Prior to 1997, Sudan's railways, then the largest network on the continent, transported millions of tons of goods and passengers annually. But two decades of US sanctions have crippled the railway system. Unable to import spare parts to repair eroding tracks and a long-outdated fleet of locomotives, Sudan has been forced to ground most of its trains. Many Sudanese hope that during its final weeks in office, the Obama administration will partially lift the sanctions. A programme prepared by Patrick Lovett and Elom Marcel Toble