books.google.com - This book presents a thorough survey of electric railway development from the earliest days of the London Underground to modern electrified main line trains. Coverage includes chapters on signaling and communications, power supplies, and a detailed survey about traction systems, both AC and DC. The introduction,...http://books.google.com/books/about/Electric_Railways_1880_1990.html?id=cpFEm3aqz_MC&utm_source=gb-gplus-shareElectric Railways 1880-1990