By 1880 the coal mine owners in the upper Rhondda valley needed an alternative outlet for their coal other than the existing Taff Vale Railway route to Cardiff docks. The Rhondda & Swansea Bay Railway was constructed in the 1880’s from Port Talbot into the Afon valley, the first section to Pontrhydyfen opening in June 1885. The line was subsequently extended to the head of the valley and through a 2 mile tunnel to form an end on junction with the Taff Vale Railway at Treherbert and, with a further extension in the opposite direction to Swansea docks, enabled coal produced in the Rhondda valley to be taken down the Afan valley and on to Swansea docks. It also allowed through running of passenger trains between Cardiff and Swansea via the valleys so relieving the busy coastal main line. The R.& S.B.R. and T.V.R. both provided through trains though engines were changed at Treherbert. As can be expected with the opening of this new route coal mining in the Afan valley itself developed rapidly.

The G.W.R. took a controlling interest in the R.& S.B.R. in 1906 and provided engines to supplement those of the R.& S.B.R. These engines were repainted and renumbered as R.& S.B.R. Locos.

We have based our model of Ynysafan on Pontrhydyfen as it would have been in the pre-grouping period. The baseboards are 12mm ply, the track is SMP Scaleway with scratch built points operated by wire in tube and ballasted with ash collected from local closed railways. All the buildings are scratch built, copied from old photographs and plans we have managed to collect of buildings that existed at Pontrhydyfen and Cwmavon. The prototypical rolling stock is a mixture of kit built and ready to run suitably altered for the period.