We're trying to find out some info on some distant family, one of who worked on the railways in days of old. Could anyone give any info on this picture please? Location could be difficult, but an idea of the year, type of loco and nature of the work this loco would carry out. It's possibly pre-nationalisation as there's LNER on the tender. The loco number is 4124.

Thanks very much for any help.
The Stoat.