Tim was a black narrow-gauge tank engine, with a gold dome.
Tim worked on the Mid Sodor Railway with Duke and many other engines, as tram engine modified with sideplates to work on the roadside tramways that went to the mines at Cas-ny-Hawin. He waas one of the strangest locomotives on the railway because no one knew what locomotive class he was nor where he came from, but looked similar to the Avonside built Charlton class locomotives He was described as the more pessimistic engines of the fleet, and one of the first group of engines to be sold during the railways decline. He was one of the locomotives sold away in 1936. It's unknown what happen to him after the Mid Sodor Railway closed.
Tim is mentioned by name, but appeared on the Reverend W. Awdry's model layouts of the Mid Sodor.
Tim's basis was a Gem Vari-kit. He was built, by Awdry, as a generic tram locomotive.