Carl J. Eckhardt Jr., head of the Physical Plant in 1931, supervised the construction of the Main Building Tower. Eckhardt devised a lighting system to take advantage of its commanding architecture to announce university achievements. Beginning in 1937, orange lights were used to symbolize important events at the university; by 1947, standard guidelines for using the orange lights were created, and these have been updated since. Today there are many different options for lighting, including a darkened tower to signify solemn occasions. An orange tower with office windows lit to form the numeral "1" is used for national championships in NCAA sporting events.