The Skirt Of The Black Mouth is a sculptural installation that frames the building site of the Tate Modern Project. It sits at the back of Tate Modern, near to IPC’s Blue Fin building and the offices alongSouthwark Street. The gallery’s new building is growing by the day, managed from a cluster of temporary portacabin offices, which rise from behind the burnt wood of the installation. There are tourists – groups of teenagers with matching backpacks; couples clutching guidebooks – but the people who eat their lunch in the space are most often those who work nearby. 

I’m interning at IPC
I work for Ofcom
I work for an events company
I’m an engineer
I sell mozzeralla and parma ham
I’m a security guard
I’m a journalist
I work for Groundwork
I’m a teacher
I work in IT – back office stuff
I’m an architect
I work for an ethical supply chain company
I’m a textile artist
I work for a bank
I’m a project manager
I am on holiday

I sit and watch people walk past – the careful tread of a woman in new heels; the lolloping gait of another in trainers and a smart skirt; three men hurrying to a meeting in their suits and polished black shoes.

We dress for work. A suit. A tie. Heels. Flats. Steel toe capped boots. A fluorescent jacket. A t-shirt with a machine-embroidered logo. Trousers spattered with paint. An ID badge hanging from a lanyard or clipped to a belt. This is what I do, our clothes say; this is who I am today.

He takes her a cup of tea each morning. Even though she’s asleep. Even though it’s too early for anyone to be awake – before the trains have started running, before the sun’s shown its face. It makes him feel better, stood at the gate in his uniform, waving the lorries into and out of the site, to know she’ll be waking up soon, will see the tea, cold now, on the bedside table and know he loves her.

What we do, day in, day out, affects how we see the world as much as it affects how the world sees us. If we build, we notice how things are put together; if we’re a textile artist we register the combination of colours on a vegetable stall; if we’re a writer we’re always on the lookout for a good story…   

It follows him wherever he goes – his eyes straying to ceilings and walls instead of exit signs and furniture. He sees the building’s body, its bones, its breath, each pock of air, each edge, each line; can guess how many rods and links are hidden inside; knows that just below the surface are the rough corners of stone.

The people who walk past The Skirt Of The Black Mouth – or stop there to eat a sandwich, take a phone call, drink a coffee – make up the city: carving their daily paths through it; running its transport; building its buildings; making its systems work. For some, their efforts are visible: a concrete wall; a shop filled with hand-woven scarves; an article in a magazine; an arts festival. For others, what they do goes unseen except by a few: making sure an IT system works; punching numbers into a database; planning for risk.

It is eerie, to walk into a just-made space and know it intimately – the lines on a piece of paper given dimension; a scribble in the margin turned to steel; carefully drawn rectangles now rough, baked brick. It is eerie, to turn a corner and feel surprised, even though you knew exactly what would be there. It feels good, to see it come about.

The Tate Modern Project is a huge undertaking, spanning years. The process of turning it from an architect’s drawing into a physical reality involves bringing teams from different companies together into what is effectively a new, temporary, organisation. The Skirt Of The Black Mouth has made some of that process more visible – through the slats you catch glimpses of people (men, mainly) in fluorescent yellow jackets and hard hats, the bulk of delivery lorries, concrete slabs, machinery. Outside the site, contractors and project managers sit on the installation’s concrete bench to eat sandwiches or smoke a cigarette; they walk up and down the street with their name badges and clipboards. Yet many people are surprised when I tell them about the new building – they assume it’s an office block, new flats, a car park, or they simply haven’t looked up and seen it at all.

She was taught to take her time and look around her: see the leaves turn to liquid amber; the birds pull worms from chestnut soil; the bees kiss one flower, then another, then another.

Visibility is about looking as well as about being seen. We might notice a fluorescent jacket or a smart suit, but do we really look at the person wearing it? We might glance out of our office window, but do we register what is going on? We might live in a city, but do we take the time to see it?