SIX months in the making, a 600-tonne subsea arch is heading out to the Outer Moray Firth where it will be installed on Ithaca Energy’s Athena development.
The imposing 17m (55ft) stainless steel structure and its gravity base, heavy clump weights and piles, weighing a massive 600 tonnes altogether, were all constructed at A&P Tyne’s yard at Hebburn, in Tyne and Wear, north-east England. It will be used to support the Athena field’s control cables as they rise from the depths of the seabed to the surface.
For A&P, the project marks its second subsea construction order following the completion of two buoyant subsea structures for an African offshore oil field.
Project director Iain Campbell said: “This job was totally different in that the Athena arch is supported by pressurised steel cylinders, as opposed to the polymer buoyancy units that the earlier subsea arches were built around.
“The pressure vessel buoyancy tanks are a new design and required very high standards of welding and fabrication. It was very challenging but everything came together and the whole project went extremely well.”
Final assembly took place at a yard in Invergordon.
The Athena field is due to start production towards the end of this year.