OYSTER PROJECT

In 2008 Leask Marine Ltd. became involved in the Aquamarine Power Ltd ‘Oyster Project’.

This was to be a worldwide first time deployment of a renewable energy prototype system for producing electricity from wave energy, rather than tidal flow, and would prove to be a challenging project, with an often steep learning curve for all involved.

The test site for the prototype was to be the EMEC site at Billia Croo, on the west coast of mainland Orkney, an area renowned for its ferocious winter storms and almost constant Atlantic swell.

Following on from hydrographical surveys of the area, Leask Marine’s first task was to locate and survey possible target areas for the deployment of the Oyster. Once this was achieved, there was a long wait while directional drillers established the necessary sub-surface pipelines from the mainland to the deployment area, and fabricators in Nigg built the Oyster.

In the summer of 2009 all was ready. Leask Marine provided a 10 man dive team, and Fugro Seacore provided the jack-up barge ‘Deep Diver 1’ which was to be the work platform for a majority of the project.

With the 10 man team diving in pairs, the first major task was to land the 50 ton, 12 meter square, pile can frame (PCF) on the seabed and prepare it for drilling. With positioning tolerances of only 1 degree horizontally, and 2 degrees relative to the predominant sea swell, several days were allowed for this phase. In the end, it took only 2 days.

Leask Marine then provided support for the Fugro Seacore drilling team as they drilled each of the four pile cans and inserted the structural supporting piles. Each drilling phase took approximately 4 days.

Once the PCF was firmly secured to the piles, things got serious. The power conversion unit (PCU) is the working part of the Oyster. Coming in at over 250 tons it was beyond the lift capabilities of Deep Diver 1, so the heavy lift barge GPS Apollo was brought in. As this is a floating barge, the weather and swell conditions had to be perfect......so we waited......

On the day of installation the wind was negligible, but the swell was at about 0.5 meters. Although nothing on the grand scheme of things, this was enough to make diving conditions arduous when the PCU picked up momentum, and was bouncing over 2 meters in the water column.  Luck was on our side though, and within 2 hours it was located on the PCF ready to be bolted down and attached to the shore side works.

It was a further 2 months of working in gradually deteriorating conditions until the Oyster was ready to generate electricity and, in all, what has taken less than a page to highlight, took over 6 months of hard work to complete.

Leask Marine is still involved in the ongoing maintenance side of the Oyster, and plans are already afoot to install 3 x Oyster 2 in the same location in 2011.