The upcoming event, The Greatest Gathering in Derby, is set to make history with the debut of the UK's first passenger-ready hydrogen train, the HydroFlex unit 799201. This innovative development is made possible thanks to Porterbrook, a leading rolling stock company. The event, scheduled for August 1st to 3rd at Alstom's Derby Litchurch Lane Works, aims to mark 200 years of passenger railways by bringing together a remarkable collection of locomotives. The showcased locomotives include iconic steam engines like the LNER A4 No. 60007 Sir Nigel Gresley and modern electric trains such as Class 390 Pendolino No. 390119, emphasizing the evolution of rail transport over centuries. However, the spotlight will undoubtedly be on the hydrogen-powered Class 799 Hydroflex No. 799201, symbolizing a new era of eco-friendly and sustainable rail travel. The decision to feature a hydrogen-powered train at this historic event signals a positive shift towards embracing cleaner energy sources in the railway sector. It underlines the industry's commitment to reducing carbon emissions and promoting environmentally friendly practices. By integrating hydrogen technology into rail transport, the event showcases the potential for innovation and sustainability within the railway infrastructure. The Greatest Gathering not only serves as a celebration of the past but also as a platform for discussing the future of railways. By combining heritage locomotives with cutting-edge technologies like hydrogen propulsion, the event sparks conversations about the importance of sustainable practices in modern transportation. The inclusion of the HydroFlex unit highlights the industry's efforts to adopt greener solutions, setting a precedent for a more environmentally conscious approach to rail travel.