An investigation into monitoring rail stress in continuously welded rails through stress-free temperature

The two most important parameters affecting stability of Continuously Welded Rail are rail stress and lateral resistance of the track. It has been identified that Stress Free Temperature of rail plays the most important role in the understanding, monitoring and managing of rail stress. Railway companies are focussed on finding an effective means of measuring longitudinal rail forces through use of Stress Free Temperature.The effectiveness of commercially available rail stress monitors manufactured by Salient Systems and the rail creep measurement method to monitor rail stress in railway systems has been investigated. A field investigation of a section of track at Edungalba in Aurizon’s heavy haul coal network has enabled observation of Stress Free Temperature through several testing methods. The investigation and analysis has led to insights into track behaviour and stress state. The study concluded that the conventional rail creep method is useful for general indications of track stress condition and follows a similar trend to rail stress monitor data. It was also concluded that accurate measurement of Stress Free Temperature throughout the entire network through installation of rail stress monitor modules is not a cost-effective solution for the management of rail stress. However, the modules demonstrated an effectiveness to monitor and manage rail stress in targeted problem areas.