The collapse of a supporting pier carrying the viaduct across the Broadmeadow Estuary 13km north of Dublin on 21 August was caused by tidal “scouring” of the foundations, subsequent investigations determined. Only luck prevented what would probably have been the worst railway accident in Irish history, as several heavily laden passenger trains were scheduled to cross within minutes after the bridge failed. The driver of the last train over reported visual signs of subsidence when he arrived at the next station, Malahide, and all traffic was stopped.
A major inquiry by the Railway Safety Commission’s rail accident investigation unit is currently under way, looking not only at the Broadmeadow incident itself, but also the adequacy of the railway’s inspection procedures for bridges over water. Though all have been inspected in recent weeks, they are to be examined more closely by experienced divers for scouring of their foundations, a phenomenon mainly associated with tidal movements.
Iarnród Éireann (IE – the Irish state railway) was alerted five days before the Broadmeadow incident by one of the leaders of Malahide Sea Scouts who suggested there was a risk to the structure. An inspection carried out the following day by an engineer and a subsequent report by the crew of a track-monitoring vehicle found no detectable problems. Yet within 24 hours, one of the 11 piers fell into the sea.
Daily commuters as well as users of the Dublin-Belfast main-line service are suffering massive inconvenience by the closing of the line, which ordinarily carried 90 trains every weekday. It is hoped to complete repairs before the end of November.
[ The Irish railways have had no fatal accidents in the last 26 years. – editor