How to Select a Bridge Crane?

Bridge crane selection follows a five-step process: "Define Parameters — Determine Level — Determine Type — Determine Environment — Determine Safety and Configuration," ensuring coverage of the work scope, intensity, and safety compliance.

I. Determining the Foundation with Core Parameters

Rated Lifting Capacity: Maximum lifting capacity + lifting gear/rigging + 10%–20% safety margin; ≤20t commonly uses single beam, >20t prioritizes double beam/cable double beam.

Span: Main beam rail center distance = factory clear span − safety margin on both sides (0.5–1m on each side), commonly 10.5–31.5m.

Lifting Height: Effective height from the lowest point of the hook to the ground/rail top, meeting maximum lifting depth and stacking height requirements.

Operating and Lifting Speed: Matched to efficiency and stability: Lifting, trolley, and overhead trolley speeds are selectable in stages; high speed is selected for heavy loads/high frequency operations with brake redundancy.

Wheel pressure: Check the load-bearing capacity of the factory/track foundation to avoid exceeding limits that could lead to settlement or structural damage.

II. Working level to determine strength (GB/T 3811)
The working level of the entire machine is determined by **utilization level (U0–U9, total number of cycles) and load spectrum coefficient (Kp, light/medium/heavy/extra heavy)**. A1–A8:

A1–A3: Light load, occasional use (e.g., maintenance, occasional hoisting in warehouses)

A4–A5: Medium load, frequent use (8-hour workshop operation, frequent hoisting on production lines)

A6–A7: Heavy load, high frequency (continuous production, material yard loading and unloading)

A8: Extra heavy, continuous (ports, metallurgy, 24-hour operation)
Selection principle: Select the corresponding level according to actual strength to avoid early wear and failure caused by operating at a low level with high intensity.

III. Type and Mechanism Selection

Table Type           | Applicable Lifting Capacity             | Features

Electric Single Girder Bridge Type | ≤20t | Simple structure, low cost, commonly used for medium and light loads

Electric Hoist Double Girder Type | 5–32t | Large lifting height, stable operation, strong versatility

General Double Girder Bridge Type | ≥10t | Good rigidity, strong load-bearing capacity, preferred for heavy loads/large spans

Metallurgical/Explosion-proof Bridge Type | Special working conditions | High temperature resistance, dustproof, explosion-proof, meets special environment requirements

Mechanism Configuration: Select frequency conversion or brake redundancy for lifting/traversing mechanisms; high frequency and heavy loads require dual brakes; metallurgical environments require high temperature resistance and dustproof sealing.

IV. Environmental and Safety Configuration

Environmental Adaptability: For special working conditions such as high temperature/dust/explosion-proof/outdoor, select the corresponding protection level and special model (e.g., QB explosion-proof, metallurgical bridge type).

Safety Devices
Required: Lifting capacity limiter, travel limit switch, buffer, windproof and anti-slip device; high frequency/large spans require additional anti-collision devices, anemometer, and monitoring system. Power Supply Method: Conventional cable reel; for long spans/high frequencies, select sliding contact line or cable chain to reduce maintenance and malfunctions.

V. Compliance and Implementation:

Qualifications: Select manufacturers with special equipment manufacturing/installation, modification, and repair licenses, providing certificates of conformity, test reports, and technical documents.

Installation and Acceptance: Install according to specifications; can only be used after passing acceptance by a special equipment inspection agency.

VI. Quick Selection Examples:
Workshop hoisting of 10t workpieces, 8 hours per day, frequent lifting: Select a 10t double-girder bridge crane, 18m span, 9m lifting height, A5 working class, equipped with variable frequency hoisting/running and dual braking.

Stockyard continuous loading and unloading of 15t materials, 24-hour operation: Select a 15t double-girder bridge crane, 22m span, 12m lifting height, A7 working class, equipped with high-temperature resistant mechanisms and a monitoring system.

VII. Selection List (Can be directly applied)
Rated lifting capacity (including margin)
Span, lifting height, operating speed
Working class (A×)
Type (single beam / double beam / hoist)
Environment and special requirements
Safety configuration and power supply method
Manufacturer qualifications and acceptance requirements