15xx Class 0-6-0PT 1501 leaves the Severn Valley Railway's Kidderminster station on 17 April 2016 with the late running 09:30 service to Highley, while 50035 Ark Royal waits in the background, ready to follow it out with the 09:45 Kidderminster to Bridgnorth. Although designed by the GWR, the 15xx Class did not appear until 1949. Ten of these unusual outside cylinder pannier tanks were constructed, of which 1501 is the only survivor. The design was not particularly successful, as their high axle weight restricted their usefulness. They were largely employed on empty stick workings between Old Oak Common and Paddington.