World's swankiest manhole covers? A thrilling tour of the new embankments concealing London's £4.6bn super sewer

The Guardian

5 days ago

A group of colossal black tombstones has landed on the north bank of the Thames in London, looking like mysterious monoliths from another civilisation. They stand near Blackfriars Bridge as imposing bookends, rising almost 10 metres, folded in places to form platforms and benches, slipping down in others to become one with the pavement. Water trickles from the summit of one huge slab, running down ridges and splashing into a sunken pool. Another pair rise straight out of the river wall, hoisting wooden fenders with them from the swirling brown waters below.
'I wanted to make something that comes from nowhere,' says Scottish artist Nathan Coley, as he clambers on to one of his concrete blocks, which form part of the most prominent new public artwork in Britain's capital, set to be unveiled next month. 'They are chunky, abstract, brooding objects that don't reference anyone or anything. They can be joyful, beautiful and brutal at the same time.'
Coley is better known for his big illuminated signs, but there may be a good reason he didn't want his sculptures to reference their subject this time. His slabs are the most visible part of the Tideway project, London's £4.6bn super sewer, built to prevent 18m tonnes of sewage overflowing into the river each year. These enigmatic structures are, in effect, memorials to the era of flushing fecal matter straight into the Thames. 'The thing about the super sewer,' Coley says, 'is that it's all hidden. So no one knows where they're spending all this money. I wanted to make something really exciting to celebrate it.'
There has been much talk of Tideway's spiralling budget and endless delays, its questionable usefulness, and its boss's pay. But little attention has been given to the fact that a consequence of this costly pipe is a series of new, truly public spaces on the river, for the first time in a generation.
One of the seven spaces created as a happy byproduct of the sewer is the 250-metre long stretch where we're standing: a broad granite expanse dotted with trees, benches and Coley's black slabs.
From Putney in the west to Deptford in the east, Tideway's meandering 25km path has necessitated the construction of new bits of land, poking out into the Thames to connect the existing overflow sewers (or 'lost rivers' to the romantically inclined) to the new tunnel below. Totalling more than three acres, the spaces vary in size according to the volume of waste that must be intercepted and sent whooshing on its way in a spiralling vortex down huge new drop shafts – all of which happens beneath the neatly paved plazas.
'They are essentially giant manhole covers,' says Roger Hawkins of Hawkins\Brown, the architects responsible for the five central spaces, from Chelsea Embankment to Blackfriars, that together make up the size of Trafalgar Square. 'In an ideal world for the engineers, they would be fenced-off compounds that they could easily access. But instead, Tideway decided to create new public spaces, in just the same way that the original embankments were given back to the public in return for the disruption that was caused.'
Before Joseph Bazalgette built the Victorian network of sewers in the 1860s, London met the Thames with a muddy, sewage-soaked foreshore. The construction of the sewers led to the creation of the embankments: great brick and stone feats of engineering that introduced stately, tree-lined riverside promenades for the first time. Stroll along Victoria Embankment today and you will find the original cast-iron benches held up by sphinxes and camels, lamp-posts supported by entwined dolphins, and ornate sewer ventilation chimneys, or 'stink pipes', in the form of stylised doric columns. So how do Tideway's contemporary equivalents compare?
The separation of architecture and engineering in the ensuing 160 years, along with the rise of bureaucratic procurement systems, has led to somewhat more fragmented results. 'Tideway was a totally engineering-led project,' says a member of the team who has worked on it for the last decade. 'When you're sitting in meetings with a couple of hundred civil engineers, they see the architecture and landscape as a kind of fluff on top.'
Accordingly, the results feel less tied together by a unifying Bazalgettian hand than pieced together by committees with catalogues – something one artist involved describes as 'Screwfixation'. Service and inspection requirements mean the pavements have become hymns to the manhole cover, peppered with innumerable service hatches for sewer buggies, drones and probes. One site features 55 hatches in an area half the size of a tennis court. The spaces are not all yet fully complete and open, but they have the slight sense of engineering that has been tiled with a coating of architecture, and garnished with public art.
