DRUMHEAD (SIGN)

The term 'drumhead' refers to a type of removable lighted sign that was prevalent on American railroads of the first half of the 20th century. The sign was posted on the rear of passenger trains and consisted of a fully-enclosed box with lights inside it that would illuminate a tinted panel showing the logo of the railroad or specific train. Since the box and the sign were usually circular in shape, they resembled small drums; thus these signs came to be known as drumheads.
Railroad drumheads were removable so they could be mounted on different passenger cars (usually on the rear of observations) as needed for specific trains.