Book excerpt: The London Underground Electric Train tells the story of the development of electric traction on the London Underground system. It combines technical knowledge, historical context and practical experiences, and covers the history of underground lines since the opening of the first deep-level underground rail system in the world in 1890: the City & South London Railway. The evolution of train design, including power, lighting, heating and design of the Underground cars is also covered along with the development of operational, engineering and safety devices on trains. Highly illustrated with period and new photography and technical diagrams, this book is a reference work for electric traction and underground rail enthusiasts.