The AK-1000 tidal turbine and its supporting structure, which together weigh 1300 tonnes, have been deployed in a harsh open-ocean environment at the European Marine Energy Centre (EMEC).

Each of the twin turbines has a rotor diameter of 18 metres and is 7.8 metres long, with a cone diameter of 2.4 metres. The full structure is more than 25 metres in height and was installed in a depth of 35 metres.

Developed by Atlantis Resources Corporation (ARC), the AK 1000 is intended to generate enough energy to the Orkney grid to power 1000 homes, while its low rotation speed will curb its environmental impact.

"The AK1000 is capable of unlocking the economic potential of the marine energy industry in Scotland and will greatly boost Scotland's renewable generation capacity in the years to come," said Atlantis' CEO Timothy Cornelius earlier.

Hallin was contracted by ARC to provide specialist services as an experienced subsea contractor to plan, help design and install the turbine.

By its nature, the generator site has strong currents, posing major challenges for installation, which relied on slack water periods.

Component parts were sized at the manufacturing stage to ensure build assembly during installation could be reconciled with the duration of periods of slack water.

"I am very pleased with the successful installation of the AK 1000 in the EMEC test site," said Cornelius.

"The partnership approach and support that Hallin has provided to ARC during the early development and planning stages of the project have resulted in yet another world first for the company."

Hallin's offshore installation manager Steve Offler said: "This has been a challenging installation project that started nearly six months ago at the planning stages. We worked inside the ARC project team to develop an installation plan to install over 1300 tonnes of gravity base and subsea turbine in the harsh tidal environments of the EMEC test fields."

Hallin's Group Business Development director John Payne described the installation as "a very satisfying end to what has been over a year's engineering and planning work".

A very satisfying end to what has been over a year's engineering and planning work - Steve Offler, offshore installation manager, Hallin Marine Subsea International Ltd