Impossible Railways

Since the dawn of the 19th Century, rail networks have overcome almost all nature can throw at them. But there's one environment, which is their nemesis. Water. In this episode we discover how some of our greatest Railways have challenged engineering's greatest minds in their efforts to conquer our ‘water world's'. Whether bridging the notoriously swampy waters encountered in America's New Orleans, or tunnelling beneath the World's busiest shipping lane, the English Channel, or helping ships to navigate through the Panama Canal, each railway has solved a seemingly impossible problem, to create some of the most dramatic train journeys in the world.

A look at the planet's most incredible metropolitan railways, and how they help people solve distinctly urban problems. Including a project to upgrade New York's transit system.

For over 150 years, our railways have been pushing engineering to its limits, in order to open up our world. Trains can now travel further, and climb higher, than ever before. But for train engineers, it's the need for speed that has inspired the greatest innovations of all.

From the technology that allows trains to navigate the winding mountains of Spain at speed, to the machines that allow engineers to lay tracks in record-breaking times and the super-fast new form of transport for the future, Hyperloop One; this episode investigates the incredible engineering breakthroughs that allow trains to go faster than ever thought possible.