Beneath the River Thames in London lie the remnants of a marvel of 19th century engineering, once described as the "eighth wonder of the world". The Thames Tunnel, the first in history to run underwater, was conceived and built by Anglo-French engineer Marc Brunel, with help from his young son Isambard Kingdom Brunel, who would go on to become one of the true giants of Victorian engineering.
The tunnel, built between 1825 and 1843 in a protracted and oft-troubled construction project, ran from Rotherhithe on the south bank of the Thames to Wapping on the north bank. The tunnel was originally used by pedestrians, and indeed became an incredibly popular tourist destination, attracting around two million visitors a year. In 1865, the tunnel was purchased by the East London Railway Company for use as an underground railway between Wapping and the South London Line, and it is still in use today as part of the London Overground network.
Although Isambard Kingdom Brunel was heavily involved in many aspects of the Thames Tunnel's construction - even going so far as personally lowering a diving bell to the riverbed to plug a hole in the tunnel's roof in 1827 - the Thames Tunnel was Marc Brunel's baby, and the same goes for the entrance shaft at Rotherhithe. The shaft was installed using an ingenious method developed by the elder Brunel; instead of digging a shaft and lining it with bricks, the shaft was built aboveground and sunk into the soft riverbank, saving time and money by using the structure's weight.
The shaft was initially used as a spectacular entrance point for pedestrians, with twin staircases descending around the shaft's circumference to grant access to the tunnel below. The structure served as a ventilation shaft when the tunnel was later re-purposed for steam trains, leaving the walls blackened with soot.
In 2011, the shaft was bottomed out with concrete, separating it from the tracks below and allowing visitors to access the shaft. Visits and performances in the shaft today are organised by the Brunel Museum on the site of the Rotherhithe shaft and the restored engine house, originally built to house drainage pumps for the tunnel. Access to the shaft is somewhat limited by the narrow entrance and rickety scaffold stairs leading down to the space.
A photo taken by a concertgoer showing the ad hoc stairway leading down to the space, which has limited its potential as a performance and exhibition space. But that's all set to change with a new project announced in April 2015, which will overhaul access to the shaft and help support the Brunel Museum's aim to create an accessible, subterranean performance space whose walls are literally caked in Victorian history.
London-based architect Tate Harmer has designed the new entrance and access stairs; the above illustration shows the design for the museum's exterior, with the new public entrance visible beneath the Brunel Museum mural.
"We're so pleased that this project is to become a reality," said Tate Harmer director Jerry Tate at the time of the announcement. "It's a rare honour to work in such an important historical setting."
Of course, working within a historically significant edifice brings its own challenges. The shaft's status as a grade II-listed structure (in common with the rest of the Thames Tunnel) means that the new cantilevered replacement staircase will have to stand independently of the structure itself. The soot marks, after all, are protected stains of historical significance.
"We had to respect and protect Brunel's legacy while providing people the opportunity to enjoy the space in new and exciting ways," said Tate.
A wooden cut-out giving a three-dimensional view of the freestanding staircase and its relationship to the shaft. Tate Harmer's 'ship-in-a-bottle' design limits construction work to the new public entrance, and the freestanding staircase will improve access to the shaft while satisfying planning authorities that the interior will remain virtually untouched.
Permission to go ahead with the project has been granted, with construction work set to start in September and be complete before Christmas 2015. The result, as this render shows, could help revitalise the shaft as a unique and viable venue for arts and culture in the capital.
"We are delighted to be able to forge ahead with our plans to grant a new lease of life to this important piece of engineering history," said Brunel Museum director Robert Hulse. "Brunel was a showman as well as an engineer, and I'm sure he would have approved of holding performances in this new underground gallery. This will be one of the first exciting steps in the Brunel Museum's ongoing plans to preserve Brunel's first project and his enduring legacy for the enjoyment of the public."