Case study of acoustics and vibration of mine fans

In December of 1991, several residents of Hueytown, AL began hearing what they referred to as a mysterious sound. This sound, which became known as the Hueytown Hum, was alleged to be so disruptive that one resident claimed it made it impossible to hold a prayer meeting in his house. Bathroom pipes were said to rattle, and the sound would quickly come and go. This phenomenon attracted considerable attention from the news media, including ABC evening news, CNN, the New York Times, A Current Affair, and others. Jim Walter Resources, Inc. (JWR) owns and operates a large underground coal mine in the vicinity of Hueytown, and city officials were quick to blame the mysterious sound on a mine-ventilation fan which was installed at approximately the same time the noise began. To address the concerns of the city officials, JWR contracted with The University of Alabama to perform a study to determine if the ventilation fans were a contributing factor to the Hueytown Hum. The purpose of this study was to investigate the acoustical and vibrational characteristics of the JWR fans operating in the Hueytown area. This paper presents the findings of this investigation.