United Kingdom, June 19 -- Alstom, global leader in smart and sustainable mobility, is delighted to announce that Thomas the Tank Engine documentary, An Unlikely Fandom, will receive its UK premiere during this summer's The Greatest Gathering.Alstom's three-day festival in Derby will be the world's largest-ever gathering of historic and modern rolling stock. It forms part of the wider festivities for Railway 200, a year-long celebration marking the opening of the Stockton and Darlington Railway (S&DR) on 27 September 1825 - and a journey that gave birth to the modern railway. An Unlikely Fandom: The Impact of Thomas the Tank Engine explores the profound influence of the beloved children's television series on popular culture and its endurin...