Sir Herbert Nigel Gresley is Gordon and Scott's streamlined father, and Spencer's uncle. He's very competitive, and wants to prove his speed and strength. He is one of the preserved A4's, and is proud of his heritage like his sons, and can be a bit boastful. His wife is Great Northern "Gwendolyn" Gresley.
Sir Nigel, like Spencer, is based on the LNER Class A4, and is remarkably a real engine.