Truss, portals and towers: choosing an event structure

    Start with what must be positioned and what the audience needs to see. These terms describe different parts or arrangements of a structure, so a shared sketch is more useful than asking for “some truss”.

    Describe the job before naming the structure

    A truss is a structural component; a portal is an arrangement with uprights and an overhead member; a tower is a vertical support assembly. They are not three interchangeable rental products. Depending on its design, a larger installation may use all of them. The useful buying question is: where must the lights, display, signs and scenery sit, and which support positions can the venue accept?

    Begin with a floor plan and a front view showing the desired result. The technical supplier then identifies a suitable system, connections, support method and review requirements. A photograph can communicate appearance, but cannot establish that the photographed structure suits a different room or payload.

    What the common terms mean in a brief

    Concept arrangements and the questions they raise
    TermTypical planning purposeWhat to confirm
    Truss spanA line along which equipment can be positionedSupport locations, equipment positions and the specific truss system
    Portal or goalpostAn overhead line between side supports, for example around a presentation areaUsable opening, bases, stability design and sightlines around uprights
    Tower or upright assemblyA local elevated position or a support within a larger systemIts intended function, complete base arrangement and permitted equipment
    Ground-supported gridSeveral equipment positions above an area where support is taken to the floorAll floor support zones, access and the overall structural design
    Flown truss or gridEquipment positioned using approved overhead suspensionVenue points, coordination, height and the approved rigging plan
    Dedicated display supportA structure designed around a particular screen installationScreen compatibility, service access and the complete installation footprint

    The vocabulary above describes concepts, not permission to assemble them. Prolyte, for example, separates truss profiles, tower systems and LED support products in its catalogue. A square-looking truss alone does not identify the complete system or its approved application.

    Appearance and function are separate choices

    Ask whether the structure should be visible, concealed behind scenery or integrated into branding. Concealing a base changes how visitors perceive the area, but does not make the base disappear from the floor plan. Decorative panels and fabrics also need to be included in the technical brief rather than added after the structure is approved.

    Lighting positions depend on the area being lit and on camera views. A sign may need a clear approach view, while a display needs useful viewing angles and service access. Combining these jobs can reduce the number of separate structures, but can also create a compromise: the best lighting position may place an upright in front of a screen. Ask for the audience and camera views alongside the attractive front rendering.

    Hypothetical example: a conference presentation area

    Suppose an organiser wants a central display, a logo above it and lighting for two speakers. The venue has supplied a floor plan, but has not confirmed overhead suspension. Three concepts are worth discussing:

    • A portal around the presentation area could bring the upper equipment into one visual line. Its side supports and complete bases must fit outside the speaker route and important audience views.

    • Separate local lighting supports and a dedicated screen support might offer more freedom to position the display. Several individual footprints may, however, complicate movement around a compact stage.

    • A flown arrangement may clear selected floor positions if the venue approves it. It introduces a separate suspension design and venue coordination process.

    No option wins from the sketch alone. The next decision is to request a dimensioned concept with the required equipment list and venue constraints. If the ceiling option is rejected, the floor-based alternative must be checked as a new arrangement, not assumed to fit into the same space.

    Prepare a useful request

    1. Mark the audience, stage, entrances, camera positions and areas that must remain unobstructed.

    2. List every intended attachment, including display, lights, signage, fabric, scenic elements and associated equipment. Identify who supplies each item.

    3. State the desired image and sign positions, not just an overall structure height.

    4. Obtain the venue's current floor and suspension information, access arrangements and approval contact.

    5. Ask the supplier to show the entire support footprint, installation space and any choices awaiting technical confirmation.

    Common misunderstandings include ordering by metres of truss alone, treating a tower as a complete ready-to-use support, and approving a visual that omits bases. Discuss the arrangement through structures and truss; use design and visualisation to agree placement and installation planning to turn the concept into an executable scope.

    Further reading

    Prolyte product families illustrate the difference between components and complete support systems. Product documentation must be checked for the system actually proposed.

    Related service

    Installation & dismantling

    Professional crews to install, rig and dismantle AV setups safely and on time.

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