Bristol: Hammerfest Strøm's HS1000 tidal-energy turbine is a single-axial-rotor, fixed-nacelle concept, designed to produce power from both incoming and outgoing currents by switching the pitch of the 9.5-metre blades as the tidal cycle turns. Its tripod substructure - which will be ballasted and may be fixed to the seabed with "mini-piles" to prevent it sliding - is tilted to reduce the wake effect created behind the rotor, in order to minimise vibration and other potentially damaging dynamic effects on the turbine.