His nickname is the fat controller. The UN backed new …

A funny spoof of Thomas The Tank Engine, featuring the Fat Cont, the Fat Cont, the Fat Controller! Thomas the Tank Engine has made some gender-balanced and multi-cultural new friends following a politically correct revamp.

His name is sir topham hat. There is also the thin controller (Perigrine Percival) on the narrow gauge railway with skarloey etc. It's the author's way of differentiating between the two without using full titles each time.