https://beardcirrus3.werite.ne....t/why-nobody-cares-a
https://www.openlearning.com/u..../hellercoley-sp370e/
Customizing Constrained spaces are an underground sewer tank, or a large underground excavated area. They are often enclosed, have limited access and could be hazardous. This equipment is designed to minimize and eliminate these risks. It includes monitoring of the atmosphere as well as personal protective equipment emergency response procedures, and training. Safety Closed spac