Strata and CCCUG conducted the test at Shendong Coal’s Da Liu Ta operation in Shenmu County in the Shaanxi Province. It is the largest underground manned test performed in the world to date.

The 16-man chamber was fully occupied at the active mine and all testers remained for 96 hours. All of the unit’s life support systems were used as intended, Strata said, and each system performed as it was designed to meet China’s stringent standard requirements.

“The information and knowledge we obtained from this manned test cannot be learned through calculations and laboratory testing,” Strata Worldwide engineering vice-president John Reinmann said.

“Participants provided invaluable feedback that will help us improve our designs and enable us to develop better chambers in the future.”

All participants received pre- and post-test medical evaluations, and each individual was constantly monitored both underground and at the surface.

“We are very pleased with the success of this project, and are happy to note that all participants were in perfect health following the test,” Shendong Group chief engineer of safety Zhang Richen said, noting that the mine’s management team was on hand to support and offer congratulations to the testers at the test’s conclusion.

The Strata Fresh Air Bay, designed for use in emergency situations to provide breathable air, food and water to sustain the lives of trapped miners for a minimum of 96 hours, is available for capacities of 16 workers up to 36.

CCCUG is a subsidiary of China National Coal Group, the second largest coal group in China.

Its core business includes coal production and trade, coal chemicals, coal bed methane exploration, pit-mouth power generation, coal mine construction, coal mining equipment manufacturing and engineering technical services.

Strata is currently working with CCCUG to manufacture coal mine refuge chamber products in China.