Broken skid shifted power plant turbine, not human error

By MEDICINE HAT NEWS on January 20, 2023.

https://www.medicinehatnews.com@MedicineHatNews

A broken skid, not human error, caused a turbine to shift four inches at the Medicine Hat power plant, utility officials have told the News this week.

The incident, which resulted in a $1-million expenditure to ship the engine back to the manufacturer for inspection and repairs, required a budget amendment that was approved by council Monday.

Councillors called for more information about the incident and what steps are being taken to avoid future accidents.

“In this case it appears to be a true accident,” said utility division head Brad Maynes, adding the employees should receive accolades for reporting the seemingly minor incident on the “extremely sensitive” machine.

“We’ve done this procedure many times before with similar units, using the same substructure that had never failed.

“What’s positive is our safety protocols works. No one was injured, and our employees reported it right away.

“Had they not reported it and it had been put into service… today’s replacement cost would be $28 million.”

Maynes also said the $1-million cost covered the re-inspection and repairs. Since that amount is about equal to the city’s insurance deductible, the cost will be paid out of the utility’s capital budget which is funded from power profits.

In 2021 council approved a place to retain an LM6000 generator at the cost of $3.2 million, when a city unit was changed out to be refurbished. That would leave a spare on hand in case of emergency breakdown. The typical lead time to order and obtain the specialized equipment can be up to a year, which would lead to significant loss of revenue, administrators said.

The unit was returned to the city, but was reportedly damaged during the unloading process when the unit was in the city’s care, rather than the transport company.

The process, said Maynes, is to build a crib of heavy timbers for engine to rest, but workers told managers that one timber split under the unit’s seven tonne weight.

In total, the break caused one end to drop about 10 centimetres (four inches) – enough for the manufacturer, General Electric, to recommend it be reinspected before installation to avoid the potential for a catastrophic operating breakdown.

Such a breakdown would not have been covered by insurance, Maynes said.

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