An opening in a mine having an inclination above the horizontal of 150 or more (a) through which employees or materials are transported; or (b) that is used as a main intake or outlet for ventilation
Ministry of Business, Innovation and Employment, Glossary of terms and acronyms, Wellington, New Zealand 2010. http://wwwsosh.govt.nz/resources/glossary-u.shtml, (Occupn Hlth and Sfty - Brit) {530}