The inspection regime at Ireland’s rail operator Iarnrod Eireann has been slated by Ireland’s Railway Accident Investigation Unit following an investigation into last year’s Malahide viaduct collapse.
It found that a shocking lack of maintenance was the root cause of the failure, which was triggered by the long-term undermining of the weir that supported the viaduct’s pier 4 through scour.
It found workmen were not property trained to assess the safety of the bridge, with investigators specifically highlighting the failure of an engineer to spot defects on the Malahide Viaduct three days before the accident, which happened almost a year ago.
Four specific maintenance failings have been identified:
- An inspection carried out on the Malahide Viaduct three days before the accident did not identify the scouring defects visible at the time;
- A scour inspection undertaken in 2006 did not identify the Malahide Viaduct as a high-risk structure to the effects of scouring;
- Iarnród Éireann’s likely failure to take any action after an independent inspection carried out on the Malahide Viaduct in 1997 identified that scouring had started at the base of Pier 4 and that the rock armour weir was “too light for the job”;
- The historic maintenance regime for the discharge of stones along the Malahide Viaduct appears to have ceased in 1996, resulting in the deterioration of the weir which was protecting the structure against scouring.
Nine further factors contributed to the collapse, including Iarnród Éireann’s ignorance about the structure of the viaduct, an ignornance compunded by “corporate memory loss” caused by engineers leaving Ireland’s state-run rail company without passing on vital information.
Iarnród Éireann’s own report into the disaster already found that its engineers were unaware that the viaduct across Broadmeadow Estuary was in effect two distinct structures - a causeway/weir and the viaduct that sits on top of it.
Ireland’s Railway Safety Commission (RSC) has also published its review of the collapse alongside the accident investigation unit’s findings. It is responsible for monitoring compliance with safety standards.
The commission found four safety non compliances by Iarnród Éireann. It found that front line inspection staff failed to carry out monthly and yearly inspections of the viaduct, as laid out in Iarnrod Eireann’s own standards. There was also a failure by engineering staff to undertake the required number of inspections/ checks, a failure to carry out structural inspections and keep proper records using the correct forms, and Iarnród Éireann had failed to implement a competence assessment for all personnel engaged in safety critical roles.
Despite the shocking failings identified, limited action has so far been taken against Iarnród Éireann and its management. RSC said Iarnród Éireann was requested and has provided an improvement plan and that it will “monitor the implementation of this plan closely”.
RSC deputy commissioner Mary Molloy said the two documents show up a range of issues which Iarnród Éireann needs to address.
“A detailed plan of action has been produced by Iarnród Éireann, which we will be supervising closely. We will be considering whether further sanctions are appropriate in light of the findings of the RAIU report, once we have considered the report in detail,” she said.
A major accident was narrowly avoided on 21 August 2009, following the collapse of pier 4 of the viaduct. The line was closed for almost three months, reopening on 16 November 2009.
Irish transport minister Noel Dempsey said the reports detailed a worrying account of the inadequate maintenance and inspection regime in Iarnrod Eireann in recent years which failed to safeguard the viaduct structure from the impact of scour and erosion.
“It sets out a series of recommendations addressed to Iarnrod Eireann in areas such as future inspection standards and their implementation, training of key personnel, risk assessment of railway structures and the provision of physical and flood protection for structures at high risk,” said Demspsey.
“I understand from the report and from updates by Iarnrod Eireann that significant changes have now taken place to meet the short-comings identified and to ensure that there is no repetition of this event.”
Rail chiefs had been warned about the state of the viaduct by the Malahide Sea Scouts days before the incident on 21 August last year after a canoeist saw a stone washed away.
A passenger had even photographed a three-metre wide whirlpool on the edge of the viaduct half an hour before it collapsed.
But Iarnrod Eireann maintained an engineer who checked the viaduct over the Broadmeadow estuary, north Dublin, only looked at the piers and not underwater foundations being eroded.