Understanding the Differences Between Single and Double Girder Cranes and When to Use Each Type

Overhead cranes are essential tools in various industries, providing the necessary lifting capabilities to handle heavy loads efficiently. Among the different types of cranes, single girder, double girder, and box cranes are commonly used, each offering distinct advantages and disadvantages. Understanding these differences is crucial for selecting the right crane for your application. This article explores the key features of single girder and double girder cranes and highlights when to consider each type.

Single Girder Cranes

A single girder crane consists of one bridge beam, with the hoist trolley operating on the lower flange of the bridge girder. This design is often the most cost-effective solution for many applications and industries. Here are some advantages and disadvantages of single girder cranes:

Advantages of Single Girder Cranes

1. Single girder cranes use less material, making them more compact and lightweight compared to double girder cranes. This results in significant cost savings in terms of material, freight, and installation.
2. With only one bridge beam, single girder cranes have less deadweight. This allows for the use of lighter runway systems and easier integration with existing building support structures.
3. Single girder cranes are easier to install, service, and maintain due to their simpler design.
4. These cranes offer a better hook approach for both trolley travel and bridge travel, making them ideal for workshops, warehouses, material yards, and manufacturing facilities.
5. The lighter load on runway rails or beams results in less wear on the beams and end truck wheels over time, enhancing the crane’s longevity.

Disadvantages of Single Girder Cranes

1. Single girder cranes have a capacity limit, span, and hook height, making them unsuitable for applications requiring capacities over 15 tons.
2. The hoist is placed under the cross girder, providing less hook height compared to double girder cranes.
3. Incorporating specialised features such as service walks, lights, and heavy service components can be expensive or difficult.
4. The under running hoist trolley on a standard rolled steel bridge beam may cause premature wear to the bottom flange of the beam.

Double Girder Cranes

Double girder cranes have two bridge beams, with the hoist trolley traveling on rails typically attached to the tops of the crane girder. These cranes are designed for heavy-duty applications and can handle heavier capacities and longer spans.

Advantages of Double Girder Cranes

1. Double girder cranes provide greater hook height, as the hoist is placed between or on top of the cross girders.
2. There are no limits to maximum span or capacity, making them ideal for handling heavy equipment and frequent lifting of heavy loads.
3. Double girder cranes can be used both indoors and outdoors, in bridge or gantry setups. They are frequently employed in industries such as mining, iron and steel production, railyards, and shipping ports.
4. Added features like walkways, maintenance platforms, cabs, magnetic reels, and lights can be easily incorporated and supported by the double girder design.

Disadvantages of Double Girder Cranes

1. Double girder cranes are more expensive due to the added material costs, additional structural support, and more complex crane components.
2. There are additional costs related to freight and the installation of the crane versus a single girder crane.
3. The hook approach is lessened for both trolley travel and bridge travel, especially on double girder top running cranes.

When to Use Each Type of Crane

Choosing between a single girder and a double girder crane depends on several factors, including load capacity, span, and specific application requirements.

Single Girder Cranes

• Ideal For: Light to medium-duty applications, facilities with low headroom, and environments where cost savings are a priority.
• Examples: Workshops, warehouses, material yards, and manufacturing and production facilities.

Double Girder Cranes

• Ideal For: Heavy-duty applications, frequent lifting of heavy loads, and environments requiring greater hook height and capacity.
• Examples: Mining, iron and steel production, railyards, and shipping ports.

Understanding the differences between single girder and double girder cranes is essential for selecting the right lifting system for your needs. By considering the specific advantages and disadvantages of each type, you can make an informed decision that ensures efficiency, cost-effectiveness, and safety in your operations. Choose Lifting Systems for reliable, high-quality overhead crane and gantry solutions.