Cwm Happas (Welsh for ‘Happy Valley) is a 4mm scale OO9 layout set in Wales. It depicts a narrow gauge line winding its way through hills and tunnels from the bottom of the valley to the top. As well as passenger trains, slate and minerals are moved by rail.

Operationally, Cwm Happas is an out and back line, with a reversing loop at the top of the station. As the layout is DC, the operator has to remember to switch the power on the loop before sending a train back down the valley. At the bottom, locomotives are turned on a turntable that sits beyond the station.

Cwm Happas was donated to the Club. It was originally built as an at-home layout; hence the operating controls are at the front, rather than behind the backscene. It was first exhibited by us at the 2020 Spring Show.