Complacency Kills- Loy Lange Box Company Tragedy

Overview

On April 3, 2017, an explosion occurred at the Loy-Lange Box Company in St. Louis Missouri. A Semi-Closed Receiver (SCR) which stored high temperature water for the Clayton steam generators ruptured at the bottom of the vessel. The explosion killed the boiler operator that was nearby. The SCR took off through the roof of the building and landed a building of a nearby business ultimately killing three more people. 

Here are some photos from the accident:

What Went Wrong?

It was determined the bottom of the SCR ruptured due to metal corrosion. The bottom had been patch with a new piece of metal in 2012 after a leak was found on the vessel. The investigation from the US Chemical Safety and Hazard Investigation Board found that the repair that was made was welded to steel that was too thin for the design of the pressure vessel.

The pressure vessel was never registered with the city of St. Louis or internally inspected after the repair was made in 2012 which failed in 2017.

What To Learn from the Accident?

 From the investigation report, it is clear that there was complacency around leaks on the steam system. The SCR has leaked multiple times before the accident which allowed workers to assume that a leak was normal and just needed to be repaired in a timely manner, but wasn't worth shutting down the steam system. Even though there were licensed boiler operators operating the steam system, it did not seem they were fully supported by management with adequate process safety procedures and training.

According to the report, all the procedures and boiler log book were lost in the accident, which could be true but it seems more likely the boiler operator that was in the room doing all startup of the steam system when the accident happened had all the procedures in his head with no cross training on startup or safety on the steam system. The two other boiler operators said they did not really start up the system or know how to do it. Cross training and procedures could help prevent key man risk of the steam system.

There were many decisions from multiple parties that all lead down the path to the accident. This seems to be a case of nothing bad has happened so the line of acceptable safety standards gets pushed constantly as all the parties involved have lost "calibration" with what should be happening versus what is actually happening.

Tragically, this accident cost the lives of four people, three of whom didn't even work for Loy Lange Box Company. There was a 47 million dollar settlement that ultimately found 4 parties responsible for the accident, but money doesn't put families back together.

Please read the full investigation report. The USCSB did an excellent job with it. Please also learn from this accident and do a self evaluation of any boiler systems you may be working around. Do you have clear procedures and guidelines of what is acceptable and what to do when a condition for caution is found? Are you properly trained to identify small problems that could lead to larger ones if no action is taken?

Boiler systems can be dangerous especially if corrosion is not controlled. Proper water treatment procedures and testing are important to prevent oxygen corrosion like the corrosion that lead to the failure of the SCR. 

Link to Final Investigation Report on USCSB Website

US CSB loy-lange box company pressure vessel explosion investigation report