I don't know whether the Barry Tourist Railway sidings are these BUT there are (rwo iirc) sidings running alongside what might have been an ex-railway shed (modern). The shed is more or less alongside Barry station with the sidings hidden behind it. Those sidings where home to 4 x 231 last time I looked.
That sounds like the Barry Tourist Railway (which runs/ran on its own track across the causeway to Barry Island).