Jeremiah Jobling is a man that once was on James' passenger train in 1948 which he had some bootlaces to give the engine's crew some of these because of a broken brake-pipe.
When James bumped the passenger coaches too hard, it caused a leak in a carriage's brake-pipe. When the crew announced if anyone had a bootlace, it was Jeremiah Jobling who had them. When the Train conductor told him to please hand it over, the man said he won't and the passengers would say this is going to be a "bad railway" after all. However, James' crew hopped into him and whistled so loudly that the passengers called Jobling a "bad man" instead. He gave the Train conductor his bootlaces and the problem was fixed. It was clearly unknown if the laces were given back to Jobling.
In the television series starting off in season three, Jobling after the 1948 bootlace incident ironically appeared in two episodes as a railway inspector who needed to see The Fat Controller immediately at the station. James and Thomas actually took him to see the NWR manager or took him home to his hometown. The two episodes were No Joke for James and Thomas, Percy and the Post Train. Since the fourteenth season in CGI, Jobling is often seen with a lady who could be his wife, Mrs. Jobling.