Working on the massive job to reconstruct steam train 'The Night Owl', the Bikers forge a steel wheel taller than they are for the biggest locomotive restoration in Britain. Dave's first job was in a steelworks, and so was his dad's, so he's going back to his roots. The boys also help with the oldest steam engine still on-site in the world, sending Dave down into the cylinder to check out its condition after 60 years of neglect.