Recommendation Date
Recipient Name
NZTA
Text
The most likely reason for the side frame failures is that they had reached the end of their fatigue lives. A lack of identifying marks and records of side frame age and maintenance history means that it will be difficult to predict the onset of fatigue cracking in bogie side frames. The presence of fatigue cracking initiating in the region of the radius, just beyond the wear plate of the side frames, is difficult to detect by normal visual inspections, and at the current rate of MPIs the entire inventory of bogie side frames will not be completed until 2020. With 60% of the side frames tested consistently requiring weld repairs before being returned to service, the failure and collapse of a bogie side frame have resulted, and will continue to result, in significant damage to rolling stock and track infrastructure and the risk of serious harm to people.
The Commission recommends that the Chief Executive of the NZ Transport Agency give high priority to working with industry to conduct a formal assessment of the risks that main-line derailments pose to rolling stock and track infrastructure, and the risk of serious harm to people (industry and the general public). The results of the risk assessment should then be used to set appropriate remedial measures to reduce the likelihood of bogie side frame failures, and could also be used to set appropriate measures to reduce main-line derailments from other causes.
The Commission recommends that the Chief Executive of the NZ Transport Agency give high priority to working with industry to conduct a formal assessment of the risks that main-line derailments pose to rolling stock and track infrastructure, and the risk of serious harm to people (industry and the general public). The results of the risk assessment should then be used to set appropriate remedial measures to reduce the likelihood of bogie side frame failures, and could also be used to set appropriate measures to reduce main-line derailments from other causes.
Reply Text
We intend to work closely with KiwiRail with an aim to implementing and closing this recommendation as soon as practicable.
Discussions on it will commence on publication of the report and will be ongoing. Any outstanding Transport Accident Investigation Commission (TAIC) recommendations also form and integral part of our annual safety assessments of the rail industry. Discussions on the bogie component issues this report highlights have already commenced.
When these discussions are concluded and the appropriate evidence has been gathered, we will be liaising with TAIC with a view to closing this safety recommendation.
Discussions on it will commence on publication of the report and will be ongoing. Any outstanding Transport Accident Investigation Commission (TAIC) recommendations also form and integral part of our annual safety assessments of the rail industry. Discussions on the bogie component issues this report highlights have already commenced.
When these discussions are concluded and the appropriate evidence has been gathered, we will be liaising with TAIC with a view to closing this safety recommendation.
Related Investigation(s)