1. Definitions and Functions
Crane rail: a specially rolled steel rail section mounted on the top of the runway girder, on which the crane wheels travel. Its function is to support and guide the movement of the crane, prevent derailment and deviation, and distribute wheel loads evenly to the girder below.
Crane runway girder (crane beam): the main structural beam of the crane runway, supported on columns, which carries the crane rail, the wheel loads and the lateral and longitudinal forces generated by crane travel and hoisting. It is a fixed structural member - it does not move up and down; the hoisting motion is performed by the crane trolley and hook block.
2. Structure and Material
| Item | Crane rail | Runway girder |
|---|---|---|
| Form | Rolled rail section (head, web, base) | Welded I-section, box girder, or lattice girder |
| Material | Rail steel (e.g., U71Mn; QU-series per GB/T 3426) | Structural steel (e.g., Q235B/Q355B per GB/T 1591 or equivalent) |
| Typical sections | QU70, QU80, QU100, QU120; P38/P43/P50 for lighter cranes | Welded H-section, plate girder, box girder (span-dependent) |
| Function | Wheel running surface, guidance, derailment prevention | Carries rail and wheel loads; spans between columns |
| Design loads | Wheel load concentration, wear, contact fatigue | Vertical load, lateral (crabbing) load, longitudinal braking load, fatigue |
| Fixing | Rail clips, anchor bolts, welded joint or fishplated joints | Bolted or welded connection to crane columns; base plates and anchor bolts |
3. Installation and Alignment
Rails are installed on the girder top flange using rail clips or anchor bolts, with the rail axis aligned to the girder centerline. Installation tolerances - rail gauge, level and straightness (typically ±2 mm over the runway) - are critical for smooth crane travel and load sharing between wheels. The girder top flange must be machined or leveled to receive the rail, and rail joints should be staggered between the two rails and located away from high-stress zones where possible.
4. Application Scope
Crane rails and runway girders are used together in all types of overhead and gantry crane runways - workshop cranes, shipyard goliath cranes, port quay cranes and container yard cranes. The rail section and girder size are selected per crane wheel load, span, duty class and operating speed, following structural design codes.
5. Selection Notes
For a new crane runway, specify: crane capacity and wheel loads, runway span and height, duty class, rail section (QU series for heavy cranes) and the girder design with fatigue assessment. Regular inspection of rail wear, rail fixing looseness and girder welds is essential for safe crane operation.
Get a Quote for Crane Rails
Crane rails and crane runway girders perform different but complementary roles: the crane rail provides the running surface for crane wheels, while the runway girder supports the rail and transfers crane loads to the building structure. GNEE RAILWAY RAILWAYL supplies crane rails in different profiles, materials, and specifications for industrial crane track applications, with technical documentation and project-based support available.
