Broadmeadow viaduct
| Broadmeadow viaduct | |
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Broadmeadow Estuary (bridge at right)
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| Coordinates | 53°27′N 6°10′W / 53.45°N 6.17°WCoordinates: 53°27′N 6°10′W / 53.45°N 6.17°W |
| Carries | Dublin – Belfast railway |
| Crosses | Broadmeadow estuary |
| Locale | Malahide, Ireland |
| Characteristics | |
| Material | Stone piers & prestressed concrete spans |
| Total length | 180 metres (590 ft) |
| Piers in water | 11 |
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The Broadmeadow viaduct, in Ireland, carries the main Dublin to Belfast railway across the Broadmeadow Estuary, about 13 kilometres north of Dublin, just north of Malahide. It is approximately 180 metres (600 feet) long and it is a section of a longer crossing constructed as an embankment. The viaduct carries around ninety trains, including commuter services and heavy freight, per day and it is the sole rail route between Dublin and Belfast. It has had a history of problems with its foundations being scoured out by strong currents.
The present structure is the third on this site. The first was built in timber for the Dublin and Drogheda Railway in 1844. Its stability was badly affected by erosion of the river bed around the piles and, after short-term remedial work, it was replaced in 1860 with a new structure of wrought iron spans on masonry piers. This sufficed until the early 1930s when new locomotives (4-4-0 Compounds) required strengthening of the piers and continued maintenance. Additional ballasting of the piers was also needed. The sea air caused deterioration of the wrought iron and these spans were replaced during 1966–1968 with the current prestressed concrete structure. At this time, the tracks were laid on ballast, reflecting modern practice.
On Friday 21 August 2009, at 6:30pm, a 20-metre section of the viaduct collapsed. Some reports state that the collapse started while a passenger train was passing over it, others say shortly after. The Driver of the Balbriggan to Dublin Pearse service was passing over the viaduct and noticed the section crumbling away. He coasted the train (not increasing the engine revs in case the vibrations made it collapse while the DMU was on it) across it. The train was not derailed and no one was hurt: the driver raised the alarm when he arrived at Malahide. The repairs took roughly three months, with curtailment of all services north of Malahide. The competence of Iarnród Éireann's maintenance regime has been questioned and there have been previous critical reports of the viaduct's structure. Iarnród Éireann stated that the structure had been inspected three days previously. Erosion had been reported by an Irish Sea Scout leader who later opined that a superficial inspection might have missed scour damage below water level.
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