Ask for a “spreader” on most sites and you will be handed whatever beam is nearest. That is a problem, because spreader beams and lifting beams are different devices that put very different forces into the crane, the slings and the load. Choosing the wrong one wastes capacity at best and, at worst, bends the beam or crushes the load. This guide explains how each works, when to use which, and what the regulations expect of anyone specifying or using them.

The basic distinction

A lifting beam is lifted from a single point at its centre. The load hangs from two or more points along its length. The beam is loaded in bending: the crane hook pulls up in the middle while the load pulls down at the ends, exactly like a floor joist turned upside down.

A spreader beam is lifted from two points at its ends by slings that meet at the crane hook above. The load hangs vertically from the same two end points. Because the slings angle inwards, they push the ends of the beam towards each other, so the beam is loaded in compression rather than bending. It acts as a strut holding the slings apart, which is where the name comes from.

That single difference in how the crane connects to the beam changes everything else about the two devices.

Lifting beams

How they load

Because a lifting beam resists bending, it needs to be deep and stiff. For a given capacity and span a lifting beam is heavier and bulkier than a spreader, and the bending moment rises quickly with span, so long lifting beams become very heavy indeed. That self-weight comes straight off the crane’s available capacity.

Where they excel

• Low headroom. The beam sits directly under the hook with no sling triangle above it. If the crane hook cannot go high, a lifting beam is often the only option.
• Loads that cannot take inward force. Slings from a lifting beam hang vertically, so no compressive load is put on the item being lifted. Thin-walled tanks, bundles, panels and long flexible loads that would buckle under angled slings are lifted safely.
• Multiple or adjustable pick points. Lifting beams are easily built with several lifting points, sliding shackles or a row of holes, so one beam serves loads of different lengths or with an offset centre of gravity.
• Unbalanced loads. A lifting beam with an adjustable top lug can be set so the hook sits over the load’s true centre of gravity, keeping the lift level.

Spreader beams

How they load

In compression, a beam works far more efficiently than in bending. A spreader of the same capacity and span is much lighter than a lifting beam, and modular spreaders, built from standard end units and struts, can be assembled to almost any length from a small kit. This is why spreaders dominate heavy lifting, offshore work and construction, where spans are large and every tonne of rigging weight matters.

Where they excel

• Long or heavy loads. The compression design keeps beam weight manageable at spans of 10, 20 or 30 metres that would be impractical for a lifting beam.
• Stable lifts. Because the load hangs from points well apart, and the sling triangle above adds height to the rigging, the load is inherently stable and resists tipping.
• Modular reuse. A single kit covers a wide range of jobs, which suits contractors and hire fleets.

Where they do not

• Headroom. The sling triangle above the beam needs height. A spreader with a 10 metre span and slings at 60 degrees needs nearly 9 metres of headroom above the beam before the hook.
• Angled slings below. Slings from a spreader should hang vertically to the load. If they must angle inward, the compression in the beam rises and the load is squeezed, defeating the purpose.
• Offset centre of gravity. A standard spreader assumes the load is balanced between its two end points. Unbalanced loads need careful calculation or a lifting beam.

Choosing between them

Combination beams that can be rigged either way are available, and for complex loads a spreader can carry two lifting beams beneath it in a frame arrangement.

What the standards and regulations require

In the UK both devices are lifting accessories under the Lifting Operations and Lifting Equipment Regulations 1998 (LOLER) and are supplied under the Supply of Machinery (Safety) Regulations. The design standard for both is BS EN 13155, which covers non-fixed load lifting attachments. In practice this means:

• The beam must be designed and tested by a competent person, with a declaration of conformity and CE or UKCA marking.
• The working load limit, self-weight and any restrictions on sling angle must be clearly marked on the beam.
• Lifting accessories must be thoroughly examined at least every six months by a competent person, and the report kept.
• Every lift must be planned and supervised. The plan must account for the beam’s self-weight against the crane’s capacity, the sling angles, and the position of the load’s centre of gravity.
• Before use, check for bending, cracks, corrosion, damaged lugs and worn shackles. A bent lifting beam has been overloaded and must be withdrawn.

Common mistakes

• Lifting a spreader beam from its centre. It is not designed for bending and can fail well below its rated load.
• Rigging a lifting beam with slings angled inward to the hook. The beam’s end lugs are rated for vertical pull.
• Forgetting the self-weight of a large lifting beam when checking crane capacity.
• Using a spreader with angled slings to the load, which loads the beam beyond its rating and squeezes the load.
• Ignoring an offset centre of gravity. The load tilts on lift-off, slings load unevenly, and the beam sees forces it was not designed for.

Specifying a new beam

Give the supplier the maximum load, the span between pick points, the available headroom, the crane capacity, the lifting point details on the load and, critically, whether the centre of gravity is central. A reputable manufacturer will recommend the type, provide calculations and test certificates, and mark the beam correctly. For lifts in hazardous areas, see MEPCA’s coverage of explosion proof lifting equipment. More lifting and handling coverage is in the materials handling section.