Soon, the day shift was replaced by the evening shift. Despite the delay, the emergency core cooling system was left disabled—it was disconnected by a manual isolating slide valve which in practice meant that two or three people spent the whole shift manually turning sailboat-helm sized valve wheels. The system would have no influence on the events that unfolded next. Allowing the reactor to run for 11 hours outside of the test without emergency protection was indicative of a general lack of safety culture.