Britain's iconic and 'secretive' engineering companies reveal how they build the world's most amazing machines. The first part of the series "How to build a nuclear submarine" a documentary following the construction of the Astute nuclear submarine. The second part of the series "How to build a jumbo jet engine", the story of the thousands of people who design, build and test engines at Rolls-Royce’s manufacturing plants in Derby and across the UK, making Rolls-Royce a central part of life for the people of places like Derby. The third and final part of the series "How to build Britain's secret engineers" when the documentary team follows workers at a leading British company on a global journey, as they reveal a handful of their secretive projects including getting Chinook helicopters ready for front line service.