A Digital Twin Framework and Requirements for Lifecycle-Optimized Turnout Maintenance: A Crossing Case Study

Paper in proceeding, 2026

Turnouts are crucial assets within the railway system. However, their design makes them prone to deterioration and requires continuous inspection and maintenance. Failures typically result in train delays and associated socio-economic costs. Current maintenance practices remain largely reliant on manual, in-track inspections and follow a combined corrective/preventive strategy. This paper presents a digital twin framework for turnout maintenance, supporting a transition towards condition-based, predictive, and prescriptive strategies. The framework integrates inspection data to assess the current condition, deterioration models to forecast future condition, and a life-cycle cost model to evaluate maintenance scenarios. The crossing rail is used
as a case study with inspection remarks and maintenance statistics from the Swedish railway network to identify the requirements of the digital twin. For example, rolling contact fatigue is a key damage mode to monitor and predict, as it drives most crossing rail replacements and urgent maintenance actions. The study highlights the potential benefits of adopting a digital twin for turnout maintenance while also identifying the critical research needs and development steps required for successful implementation.