A cursory browse through the growing catalogue of reports on this site may have had you under the illusion that this is a pastime without pitfalls.

It is for this reason that I have decided to incorporate a list of massive urban exploration failures – to serve as a reminder that things rarely go to plan, and that some of the more memorable adventures are those that end in disaster.

And so with that in mind, I have decided to kick off with one from the vaults… a catastrophe of epic proportions, that befell during an exploration of Bristol’s network of caves and forgotten rail tunnels back in 2009.

Here’s what a local paper had to say about the event:

First off, I’d like to address a few errors in the reporting:

• The caver’s rope did not snap
• The caver did not fall
• “The caver, thought to be in his 30s”, was actually accompanied by a dashing young explorer in his 20s; to whom fell the responsibility of climbing back out, getting to the main road, and fetching help.

Here’s what really happened.

A friend tipped me off to the existence of a tunnel network, located deep beneath the rocky bluff that supports the Clifton Suspension Bridge. Some parts consist of natural caves, while others were blasted out during the mid-nineteenth century. The celebrated civil engineer Isambard Kingdom Brunel had a vision of building an underground railway system, for transporting freight between Bristol city and the nearby docks. This pioneering mechanic oversaw the creation of the first railway tunnels, and began the construction of brick-lined passages deep beneath the city. In 1859 however, the dream died with him – those left behind decided that the notion of underground trains would never catch on, and the existing tunnels were sealed up and forgotten.

Myself and the friend in question found our way in easily enough. He had been before, and was keen to explore a deeper cave system that led off from the main network. To this end, he had packed a ladder for the descent.

From the discreet entrance hidden just off a main road on the city’s outskirts, we had to squeeze through a narrow rocky fissure to reach the abandoned train tunnel beneath. This meant crawling on hands and knees through a shaft lined with thick webs, from which hung dozens of fat black spiders and their powdery-white egg sacks.

Once past this first ordeal though, we came into a long, vaulted chamber. Here the walls and ceiling were embellished by Victorian-style brickwork, while rusted iron pipework sprouted from walls and floor.

This was as far as my friend had been before, and he eagerly showed me to the next challenge… a vertical brickwork shaft at the far end of the tunnel, whose depths were well beyond the reach of our torches. He opened his bag, and brought out the ladder.

Now, I had been imagining one of those compact metal ladders you sometimes see in outdoor sports shops; solid construction and metal rungs, which roll up to fit inside a cylindrical canvas bag. Instead he pulled out a homemade rope ladder, which he had tied together the night before. He proceded to attach the top end to one of the metal pipes extending from the floor, dropped the other over the precipice, and gestured for me to give it a go.

“After you,” I said.

I still don’t know exactly how far the tunnels go – but I have heard rumours before and since that they connect to other natural fissures, and lead right beneath the city itself. One of these fabled tunnels was supposedly built to connect the pirate Blackbeard‘s house to the docks, for the purposes of smuggling.

My friend started climbing, and was making good progress at first. It turned out however that the shaft opened up into a bottleneck after a drop of roughly ten feet; one moment he was making his way down a narrow well shaft, and then suddenly the walls disappeared from around him, and he was swinging free in the darkness. He panicked, and his foot got twisted in the rope – tangling worse the more he tried to struggle.

As I said before, the caver did not fall.

He struggled blindly to the bottom after losing his torch and one of his shoes, the ladder coming to pieces in his hands, and at the end of the rope he dropped with a heavy splash into the water beneath. Shaking and shivering, up to his chest in the black water, he called up to me to get help.

Unsurprisingly the cave didn’t have mobile reception – so I had to climb all the way back out, and get down to the main road. I called the fire brigade, waited, and then flagged down the engine when it arrived. There was nowhere to park along the busy main road however, so soon there were police on site redirecting the traffic into one lane. I had to lead a team of four firemen down the shaft, through the narrow crack and into the main chamber, all the way to the edge of the pit.

Sending a man on a harness and winch down the hole to fetch my friend was easy enough, but the fire brigade didn’t leave just like that – the members of the White Watch team had no idea that these tunnels even existed up until now. Equipped with harnesses, climbing ropes and spotlights, they couldn’t resist the chance to have a little explore around the caves for themselves.

When we eventually made it back out to the light of day, we were in for a surprise; five fire engines, two ambulances and a police car stood in wait, while traffic was backed up as far as the eye could see. The fire brigade must have been having a quiet day, as most of them were down in the tunnels already. A couple of paramedics insisted on giving us a check over in the back of an ambulance, but it was the next meeting I was dreading.

As it turned out though, Her Majesty’s Finest were a pretty reasonable bunch. The two of us got a good telling off, but no more. After all, the caves were located on public ground and we walked in freely – Old Bill had nothing on us.

“Do you always dress like that when you go caving?” one officer asked, sneering at my trainers.

So the moral of the story is… well, I expect you’ve already worked it out.