Just wondering if anyone has 'done' a tunnel and walked through a disused one that is still accessible? In particular any big ones and what is the experience like? I have gone to look at the old Harecastle tunnel and whilst it has a gate, it probably wouldn't be too difficult to go in. But going right up to entrance gives a rather forboding feeling given the sheer size of it, ironic considering this tunnel was closed because it was too small for the overhead wires.
Apart from the obvious things like a good torch and a helmet, is it a reasonably safe, if spooky, experience?
The answer is it varies according to the tunnel concerned. Some are benign whilst others are quite hazardous but manageable if one takes suitable mitigations, whilst a number are extremely dangerous for one reason or another.
Collapses are rare, though a small number of tunnels have suffered collapses since closure. Ones which spring to mind are Burdale (which has two collapses and thus a sealed section in the middle), Perridge, Cheadle, Bolsover, and more recently Lydbrook. So accessing *any* tunnel carries a small but tangible element of risk. There are a small handful of tunnels which are deemed too dangerous to receive an internal inspection or maintenance regime. Whilst one may wish to work on the basis that being present beneath a collapse at the precise moment is statistically sufficiently unlikely to be a worry, quite a few tunnels have had one end blocked up so any collapse could block the single point of exit, which is another point to consider.
Other potential hazards are flooding or bad air. A handful of tunnels have suffered partial or complete flooding over the years, whilst a handful of tunnels experience issues with gases or various kinds. Another risk one might not readily think of is that most tunnel portals are situated in cuttings, sometimes deep, and there’s always the possibility of landslide, particularly during prolonged periods of wet weather. Tunnels in urban areas may contain detritus such as needles, or even undesirables lurking inside.
Entering disused railway tunnels is an extremely rewarding, interesting and at times spectacular pastime, but one needs to be clued up on the potential hazards. There's plenty of material on the internet which will assist in making informed decisions, planning being the key to an experience which is as safe as practicable.
