I left the house as my wife was going to bed. I'm spending a night with the staff of London Underground as part of our research project looking at the lives of some of the million people in Britain who regularly work at night.

It's a very strange sensation to be going to work when everyone else is heading home. The night bus smells of stale alcohol as we weave our way through East London. I've spent the last five hours tossing and turning in bed, struggling in vain to get some sleep. The words of one of the other shift workers I had interviewed came back to me "the more you try to sleep, the harder it gets." I wonder what on earth I was thinking when I came up with this project.

When I get off the bus, the King's Cross area is busy. Hoards of people are milling around the station. Again, the smell of alcohol fills the air. Couples embrace before heading off in different directions. The crowds of merry-makers are mixed with groups of workmen in high visibility jackets, lugging tools, boxes and bags towards the entrance of the station.

Inside, the corridors and platforms are full of people on ladders adding emergency lighting, building new ramps, assessing how to solve drainage problems, switching electrical supplies, testing fire systems, repairing the ticket machines, checking the rails and points. It is heaving. I had never imagined that there would be so many people. "Every underground station is open at night," one of the engineers explains as we wander around. "There are over 400 hundred people working down here on the average night."

The tube stops running at 1am, after which point the legions of contractors arrive. They work to strict deadlines. At 4.52am the first trains start running. By this time the contractors have to have fixed, checked, replaced or cleaned whatever they've been working on. They are under massive pressure, if they don't finish in time then the journeys of millions of Londoners will be disrupted. If they make a mistake or forget to clear away a piece of equipment from the lines, it could be far worse.

"This pressure gets to them," Dave tells me. Dave is a controller. He sits in front of the bank of cc-tv screens, monitoring the public during the day and the contractors during the night. "You can see what they are all doing from up here," he says, waving his arms at the wall. "There can be so many of them. Literally hundreds. One of the things we've got to watch for fights breaking out. Yes, physically fighting. Fists and everything. They're all crammed into these small spaces and need access to different things. Some need the power on; some need it off. They all work for different companies and have loads of targets to meet. If they don't their companies get fined. The pressure builds up down there and they crack. We're the ones who have to go in and break them up. I dunno what's worse, dealing with the public or the contractors."

Later, in the very early hours of the morning, one of the station supervisors reflects on how much gets achieved every night. "Everything down here is at least fifty years old," the station supervisor tells me. "It all needs checking, repairing and modernising. There just isn't enough time. People need to get in and out with their gear and everything needs to be tidy before the first trains roll out. The tunnel dust gets everywhere; it permeates everything down here. Cleaning up takes ages. But there would be no tube if we weren't here. Without night workers, London just wouldn't run."

He's right. Our lifestyle depends on the legions of people who keep our cities and infrastructure running. The office cleaners, the hospital staff, the emergency services, the bus drivers, postal workers, cab drivers, factory workers, call centre operators, hotel workers, engineers, lorry drivers, shop keepers, the people who our water, electricity and gas supplies running, the people who keep our supermarket shelves stacked, the list goes on and on.

As we move ever closer to a 24-hour society, night work is going to be an important part of the modern economy. The night work force is likely to grow in the foreseeable future. And yet most of us know very little about night working or the night workers themselves. We know little about how working at night affects people: their health, their social lives, their family lives and relationships.

With the support of the Big Lottery Fund, the Young Foundation is undertaking research looking at the UK's night work force. We're spending time with night workers, listening to their stories and experiences to find out more about their needs and the problems and issues that are particular to working ‘the graveyard shift'.

If you would like to find out more, tell your story or even take part in the research please take a look at www.nightworker.org