U.S. Steel sets 2 batteries involved in deadly blast at Clairton Coke Works to 'hot idle' mode

U.S. Steel officials announced Friday they set two coke batteries at the heart of a deadly Clairton Coke Works explosion this month to “hot idle,” meaning they will remain heated but not being used for coke production.

“The hot idle state of the batteries will allow them to maintain their temperature and for us to continue to assess for any damage to the ovens and determine the course of action to repair,” the steelmaking giant said in a prepared statement.

This week, officials said batteries Nos. 13 and 14 would be inspected once the coke was removed to determine if they can be repaired. In the meantime, no coking or production will take place.

A coke battery is a large industrial structure housing multiple slot-shaped ovens, each of them arranged side by side. Coal is heated in an oxygen-free environment inside these batteries to create coke, a key ingredient in the steel-making process.

U.S. Steel has said the initial explosion Aug. 11 occurred at batteries Nos. 13 and 14. Two workers were killed and 10 others hospitalized as a result of the blast, which remains under investigation.

The explosion occurred about 10:47 a.m., according to video recorded by the Breathe Project, a clean-air group whose cameras in Clairton captured an enormous plume of black smoke billowing skyward.

Multiple first responders rushed to the coke plant’s 392-acre site on the banks of the Monongahela River. They represented emergency response units from two counties, 14 fire departments and 20 EMS companies.

Clairton Coke Works, which U.S. Steel opened in 1916, remains the nation’s largest coke manufacturing facility.