>>1281199In 1981, British Leyland was planning their proposal for their Railbus. The main issue was that in 1981, British Rail did not want to get some prototype which was unproven.
So, British Leyland made a prototype, and gave it away fro free to Northern Ireland Railways in Irish Gauge, which was easier thanks to the already wide axles.
NIR liked it, and kept it running in service for many years until the BREL Class 450 (which was a Sprinter but in Irish Gauge) came into full service.
After the "success" of the Railbus prototype, British Leyland moved onto the Pacer, and they outsold BREL for a lot of DMUs.
