Dundrum has acquired a modern landmark - and the long-delayed Luas light rail project a powerful symbol - with the construction of a spectacular bridge spanning one of Dublin's busiest junctions, at Taney Road, writes Frank McDonald.
Scheduled for completion in October at a cost of €11 million, the dramatic cable-stayed structure is already a source of awe for local residents and for the thousands of motorists who pass through the junction every day.
Its asymmetrical single pylon, standing 50 metres high, was consciously designed by consultant engineers Roughan O'Donovan as a landmark in an area that lacks vertical points of emphasis, apart from the tower of Taney Church.
But there was also a practical reason for the form of structure chosen by the engineers: it would permit the main span of the bridge, at 108.5 metres, to be erected without disrupting the flow of traffic, other than at weekends.
The deck is expected to be finished by the end of August. "Thirty local residents were out the other night marvelling at the work continuing under arc lamps on this serious piece of infrastructure," said Mr Éamonn Brady, the Luas information officer.
In terms of public perceptions, it has turned Luas Line B, from Sandyford to St Stephen's Green, into a concrete project much more dramatically than any of the road works or building demolitions along Line A from Tallaght to Middle Abbey Street.
Apart from the main span over Lower Churchtown Road, the Taney bridge - which is being built by Newry-based Graham Construction - has a "back span" of 21.5 metres behind its inverted Y "tuning-fork" pylon and two approach spans of 18 and 14 metres.
The deck is being erected using pre-cast concrete shells which are filled with concrete to form its soffit.
As it proceeds, the 52 galvanised steel cable stays are installed, eliminating the need for temporary supports that would have interfered with the road beneath.
Mr Cormac Allen, project architect for Luas Line B, said the bridge was designed in 1995 to take account of the existing road layout on the edge of Dundrum, as well as the radically altered layout following completion of the village's recently-opened bypass.
Having done his final-year thesis in the UCD School of Architecture a year earlier on the impact of Luas and the bypass on Dundrum, he joined his former tutor, Mr Alan Mee, in CIÉ's Light Rail Project Office to work on the architectural aspects of Line B.
Mr Allen says he was inspired by what had originally been built by the Victorian railway engineers, especially the village's granite-walled station on the old Harcourt Street line, with its "beautifully scaled public forecourt" and its associated embankment.
"The closure of the Harcourt Street line in 1959, combined with the extension of Churchtown Road to Taney junction in the early 1970s, led to the complete destruction of the north end of the village . . . by a haphazard array of poorly-designed buildings."
His main contribution to the project was to develop an urban design framework plan for the integration of Luas, and the Taney bridge in particular, into the essentially domestic scale of Dundrum Seven years later, this strategy has yet to be implemented.
Its central feature was a civic space in front of the Luas station, to provide a new focal point for Dundrum, including an undercroft scheme infilling the village end of the bridge.
But the huge cost of the bypass, at €44.4 million, has probably jeopardised its realisation.
"It is crucial to the success of the project that these design proposals, which were incorporated in the Light Rail Order documentation, are executed.
"Otherwise, the bridge will remain architecturally incomplete in a sensitive urban setting," Mr Allen said.
He left the Luas project in 1997 to work in the private sector, having had enough of "politicians talking about building a light rail system".
In the intervening period, he has designed and built an art gallery, a theatre, an office block and a research building.
The bridge he played a part in designing is due for completion in October.
What Mr Mee finds amazing is that it's "so uncannily like the first drawings that were done seven years ago" - proving, in effect, that dramatic bridges do not necessarily need a Calatrava.
The Luas project director, Mr Donal Mangan, said he was "very proud of it. It's the product of young architects in the light rail office, CIÉ's engineering department and talented consultant engineers, in line with the highest tradition of Irish railway bridge-building."
Somewhat surprisingly, neither local residents' associations nor An Taisce objected to the design. Any fears they had were put to rest by an assurance that the pylon would be no higher than the tower of Taney Church, a much-loved Dundrum landmark.
