The first three teams are set the challenge of constructing layouts based on the theme of classic movies in just three days. The scratch-build challenge involves lipstick and high heels.
Heat two's theme sees the judges tuning in to model railway layouts inspired by beloved television programmes EastEnders, Doctor Who and Blackadder Goes Forth.
In heat 3, Team Tonbridge, Basingstoke Bodgers and Team Steampunk are tasked with creating layouts inspired by locations around the world. Sponges and plungers feature in the scratch build.
The Fawley Fliers, The Diesel Dynamos and The Railway Children are the teams competing, and they each have to create a railway layout based on the creatively taxing theme 'Fire and Ice'.
The Wakefield RMS, Aberdeen Model Railway Club and the Shunter Guys compete for a place in the final by creating railway layouts based on the theme 'Waterworld'.
The five teams compete in the final on the theme A Journey Through Time, creating models based on the Cold War, the industrial revolution, 1950s West Country railways, the 2012 Olympics, and all the way into the future.