N18 National Primary Road Upgrade

Key Data

The N18 is a 100km-long national road in Ireland starting from Claregalway, passing through Ennis and Shannon, and terminating in Limerick. Under the National Development Plan and the Transport 21 programme, the government of Ireland is upgrading the N18 into a dual carriageway. The Transport 21 program represents the largest investment made by Ireland to improve the country's transportation infrastructure including national roads, rail, bus and airports.

The N18 upgrade is included in the Atlantic Corridor Letterkenny to Waterford improvement programme. The schemes in the programme include the 14km Ennis Bypass, the 28km-long Oranmore to Gort section and the 22km-long Gort to Crusheen section.

Construction of the Ennis Bypass commenced in April 2004 and was completed in January 2007. Construction of the Gort to Crusheen section started in 2008 and completed in November 2010. The N18 Oranmore to Gort section was combined with M17 Galway to Tuam section and N17 Tuam bypass section, and was made into a single section of 57km long. The project is currently at tendering stage.

Project

The Ennis Bypass includes 14km of dual carriageway and 6km of the N85 Western Relief Road. Construction of bypasses at Ennis and Clarecastle, 16 new structures including three river and three railway crossings were part of the scheme. An interchange at the N18/N85 junction was also built.

The N18 Oranmore to Gort scheme (28km) has been combined with the N17/N18 Gort to Tuam scheme, which includes the M17 Galway to Tuam scheme (25km). The combined scheme will include 53km of motorway and the 4km Tuam Bypass.

"The Ennis Bypass includes 14km of dual carriageway and 6km of the N85 Western Relief Road."

The Gort to Tuam section will start from Gort in the south and end at Tuam in the north. It will connect to the M6 motorway and provide a link between Dublin and western Ireland.

The Gort to Crusheen scheme consists of a 22km dual carriageway starting from Ballinger's Corner to Cragard where it will connect with the 21km Ennis Bypass. The project also includes 10km of realigned local roads and 12km of accommodation access tracks.

Construction

The N17/N18 Gort to Tuam scheme will include construction of three interchanges at Rathmorrissy, Kiltiernan and Gort. Two bridges over the Clarinbridge and Dunkellin Rivers, 19 road bridges and one railway bridge will be constructed. Four accommodation bridges and underpasses are also part of the project. About 240ha of land is expected to be required for the project.

The Gort to Crusheen scheme will include construction of 14 new bridges, a grade-separated junction and an at-grade roundabout junction.

Financing

The National Roads Authority has provided €500,000 for the funding of the N18 project.

Contractors

In September 2010, a consortium of BAM Balfour Beatty was awarded a £250m contract for constructing the M17/M18 Gort to Tuam scheme.

Gama Strabag Construction, a joint venture between Gama Turkey and Strabag, was awarded a €119m contract for construction of the Ennis Bypass. TMS Consultancy was contracted to carry out road safety audits. Jacobs Babite Consulting Engineers were appointed as the engineer.

Gama Strabag subcontracted Mott MacDonald Pettit to carry out the design work for the project. Pipeline and Drainage Systems was subcontracted to construct a 300m Hydrodeck Drainage system.

Mechanical Engineering Construction (MEC) assembled and installed a 5,200t under-structure for a road bridge at Dromoland for the Ennis Bypass. MEC also assembled and installed a 700t under structure for a road bridge over the River Fergus.

"The National Roads Authority has provided €500,000 for the funding of the N18 project."

A consortium consisting of Tobin Consulting Engineers, Hyder Consulting and PH McCarthy & Partners was awarded a €220m contract to carry out the preliminary design and environmental assessment for the N18 Oranmore to Gort scheme. Eachtra Archaeological Projects provided archaeological services for the project.

The €92m design build contract €92m for the Gort to Crusheen section was awarded to a JV of Wills Brothers and SIAC Wills in November 2008.

Babtie Pettit was the main consultants for the Gort to Crusheen section. Sub consultants included RPS Group, Komex Environmental, Biosphere Environmental services and Jonathan Blackwell & Associates.

Bardon Composite Pavements, a division of Aggregate Industries, was responsible for placing 94,000 cubic yards of cement bound granular materials (CBGM) base for the Gort to Crusheen section.

The N18 is being upgraded under the Atlantic Corridor Letterkenny to Waterford improvement programme.

N18 looking south from the Ennis junction.

The Gort to Crusheen section under construction in June 2009.