London Gateway Eastern Outfall

London Gateway Eastern Outfall

THE CHALLENGE

Laing O'Rourke/Dredging International JV are the main contrators for building the new London Gateway Port.  The site was an undeveloped marsh area protected by an Environmental Agency flood defense wall that could not be breached.  To manage the rainwater run off from the 300 hectare site, surface water had to be pumped over the wall by high volume pumps without degrading the river bank.

THE SOLUTION

UMC installed piled concrete plinths to stabilise the manifold and pipework for 8 million cubic metre per hour maximum discharge outfall on both the land and river side of the wall including framework design and installation, lifting and ancillary plant.  The river side tasks required working in tidal waters for piling, rebar and concrete operations with provision of marine safety supervision, training and rescue facilities for contractors working outside the wall plus additional safety coordination with vessels and the Sierra oil jetty operators.

Pumping large volumes of water onto the river bank presented a scour hazard mitigated by the installation of gabion and grout mattresses.  Due to the exposed site and the severe wave actions the gabions were specially designed with protective kerbs to extend service life and reduce distortion.

The river bank was eneven, containing boulders and obstructions that were surveyed and remediated with additional stone added to infill areas producing a within specification platform for mattress installtion.  UMC coordinated activites of multiple trades, floating plant and contractors in a hazardous marine and oil environment.

The port is a high value intervention site for UK HSE.  Random inspections were carried out, all of which passed.  The project lasted over six months without accident or incident.

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