UIC 720:2005-03

This leaflet contains guidelines for the use, installation and inspection of ballasted track with continuous welded rails (CWR), and also lists the associated safety criteria. It is based on the practical experience of several railways and a large number of tests and theoretical studies carried out over a period of more than 40 years. It also includes the results of studies undertaken by ERRI Committee D 202. The leaflet has been enhanced by inclusion of a point on safety aspects and a point on case studies conducted using the CWERRI and CWR-BUCKLE models. A new safety criterion has been formulated on the basis of maximum and minimum buckling temperatures (Tb,max and Tb,min). The parameters were selected to reflect a maximum temperature which corresponds to 50% of the buckling energy level. In addition, a concept of buckling safety based on risk assessment methodology has been introduced. The case studies include examples of high-speed, main-line passenger tracks on both concrete and wooden sleepers, together with secondary and freight tracks. Permissible rail temperatures for the various scenarios studied are presented graphically.