You can see much of the mine on the NLS aerial photos, just on the edge of the coverage.

MB

Some proper location information. The miners housing (Castle Square, etc) were around NS704588, while the shafts of the colliery were (are, hmmmm!) close to NS702586. Both areas covered with modern housing.
Navigator

I've changed the Map Sandbox content to the values given above, and placed the colliery location as the coordinates for the other map links.

In old-maps this shows it to be Bothwell Castle Colliery Pit No 1, with th e Caledonian Cottages to the north west, where the second marker lies.

If the miners had just followed the railway track to get to work, they couldn't have made any more noise walking that the locos and trucks of the time would made to disturb the sleeping gentry. Doesn't seem much point in having a tunnel under an active railway of the time.

Quoted from The Navigator

You are a bit out there, Captain.

Yes I was indeed. I think I was 'blinded' by the location being described on the accident report as between Uddingston and Bothwell and never bothered to consider it was within Bothwell. I'd say the 'tunnel' must have been the through and alongside the railway where it goes under the main road which would tie in with what Apollo suggested and by the looks of the locality there were miner's rows situated to the N.E. of the pit.
The old NBR line under the road line has been converted to a pedestrian path last time I looked.

Most of the newspapers have coverage today of the TARA wartime pictures on the RCAHMS website

Google Earth during the Second World War: Amazing aerial images taken by the daring Allies which revealed Hitler's weapons

Flash, bang, wallop – high point for war pictures

RAF's wartime reconnaissance photos go online in new archive

MB

Just browsing through some of the images to see if there is anything that I could look for on modern images.  The camp in the foreground of "Dumbarton, Scotland, Sortie 540/A/417 PFFO, Frame 0394" shows nicely on Google Maps aerial view.  You can identify the bases of the various buildings seen on the 1949 image.  All gone now of course so will disappear from the next update to Google Maps.

MB

The original pics must have been incredibly sharp.  The Daily Record yesterday showed Colditz and you could see the prisoners wandering about.  The online pics are nowhere near as sharp nor was the one the BBC used.

Poking around for something else, I found an article from 1999 which referred to the tunnel mentioned above, for Bothwell...

New Statesman - Fresh in from far out - Bothwell