Scope of Application and Machine Classification

GB/T 26470-2011 applies to all types of bridge erecting machines used in highway and railway bridge construction. A bridge erecting machine is a specialized piece of engineering equipment designed to install precast girders (T-beams, box girders, hollow slab beams, etc.) and falls under the broader category of construction cranes. The standard classifies bridge erecting machines into four types based on structural configuration: the double-guide-beam bridge erecting machine (comprising two parallel guide beams, front and rear outriggers, and a lifting trolley; it is the most widely used type and the dominant machine for highway bridge erection), the single-guide-beam bridge erecting machine (featuring one guide beam and a counterweight balancing system; its simple structure and light weight make it suitable for small- and medium-span bridges up to 40 m), the walking-type bridge erecting machine (which advances along the completed bridge deck via a stepping travel mechanism without external traction, designed for 32 m and 24 m standard precast girders in railway bridges), and the transport-and-erection integrated machine (which combines a girder transport vehicle and an erecting machine on a single platform, capable of self-propelled travel and self-hoisting on the bridge deck for rapid erection of standard girders on high-speed railway lines).

Key parameters specified in the standard include the rated lifting capacity (100–2,000 t), with typical values of approximately 140 t for 40 m highway T-beams and approximately 900 t for 32 m railway box girders; the applicable span (the range of bridge spans the machine can handle, in meters); and the guide beam length (which must be at least twice the maximum erection span). The standard also defines protection ratings for the major mechanisms — electric motors on all mechanisms must meet IP55 or higher, and the electrical system insulation resistance must be at least 1 MΩ. Overall transport dimensions (width, height, and length) are constrained by road transport clearance limits, requiring disassembly or the use of specialized transport vehicles for relocation. Kelude Heavy Industry manufactures its supporting equipment in strict compliance with this standard.

Core Technical Requirements

The standard's technical requirements cover four critical systems: the main girder (guide beam) design, the outrigger system, the lifting trolley, and the girder transport access system. The main girder is the primary load-bearing component of the bridge erecting machine. For double-guide-beam machines, the main girders use a box-type or truss-type structure fabricated from Q345B or Q390D high-strength low-alloy structural steel. Under rated load, the mid-span deflection of the main girder must not exceed 1/400 of the span — a stiffness requirement that is essential for maintaining the horizontal attitude of precast girders during lifting.

The front and rear outrigger systems are what set bridge erecting machines apart from other crane types. The front outrigger is positioned at the pier awaiting erection, while the rear outrigger rests on the already-completed bridge deck. Both must provide adequate load-bearing capacity and height adjustment. The verticality adjustment range for the outriggers must be at least ±500 mm to accommodate varying pier heights and deck slopes. The lifting trolley travels along the guide beams with both longitudinal movement (≤5 m/min) and transverse movement (≤3 m/min), and is equipped with dual brakes (one in service, one standby) to provide braking redundancy.

Overall stability requirements specify an anti-overturning stability factor of at least 1.5 in working condition and at least 1.25 in non-working condition under maximum wind load. For wind resistance, the allowable wind speed is ≤20 m/s in working condition and ≤55 m/s in non-working condition (consistent with harbor crane standards). In non-working condition, the lifting trolley must be locked at the mid-span position of the guide beams, and the outriggers must be secured to the bridge deck using anchor bolts or wire ropes; where necessary, rebar anchoring into the deck is required.

Safety Devices and Testing Requirements

The standard divides safety device requirements into mandatory and recommended levels. Mandatory safety devices include the load limiter (which automatically cuts off the hoisting-up action and triggers an alarm when the load exceeds 110% of the rated capacity), the load moment limiter (alarm at 105% of rated moment), the hoisting height limit switch (automatic stop when the hook reaches its highest position), the travel limit switch (automatic stop of the lifting trolley at both extreme ends of the guide beams), outrigger pressure monitoring (real-time monitoring via pressure sensors on each outrigger hydraulic cylinder, with an alarm in the event of abnormal readings), and an anemometer (mounted at the highest point of the machine, providing a pre-warning at wind speeds ≥20 m/s and a red alarm with automatic shutdown of operations at ≥25 m/s).

The standard also requires an interlock protection system between the bridge erecting machine and the girder transport vehicle — the erecting machine cannot begin lifting girders until the transport vehicle is properly positioned, and the transport vehicle cannot move while the erecting machine is in the middle of a lifting operation. The hoisting rope safety factor must be at least 6, which is higher than the general crane standard requirement, reflecting the high unit value of precast girders and the severe safety and schedule consequences should one be dropped.

The standard specifies four types of tests: the no-load test (each mechanism runs through at least 2 full cycles to verify smooth operation and accurate limit switch actuation), the rated load test (one complete girder lifting cycle to measure main girder deflection, which must be ≤L/400, and beam landing accuracy, which must be within ±10 mm), the 1.25-times static load test (lifting at the most unfavorable span and holding for 10 minutes to verify the absence of permanent deformation), and the 1.1-times dynamic load test (three combined operating cycles to verify the reliability of brakes and safety devices).

Kelude Heavy Industry: Engineered for the Toughest Lifting Challenges

Kelude Heavy Industry specializes in the design and manufacture of heavy-duty industrial overhead cranes and hoisting solutions. Our product range is built to meet the rigorous demands of modern manufacturing, logistics, and heavy fabrication environments, delivering superior performance, reliability, and safety.

Frequently Asked Questions

Q: What is the typical lead time for a standard overhead crane?
A: Lead times vary depending on the crane's configuration and specifications. A standard single-girder crane can typically be delivered within 6-8 weeks, while more complex double-girder or explosion-proof systems may take 12-16 weeks. Please contact us for a specific timeline for your project.

Q: Can you provide cranes that meet specific international standards?
A: Yes, our cranes are designed to comply with major international standards, including ISO 4301 for classification, ISO 12480 for safety, and IEC 60204-32 for electrical installations. We can also engineer solutions to meet other regional or project-specific requirements.

Q: What kind of maintenance does a Kelude crane require?
A: Regular maintenance is crucial for safe and efficient operation. We provide detailed maintenance manuals and recommend a scheduled inspection program. Our service team can also offer comprehensive maintenance contracts to handle all routine checks, parts replacement, and emergency support.

Q: Do you offer spare parts for your cranes?
A: Absolutely. We maintain a comprehensive inventory of spare parts for all our crane models to ensure quick and easy replacement parts availability, minimizing any potential downtime for your operations.

Related Standards: GB/T 3811-2008 Crane Design Standard — Key Clause Interpretation: Load, Structure, Mechanism, Electrical, and Safety Systems · GB/T 28264-2017 Safety Monitoring and Management System for Lifting Appliances — 9 Mandatory Monitoring Points and System Architecture

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