An aerial view of the new and refurbished bridges over the River Barrow, part of the Athy Distributor Road scheme.
Summary
Roughan & O’Donovan-AECOM was appointed to provide technical consultancy services for the Athy Distributor Road project in April 2015. Our appointment covered all stages of the project, including detailed design, procurement, construction supervision and contract administration.
The project involved the construction of a 3.4km single carriageway distributor road around the southern side of Athy, largely following the line of the disused Athy-Wolfhill railway. The route crosses the River Barrow, a Natura 2000 site that forms part of the River Nore and River Barrow Special Area of Conservation. It required the construction of an 80m single-span steel composite bridge across the River Barrow and a two-span bridge over the Dublin to Waterford railway line.
The design incorporated extensive improvements to pedestrian and cycle facilities, including the repair and repurposing of a listed, disused railway bridge over the River Barrow as a cycleway/footway. Dedicated links were provided to Barrow Way, a long-distance walking trail that follows the original towpath of the river, and to Athy Railway Station.
In addition to providing the Employer’s Representative, ROD-AECOM placed a team of supervision personnel on site to undertake the administration of the contract through the construction and handover stages.
The scheme was officially opened on 31 October 2023.
Solution
Traffic patterns
ROD–AECOM developed both macro-simulation and micro-simulation traffic models to assess the optimum solution to traffic congestion on the N78 through Athy.
Constraints and route selection studies
We undertook constraints and route selection studies of routes to the north and south of Athy, which were assessed in accordance with the Common Appraisal Framework headings of economy, safety, environment, integration, accessibility and social inclusion.
Preferred Route
Following the publication of the Route Selection Report in August 2016, we further developed the preferred route. This culminated in the publication of the Environmental Impact Statement (EIS), Natura Impact Statement (NIS) and Compulsory Purchase Order (CPO) in April 2017.
Planning
ROD-AECOM provided expert witness testimony in support of the proposed development at an oral hearing, which took place in July 2017.
In October 2017, An Bord Pleanála granted planning consent and CPO approval for the scheme without the imposition of any additional conditions.
Two 80m long braced steel plate girders, constructed of weathering steel, were required for the new road crossing over the River Barrow and Grand Canal.
Challenge
The River Barrow SAC
Developing a bridge solution that minimised impacts on the qualifying interests of the River River Barrow SAC represented a challenge. The bridge was designed as a single span structure to minimise its impact on the SAC while weathering steel was selected to mitigate the health and safety risks associated with maintenance regimes on a painted structure.
Asbestos materials
Athy has a manufacturing past that produced asbestos materials, and there are a number of known asbestos disposal sites in the town. During the route selection phase, the known sites were identified, and the route options were designed to avoid impacts on these sites.
The ground investigation works undertaken as part of the preliminary design sought to determine the extent of a known asbestos disposal area located adjacent to the scheme and whether any previously unknown sites existed along the route.
Works
An advance works contract was carried out to install the Bennetsbridge Stream culvert and fencing and walling between the N78 and Fortbarrington Road.
Other enabling contracts to facilitate the main construction works included:
- rail removal contract
- advance fencing contract
- diversion of a 315mm diameter gas main
- diversion of the 110kV overhead high voltage ESB powerline
Services provided:
- Multidisciplinary ecological surveys
- Screening for Appropriate Assessment
- Stage 2 Appropriate Assessment (Natura Impact Statement)
- All assessments for, and the preparation of, the Environmental Impact Statement (EIS)
- Advance contracts, including topographical survey and geotechnical investigation
- Design of all roadworks elements
- Design of an 80m single span bridge crossing of the River Barrow and a two span crossing of the Dublin-Waterford Railway
- Economic and Project Appraisal in line with government requirements for Capital Works
- Development of land requirements, including the preparation of Compulsory Acquisition plans, schedules and forms
- Statutory approvals
- Detailed design
- Procurement
- Construction supervision
- Contract administration
