At about 2218 on Friday, 23 February 2001, northbound Train 144 struck a derailed wagon while passing southbound Train 237 between Pukekohe and Paerata on the North Island Main Trunk line. The incident occurred when a PK wagon conveying containers on Train 237 became derailed at Paerata as a result of a wheel bearing failure. The LE of Train 237 had seen sparks coming from the middle of his train and suspected a possible dragging brake rod. He was unaware of the derailment and proceeded slowly from Paerata towards Pukekohe where he intended to stop and inspect his train. The collision occurred as Train 237 reached Pukekohe, causing minor damage to locomotives and wagons on Train 144 and derailing a loaded C coal wagon. Major damage to the PK wagon and track resulted from the initial derailment. There were no injuries.
The safety issues identified were the potential consequences of derailed wagons on double line track.
