Adman were appointed by ESB Wind Development to undertake the advanced access works for the 5 turbine Crockdun Wind Farm located in Co. Tyrone. The infrastructure design in the site access tracks required a new bridge crossing of the Granagh Burn (a tributary of the Camowen River) to facilitate the wind farm construction and delivery of turbines.
A new 12m single span reinforced concrete vehicular access bridge, designed to accommodate 20T Axle loads, was sited at the mid-point of a 750m long access road, constructed from both ends thus providing access to each embankment.
The bridge abutments were formed using 275 x 275 precast concrete load bearing piles driven to refusal on each river bank. 1m x 1m cross section in-situ reinforced concrete pile cap beams complete with seating rebate were constructed as bridge abutments. 500mm precast, prestressed concrete bridge beams were installed between seating rebates to form the main deck structure. This was then sealed and waterproofed before a final running surface was laid along with 300mm high in-situ reinforced concrete kerbs and traffic restraint barriers.
All bridge works were undertaken in accordance with strict environmental constraints with no “in-stream” works allowed, the installation of silt fencing and filtration systems to prevent contamination of the watercourse and the implementation of a robust regime of water sampling, monitoring and testing to ensure compliance and protection of the watercourse.