Thrybergh Hydro Scheme
Overview
The construction of a fish and eel pass will enable salmon and trout, and other migrating fish to swim upstream to spawn, an occurrence not seen for more than 100 years due to river pollution, and made obstacles such as Weirs.
Eric Wright Civil Engineering installed temporary and permanent sheet piles up to 13 metres in length to form a cofferdam adjacent to the River Don to create a dry working environment.
Next the team constructed the reinforced concrete structure, approximately 50m long and varying between 3 and 7 metres in depth, required to accommodate the Archimedes screws and associated M&E installations.
The works also included the construction of a 800m long access track, steel work design and installation for intake and outlet screens and walkways, attendance, lifting and positioning of equipment including the two Archimedes Screws and control panels, contractor designed generator and transformer housings, construction of fish and eel pass, alteration works to existing bye wash and LV electrical works.
Awards
The project received a Smeaton Award ‘Commended’ at the annual ICE Yorkshire & Humber Civil Engineering Awards 2016, in category the ‘Projects greater than 500k less than £5m’.
Key Challenges
Sheet piling on river sides with associated constraints concerning stability of piling plant and equipment. Closely managed health and safety issues associated with working close to/over water and on the existing weir.
Meeting key client dates for power generation whilst working through adverse weather conditions and floods.
Developing the temporary works designs to minimise the impact on the programme yet still present a value for money solution.
Added Value
Significant improvements were identified to the proposed temporary works arrangements and affected permanent works which successfully mitigated risks from unforeseen ground conditions, simplified the potential multi-phase propping and construction sequence, and generally reduced the duration of on-site construction.