the front conductor is in charge of the movement of the train. during a normal passenger loading procedure, the station master must clear the station platform with a thumbs up signal, at which point the back conductor must clear the front conductor for movement with a hand signal known as a "highball". once the front conductor verifies the highball from the back conductor and the clear from the station master, the front conductor will "highball" the engineer, who then proceeds with operation of the locomotive. "highball" hand signals are also given at two locations along the train route, between the front and back conductor, to signal that everything is clear on all six passenger cars.