Report 2014/03

On 22 July 2013, track buckling occurred at kilometre point 281.5 between Kvam and Sjoa on the Dovrebanen line. Hector Rail AB's northbound freight train 41631 derailed as a consequence of this. Three days prior to the incident, packing had been carried out due to uneven settlement of the track. It is assumed that the work that was done, together with high rail temperatures, temporarily weakened the track's lateral stability to a sufficient extent to cause buckling. The packing had not been followed up by daily inspection visits.

The Accident Investigation Board Norway recommends that the Norwegian Railway Authority recommend that the Norwegian National Rail Administration review the inspection procedures for this type of track work, assess whether they are adequate and, if applicable, update the procedures.

The purpose of establishing permanent geodetic control marks along the track is to define the track's position in an external local reference system. The method is based on comparing the theoretical position of the track with the position of the track relative to a set of geodetic control marks along the track. Excessive deviation between these positions indicates that the track has been displaced, and that stresses may have developed in the track. A lateral displacement towards the inside of a curve will reduce the fastening-down (neutral) temperature of the rails, and thus increase the stresses at high temperatures. Geodetic control marks had been surveyed at Heggerusta on the Dovrebanen line, but the marks had not been maintained. 

The Accident Investigation Board Norway recommends that the Norwegian Railway Authority recommend that the Norwegian National Rail Administration establish a binding progress schedule for updating existing track sections and for establishing geodetic/permanent geodetic control marks on any sections lacking such marks.