Wells : A well is a permanent complete enclosure around a fixed ladder, which is attached to the walls of the well. Proper clearances for a well will give the person who must climb the ladder the same protection as a cage
Environmental Health and Safety, Glossary, University of Chicago, Illinois, USA 2010. http://safety.uchicago.edu/tools/glossary.shtml, (Ergo - Amer) {753}