Tunnel

I have returned, as promised, to look further. Was there a spur built into the tunnel, running away from the main line towards the Project Riese complex? Dug out in total secrecy during the war, then bricked off as the Red Army was closing in, hiding who knows what? Only one way to find out.

[Health & Safety note: I know what I'm doing. This is a live line, with one train train running in each direction every two hours. The twin-bore tunnel is 1,170 metres long - a 12 minute walk in usual circumstances, no more than half an hour taking it slowly. I check the train app (Bilkom) for train times and delays. The next one is due on time. So I have to keep a close eye on my watch. I'm wearing a high-visibility coat, trousers with knee-pads, stout boots and a hard-hat with miner's-style lamp on the forehead.]

Below: I approach the tunnel (this bore built between 1909 and 1911, the other one between 1876 and 1879) from the north-west portal. If the Nazis had built a spur running off from this tunnel, the line towards Riese would have swung off to the left. Click to enlarge - you can see the light at the other end - the tunnel's dead straight. Right - so where would the signal box have been? Here - a concrete bunker behind and to the left of me.

Below: I go in, turning back towards the north-west portal. Look at the brickwork along the right of the photo...

I am looking for anomalous bricks, mortar, joints, gaps - anything that might suggest that a stretch of brickwork was removed, an underground junction created, and then sealed off again. Tapping the bricks with a small hammer to check whether there was the dull thud of sound brick against solid earth - or the resonant echo of a hollow space... Why does one brick make a certain sound when struck, while the next brick quite a different sound?

Close-up on the bricks, the mortar, the layers of soot (this line was steam-powered until the 1970s), the lichen; some bricks are damaged by age, their facing has dropped off, others are as sound as they day they were laid.

Every 25m there is a refuge - a shallow indentation built into the brickwork - allowing workers to shelter as trains pass. These are outlined in white and are easy to see, even in the dark. But there are also two short transverse tunnels, linking both bores. These are low, less than a metre and half high, and about 12m long. One is 550m from the south-east portal, about halfway through the tunnel, the other is 275m from the north-west portal, about a quarter of the way in. There's apparently a third such link, but I saw only two...

I had gone this far when I took note of the time; there will be a north-westbound train in around eight minutes. This will be a good place to watch it pass in safety. I watched the minutes pass on my phone. Then - right on time, I heard the train's horn at the south-east portal. I switched off all my lights and sat, several hundred metres below the surface of the earth and over half a kilometre from either portal.

As the train approached, it acted as a piston - this is a phenomenon well-known to Tube passengers. A mighty rush of wind blew through the narrow transverse tunnel in which I was sheltering. The short train passed quickly. But as it did, there was a tremendous suction of air rushing around me, back the other way, replacing the air displaced by the train. Quite an experience!

Once it had gone, there would be two hours until the next train. I walked on to the south-east portal. Below: looking into the tunnel from the portal, the first two refuges are visible, as is the north-west end of the tunnel in the distance. Deep underground, the mind plays tricks. Was that a human form, stationary, silhouetted against the light of the north-west portal? As I got closer, could I see the shape swaying somehow? It was clearly there... Who is it? Are they waiting for me? Turned out to be a branch of a bush, waving in the breeze.

Left: just outside the south-east portal, there's a drainage culvert taking water from the hillside and under the track. The quality of the engineering shines through.

Below: looking at the south-east portal. Note the bridge in the foreground. The north-westbound track goes under the left-hand span; the central span did not have a track under it.

I'm not giving the game away to those not in the know as to the tunnel's location! Those who are in the know, who've followed the story here will be well aware of where these pics are from.

This time last year:
Planes and trains on pedestals around Poland

This time five years ago:
Twilight, ul. Karczunkowska

This time eight years ago:
First hints of autumn in the air

This time nine years ago:
Slovakia - we were not impressed

This time ten years ago:
Jeziorki - late August cultivation