At Australia's largest coal export terminal, a 550-tonne excavator breaks down and maintenance supervisor Kenny and his crew have to track down the fault before it costs the operation a full day's production. Tradesperson Darren works through the strip-down and service of a 23-tonne gearbox, while mechanical fitter Sean runs into a problem underground: the lifting point needed to raise a roof support has gone missing, forcing him to improvise a fix on the spot. The episode follows these three jobs in parallel, with the crews explaining what they're checking for and why as they go, and the cameras staying close on the actual mechanical work, oil, hydraulics, cranes, torque wrenches, rather than cutting away to generic industrial b-roll. It is one episode of a series about heavy machinery maintenance across Australian mining and industrial sites, built around the pressure of deadlines and the scale of the equipment involved. The stakes are practical throughout: every hour a machine this size sits idle is production lost.