R40510 Mark 1 CK Composite Corridor BR Maroon W15114Expected Delivery Q2 2026 (Subject to Change at Manufacturer's Discretion). The MK1 was BRs first standardised design of railway carriage with thousands built across BRs carriage works in Derby, Wolverton, Doncaster, York, Eastleigh, and Swindon between 1951 and 1963. The design was also used on first generation Diesel Multiple Units (DMUs) until 1974 and for non passenger stock such as parcel vans and full brake vehicles. The new coaches gradually