Class 50 locomotives in Cardiff Two Boden Rail Class 50 locomotives - Nos. 50017 Royal Oak and 50007 Hercules - approach Cardiff from Washwood Heath on a mission to collect a failed Colas locomotive. The locomotives were built 1967-8 and retired from British Rail service in 1994. The former is in Network SouthEast livery, adding a splash of colour to a grey and wet day; the latter is in BR blue livery.