When planning material handling equipment for a warehouse or industrial facility, terms likesingle-girder crane,monorail, ordouble-girder crane often come up. These terms can be confusing for new business owners and warehouse managers unfamiliar with industrial cranes. This article breaks down what each means and their key differences, along with practical considerations like cost, usage, and space requirements.

What Is a Single Girder Crane?

Asingle-girder overhead bridge crane spans the width of a factory bay. The hoist trolley runs along the bottom of the girder to lift and move materials.

A single-girder crane is an overhead bridge crane that uses one main horizontal girder (bridge beam) spanning the work area. Thisgirder is supported at each end by wheeled end trucks that run along elevated runway rails attached to the building's structure.

The hoist (lifting mechanism) travels along the girder, moving back and forth across the bridge.

“Single girder cranes are a great fit if you're looking for efficiency without breaking the bank. They comfortably handle loads between 1 and 20 tons, making them ideal for warehouses that need solid performance with budget-friendly flexibility.”– Nathan Stout - HOJ Innovations Crane Engineer

Single-girder cranes are very common for light to medium-duty applications, typically handling loads between 1 and 20 tons. Above those limits, a double-girder crane is usually needed for heavier loads or wider coverage.

With only one main beam, a single-girder crane uses less steel and has less weight than a double-girder crane, which translates to lower material cost and reduced load on the building's structure.

In practical terms, this makes single-girder systems more affordable to purchase and easier to integrate into many facilities. However, it's important to keep in mind the limitations of this crane.

Monorail vs. Single Girder Crane

Both monorails and bridge cranes handle overhead lifting, but their configurations differ. A monorail crane consists of a single beam or track along which a hoist trolley travels. Unlike a bridge crane, a monorail hasno movable bridge – the hoist runs along a fixed I-beam path attached to the ceiling or support structure. The hoist can only move along the beam's path (forward/back on that fixed track).

By contrast, a single-girder bridge crane moves in two horizontal directions (the bridge travels along runways, and the trolley travels along the bridge), allowing the load to be positioned anywhere in a rectangular area. A bridge crane can thus cover a broad workspace, whereas a monorail only moves the load along its fixed track.

Monorail systems are best suited for processes that follow a fixed path. A monorail carries materials through a fixed route in an assembly line or paint line. For such dedicated applications, monorails are even more economical than single-girder cranes—theyinvolve less steelstructure than a single-girder bridge crane and are straightforward to install.

The downside is flexibility. Monorails lack the versatility of bridge cranes.

The hoist cannot travel outside its single track, so if you need to reach multiple areas, a monorail won't suffice.

Monorail setups are generally limited to specific routes and are not easily repurposed for other lifting tasks beyond that linear path. A single girder bridge crane, on the other hand, provides far greater coverage and flexibility. In contrast, a monorail is a simpler, lower-cost choice for repetitive movement along one fixed path.

Single vs. Double Girder Cranes

As their names imply, a single-girder crane has one main bridge beam, while a double-girder crane has two main bridge beams running parallel across the span. That additional girder makes a big difference in performance and design:

• Lifting Capacity & Span: Double-girder cranes are built for heavier loads and longer spans. As mentioned above, a single—girder crane is generally limited to ~1–20 tons, whereas a double-girder crane is excellent at handling 21-100-ton loads and covers much wider spans.

• Cost: Single-girder cranes are generally less expensive to manufacture and install since they use only one beam and simpler components (requiring less steel and labor). Double-girder cranes, in contrast, require more material and complex components, so they cost more upfront, and their greater weight may require additional structural support in the facility.

• Applications: Single-girder cranes are well-suited for standard-duty lifting in warehouses, workshops, and smaller factories, where a lighter crane can handle moderate loads. Double-girder cranes excel in industrial settings where payloads weigh much more heavy-duty use.

That said, if you are looking to get a crane, ask yourself, "How heavy are the materials that I need to lift?" If you still have questions after answering that, then speaking to a bridge crane distributor or manufacturer would be your best course of action.

One such resource is Hoj Innovations. We have been in the overhead crane business for over 60 years and have helped thousands of customers get exactly what they need for their facilities.

Girder vs. Beam: What's the Difference?

A girder is essentially a beam that serves as a primary support. All girders are beams, but not all beams are girders – the termgirder indicates a main load-bearing beam, often one that supports other beams or very heavy loads. 

There's no strict size threshold that defines a girder – it's defined by usage. In a crane, the bridge beam is called a girder because it is the crane's primary load-carrying beam that the hoist runs on.

Choosing Your Overhead Lifting Solution

Choosing the right overhead lifting solution is crucial for optimizing efficiency and safety. Understanding the distinct characteristics of single-girder cranes, monorails, and double-girder cranes is also crucial.

Each system offers unique lifting capacity, spatial coverage, flexibility, and cost advantages, making it essential to align the equipment with your specific operational needs. Ultimately, a thorough assessment of your load requirements, desired travel paths, and budget will guide your decision.

When in doubt, consult with experienced professionals like Hoj Innovations to ensure you select the most effective and efficientoverhead material handling system for your business.