The Railway Conversion League lives on? A former work colleague, who was a railway manager for some years, was told by a GWR senior manager a while back that there were concerns about running a passenger service through Pill tunnel, as it is slightly below gauge for passenger trains. He pointed out that trains run through Ledbury tunnel which is well below gauge, and that, since all stock now has sliding doors and non-opening windows, narrow tunnels shouldn't be a problem! I imagine this also applies at Whitehaven and perhaps one or two other places.