Sustainable Railways and the Impact of Freight Trains: The Case Study of the Shunting Area of the Strait of Messina

Rail transport is a sustainable mode of transport for people and goods due to its energy efficiency, lower greenhouse gas (GHG) emissions per passenger-kilometer and tons-kilometer, and reduced congestion on the road network. This paper explores the sustainability of railway transport, focusing specifically on the impacts produced by freight trains. Indeed, freight trains are usually powered by a combination of electric and diesel locomotives. Diesel locomotives are frequently used for shunting activities in shunting yards where the processes of sorting, organizing, and reconfiguring railcars take place to prepare freight trains for departure, while electric locomotives are usually used on long-distance rail routes. The emissions produced by diesel-powered locomotives pose worldwide environmental concerns, which is why regulatory constraints have recently increased. Considering the relevance of this topic, a case-study on the estimation of emissions from different diesel and electrically powered locomotives used in the shunting area of the Strait of Messina has been analyzed and discussed. The method used is based on the EMEP/EEA procedure outlined in the joint EMEP/EEA air pollutant emission inventory guidebook. The results show that implementing advanced technologies and fuels produced from renewable sources such as Biodiesel, Hydrotreated Vegetable Oil (HVO) and the future electrofuel Power-to-X (PtX), significantly reduces the CO2 emissions while maintaining the same performance level of the entire system.