Algae, barnacles and sea anemones
The Northern Isles underwater datacenter was manufactured by Naval Group and its subsidiary Naval Energies, experts in naval defense and marine renewable energy. Green Marine, an Orkney Island-based firm, supported Naval Group and Microsoft on the deployment, maintenance, monitoring and retrieval of the datacenter, which Microsoft’s Special Projects team operated for two years.
The Northern Isles was deployed at the European Marine Energy Centre, a test site for tidal turbines and wave energy converters. Tidal currents there travel up to 9 miles per hour at peak intensity and the sea surface roils with waves that reach more than 60 feet in stormy conditions.
The deployment and retrieval of the Northern Isles underwater datacenter required atypically calm seas and a choreographed dance of robots and winches that played out between the pontoons of a gantry barge. The procedure took a full day on each end.
The Northern Isles was gleaming white when deployed. Two years underwater provided time for a thin coat of algae and barnacles to form, and for sea anemones to grow to cantaloupe size in the sheltered nooks of its ballast-filled base.
“We were pretty impressed with how clean it was, actually,” said Spencer Fowers, a principal member of technical staff for Microsoft’s Special Projects research group. “It did not have a lot of hardened marine growth on it; it was mostly sea scum.”
Power wash and data collection
Once it was hauled up from the seafloor and prior to transportation off the Orkney Islands, the Green Marine team power washed the water-tight steel tube that encased the Northern Isles’ 864 servers and related cooling system infrastructure.
The researchers then inserted test tubes through a valve at the top of the vessel to collect air samples for analysis at Microsoft headquarters in Redmond, Washington.
“We left it filled with dry nitrogen, so the environment is pretty benign in there,” Fowers said.
The question, he added, is how gases that are normally released from cables and other equipment may have altered the operating environment for the computers.
The cleaned and air-sampled datacenter was loaded onto a truck and driven to Global Energy Group’s Nigg Energy Park facility in the North of Scotland. There, Naval Group unbolted the endcap and slid out the server racks as Fowers and his team performed health checks and collected components to send to Redmond for analysis.
Among the components crated up and sent to Redmond are a handful of failed servers and related cables. The researchers think this hardware will help them understand why the servers in the underwater datacenter are eight times more reliable than those on land.
“We are like, ‘Hey this looks really good,’” Fowers said. “We have to figure out what exactly gives us this benefit.”
The team hypothesizes that the atmosphere of nitrogen, which is less corrosive than oxygen, and the absence of people to bump and jostle components, are the primary reasons for the difference. If the analysis proves this correct, the team may be able to translate the findings to land datacenters.
“Our failure rate in the water is one-eighth of what we see on land,” Cutler said.
“I have an economic model that says if I lose so many servers per unit of time, I’m at least at parity with land,” he added. “We are considerably better than that.”