4-SUB Unit 4732

The Heritage Electric Trains Trust is dedicated to preserving and restoring two iconic examples of 20th-century suburban rail travel: the Southern Railway’s 4-SUB EMU and the London Midland & Scottish Railway’s Class 503 Wirral EMU. Established in 2019 as a registered charity, HETT’s mission is to fully restore these unique units and eventually display and operate them, sharing their remarkable history with visitors to heritage railways across the UK. These trains, built between 1941 and 1951, and 1938 and 1956 respectively, served millions of passengers during the mid-20th century, connecting suburban communities across London and the Wirral Peninsula. Recognizing the challenges of operating third-rail electric units, the Trust is focused on equipping the trains with bi-mode technology, enabling them to be showcased and experienced in a heritage setting. The 4-SUB, a product of the Southern Railway’s innovative design, and the Class 503, a vital part of the Mersey Railway’s expansion, represent a significant chapter in British railway history, and HETT is committed to ensuring their legacy endures.