The visit begins well: pedestrians have a choice of walking down the gentle slope descending to the tunnel entrance or nipping through a welcoming gate and down some steps. At first, with the open air above and an adequately wide footpath, all seems good.
However, the interior of the tunnel is definitely not pedestrian-friendly. As the inscription above the entrance reminds us, it was opened in 1908 when most traffic was horse-drawn. Although the air may have been made piquant by horse manure and the occasional petrol engine, it must have been like nectar compared to the thick exhaust fumes filling the space today. Whatever the Edwardian creators of this tunnel may have intended, it's no place for the non-motorist now.
While pollution and congestion are the main criticisms levelled at the tunnel by modern users, the concerns at the time of its construction were rather different. That gentle entrance slope (vital for horse-drawn vehicles), the ventilation shafts and the new roads all take up substantial space, and the 3,000 local residents displaced by its building were vehement opponents of the scheme. Nonetheless, London County Council proceeded with the project.
The wonderfully-named Sir Maurice Fitzmaurice, the council's engineer, designed it; Edward H Tabor directed construction. Fitzmaurice had been engineer (with David Hay) for the Blackwall Tunnel, before going to Egypt to work on the Aswan Dam. After his return to London, he was the council's chief engineer and among his other major projects was the Woolwich foot tunnel.
Part of the construction was by the cut-and-cover method but most required the use of tunnelling shields. Their cutting edges remain on-site, forming the entrance arches to the tunnel which is lined with cast-iron segments, covered in tiles. It is just under 1.5 kilometres long, and its maximum depth is 23 metres below the surface.
Given that length, ventilation is essential. There are four ventilation shafts: two marked by cupolas familiar to travellers along the Thames, and two rather more plain models set back from the river. The cupolas have staircases which once allowed pedestrian access to the tunnel, but they were closed due to damage in the Second World War and have never reopened.
From the Rotherhithe end, the tunnel soon angles to the right and so it emerges further east across the Thames, in Limehouse. The tunnel's purpose was to serve the docks at its termini; a straight line between them would have had two problems - the docks themselves were in the way; and it was feared that if there was daylight visible ahead, horses might bolt.
In 1908, the tunnel was opened by the Prince of Wales (the future George V). Welcoming 2,600 vehicles a day, it was considered a great success. Today, about 34,000 pass through each day, along with an estimated 20 (fool)hardy pedestrians. As for me, having washed the exhaust fumes away, I'm in no hurry to descend into the tunnel again.
Further reading: Dr Amanda Squires' article for Rotherhithe & Bermondsey Local History Society. Fin Fahey's photographic comparison ofthe entrance 1909/2006. Wonderful photos of the tunnel's construction in the Science & Society Picture Library.
I have also walked in the more pleasant Woolwich foot tunnel and - just before London Overground moved in - the historic Thames Tunnel.
