David J Hayes says "I'm guessing this is the English side of the Severn Tunnel? (Yes it is -Tony). Assuming it is, I thought at first that it might be a special Merry-Go-Round (MGR) coal working from South Wales to Didcot Power Station (DPS). However, the 6Z51 inter-regional special headcode would suggest not, as DPS is (or was) located on the Western Region, so the use of a letter "Z" would not be applicable. Could it, therefore, be a special MGR empties from Aberthaw Power Station (but to where?) or perhaps the wagons were in use for fly ash used in connection with road/motorway construction?"

and " Further to my earlier comment and having since viewed an enlarged version of this image the hopper wagons do, indeed, appear to be loaded with coal. Assuming the train has originated in South Wales, which seems most likely, Didcot Power Station could actually well be the destination, despite the inter-regional 6Z51 special headcode being displayed. Or has it, indeed, originated off the Western Region and perhaps traversed the North & West "Welsh Marches" line axis or is it a special consignment of Welsh coal destined for a Kent cement works or paper mill? Further food for thought..... "