signal de la cage

OBS: [...] le machiniste d'extraction a la responsabilité de transporter quotidiennement plusieurs centaines de passagers, au gré des signaux sonores et lumineux qui rythment les mouvements de la cage.

CONT: There were twelve heroes, men who went down into the mines six times and saved lives which otherwise would have been lost. On the seventh trip, due to a miscommunication of cage signals, these heroes perished in the fire.