Grwpiau

This looks like the old power station that was by the North Dock at 51°40'37.22"N 4°10'18.06"W from the 1920's.

You're right Tony, the south Wales main railway line was to the right while North dock was to the left, check this photo out,



http://www.oldukphotos.com/graphics/Wales%20Photos/Carmarthenshire,%20Llanelli,%20Docks.jpg



it shows the power station from the North dock (top right)



Dai

Would like to get in contact with the owner of these photographs.