Kayleigh is a diesel shunter who lives and works in the United States of America.
Kayleigh was seen pulling a goods train through Arizona, where she nearly collided with Thomas, Ace and Nia when they were rolling backwards down the Morenci Loop. Nia apologised to her, but the diesel reassured her that she was fine before the engines then set off again and parted ways.
Kayleigh is a wild, but sassy diesel who forgives easily.
Kayleigh is based on the Hudswell Clarke 0-6-0 diesel shunter which worked at the Manchester Ship Canal. No. 4002 Arundel Castle, affectionately known as "Billy", is preserved in working order by the East Lancashire Railway Diesel Group. Sister locomotive No. 4001 Alnwick Castle is also preserved as a static non-operational exhibit at the Winfields Store site at Rising Bridge. Frankie is another member of this class.
Kayleigh painted blue and orange with gold lining.