Our package of works was for the drainage and linear drainage channel systems on the Testo’s and Downhill Lane junctions to the A19. The Testo’s junction had a long history of congestion as it was the only major ‘at grade’ junction on the A19 south of the River Tyne and had to cope with all through traffic. The Downhill Lane junction is one of the main access points from the strategic road network to the Nissan Car manufacturing plant and the construction of a new manufacturing park meant that forecasted travel flows would cause significant congestion.
The team undertook both daytime and night-time working. Night-time working enabled work to be completed near carriageways whilst traffic was at its quietest. Excavations were required for the 7km of drainage to the Testos junction and 6km of drainage to the Downhill Lane junction, manhole chambers, 98m3 and 22m3 geo-cellular attenuation tanks and surface water storage ponds. The surface water storage ponds and attenuation tanks have been fitted with hydro brakes to effectively control the flow of water into the drainage system and new headwalls and outfalls constructed using pre-cast concrete or concrete filled hessian bags. Over 4km of combined kerbing and kerb drains were installed to the Downhill Lane junction and existing drains, service ducts and culverts were grouted up.