Two platforms, but on the same side.
http://maps.nls.uk/view/104197876
There were a number of single sided broad gauge stations, and non Great Western narrow gauge* ones too, but as far as I know they were major stations on the edge of a town/city centre to make both platforms easily accessible. In less important places, passengers had to cross the line to get to the other platform.
*Narrow gauge AKA standard gauge to those with non broad gauge interests. Causes great mental confusion to those of us who model broad gauge, standard gauge and less than standard gauge (Broad, Narrow and Narrow Narrow?)!