Engineers of tides
High and low water, the weather and the wind governs the working day for Mark Williamson, marine coordinator at the Sheringham Shoal offshore wind farm.
“Each day is different, and that is part of what makes the job exciting,” says Mark Williamson.
Statkraft took over as operator of the wind farm with the massive turbines out in the North Sea on New Year’s Day 2014. The wind farm is operated and managed from a new base of operations just outside Wells-next-the-sea, a small North Norfolk coastal village.
Williamson is one of four coordinators working shifts to organise boat traffic between the port in Wells and the wind farm about 20 kilometres offshore. The boats take crews and equipment out for repairs, maintenance and operation of the turbines.
The wind may be free, but it costs time and money to keep 88 wind turbines running for as many hours, days and weeks of the year as possible. When all turbines are in operation, the wind farm can supply 220,000 British households with renewable energy.
How high are the waves?
Large screens with a live feed from the wind farm, and graphs showing wave height, wind speeds, temperature and visibility for days ahead dominate the control room where Williamson sits.
Based on the information they receive, he and his colleagues decide whether it is safe for crews and boats to go out to the wind farm. Is visibility good enough? How high are the waves? How strong is the wind? And how will the weather develop over the course of the day?
“A lot has to come together,” says Williamson.
“So far this winter, we have been able to get out there for 10 out of 30 days.”
Another complicating factor for the boat traffic is the conditions along the coast, with large sand banks and several metres difference between low and high tide.
A separate port has been built for the vessels going out to Sheringham Shoal, and the boats have to go through a long channel that is only deep enough at high tide. This means that they can only go out or come in every 12 hours, and at different times each day.
“The boats are equipped to moor up to the wind turbine pylons, enabling the crew to climb over the do their job,” he explains.
“However, to do this safely requires a wave height of no more than two metres. We are taking no chances. Crew safety always comes first.”