Why look when you first rise overhead crane fall?

In general, more than 32 tons overhead cranes will happen, this action is called reverse braking, is to prevent the crane fell because of heavy inertia brake not brake, so will this action in the circuit design .
In operation, the controller should drop pulled directly highest gear, while declining to stop, to brake in reverse gear (some first gear is reverse braking, second gear is a single-phase brake, electric hoist double girder overhead crane there is a stall is neutral, second gear is reverse braking) pause 0.5 seconds to achieve the best braking effect.