[0:03]Today's tube is full to bursting. We can't physically cope with the amount of people that we carry. Madam, come to me. That's it. Come on. Home sweet home. And the underground staff are flat out. Dealing with us. At ten past the hour a day. I just seen the person squatting. For the 20,000 people who keep the tube running. International rescue. Every day brings new challenges. We are a mobile Swiss army knife. Excuse me, sir. Ticket inspector. Yeah, but it's not a free service on the underground, is it? that could bring the tube to a halt. Chaos. Chaos. Chaos. Everything running smoothly has now gone the opposite route. See? Just like that. Until I get the shout, I'm going to stand here and just look pretty in front of my public. Chaos. Game. Chaotic as always. So this year, it's all change on the world's oldest underground. This could be the future. This could be the revolution. Join the revolution everybody. But for the tubes long suffering workers, it's more than a job. It feels like home. Just like family. Sometimes we love each other, sometimes we don't. This way out. I'm a parent and they're my children. Mate, mate. This is their story. We cope. Because that's what we do. We cope.

[1:35]This time on the tube, the secret army battling to keep the underground alive. Piccadilly Line is running an a 1973 stock train. That's how old it is. How the tube staff deal with the daily challenge of the rush hour. It's the same number of people who was making us walk all the way around. Pointless. When one small delay can send a whole line into meltdown. I don't know how it can be allowed. If we were animals, there'd be a law against it.

[2:12]The tube, going underground.

[2:24]Every working day, London is on the move. Right down inside, thank you. Millions of people commuting to work, study, or just out and about to have fun. Can you move down the back? Thank you. Move down. Wow. Huge amount of people suddenly and the platform's just not big enough to cope with it. The tube carries more passengers than ever before. But most of these, during two short periods of the day, when the traffic hits critical levels. Base two, Radio Five, too crowded. You can't get on, one minute for the next train. Today, staff on the underground have to battle around the clock just to keep Londoners moving and the network on track. This way down, please. But there's more to running the oldest underground in the world than meets the eye. North line down and left, please. Thank you.

[3:19]The Piccadilly is one of the oldest lines on the network, and it's all run from behind closed doors here at Earl's Court. You're receiving 234. Can you state your location and message for me, please? Over. It's 7:20 in the evening, and the line is running at full capacity. No problem. I'll get some staff down to help him out. Thanks for that, driver. Controller out. The Piccadilly, with its 53 stations, runs from Heathrow Airport, through the West End, out to North London. If the line goes down, it can affect the whole network. There's a guy, it looks like he's been sick on the floor and maybe over himself, so he might need some staff to go down and help him. You don't know, they could be drunk, maybe just not well. Imagine if they'd got sick on our train. We'd have to get it all cleaned and everything. Charlotte has spent her entire career underground, first as a station assistant, then as a driver. For the past three years, she's been responsible for one of London's busiest tube lines. I am in charge, theoretically, of the whole of the Piccadilly Line. So we deal with everything that happens, from signal failures. Drivers not being in position, so we have a train that's not moving, to passenger emergency alarms, so we get people fainting on trains or or being taken ill. All those calls come through to us, and we'll deal with that.

[4:37]To reduce a buildup of passengers, the pick tries to deliver a train every two minutes during the rush hour. Okay. It's just shut his doors literally now as we're speaking. Here he goes on the move. Oh wait. Cheers. Holborn, they're like five people deep queuing to get on one train. When that train comes in, and that train is is packed, then people ain't going to get on a train. They might be one or two getting on every single train that comes in. The Piccadilly Line has minor delays due to a shortage of trains. Message end. Out. Everyone's not really happy at the moment with the way things are running, but we're doing our best and that's all we can do.

[5:24]Not a job for everybody. I prefer working on me own. I'm not sitting at a desk, but it's not in an office where I've just got one view out of the window. My view is always changing.

[5:47]It does help being slightly insane to do this job. From Whitehaven, traditionally a mining town, go down the pits, go down the tube. It's a big black hole. What's the difference?

[6:03]During the rush hour, up to 1,000 people can squeeze onto just one of Keith's trains. If he's to keep the network running, Keith can't be stopped at a station for longer than 60 seconds. Miserable faces. Nobody smiling, which, let's face it, is understandable when you're going to get packed in like sardines on one of these. You basically can't see any piece of the platform. We've got to watch them basically like hawks. Actually nobody gets trapped in the doors, nobody falls between the train and the platform.

[6:38]Train is ready to depart, stand clear.

[7:00]Customers advise, please allow all customers off the train before boarding. Naeem is new to the underground, and it's his job as customer service assistant to hurry commuters through before the next packed train full of passengers arrives. Bank is is quite tough. When you have a lot of passengers, we actually got to make sure that the platforms don't get really busy, because if they do, they'll overflow onto the track, that's the worst scenario. Please remain behind the yellow line. This is for your own safety. Get lost. When I pull out my iPad, they're like, "Oh, look, he's got a new guy. He doesn't know what he's doing." It's all part of a learning curve. How long will it take me to know everything? Maybe 20, 30 years. Will I ever get there? Who knows? You say your message. One day, Naeem hopes he might make it to the heart of the operation, the station's control room. Yeah, we save lives. Thanks very much. Paul and Ola are the eyes and ears of Bank Station, constantly scanning scores of monitors covering 10 platforms and miles of corridors. At the present moment, it's going quite well. It's their job to ensure the buildup of passengers never reaches dangerous levels. Hello, Bank Station. Receiving you. Over. What train is it? The train tracks. Yeah. It's five past, and a train has failed to arrive, and thousands of passengers are heading towards an already packed platform. Yeah, apologies to customers at the present moment. The Waterloo and City Line is suspended due to a defective train. Could all customers please make their way up from the platform area? Years of experience tell Paul and Ola that public announcements are rarely enough. The platform is not clearing. It's getting busier. Everything running smoothly has now gone the opposite route. See? Just like that.

[8:56]We've quickly gone and close the gates, close the gates. Shut the gates down to the traffic. Better to obviously keep the customers upstairs in that area and reducing the gateline rather than them being like packed up on the platform. So it's just having your finger on the pulse, straight away to be able to deal with it. Right. I've just noticed on platform 7 a train birthing. With the passengers behind the gates for their own safety, Paul is the first to spot the service is back up and running. Am I still customer concerned? The Waterloo and City Line service is, is service has now resumed. Once again, the Waterloo and City Line service has now resumed. Thank you.

[9:39]Thanks to Paul's quick thinking, a rush hour crush has been averted. There is proof in the pudding. Now we have a good service within three minutes.

[9:55]What was absolutely packed up here is now flowing. This is basically how we work. Start the day, we do one of these, back of the day, we do one of these, during the course of the day, keeps us sort of focused.