Client: Northumbrian water Ltd
Location: Ryhope, Sunderland
Contract Value: £0.45 million
Contract Period: October 2010 until April 2011
The works undertaken for Northumbrian Water Limited and Sunderland City Council comprised the construction of a new 900mm foul overflow pipe incased in 300mm thick concrete.
Ryhope outfall discharges to the sea and as a result of coastal erosion the pipeline has become unsafe and requires repairing. The works involved:
- Creating safe access onto the beach
- Establishing road closures and signposting diversions for footpath routes
- Removal of 50m of old outfall pipeline where it is suspended above beach level
- Construction of concrete foundation 1.5m below beach level
- Construction 70linear metres of 900mm diameter ductile iron pipework with reinforced concrete surround
- Construction of three new manholes
- Building 40m of concrete steps to provide future public access to the beach
Due to the area being a Specialist Site of Scientific Interest (SSSI) communication with Marine Management Organisation, Natural England, East Coast Community Association and the Environment Agency was essential during the Contract to ensure there were no environmental impacts during construction.
The main points of the Contract below needed to be organised to a very high standard:
- Access was via a railway line underpass that had a “RESTRICTED HEIGHT AND WIDTH”. All plant and material movements had to be managed at all times on site
- Suitable surfacing and lighting to be provided along access routes to ensure safe access for staff, especially at night
- Extreme tides may destabilise the cliff edge. Limited working period. No plant materials, equipment or rubbish to be kept on the beach where it could be inundated by the sea
- Working in tidal zone, ensuring that Tide Timetables were used to plan working hours as high tides and being aware of storm surges increasing tide levels. The Coast Guard was informed of our working hours and the use of floodlights on the beach pointing out into the shipping lanes near the two harbors Hendon and Seaham, and were informed of our emergency procedure and a temp station on the beach was operational at all times with our buoyancy aids and life jacket at all times when working. Where possible low tide double shifting was carried out to utilize two low tides.
- Pedestrians, ensuring suitable fencing and signs to identify site working areas
- For Spills and Plant break downs, we had 24 hour call out from our fitters and recovery vehicles incase of a breakdown on the beach.
We also had a spill station set up on the beach before the start of every working shift with all necessary equipment in case of a spill. The use of materials had to be managed so as to get the best time available for work due to tide times we used a double shift to maximize production. A special C50 marine concrete was used for all our work with a very fast curing period skips were placed on the beach for concrete washout and prevent pollution.
