Trench Shield 2 : A steel-framed box with two vertical side plates permanently braced apart by cross frames or struts, to provide a safe working place for employees while work in an excavation is being carried out
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}