Hi,
Digging around on www.old-maps.co.uk with co-ordinates of 506121, 164170 (or hopefully this link will work: http://www.old-maps.co.uk/maps.html)...
The post-WWII 1:2,500 map shows a long siding, then loop, then fork into two sidings, perpendicular to the quay.
You may get more detail if you subscribe (I don't).
Cheers, Steve.