preheating it, and igniting a chemical mixture that pours molten steel into the gap. After cooling, the weld is ground perfectly flush with the rail head, ensuring smooth, vibration-free crane travel.

5. Fastening the Rail Clips

The final step is securing the QU120 rail using heavy-duty, adjustable crane rail clips (such as weldable forged clips). Unlike standard railway spikes or bolts, these specialized fastening systems consist of a weldable base that is permanently welded to the sole plate, and an adjustable upper clip with a rubber nose. The rubber nose applies a controlled downward compressive force on the rail's base flange while allowing for minor lateral adjustments to fine-tune the gauge. The bolts on the upper clip must be tightened to the exact torque specified by the manufacturer to ensure the rail is locked in place against intense lateral forces.

From producing the raw QU120 rails with strict straightness tolerances to manufacturing the exact matching weldable clips, sole plates, and continuous elastomeric pads, GNEE RAILWAY RAILWAY provide a 100% compatible, one-stop solution. We can even pre-cut and drill the rails at our facility to match your exact site blueprints, saving your team countless hours of field labor.

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