London 2012 engineers were attempting to minimise the risk of the Olympic Park’s proposed wind turbine showering lumps of ice onto members of the public this week.
Fears have been raised over the safety of the 130m tall structure in the winters following the Games. “There is a concern over the potential for ice to form on the blades in legacy mode, and the risk that could pose to members of the public should the ice detach and fall,” said one engineer close to the project.
Ice forming on turbine blades is a common problem in northern Europe. But because the majority of turbines are in remote areas there have been no documented cases of falling ice causing injury to members of the public. “At the moment the main mitigating factor is that after the Games the area around the structure will comprise hockey pitches and tennis courts which are summer sports,” added the engineer close to the project. “It is therefore highly unlikely that members of the public will be near the turbine at the times of year when the risk of ice forming is at its highest.”
The Olympic Delivery Authority (ODA) declined to reveal what solutions are being the risk from the structure in the north of the Olympic Park, Stratford, which will comprise an 83m high turbine with three 47m long blades.
Mott MacDonald energy director Simon Harrison said that any turbine at risk of icing should be monitored with CCTV or ice detectors and shut down when icing is thought to occur. “One of the main issues that needs to be addressed to reduce the risk of injury in public areas from icing is the conditions under which the turbine may restart after icing has occurred,” said Harrison. “The movement of the rotor will increase the risk of ice falling. In a public area it would be recommended that the turbine is not restarted until all the ice has thawed. It may also be advisable to conduct a visual inspection.”
Npower renewables offshore development manager Mark Legerton said that in the UK the icing of turbine blades only occurred during severe winters in the north of England and Scotland. It was unheard of for the phenomenon to occur in a temperate, urban environment such as London. The possibility of winter shutdowns for the London 2012 turbine follow concerns that it will have to be shutdown during the Games due to it creating a “flicker” that will distract the athletes (NCE 29 March 2007).
An ODA spokesman said: “The ODA is in consultation with industry bodies and sporting authorities to ensure that the plans to erect a turbine will ensure public safety and that sporting events within the Park will be unaffected.”