The Athena Midwater Arch and Tether Base for Ithaca is currently being installed in North Sea Block 14/18b 180km NE of Aberdeen by Bibby Offshore.
Designed by Sea and Land Project Engineering Limited under contract to SLP Precast Limited, the twin tank MWA is installed in 130m water and supports six flexible risers of up to 250mm diameter that are supplied by Wellstream International of Newcastle. The MWA weighs approx 150 tonnes and is anchored to the seabed by two composite tethers attached to a piled Base Unit and 300 tonnes of clump weights. It was constructed by A&P Tyne at their Hebden yard on the River Tyne. The project took 7½ months from contract award.