{Reels} with means to tension the belt in an emergency {by forced winding up characterised by fluid actuators, e.g. pyrotechnic gas generators comprising venting means, e.g. for avoiding overpressure in case of fire or for allowing return motion with energy absorption}
{Reels} with means to tension the belt in an emergency {by forced winding up characterised by fluid actuators, e.g. pyrotechnic gas generators comprising venting means, e.g. for avoiding overpressure in case of fire or for allowing return motion with energy absorption}