"John B" wrote in message
ups.com...

Blimey, you mean it's legal to walk through it? Always assumed it was
strictly motorway-tunnel-style "no pedestrians, cyclist, horses or
stuff that's on fire".

Yep you can walk through it. I have done an amount of technical work
relating to that tunnel and even we are amazed that people choose to walk
through let alone cycle! I don't even like it when I have to go down for
work (Either driving through, or at night when its closed)

If you are planning a trip then don't hang around its gets quite 'foggy'
down there some days and everything is soot covered (So touch nothing!) and
watch out for the vans as the come round the bends - you don't want to get
taken out by a wing mirror.

As other have said all of the vent shafts are there - none are missing, and
all are very much in use.

If you drive through leave the car/van radio on - if your really really
lucky you might hear something interesting.