Atkins carried out the feasibility study and detailed design on the green route, including the feasibility study between Ashtown and Confey (11km) and the detailed design on the Ashtown to Castleknock section (2.2km).
The greenway will be a major asset for outdoor recreation and tourism in Ireland, while also providing a real “traffic-free” alternative for commuter cyclists travelling between Dublin City Centre and the Blanchardstown / Castleknock areas.
The project is based in a very sensitive ecological corridor within the Dublin area. The canal corridor itself is a designated proposed Natural Heritage Area and the environmental, ecological and industrial heritage sensitivities of the site provided significant challenges for the development of the scheme design. The biggest challenge on the project was dealing with the habitats of protected species and minimising the impacts on those habitats. As an example, extensive habitat surveys were carried out to determine the presence of protected species. Bespoke design features were developed in consultation with the National Parks and Wildlife Service (NPWS) and Fingal County Council Conservation Department to mitigate and minimise the impact the scheme would have on bats in particular. A bespoke lighting system was developed incorporating automatic dimming and remote monitoring technology so that natural environmental conditions could be maintained at dawn and dusk when bats are most active and feeding along the canal corridor.
The scheme involved the development of proposals which took into account the interfaces with traffic, integration of adjacent communities and connections to public transport and cycle networks. The option development stage included various options to develop the "deep sinking", a 4km stretch of the towpath where the canal channel is sunk into the bedrock to a depth of approx 9m. This area presented exceptional challenges in terms of the adjacent railway, deep cuttings and earthworks slopes and environmental/ecological concerns.
Other challenges included:
- Public and stakeholder liaison (including Irish Rail, which owns the railway adjacent to the whole length of the route
- Junction design incorporating a level crossing
- Tie-in to an existing scheme to the east
- Soft and hard ground conditions
- Existing brick culverts which had to be widened/strengthened.