BAKERSFIELD, Calif. (KGET) - Out with the old and in with the new: Friday marks new fire truck day for the Kern County Fire Department.

Four of them, to be precise - Wisconsin-built fire engines that were ordered two years ago. Yes, that's how long it takes for the factory to build one of these $850,000 life-saving machines on wheels. Two, often as long as four years. It'll take another $150,000 for the KCFD garage to finish the job to its particular specifications. Yes, these are $1 million investments.

Jonathan Drucker, the agency's information officer, says KCFD has its own distinct needs and preferences.

"Over the years we've learned how to best set up a fire engine for most efficient use in our service to the community," he said. "So that's what gets down here. It's about two weeks or so of time that individuals here will fabricate the compartments and start putting equipment on the engine and setting it up the way it's gonna be when it goes out into a fire station and begins running 911 calls."

Ron Fox, the county fire department's fleet manager, says his mechanics are as invested in the mission as the front line firefighters.

"At the end of the day we're working on stuff that saves people's lives," Fox said. "That's the one thing I say when we hire new mechanics, is this thing could respond to your family, so you need to be thinking about that when you're working on them."

The older fire engines being replaced will go to fire stations that may experience less demand, cover fewer miles or otherwise face lesser challenges. One will be the new front line engine at station 66; the older engine next door, is the oldest engine still in service - model year 1997. Eventually, an old engine may be auctioned off, reconfigured for a different use or end up fighting fires in a different country.

In a few months, as the Wisconsin-based manufacturer completes another batch, the process will repeat itself.