- Dec 02, 2024
- News
Top-Running Crane vs Underhung Crane
Top-running cranes provide heavy loads(20 tons or more) and higher lifting, while underhung cranes are flexible and better for lighter loads.
When selecting an overhead crane for your facility, understanding the differences between a top-running crane and an underhung crane (also called an under running crane) is essential. These two configurations offer unique benefits depending on the application, load requirements, and structural considerations. This article delves into the difference between top-running and underhung cranes, their pros and cons, and practical guidelines for making the right choice.
What is a Top-Running Crane?
A top-running crane features a bridge that travels on rails mounted atop runway beams, which are typically supported by the building's columns or a freestanding structure. This configuration is well-suited for facilities requiring high lifting capacities and is commonly employed in industries such as steel manufacturing, shipbuilding, and heavy equipment assembly.
Features of Top-Running Cranes
- Higher Load Capacities: Top-running cranes are capable of handling substantial loads, with capacities ranging from 20 tons to over 100 tons, depending on the design. Single-girder configurations are suitable for moderate loads, while double-girder designs accommodate heavier loads and offer greater stability and lifting height.
- Maximized Hook Height: The design allows for a higher lifting height.
- Customizable Designs: They are compatible with both single-girder and double-girder configurations.
Applications of Top-Running Cranes
- Heavy-duty industrial environments such as steel mills, manufacturing plants, and warehouses.
- Areas requiring frequent lifting of heavy materials.
What is an Underhung Crane?
An underhung crane, or Single Girder Suspension Overhead Crane, is suspended from the bottom flange of the runway beams. This setup maximizes floor space and offers versatility in smaller facilities or areas with limited overhead clearance.
Features of Underhung Cranes
- Light to Moderate Loads: Underhung cranes are designed for light to moderate loads, typically ranging from 1 to 10 tons. Their suspension from the building's existing structure eliminates the need for additional floor-mounted runways, making them ideal for facilities with limited floor space or where maximizing workspace is essential.
- Space-Saving Design: Does not require floor-mounted runways, freeing up valuable workspace.
- Ease of Installation: Can be mounted directly to the building structure.
Applications of Underhung Cranes
- Assembly lines, workshops, and maintenance areas.
- Facilities with low ceiling heights or space constraints.
Difference Between Top-Running and Underhung Cranes
| Feature | Top-Running Crane | Underhung Crane (Under Running) |
|---|---|---|
| Load Capacity | Up to 100+ tons | Typically 1&10 tons |
| Runway Support | Requires independent runway structure | Utilizes the building's existing structure |
| Ceiling Height | Suitable for high ceilings | Works in facilities with low ceiling heights |
| Floor Space | May require additional floor support for runways | Frees up floor space due to suspension design |
| Installation Costs | Higher, due to structural and rail requirements | Lower, as it integrates with the building structure |
| Hook Height | Provides maximum vertical clearance | Limited by the beam height |
Pros and Cons of Top-Running Cranes
Pros
- High Lifting Capacities: Ideal for heavy-duty applications requiring the movement of substantial loads.
- Optimal Hook Height: The design allows for greater vertical lift, beneficial in facilities with high ceilings.
- Flexibility: Can be installed with independent runway structures, making them suitable for facilities lacking adequate ceiling support.
Cons
- Higher Installation Costs: The need for additional structural support and rail systems increases initial investment.
- Space Requirements: May occupy more overhead space, which could be a limitation in facilities with height restrictions.
Pros and Cons of Underhung Cranes
Pros
- Space-Efficient: Suspension from existing structures frees up floor space, optimizing workspace utilization.
- Cost-Effective: Lower installation costs due to the use of existing building structures.
- Versatile: Ideal for smaller or low-ceiling facilities.
Cons
- Lower Load Capacities: Not suitable for heavy-duty applications due to lower load limits.
- Dependent on Building Structure: Relies on the building's structural integrity, which may not be adequate in all cases.
Safety Considerations for Both Cranes
Regardless of the configuration, safety is paramount in crane operation. Here are key safety measures:
- Routine Inspections: Regularly inspect crane components such as rails, wheels, and limit switches.
- Proper Training: Ensure operators are trained to handle specific crane types.
- Load Monitoring: Adhere to the manufacturer's load capacity guidelines.
- Emergency Features: Equip cranes with emergency stop systems and overload protections.
According to OSHA, “Overloading is one of the primary causes of crane accidents,” highlighting the importance of adhering to weight limits and maintenance protocols.
How to Choose Between a Top-Running and Underhung Crane
Top-Running Cranes Are Best For
- Industries requiring heavy lifting (steel manufacturing, automotive assembly).
- Facilities with ample overhead clearance and additional structural support.
Underhung Cranes Are Best For
- Workshops and maintenance areas with lighter load requirements.
- Buildings with limited ceiling height where space optimization is critical.
Conclusion
Understanding the differences between top-running cranes and underhung cranes is crucial for selecting the right solution for your facility. While top-running cranes excel in heavy-duty applications, underhung cranes are perfect for light-duty tasks in compact spaces. You can evaluate the specific operational needs, facility design, and budget to make the best choice.
Yuantai offers a wide variety of cranes, including top-running cranes and underslung cranes. If you have any questions about cranes, you can always contact us to solve them for you.
