47531 passes Duffryn on 15 August 1987 with the 2V56 05:50 Portsmouth Harbour to Cardiff Central service. These trains would go over to Class 155 Sprinter operation the following year, but in 1987 it was mostly Class 33s or 47s, with occasional Class 31s, 37s or even Class 50s. With hindsight I should have taken more pictures of these inter-regional workings.