A longtime Colorado Springs Utilities mechanic changed the wrong filter on a Martin Drake Power Plant turbine oil system and oil squirted out and hit the hot pipes below, igniting a flash fire, a Colorado Springs Fire Department duty report says.
The mechanic had received the go-ahead to change a filter in unit No. 5 - one of three turbines at the downtown coal-fired power plant. The pressure, or shut-off valves, in the line had been closed off.
But when the mechanic went to change the filter, he changed the wrong one - one where the valves had not been closed. The filter cracked and oil squirted out 3 feet, hitting the 950-degree hot steam pipes, the May 23 CSFD duty report obtained by The Gazette says.
"It was human error," said Steve Berry, Colorado Springs Utilities spokesman.
An administrative employee working behind unit No. 5 inside the power plant heard someone yell fire, and she turned to see an orange wall of flames. A second mechanic said flames rose instantly from the basement to the third floor and described what he saw as "pure flame." That second mechanic told investigators he was immediately concerned of an explosion due to the Powder River Basic coal, which is highly explosive.
"If the fire would have reached the bunkers, it would have been horrible," he told investigators.
The mechanic who made the error that led to the fire has been on paid administrative leave, Berry said. The mechanic is eligible for retirement. Utilities officials hope to have a resolution about his employment soon, Berry said.
"He has taken full responsibility," Berry said. "He was very forthcoming about what happened. Imagine how you would feel if something like this happened."
The mechanic is part of a 21-member team trained to work on all of the power plants. On the day of the fire, May 5, he was assigned to work on the oil filtration system inside Drake. That system had been installed four years ago. A filter needed to be changed due to a corrective maintenance request.
The filter was tagged to indicate which one needed to be changed and the pressure in the lines had been closed. According to the CSFD duty report, the mechanic told investigators that he should have changed the lower of two filters.
"He stated before making the repair he went back to verify and when he returned to make the repair that he wasn't 'thinking' and he turned the top filter."
Deputy Fire Marshal Kris Cooper was unavailable for comment Thursday. But a city spokeswoman said the Fire Department has not completed its full investigation. It could be two weeks before a complete report is issued, she said.
Most of the damage inside the power plant was to unit No. 5, the oldest of the three turbines in the plant. Utilities crews are working around the clock to assess the damage, Utilities CEO Jerry Forte reported to the City Council this week.
Since the fire, Drake has been shut down and Utilities has been relying on its natural gas-fired plant to produce electricity. It also has been purchasing natural gas on the market - which is about double the cost to produce energy at Drake. As a result, the City Council this week approved a 7.4 percent residential electricity rate increase to cover the added expense. The council said the rate raise would be temporary.
Utilities hired Sargent & Lundy, a Chicago-based engineering firm, to conduct a third-party investigation into the fire. To date, Utilities estimates it has spent $600,000 on labor costs to keep employees working around the clock at Drake. Other costs, including the contracts for the third-party investigators, clean up crew and additional lights, have not been tallied, Berry said.
Forte promised the City Council an after-action report with details on how to prevent this kind of incident in the future.
"I understand there is a desire to assess blame," Berry said. "Ultimately, these kind of situations are harder than if it would have been equipment failure. When you are dealing with human beings who care about their job, it's devastating."