Opened : (1907)

Closed : ?

Engineering code : (TFT)

Length: 150m

The Tinworks Tunnel is not a bored tunnel, but a covered passage beneath the exchange sidings at the northern end of the Cardif Railway. THis passage was built to take the unfinished northern extension of the Treforest Industrial siding northwards to Pontypridd. Since commercial services never ran over the exchange sidings, due to wrangling between thew TVR and the Cardiff Railway, and the northern portion of the industrial siding was never built, this is an unused rail tunnel. Even the girders used to align the base of the walls were never removed, and lie rusting, some having collapsed. It was porbably biult in 1907, along with the rest of the embankment. As a covered passage, not a bored tunnel, it has an unusual parabolic profile and is lined attractively in alternating stripes of black and red brick. It is also somewhat S - shaped.