Fatigue Cracking in a Steel Railway Bridge

Completed in 1902, the "Iron Ore" railway line between Luleå, Sweden and Narvik, Norway, was renewed at the beginning of the 1960s and several of the old riveted bridges were replaced by welded plate girder bridges. Replacement was undertaken not only because of the age of the original bridges, but also in anticipation of higher axle loadings in the future. Today the maximum axle load for trains on the line is 25 t. A bridge replacement program began in the early 1990s and "problem" bridges were replaced by ballasted concrete trough bridges.