But I was about to explain something unexpected. So a took the class 66 on the King’s Cross line and drove out of London. And In the distance there was an unfinished tunnel and it was shaped like a London Underground tunnel. That can’t be the Bakerloo line because the Bakerloo line doesn’t go near King’s Cross. Could it be the Victoria line because it normally goes down that direction when it leaves King’s Cross towards Walthamstow central. Feel free to write your thoughts what line it could be.
Interesting I’ve not seen this but not sure if connected but on same route I did off rail scenario yesterday one train each each way using class 150 dmu to/from faversham journey from faversham being set as AI service and on my journey from London to Kent/faversham had flashing yellow signals all way from London tunnels to ebbsfleet international
Not entirely certain I've understood your question, but immediately north of Kings Cross is Gasworks Tunnel, followed by Copenhagen Tunnel. Both of these had unused bores. Between those Canal Tunnel emerges on the left. This is where the Thameslink line from St Pancras International joins the East Coast Main Line.
