Custom Hollow Sections for SBB Railway Canopies
A station canopy is a small structure that has to keep working and keep looking right for decades, in the open air, in front of thousands of passengers a day. For a long term programme with SBB, the Swiss Federal Railways, a specialist in high quality metal construction needed custom hollow sections in carbon steel to build a series of these canopies. Montanstahl supplied them laser welded in S355J2 to the customer’s drawings, in cross-sections no rolling programme could produce, across 200 canopies delivered over ten years.
Structural Reliability and Architectural Precision Together
Railway infrastructure needs components that deliver structural reliability and architectural precision in the same part. Canopies at stations are permanently exposed to weather and to mechanical stress, from wind and snow load to the vibration of passing trains, and at the same time they have to hold a consistent visual appearance across decades of service and across an entire network. For this long term project with SBB, the customer, a specialist in high quality metal construction, needed custom hollow sections in carbon steel to build a series of station canopies designed to improve passenger comfort while integrating cleanly into the railway environment. The requirement is characteristic of architecturally exposed structural steel, where the section is seen at close range and judged as part of the design rather than hidden behind cladding.
A Geometry That Does Not Exist on the Market
Three difficulties came with the project. The hollow section geometry was defined by the structural and architectural requirements of the project itself, with no standard equivalent available anywhere on the market, and the drawing includes asymmetric shapes with chamfered corners and internal spacing that no catalogue tube covers. Dimensional tolerances had to be tight, because the glass elements integrated into the canopy sit directly against the steel and glass tolerates neither a gap nor an interference: too much clearance and the seal fails, too little and the pane is stressed. The third difficulty is serial consistency over a large volume and a long period, with 200 canopies delivered across ten years. That means a section produced in one year has to match one produced nine years later, so that spare parts fit and later canopies look identical to the first.
Application Context
Montanstahl supplied laser welded hollow sections in carbon steel S355J2, manufactured to the customer’s drawings. Laser welding made cross-sections possible that conventional rolling cannot reach, because the profile is assembled from cut strip and the shape is limited by the design rather than by a set of rolls, while the narrow seam keeps the heat affected zone small and the dimensional control precise, which is what meets the strict tolerances glass integration demands. The outcome is a profile that is technically consistent and aesthetically refined, delivered reliably throughout a partnership lasting a decade, supported by the dimensional checks built into Montanstahl quality management that keep a repeat order identical to the first. Sections of this kind extend the range of rectangular and square tubes into project specific geometries, with further points in the technical Q&A.