Steel Truss

Product Overview

MILOS S-RTW 145, also known as S-M1450 Rect, is a rectangular steel truss developed for stage structures requiring high load capacity and long spans. The system uses ultra-high-strength steel, features an approximately 1,450 × 770 mm cross-section, and can achieve a published span of up to 50 m under the manufacturer's specified design conditions.

Compared with an equivalent-size aluminum truss, the S-RTW 145 provides approximately 2.2 times the load-bearing capacity while weighing only about twice as much. This makes it suitable for main grids, roof systems, PA wings, video wings, and other structures requiring long spans while minimizing the number of towers or intermediate support points.

Key Advantages

Very High Load-Bearing Capacity

Its high-strength steel construction and deep cross-section provide high bending resistance, making the truss suitable for heavy LED, PA, lighting, and large-scale scenic loads.

Long-Span Capability

With a published span of up to 50 m, the S-RTW 145 can create wide stage spaces while reducing the number of support points required within performance and audience areas.

Optimized Load-to-Weight Ratio

The system provides approximately 2.2 times the load-bearing capacity of an equivalent aluminum truss while weighing approximately twice as much.

Rigging and Logistics Features

The truss incorporates forklift pick-up points, ladder tubes, and compression tubes at key locations to facilitate handling, rigging, and transportation.

Stage-Ready Finish

The truss features a matte black industrial coating designed to withstand impact while minimizing reflections during filming and live performances.

Operational Value

• Allows multiple pieces of equipment to be concentrated on a controlled main grid.

• Enables long-span structures for festivals and outdoor concerts.

• Can reduce the need for multiple intermediate towers where permitted by the structural design.

• Suitable for long-term investment by companies specializing in roof systems and heavy-duty rigging.

Technical Specifications

Source: MILOS S-M1450 Rect datasheet and S-RTW 145 product page.

Standard Lengths and Weights

Weights exclude connection hardware and packaging.

Reference Load Table

The values below are taken from the MILOS loading chart. CPL refers to a concentrated load applied at mid-span, while UDL refers to a uniformly distributed load along the span. The self-weight of the truss is included in the table.

Figure 3. Full loading chart for CPL, TPL, QPL, FPL, and UDL.

Loading conditions: The truss is supported or suspended at both ends; values apply to static loads only; loads are applied at nodes; spans may be assembled from multiple truss lengths; and the truss self-weight is included.

Applications in the Live Events and Entertainment Industry

The S-RTW 145 is designed for projects where conventional aluminum trusses may no longer provide an efficient solution in terms of load capacity or span. In large-scale stage designs, the truss can serve as a primary beam for roof grids, supporting loads from secondary trusses, point hoists, LED screens, and audio systems.

Concert and Festival Stage Roofs

Creates long-span main beams for canopies, lighting grids, and suspended loads within the roof system.

Heavy-Duty Main Grids

Supports lighting systems, line arrays, video equipment, moving equipment, and scenic elements simultaneously.

PA Wings and Video Wings

Can serve as a horizontal beam or primary structural member for outdoor sound towers and LED screen structures.

Large-Scale LED Screen Structures

Supports the self-weight of LED screens and their suspension systems, with wind loads to be addressed through project-specific structural calculations.

Semi-Permanent Structures

Suitable for stages installed for extended periods, performance venues, or specialized structures requiring high stiffness.

Multi-Directional Roof Grids

The webbing pattern and horizontal connection holes support the arrangement of cross trusses, nodes, and auxiliary connections.

Integration with Steel Roof Systems

The MILOS S-MR10 datasheet demonstrates how MILOS applies high-strength steel trusses to large-scale stage roof systems, combining towers, canopies, PA wings, and backstage areas. When the S-RTW 145 is incorporated into a specific roof system, the complete geometry, wind loads, ballast, guy wires, and foundations must be evaluated as an integrated structural system.

Structural Calculation and Safety Requirements

Standard design factors: According to MILOS notes, to comply with BS 7905-2, ANSI E1.2-2006, or EN 17115, the values shown in the loading chart must be multiplied by 0.85. Configurations that differ from the loading-chart conditions must be separately reviewed by MILOS or a qualified structural engineer.

Conclusion

The MILOS S-RTW 145 / S-M1450 Rect is a high-strength steel truss solution developed for heavy-duty stage structures and long-span applications. With a 1,450 × 770 mm cross-section, a published maximum span of up to 50 m, and integrated features for rigging and logistics, the system is particularly suitable for roof systems, main grids, PA wings, video wings, LED screen structures, and large-scale concert and festival stages.

However, the load values shown in the loading chart are for reference only and apply under the specific conditions defined by the manufacturer. For actual projects, the span, loads, suspension points, wind loads, ballast, towers, guy wires, foundations, and overall structural configuration must be evaluated together. Applicable design factors and operating conditions must be followed in accordance with the relevant technical documentation. Any configuration that differs from the published loading-chart conditions should be reviewed, calculated, and approved by MILOS or a qualified structural engineer before being put into service.