Complex sentence: During a braking test, the rope snaps, and "Thunderbolt" leaves the rest of the train behind; however, several villagers turn out and manage to quietly push the carriages to meet up again with "Thunderbolt", with the inspector none the wiser.
Split into simpler sentences: During a braking test, the rope snaps, and "Thunderbolt" leaves the carriages behind. However, several villagers turn out and manage to quietly push the carriages to meet up again with "Thunderbolt", with the inspector none the wiser.