Single-phase 25kV electrification of Sardinia railway: some particular problems related to an electrified railway located in an island

Italian railways are in the process of electrifying the main railway trunk of the Sardinia island because of future railway traffic increases which will probably make the use of diesel locomotives disadvantageous in a few years. The so called `Dorsale Sarda´ will connect the most important cities of the island from Cagliari to Sassari and Olbia passing through Oristano. The authors examine the technical reasons behind the use of a 25 kV, 50 Hz system and describe the benefits of such a system