Forces in the railway track structure on the Olifants River Bridge

The Olifants River Bridge is unique in that it carries continuously welded rails over its entire length of 1035 m (3396 ft).

The Olifants River Bridge is unique in that it carries continuously welded rails over its entire length of 1035 m (3396 ft). The thermal expansion of the decks and the rails interact and therefore superimpose forces on to the rails.

Due to the extreme variation in the daily temperature, these forces will build until a relative movement is produced between the rails and the bridge deck. Should these forces become high enough the rails buckle and cause a derailment of a passing train. A special monitoring system consisting of strain gages, carrier frequency amplifiers, and a scanning system was installed to prevent further derailments.