The guard, known as a conductor in America, blows his whistle when it is time for trains to leave and sits in the brakevan, where he can apply the brakes in case of an emergency. Guards also have two flags, one red and one green. The green flag means "all set", and the red flag means "danger".
A guard's uniform is blue pants, a white shirt, a black tie, with a blue jacket over it, and a blue cap.