What Is The Difference Between a Spreader Bar And A Lifting Beam?

What is the difference between a spreader bar and a lifting beam?

Selecting the appropriate equipment for heavy lifting and rigging ensures safety and efficiency on the job site or warehouse. Lifting beams and spreader bars are two commonly used and versatile below-the-hook lifting devices. While they may appear similar, they have distinct designs, functions, and applications. Understanding their differences is essential for choosing the right tool for your lifting operations.

Lifting Beams

A lifting beam is a horizontal structure with a single central attachment point on its top side, which connects directly to a crane or hoist. Beneath the beam, multiple lifting lugs or hooks are spaced evenly along its length to allow for the attachment of slings or other rigging hardware to secure the load.

Design and Mechanics:

  • Bending Forces: When a load is lifted using a lifting beam, the weight induces bending stress within the beam. The beam must be designed to withstand these bending forces, often requiring a more robust and heavier construction than spreader bars.

Lifting Beam Advantages:

  1. Reduced Headroom Requirement: Lifting beams are ideal for environments with limited headroom since they connect directly to the crane hook without additional rigging above the beam.
  2. Multiple Lifting Points: Multiple lifting lugs allow for versatile rigging configurations, making lifting beams suitable for handling loads of varying sizes and shapes.
  3. Handling Unbalanced Loads: Lifting beams can be designed to effectively manage off-center loads during construction, ensuring stability throughout the lift. 

Lifting Beam Disadvantages:

  1. Heavier and Bulkier: Because they must counteract bending stresses, lifting beams are typically heavier and use more material, making them less material-efficient.
  2. Higher Cost: The increased material and design requirements typically produce higher manufacturing costs than spreader bars.

Spreader Bars

A spreader bar, or spreader beam, is a long bar that holds two slings apart to distribute the load’s weight evenly across multiple lifting points. This reduces stress on the load and your rigging hardware. The bar is designed to convert lifting loads into pure compressive forces and spread the legs of a sling apart to maintain the structural integrity of the lifted object and prevent damage that could occur from direct lifting with a single attachment point. 

 

Design and Mechanics:

  • Compressive Forces: Spreader bars convert lifting loads into compressive forces in the bar and tensile forces in the slings. Because of this, spreader bars are highly efficient in their use of material, so they’re typically smaller, lighter, and less expensive than a lifting beam.

Advantages:

  1. Material Efficiency: The design allows for a lighter and more cost-effective solution, as the beam primarily experiences compressive forces, reducing the need for heavy construction.
  2. Load Stability: When appropriately rigged, spreader bars can reduce the chances of load tipping, sliding, or bending. Controlling the sling angles can also prevent crushing or damage to the load.

Disadvantages:

  1. Increased Headroom Requirement: To accommodate the overhead slings, spreader bars require more headroom than lifting beams. Therefore, they are not ideal when your overhead room is limited.
  2. Complex Rigging: The need for additional rigging components can complicate the setup and may require more time to assemble correctly.

Key Differences

  1. Force Distribution:
    • Lifting Beams: Experience bending forces and must be designed to handle such stresses.
    • Spreader Bars: Primarily subjected to compressive forces, allowing for a more lightweight design.
  2. Headroom Requirements:
    • Lifting Beams: Suitable for environments with limited headroom due to their direct connection to the crane hook.
    • Spreader Bars: Additional headroom is required to accommodate the rigging above the beam.
  3. Application Suitability:
    • Lifting Beams: Ideal for shorter spans and lighter lifts, especially in confined spaces.
    • Spreader Bars: Better suited for lifting very wide or heavy-duty loads.

Choosing the Right Device

When deciding between a lifting beam and a spreader bar, consider the following factors:

  • Load Characteristics: Assess the load’s weight, size, and balance.
  • Headroom Availability: Determine the vertical space available for the lift.
  • Rigging Complexity: Evaluate the complexity and time required for rigging.
  • Cost Considerations: Factor in the budget constraints and material efficiency.

By carefully evaluating these aspects, you can select the most appropriate lifting device to ensure a safe and efficient lifting operation.