The Coolest White for SBB track renewal
In June 2025, the Swiss Federal Railways (SBB) carried out a track renewal between Uttigen and Thun. A total of 2.2 kilometres of track were renewed. In this context, a rail coating was applied to the adjacent track that remained in service.
Goal: to avoid temperature-related rail deformations. Core measures: fixing the ballast by means of ballast bonding and coating the rails with The Coolest White. Result: thanks to the professional work of our partner Teko Oberflächentechnik AG, the coating was applied over just over 2.4 kilometres in only two nights and completed on schedule.
Challenge & solution
To keep train operations running on the adjacent track, supporting measures were required. To prevent heat-related rail distortions, the following two measures were combined:
• Stabilisation of the ballast using ballast bonding
• Coating the rails with The Coolest White to reduce heating
Process — precise, fast, reliable
Our partner Teko Oberflächentechnik AG (Flüelen) worked within the tight time windows set by SBB:
- Night work: mechanical cleaning / derusting of the rails with a cleaning machine
- Direct application: coating with The Coolest White using an application machine
Approach deliberately chosen: because the measure was temporary, a primer was omitted.
Result: 2.4 km completed in only two nights – thanks to precise planning and team effort.
Measurement results
- Earlier SBB tests (summer 2020, with primer) showed a temperature reduction of 4–6 °C over the summer.
- The current measurement (without primer) recorded a reduction of 2 °C at one measurement point on a single day. Important: this measurement is local and short-term.
Successful for SBB — but still open
The trackbed on the adjacent track remained passable at all times, and thermal relief was demonstrable. Whether this method will be used more frequently in the future depends on the specific characteristics of individual construction sites, SBB’s choice of measures, and the requirements of the Federal Office of Transport (BAV).
Product: The Coolest White
The highly reflective coating system from Monopol Colors offers:
• Very high Total Solar Reflectance (TSR) – less energy absorption from visible and invisible light
• Durable FEVE (fluoropolymer) technology – high resistance to weathering
• Increased abrasion resistance – especially suitable for highly stressed surfaces
In short: The Coolest White lowers surface temperatures, reduces heat radiation and is designed for longevity.
Conclusion & outlook
The Uttigen–Thun track renewal project shows that temporary measures against rail stresses can be implemented quickly with well-thought-out technology — and deliver measurable effects. For maximum cooling effect, combining The Coolest White with a suitable primer is recommended.
