Executive summary
On Friday 6 May 2005, at about 0720, pier 4 of Bridge 256 between Nuhaka and Opoutama on the Palmerston North-Gisborne Line suffered a catastrophic failure and collapsed while work Train 60 was being piloted across the bridge at the start of a 2-day work programme to underpin pier 4. A 60-tonne rail crane and the adjacent ends of spans 3 and 4 fell into the river.
There were 10 staff members making up the work gang, but because they had been moved off the bridge before the work train started to cross, there were no injuries.
The bridge was closed to rail traffic for several months until repairs were completed, including the recovery of the rail crane, the building of 4 new concrete piers and the installation of 5 new spans.
Safety issues discussed were:
• loss of corporate knowledge with successive organisational restructurings
• engineering resources and competencies
• degradation of timber piles in estuarine environments
• suitability of using 60-tonne cranes for routine bridge work
• extent of rail regulatory oversight of the rail transport industry in New Zealand.
Because of safety actions taken by Ontrack, no safety recommendations have been made. The Commission made a safety recommendation to the Director of Land Transport New Zealand as a result of rail occurrence report 05-123, relating to the regulatory oversight of the rail industry in New Zealand. This recommendation is equally applicable to this occurrence, so no new safety recommendation has been made to address this issue.
Related Recommendations
Note the failures of the regulatory system to detect shortcomings in the maintenance of infrastructure (as presented in the Commission’s report 05-116: collapse of the Nuhaka Bridge under a work train) and shortcomings in the construction and commissioning process for newly modified rolling stock (as presented in this report), and;