ST. LOUIS – St. Louis company steam condensation tank exploded, firing a quarter-mile in the air and through the roof of a neighboring business, after the tank is started despite the fact that they are emergency repairs, federal researchers said Thursday.
The U.S. Chemical Safety and Hazard Investigation Board released the findings of its investigation of the horrific April 3 explosion of Loy-Lange Box Co., to the south of the city of St. Louis. The blast sent the size of the tank hurtling through the air, landing through the roof of a neighbouring company, Faultless Healthcare Linen. Four people died.
The steam condensation tank, used in the process of making corrugated containers, the first occurrence of a leak in November 2012. The federal report said a contractor made emergency repairs and less than a month later, recommended the replacement of the lower parts of the tank.
The tank parts were never replaced, researchers said. They also found no evidence that the city ever inspection of the tank.
Engineers again saw a leak on 31 March of this year, on the Friday, the report said. The steam generation system was shut down and a repair to the technician was scheduled to arrive the following Monday afternoon, April 3.
“On Monday, despite the leak and the current technician visit, Loy-Long started with steam generation system,” the agency report said. “… it appears that the catastrophic failure occurred near the end of the startup of the process.”
The failure was caused by corrosion of a 6-inch (15 cm) ring, that was a part of the tank, the researchers said.
“The whole ring is failed suddenly,” the report said. “The tank circle blew away in a piece of the (tank), the creation of the conditions for the steam explosion.”
The result was a huge explosion “is equal to about 350 pounds (160 kilograms) of TNT” that “launched the storage tank like a rocket through the roof.”
The nearly 2,000 pound, 17 1/2-foot-long (more than 900 kilos, 5 ft long) tank increased to approximately 425 feet (130 meters above street level and was in the air for more than 10 seconds before crashing through the roof of the Buggy.
Loy-Lange engineer Kenneth Trentham, 59, died. In error-free, Tonya Gonzalez-Suarez, 46, and her husband, Christopher Watkins, 43, were completing paperwork for new jobs when they were killed. Clifford Lee, 53, was fatally injured while completing paperwork to begin with the work error-free.
The Loy-Lange Box Co. not immediately respond to a call seeking comment Thursday.
The security of things such as boilers and industrial water tanks are regulated almost uniformly in Missouri, with standards that generally include the periodic inspections. But St. Louis is exempt from the Missouri law requiring a regular inspection by an inspector or insurance company.
The city instead requires a company to have a licensed stationary engineer on the premises. Loy-Lange working three stationary engineers who are assigned to the company two tanks.
“The city that no proof of inspection,” the federal report said. St. Louis city officials did not respond to a call for comment early Thursday.
The city has insisted its system is safe to say that, because the mandates are licensed engineers to operate the tanks, they are under constant control, in place of only once per year.
The Chemical Safety and Hazard Investigation Board has the task of investigating industrial chemical accidents. It is not authorized to issue citations or fines, but it can ensure that the safety of the recommendations. The U.S. Occupational Safety and Health Administration also is investigating the accident.