Installing replacement bridge and culvert over River Esk to improve fish passage and natural river f

Tender description

The key objectives of the contract are to construct 2 new water crossings to replace existing obstacles. All works must be completed before the end of June 2023 to align with project funding arrangements. REPLACEMENT BRIDGE CROSSING, River Esk The works comprise of installing a new bridge crossing over the River Esk on a private farm road to Crag Farm. The existing bridge will remain in place as the main vehicular access to Crag Farm until the new bridge is completed and the approach roads reinstated. Then the existing bridge will be removed and the river channel reinstated to a form similar to conditions upstream. The existing bridge over the River Esk (Esk 9a) provides the only vehicular means of access to Crag Farm and it must remain open throughout the works to allow milk tankers and routine farm traffic to access the farm, as well as emergency vehicles. A Traffic Management Plan will be required to be agreed with Crag Farm (who are supportive of the works). The Esk 9a bridge is a Public Bridleway, however this designation will be subject to a temporary closure order arranged by the NYM NPA for the duration of the works to prevent public access. When the new bridge is installed, the existing bridge is to be removed. Due to the bridge removal requiring direct works in the river, these works cannot commence prior to 22nd May 2023 (subject to confirmation) due to emergence of juvenile fish in the river. All activities will require installation of appropri...erosion protection comprising riprap stone at toe of bank (approx. 30 m3), rock rolls (approx. 60 m), at lower levels, and addition of biomatting (to be anchored and pinned) (approx. 120 m2), at upper bank levels and at top of bank. REPLACEMENT CULVERT, Little Fryup Beck The works comprise of the replacement of an existing twin pipe culverted crossing of a private farm track over the Little Fryup Beck with a 4m span multi-plate bottomless arch culvert: 1. Remove existing culverts and re-grade the bed of the Beck to remove the upstream build-up of sediment; 2. Cast in-situ/precast strip foundations, incorporating arch seating channel (or with fixing/load transfer system to Contractor's design, to equivalent performance); 3. Reinstate the channel bed with stone, as per design specification; 4. Re-form the channel bed between the abutments using placed stone; 5. Assemble multiplate bottomless arch culvert from pre-fabricated plates onto strip foundations; 6. Cast in-situ concrete headwall, to tie-in to foundations and steel arch; 7. The BAC shall receive compacted fill in layers to the sides and above the crown of the arch, with a C40 fibre concrete running surface formed; 8. Place rock armour to provide a tie in between the concrete headwall and reprofiled banks upstream at culvert inlet and outlet; 9. A pedestrian handrail to be fixed to the headwall; 10. The track will be reinstated either side of the culvert with a compacted stone fill running surface.