A report into the collapse of the Malahide viaduct has found that there was a failure of maintenance because Iarnród Éireann staff did not know the type of structure they were dealing with.
The independent report commissioned by the company found that over the years, staff became unaware that the piers were resting on rocks and not pile-driven into seabed.
The report found that increased water flow because of land development and climate change brought on the collapse.
Staff did not realise the structure was two components - a viaduct on top of a causeway made of large rocks - making the piers liable to erosion.
The report recommends that in future, knowledge should be passed on by Iarnród Éireann staff who move or retire.
The report also found that a warning from Malahide Sea Scouts was misunderstood and the engineer who went to inspect the bridge examined the pier and not the causeway.
A major accident was narrowly avoided on 21 August last year following the collapse of a section of the viaduct.
No individual member of staff will be held responsible for what happened, but a train driver and signal operator have been commended for their actions on the day, which prevented what could have been a 'catastrophic loss of life'.
As a result of the collapse, the rail line was closed for almost three months, reopening last November after repairs estimated to cost in excess of €4m were carried out.
Iarnród Éireann has rejected claims in today's Irish Independent that it had received a warning in 2006 about serious erosion at the viaduct.
The company says that the 2006 Bridge Scour inspection of the Malahide viaduct, carried out by independent specialist diver engineers, did not state that there was any reason for concern at that time.
It did recommend that as the bridge was susceptible to scour, that underwater examinations should continue at intervals of not more than six years.
The company submitted its report to the Rail Accident Investigation Unit and the Railway Safety Commission on 19 February, and has published parts of it today.
The report will be considered by the Rail Accident Investigation Unit as part of its independent investigation into the collapse.
