Single Girder Vs Double Girder Overhead Cranes: Differences, Advantages, And Application Guide

In industrial lifting and material handling, overhead cranes (bridge cranes) play a crucial role in improving efficiency, safety, and productivity. They are widely used in manufacturing plants, warehouses, steel production, and assembly lines.
Among the many types of overhead cranes, the single girder and double girder bridge cranes are the most common.

While both perform similar functions—lifting and transporting loads across a designated area—their designs, capacities, and performance characteristics differ significantly.
Understanding these differences is essential for choosing the right system that matches your lifting requirements, budget, and workspace layout.

This comprehensive guide explores the main distinctions between single and double girder overhead cranes, their respective advantages, and best-use scenarios.

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1. Overview of Overhead (Bridge) Cranes

An overhead crane, also known as a bridge crane, consists of parallel runways connected by a traveling bridge.
A hoist or trolley runs along the bridge, enabling the crane to lift and move materials both vertically and horizontally within a specific working area.

Overhead cranes are ideal for indoor environments where heavy loads need to be moved efficiently without occupying floor space.
The bridge structure can be made with a single girder or two girders, which determines its lifting capacity and operational range.

2. What Is a Single Girder Overhead Crane?

A single girder overhead crane features one bridge beam that supports the trolley and hoist. The hoist is usually mounted on the bottom flange of the girder (called an under-running or top-running design, depending on configuration).

Key Features

One main bridge girder

Simple structure and lightweight design

Hoist runs on the lower flange of the girder

Commonly used for light to medium lifting (usually up to 20 tons)

Compact structure reduces headroom and space requirements

Advantages of Single Girder Cranes

Cost-Effective: Lower material, manufacturing, and installation costs.

Easy Installation: Requires smaller supporting structures, minimizing building load.

Compact Design: Ideal for areas with limited space or low ceilings.

Low Maintenance: Fewer components mean reduced maintenance needs.

Energy Efficiency: Lightweight design consumes less power during operation.

Typical Applications

Workshops and light manufacturing plants

Assembly lines and repair shops

Warehouses and logistics centers

Machinery maintenance areas

Limitations

Lower lifting capacity (up to 20 tons in most designs)

Shorter span and slower lifting speed compared to double girders

Not suitable for high-duty or continuous heavy-load applications

3. What Is a Double Girder Overhead Crane?

A double girder overhead crane consists of two parallel bridge beams with the trolley and hoist traveling on rails mounted above the girders.
This configuration provides greater stability, higher load capacity, and longer spans, making it suitable for heavy-duty industrial applications.

Key Features

Two bridge girders connected by end trucks

Hoist mounted on rails above the girders (top-running type)

Suitable for medium to very heavy loads (from 10 tons up to 500 tons or more)

Can accommodate larger spans and lifting heights

Supports more complex attachments such as grab buckets, magnets, or spreader beams

Advantages of Double Girder Cranes

Higher Lifting Capacity: Can handle much heavier loads than single girder cranes.

Greater Lifting Height: The hoist sits between the girders, maximizing vertical lifting space.

Enhanced Stability and Rigidity: Better for high-precision and continuous heavy-duty operations.

Versatile Customization: Supports additional accessories such as walkways, maintenance platforms, and cabins.

Longer Service Life: Designed for demanding, long-term industrial environments.

Typical Applications

Heavy manufacturing and steel fabrication plants

Power stations and foundries

Shipyards and port facilities

Large warehouses and assembly halls

Limitations

Higher initial cost (materials, installation, and structural requirements)

Heavier design increases building load and space demand

Requires more maintenance and skilled operators

4. Key Differences Between Single Girder and Double Girder Cranes

Although both cranes are designed to move heavy materials, their structural and operational differences make them suitable for distinct applications.

Feature	Single Girder Overhead Crane	Double Girder Overhead Crane
Number of Girders	One	Two
Load Capacity	Light to medium (up to ~20 tons)	Medium to heavy (10–500+ tons)
Lifting Height	Lower	Higher (hoist between girders)
Bridge Weight	Lighter and simpler	Heavier and more robust
Installation Cost	Lower	Higher due to complex structure
Building Requirements	Minimal	Requires stronger support structure
Maintenance	Easier and less frequent	More complex; requires professional servicing
Precision and Stability	Suitable for general lifting	Suitable for precision and continuous duty
Span Length	Short to medium	Medium to very long spans
Applications	Workshops, small factories, maintenance	Heavy manufacturing, steel mills, shipyards

 

5. Choosing Between Single Girder and Double Girder Cranes

When selecting an overhead crane system, several factors should be considered to ensure optimal performance and cost-efficiency.

a. Lifting Capacity and Duty Cycle

If your lifting requirements are under 20 tons and occasional, a single girder crane is sufficient.

For frequent heavy-duty lifting or loads exceeding 20 tons, choose a double girder crane for durability and stability.

b. Workspace Layout and Building Height

Single girder cranes are perfect for low-clearance workshops or small buildings.

Double girder cranes are suitable for taller structures requiring higher lifting heights and wider coverage.

c. Budget and Installation Costs

Single girder cranes are more economical, with simpler installation and lower maintenance.

Double girder cranes require larger investment but offer higher performance and long-term reliability.

d. Operational Requirements

For light assembly, maintenance, or occasional material handling, single girders are ideal.

For 24/7 production, heavy assembly lines, or precision positioning, double girders deliver better results.

e. Future Expansion

If your production or lifting needs may grow in the future, investing in a double girder crane can save significant upgrade costs later.

6. Common Variants and Configurations

Both single and double girder cranes come in different designs to suit specific operational needs:

Top-running cranes: The bridge runs on rails placed on top of runway beams (common for both types).

Under-running cranes: The bridge runs under the runway beams (typically single girder).

Explosion-proof cranes: Used in hazardous environments like chemical or gas plants.

European-style cranes: Advanced, compact, energy-efficient designs with low headroom and modular components.

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7. Conclusion

Both single girder and double girder overhead cranes are essential lifting solutions for modern industries. The best choice depends on your load requirements, workspace size, and operational frequency.

Choose a Single Girder Crane if:

You need a cost-effective, space-saving solution for light to medium lifting.

Your facility has limited ceiling height or small working areas.

Choose a Double Girder Crane if:

You handle heavy or high-frequency loads and require maximum lifting height.

You operate in large industrial environments demanding durability and efficiency.

By understanding their structural and functional differences, businesses can select the ideal crane system to optimize material handling, improve safety, and reduce operational costs.