Generally speaking a stopped turbine's blades are mostly stalled and under much lower stress than when rotating (albeit in different direction). The angle of at

Generally speaking a stopped turbine's blades are mostly stalled and under much lower stress than when rotating (albeit in different direction). The angle of attack of the blades is designed for moving blades. The surprising result of this is that the brake force needed to keep the turbine stopped is much smaller than the one needed to stop it, despite the relatively low mass of the blades.