The Spirit of Queensland's maintenance team race to change a bogie, the construction of a freight locomotive nears completion, and a breakdown crew hustles to get a commuter train back on track.

Skilled technicians battle with a stubborn alternator, a crew tackle a high-stakes engine rebuild for a freight train, plus it takes a team of experts to build a massive locomotive underframe.

A loco needs a double bogie change fast to get back to the sugarcane harvest, traction motors from mining trains are getting rebuilds, plus the heat is on for a tricky air conditioner replacement.