The attenuation tank is amongst a number of precast concrete products that are now accepted by Northumbrian Water within Sewers for Adoption 6th and 7th Editions and is part of the FP McCann multi-purpose StormStore™ panel tank range which can be designed and installed up to 6 metres high with overall dimensions to suit the client brief.
Measuring 23 metres long by 17 metres wide at a height of 3 metres, the online drainage precast concrete panel tank sited under the access road, manages a storm event by capturing excess surface rainwater. The water can then be released back into the drainage system at a controlled rate, thereby relieving the pressure on the main network and reducing the risk of downstream flooding into the nearby Cor Burn.
Prior to the construction of the tank, a 75mm thick blinding layer of concrete formed the hardstand to receive the poured floor slab; a 250mm thick layer of C40 reinforced concrete. The panel sections manufactured at FP McCann’s state-of-the-art precast facility in Byley, Cheshire were then delivered to site over a period of 4 days for installation by the approved FP McCann specialist fixing team.
In total, 22 external walling panels were fixed and 24 internal wall units to form four special internal support walls. Large openings in the internal walls allow water to flow freely between each section. Covering the tank are 70 individual precast cover slabs. 4 manhole openings have been cast into 4 end slabs to give easy access for maintenance purposes.
The tank has been set on a 1:400 fall towards the outlet and the base is complete with a dry weather flow channel. To complete the tank, in-situ concrete was pumped onto the roof slabs to provide an additional protection layer.
Commenting on the panel tank design and build, Steve Morris, Senior Quantity Surveyor for Esh Construction says, “With final adoption under the Northumbrian Water S104 approval process, we had to take into consideration a number of factors on tank design. Robustness and long-life, low maintenance performance was key to our choice of attenuation tank. FP McCann’s multi-purpose panel tank system fitted both the design and performance criteria. The FP McCann approved installation team undertook the work in a timely, efficient and safe manner. On future projects, we will certainly consider similar FP McCann supply and install precast concrete StormStore™ panel tanks systems.”
In addition to the tank, FP McCann has also supplied standard precast concrete spigot and socket pipes, manhole chamber rings and cover slabs to the Corbridge housing development.
FP McCann’s multi-purpose panel tanks have a 100-year design life and can be installed up to 6 metres high with no footprint size limitation and are designed for pedestrian loading through to LM1 highway loading.
Internal design features can be added such as weir and baffle walls and penstocks or flap-valves can be pre-installed. Typical uses include:
- Attenuation Tank
- StormBrake Chambers
- Pumping Stations
- Large CSO Chambers
- ASP Structures
- Clean Water Storage Tank