Quad Truss & Square Truss Frameworks
Four-chord frameworks, commonly labelled quad truss and square truss, remain a staple within event engineering. Their balanced layout handles bending, shear, and torsion with dependable predictability, allowing stage crews to build spans, grids, and self-standing towers within tight schedules. Components in this category solve daily rigging challenges while keeping overall transport weight in check.
Geometry of Square Truss
Each length features four main tubes positioned at the corners of an imaginary square. Lateral and diagonal braces connect those tubes, forming triangulated faces on every side. The result is a rigid yet relatively light aluminium structure that resists twisting far better than open, two-chord ladders. In practice this extra resistance delivers longer clear spans or larger point loads before deflection becomes an issue.
Typical Applications
- Overhead lighting grids for theatre, broadcast, and touring shows
- Goalpost arrangements supporting PA hangs and LED screens
- Multi-bay roof subframes in outdoor performance spaces
- Freestanding sign frames in retail and exhibition venues
Because square truss maintains its strength in any orientation, production teams often rotate sections to suit awkward fits, for example when depth above a ceiling is limited or when sightlines dictate minimal visual impact.
Square Tubing Trusses: Key Features
Square tubing trusses share the same four-chord logic yet rely on right-angle nodes rather than the triangular junctions seen in triangular sections. Core benefits include fast connection of corners, repeatable loading data in every plane, and an exterior shape that accepts clamps easily. For event designers the neat silhouette blends well with both contemporary interiors and industrial-style sets.
Material Choices: Aluminium Square Truss & Square aluminium Truss
Manufacturers normally specify extruded 6082-T6 or similar alloys for the main tubes. External diameters span from 29 mm up to 50 mm, with wall thickness varied to fine-tune capacity against self-weight. The phrase aluminium square truss covers the broad European offering, while square aluminium truss is regularly found in product data from North American producers; both refer to the same fundamental design.
- Natural mill finish or polished surfaces supplied as standard
- Anodised or powder coated colours available on request
- Welding performed to EN1090 or comparable quality marks
Connection Styles & Module Options
Three coupling methods dominate:
- Conical spigots locked by tapered pins for quick, tool-light work.
- Bolt plates where absolute alignment between brands is required.
- Sleeve blocks on larger formats that travel as truck-friendly bundles.
Straight sections from 0.25 m through to 4 m, plus two-way and three-way corners, form the backbone of most catalogues. Hinged joints, base plates, and pre-curved parts extend creative scope, allowing circles, arches, or split-level frames without resorting to bespoke fabrication.
Rectangular Tube Trusses: The Low-Profile Alternative
Where ceiling voids are shallow yet load remains considerable, rectangular tube trusses offer a smart compromise. By increasing width while trimming height, engineers lower the centre of gravity and create a flat underside for fixtures or scenery. This approach proves useful in television studios, cruise ship stages, and corporate ballrooms where decorative ceilings set strict upper limits.
Selecting Stage Trusses for Specific Loads
Choosing an appropriate member starts with span length and anticipated point or distributed loads. Designers then examine:
- Headroom clearance once fixtures are hung
- Support locations and whether ground support is permitted
- Wind and movement factors for outdoor or kinetic rigs
- Interface with existing stock to minimise rental overlap
In most indoor applications, quad truss satisfies both visual and structural criteria, so adoption across concert halls, music clubs, and touring theatre remains almost universal.
Handling, Care, and Routine Checks
Regular inspection safeguards long service life. The routine usually follows this sequence:
- Visual check for dents, ovalised chord ends, cracked welds
- Pin holes cleared of burrs; locking pins confirmed straight
- Spigot faces wiped clean before assembly
- Full log of item serial numbers, usage hours, and repairs
Cleaning rarely goes beyond warm water and a mild detergent as harsh chemicals may dull the surface or attack protective coatings. When damage is found, a competent fabricator must certify repairs before the part returns to load-bearing duty.