The foreign engine (known as the Big City Engine in Learning Curve merchandise) is a tender engine from the LMS built at Crewe in May 1934. He once stayed the night in Vicarstown with Gordon and Duck. When Gordon remembered a trip to King's Cross in his youth, the engine told him he went to Euston, and Duck replied he really went to Paddington. (In fact, all three were right, but that's another matter). The argument continued even after the engine had left the next day.
Big City Engine was seen on Thomas The Tank Engine Wooden Railway seires.