Charlie Stewart is the father of Andy Stewart who was injured in a rockslide outside the Ffarquhar quarry complex in the episode, Little Western.
Bio
After getting off Bertie, the workman crossed the road towards Arlesburgh Shed where he met both Oliver and Duck in their berths. Despite Duck's confusion, Charlie Stewart introduced his name after he thanked Oliver for rescuing both his brother and Tom Marc, another workman who are both recovering in hospital from their injuries. After saying thank you to Oliver, he walked away. Oliver said to Duck his account of events about what happened with Andy Stewart and being introduced to Thomas, Bertie, Percy, Toby and Harold along the way to the quarry.
Knowing that he was late, Oliver went to Knapford station where The Fat Controller was waiting and after telling him about the emergency, he sent Oliver to collect a passenger train and take it along The Little Western, starting off with Tidmouth Hault. This is where both he and Duck were arguing with each other before the 5700 Class moved off to collect his next train back to Tidmouth.