Designing multifunctional poles
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Designing multifunctional poles: tram catenary plus street lighting on one structure
In modern tram schemes, the ambition is often to do more with fewer structures. Rather than lining a corridor with separate catenary masts and lighting columns, designers increasingly ask for multifunctional tramway poles that carry both the overhead contact line and the street lighting on a single structure — sometimes with a distinctive architectural profile on top. (See: European Railway Agency technical standards)
It is an elegant idea that raises real engineering questions. This article looks at why multifunctional poles are specified, what makes them demanding to design, and how a project moves from concept to installation-ready poles.
Why combine tram catenary and street lighting
Combining functions has a clear public-realm payoff: fewer poles, fewer foundations and a cleaner, less cluttered streetscape — particularly valuable on bridges, in city centres and in landmark settings where visual quality matters.
The trade-off is that a single structure must now satisfy two sets of requirements at once: the tension and dynamic loads of the overhead line, and the cantilevered load and photometric geometry of the lighting. Coordinating these is the core design challenge.
Designing the structure
Multifunctional poles frequently call for custom cross-sections. On landmark schemes, a bespoke profile — a hexagonal or other polygonal section, for instance — may be developed specifically for the project, which means the steelwork is engineered from scratch rather than taken from a catalogue.For poles supporting tramway overhead contact lines, Valmont Structures has developed the LAC-X steel profile, combining technical requirements, cost efficiency and aesthetics, with customization options designed to complement the surrounding urban environment. The LAC-X can also integrate lighting, adding another layer of functionality to just one the pole.The LAC-X can also integrate lighting, adding another layer of functionality to the pole.
Integrated luminaire pole design adds a further constraint: the aim is often to conceal the luminaire within the pole’s structure or arm while still achieving the required lighting class. Meeting the photometric target from a small, hidden luminaire is a genuine design problem, solved jointly by the structural and lighting engineering.
From prototype to series production
Because these poles are frequently first-of-type, prototyping matters. Building and testing prototypes — with inspections at the factory and on site — confirms that the design performs before series production begins.
Manufacturing then has to feed the construction site cleanly: poles are commonly numbered, packaged and pre-assembled to specification, with dedicated installation instructions, so that the right pole reaches the right location ready to erect.
Lessons from a real project
The Kruunusillat tramway project in Helsinki is a concrete example. Alongside around 300 tapered tubular poles shared between the tram overhead line and street lighting, the project used around 100 decorative six-sided poles on the Kruunuvuorensilta bridge, fitted with custom, integrated luminaires. The hexagonal profile did not exist as a ready-made product, so it was designed and manufactured specifically for the bridge — and prototypes were built and tested before series production.
It is a clear illustration of what multifunctional pole design involves in practice: custom structure, integrated lighting, prototyping and installation-ready delivery, all coordinated on a single project.
Valmont Structures on real projects
Valmont Structures, through its Tehomet brand, engineers multifunctional and decorative tram poles that combine overhead line support, lighting and architectural design — as demonstrated on the Kruunusillat tramway. Explore our Mass Transit range: Tramway Poles & Supports and Rail Lighting.
- Can a single pole combine tram catenary and street lighting?View
Yes. Multifunctional poles that carry both the tram overhead contact line and street lighting on one structure are widely used to reduce clutter in tram corridors. The structure must be engineered to satisfy the loads and clearances of both functions simultaneously, which requires coordinated traction and lighting design.
- How do you hide a luminaire inside a structural pole?View
Integrated luminaire pole design conceals the luminaire within the pole’s structure or arm while still meeting the required lighting class. This is a joint structural and lighting challenge: the luminaire must be small enough to integrate cleanly yet powerful and well-positioned enough to achieve the photometric target.
- How are custom poles prototyped before series production?View
First-of-type or custom poles are typically prototyped: a sample is built and tested, with inspections at the factory and on site, to confirm structural and functional performance before series production. Poles are then numbered, pre-assembled and delivered installation-ready to streamline on-site work.
Designing a tram scheme with multifunctional poles? Contact the Valmont Structures engineering team to develop custom poles for your project.