Still, there are some striking flourishes. One of the most consistent, recognisable elements, which help give the project a kind of site-wide identity, are the distinctive black cast-iron ventilation shafts. These modern-day stink pipes look like the funnels of submerged ships, twisting and flaring out as they rise to five metres, their form mimicking the path of the plummeting sewage vortex.
'At one point, I was asked if I could make them look like trees, in the way they disguise mobile phone masts,' says Clare Donnelly, Tideway's lead architect at Fereday Pollard, the firm in charge of coordinating the foreshore structures. 'You don't want to scream 'sewer pipe' at people, but we wanted them to be confident features in the landscape, not trying to hide.' Softening their heft, the funnels are inscribed with gnomic lines of poetry by Dorothea Smartt, alluding to the various lost rivers being intercepted below the pavement. 'The furious Fleet flows red with Roman blood,' declares a chimney at Blackfriars. 'Boudica battles bravely.'
There are other contextual nods. At Chelsea, in front of the Royal hospital, the brick river wall has been extended out in a sinuous sweep to form a swelling, brick-paved space defined by stepped seating, incorporating colourful stripes of glazed bricks by artist Florian Roithmayr. You enter through a gap in Bazalgette's original river wall, which has been radically sliced open, with the cut granite left pleasingly raw.
'We were thinking about the alluvial geology of the river,' says Marko Neskovic, partner at Hawkins\Brown, 'imagining the beach popping up and allowing you to walk on it, as if it was an eroding island.' The wall rises from the river in banded strata, stepping back as it climbs to form little planted intertidal terraces, with grooves for aquatic life to shelter. A tempting staircase leads down to the water, although it is sadly fenced off. The architects had hoped they could provide access to the beach for mudlarkers, but the Port of London authority (controller of the Thames) vetoed the idea on safety grounds. Officially, the steps are therefore an escape route, rather than an access point.
Despite the guidance to treat the river as foe, the architects have tried where they can to soften the relationship with the water. Most of the spaces slope subtly up towards the flood defence line, so you can see the Thames more easily rather than it being blocked behind the river wall. A foot-wetting frisson can also be had thanks to the incorporation of 'floodable terraces', which get splashed when big boats pass at high tide. Elsewhere, great iron mooring rings, grasped between lions' teeth, are now surreally marooned inland, giving you a sense of transgressing beyond the river wall.
While Chelsea opts for organic curving brick, the space at Victoria Embankment, known as Tyburn Quay, is a more sober granite plaza raised on a square plinth, reflecting the formal surrounds of Westminster. A faintly Miesian pavilion will house kiosks for a cafe and loos, its stone walls inscribed with the profile of Bazalgette's sewer, while an inlaid ring of bronze in the ground marks the location of the gigantic drop shaft below the paving. 'We tried to incorporate lots of things you could enjoy if you were a river buff,' says Hawkins\Brown's Fiona Stewart. 'Like using ductile iron in the paving at Blackfriars, to reference the iron deposits at the source of the Fleet.' Budding psychogeographers will rejoice.
The artist commissions bring further intrigue, from a forthcoming flotilla of trading vessels by Hew Locke in Tower Hamlets, to playful plinths by Studio Weave in Deptford, to Claire Barclay's cast bronze oar balustrades in Putney, marking the starting point of the University Boat Race. Tyburn Quay's grey granite decorum has been cheekily disrupted by Richard Wentworth, who has installed a series of cast bronze sandbags, which droop in haphazard piles over the stone steps, alluding to makeshift flood defences. 'It's a workingman's cushion,' says Wentworth, who has long celebrated the national culture of make-do-and-mend. 'I hope the sandbags will get shiny where people sit on them. And they're a little bit erotic. You can feel that someone might propose here.'
His saucy sacks are under wraps until the space opens later this year, but the texture of the hessian has been meticulously recreated in bronze by the Lockbund sculpture foundry in Oxfordshire, which is also producing his bronze benches for Albert Embankment, near the MI6 headquarters. In an allusion to the Vauxhall origins of sanitaryware manufacturer Royal Doulton, Wentworth has designed seating in the form of conjoined loos. 'I think there's something nice about sitting on the toilet with lots of other people,' he says. 'It reminds you that pooing is public.'