Toby is based on the GER Class C53 0-6-0T Wisbech steam tram (reclassified as J70 by the LNER) built at Stratford Works. They were seen by the Reverend Wilbert and Christopher Awdry on a holiday at Yarmouth, hence Toby's origins. The J70 started their career on the Great Eastern Railway and were known as C53. They spent most of their career on the Wisbech and Upwell tramway pulling slow goods trains and, until 1927, passenger trains, though several were also assigned to the docks at Ipswich and Yarmouth. The first withdrawal came in 1942. Eventually, the sole survivor of this class was withdrawn from service and scrapped at Stratford Locomotive Works by 1955. They were replaced by BR Class 04s, Mavis' class.