Boyne River Bridge

Mary McAleese Boyne Valley Bridge
M1 traffic crossing the bridge
Coordinates	53°43′04″N 6°23′48″W / 53.717866°N 6.396704°W / 53.717866; -6.396704
Carries	Four lanes
Crosses	Boyne River
Locale	County Meath, 3 km west of Drogheda
Named for	Mary McAleese's peace process as President from 1997 to 2011
Maintained by	Celtic Roads Group
Characteristics
Design	Cable-stayed bridge
Total length	352.5 m
Width	34.5 m
Height	95 m
Longest span	170 m
No. of spans	10
Piers in water	0
Clearance above	20 m
History
Designer	Roughan & O'Donovan
Construction begin	May 2000
Construction end	2003
Opened	9 June 2003

The Mary McAleese Boyne Valley Bridge is a cable-stayed bridge in County Meath, and County Louth, Ireland. It spans the Boyne River 3 kilometres (1.9 mi) west of Drogheda on the county boundary between County Meath and County Louth and is part of the M1 Northern Motorway. When it opened in June 2003, it was the longest cable-stayed bridge in Ireland until 19 October 2009, when the River Suir Bridge opened on the N25.

Due to environmental concerns, an Environmental Impact Statement (EIS) was carried out for the bridge separately from the M1 EIS—the first such formal EIS carried out and published for a bridge in Ireland. The bridge was built from 2000 to 2003 and was designed by Roughan and O'Donovan, who were awarded the ACEI Presidential Award in 2005 for the design.

Designing a road bridge over the Boyne was not an easy task. At the chosen point, 3 kilometres (1.9 mi) upstream from Drogheda, the ground level on the south is elevated, with a sudden drop while the north bank slopes gradually down to the river. The area is environmentally sensitive, especially the reed beds on the north bank and the flora and fauna of Yellow Island in the middle of the river. The area has a rich heritage as it is also situated adjacent to the area in which the Battle of the Boyne took place in 1690.

The answer was a cable-stayed bridge. Although at a cost of €35 million it would be more expensive than a standard road bridge, it could incorporate a much longer main span without the need for supports in the river, so the engineers could protect the river and the island from any interference. It would also look attractive, with a tall pylon at the south side and cable stays fanning out from it, supporting the main structure.

Construction was carried out by Cleveland Bridge U.K. Ltd. Construction methodology by Richard Hornby & Bruce Ramsay of Cleveland Bridge. The bridge is the first cable stay bridge in the world constructed using the incremental launching method (ILM) for the superstructure erection. The construction was commenced in May 2000 and the bridge opened on 9 June 2003. The bridge is managed under a public-private partnership between the National Roads Authority on behalf of the Irish Government and a private company, Celtic Roads Group. The concession company has an obligation to maintain the road for 30 years.