Many industries require the use of cranes when moving load. In almost all of these industries, spreader bars and lifting beams are used alongside the cranes for moving loads in an overhead lift. Both pieces of equipment are referred to as below-the-hook lifting devices used to support and stabilize load during a lift.
However, for many people, the difference between both is unclear. Considering that they look similar and perform similar functions, it comes as no surprise.
Understanding the difference in the function of both is important for best practice and should be encouraged at every workplace. In this article, we’ll be taking a look at the design and functional differences between the spreader bar and lifting beam:
They are made using a simple design that consists of a beam with a single point of attachment on its top side. The attachment could be connected to a crane, hoist, or any other lifting machine. On the underside of the beam, you can find two evenly spaced lugs to which you attach and support the load using a hook or sling.
In some cases, lifting beams may have two bails, so that they can be attached to two crane hooks. This is especially useful when a single crane can't carry the load.
The design of lifting beams means that they convert the lifting load to a bending moment throughout the beam.
They can also be designed with fixed or variable lifting lugs that allow multiple lifting points during a single lift. It allows them to be used in different scenarios on diverse kinds of loads, even when the loads are out of balance. They are best used for loads that are too fragile or flexible to be lifted without support, such as metal sheets.
Lifting beams are, however, an inefficient use of material. The bending stress on the bar requires that the material used for it must be more rigid and heavier than what would be used in an equivalent spreader bar. As a result, they tend to be larger and more expensive. A lightweight load with a significant span would still require a substantially large and heavy lifting beam to carry it.
Spreader bars, also known as spreader beams, are also made with the simple design of a long bar, but in this case, the bar holds two slings apart. The bar has two lugs on the top to which a chain or synthetic sling is attached at an angle.
Similar to lifting beams, they typically have two lugs at both ends of the bottom of the bar. The idea of a spreader bar is to convert the lifted load to compressive forces in the beam and tensile forces in the slings. The slings are connected to a crane or any other lifting material of choice.
Spreader beams are highly efficient in their material use, unlike lifting beams. Due to their design, they are lighter, smaller, and less expensive. The ability to lift at two points instead of one allows them to distribute the weight of the load across the entire length of the bar, reducing the risk of a stress fracture on a single loading point.
They are often used when lifting very wide or heavy loads. When properly utilized, they can help reduce the risk of load tipping and sliding. Some designs allow for incremental adjustment of the sling angle, length of the beam, and even off-center load adjustments, as opposed to fixed dimensions. They are really common at construction sites and factories. You can find one for rent here: https://twaylifting.com/spreader-bar-rental/
Difference Between a Lifting Beam and a Spreader Bar
The ultimate difference between a lifting beam and a spreader bar lies in the design. The design of the equipment determines how the force is transmitted through it, and in turn, how it's used.
In lifting beams, the load puts bending stress on the bar, while in spreader beams, the load puts compressive stress on the barand tensile stress on the slings.
Choosing Between a Spreader Bar and a Lifting Beam
Making a choice between the two lifting devices comes down to a couple of questions you can quickly answer:- What do you need to lift?- How do you intend to lift it?- Where do you intend to lift it?
The two most important things to consider are the weight of the load and its length. If you’re dealing with load with a wide span, a spreader bar would be a better fit. However, for loads that need support throughout the length, a lifting beam would be the ideal option. In the second case, a spreader beam would be useless since it can’t support anywhere in the middle. Even if your load is light but has a wide span, it will still require a lifting beam.
Height constraints or places with low headroom are also important to take into account. Lifting beams are more effective in places with low headroom. Spreader beams require more overhead rooms due to the lifting slings attached to the top bails of the crane.
In some cases, your need may require something more distinctive. Spreader and lifting beams are also manufactured as:- Telescopic/extendable beams: They can be extended in either fixed or variable points. They're popular for lifting varying load sizes.- Modular spreader bars: Typically manufactured in pieces that can be assembled into different configurations. They're useful for many applications.- Combination beams: Consist of design elements from both spreader and lifting beams. They often have acentral lifting point alongside lifting points at both ends of the beam's topside. - Specialized pipe lifting spreader bars: They're specifically used for lifting equipment used in the pipeline and coal seam gas industries.