For our Ministructures series, artist Lucy Sparrow sews us a mini version of a famous London landmark each week. For each one she sews, we meet a person with an interesting story to tell about it. For the final interview in our series, we meet Glen Ellis, 57, Technical Officer at Tower Bridge.

So you’re the guy who opens Tower Bridge?

‘I am. I’m part of the team responsible for looking after and maintaining the bridge – repairing it if there are any breakdowns, and performing operational duties – which includes opening and closing it.’

How do you do it? Is there a big red button?

‘There are lots of buttons. There’s one to set the traffic lights to red, and buttons to close the road gates, the pedestrian gates and the footpaths. Once the bridge is nice and clear we take out the four bolts that hold the bridge up at the back. Once they’re out it goes up.’

Do you ever worry that you might cock up?

‘Operating the bridge is a responsibility, because when you press that button you’ve got half of London at a standstill. But I’ve been doing this job for 20 years…’

Ever had any mishaps?

‘In ’95, a few years after I’d started here, there was lots of activity one morning – there were police everywhere. I asked what was going on and they said it was top secret. Someone told me that Bill Clinton and Tony Blair were having lunch in the nearby Le Pont de La Tour restaurant. That night, I was doing the bridge lift. It was just starting to rise when I saw blue flashing lights on the south side. My phone rang, and it was Scotland Yard – they said Bill Clinton wanted to cross the bridge. I said, “Well, he’ll have to wait, because I’ve got a boat coming through!”’

 You took the hard line.

‘It’s an act of Parliament – vessels have right of way over road traffic. Boats used to be able to get us to raise the bridge on demand until 1976 – they’d just turn up and signal us and we’d open it.’

Tell us something we might not know about the bridge.

‘Under each main tower there’s something called a bascule chamber. It’s well below river level, and it’s where the back of the bridge disappears to when the bridge goes up. It’s like a seesaw – bascule is French for seesaw. People drive across the bridge every day and don’t realise what’s going on down there.’

 Why do you think Tower Bridge is so well known?

‘Because it’s unique. There aren’t many other bridges with this sort of design, which are still operational. It’s still got some of its original gears and cogs from when it was built in 1894.’

What do you do when you’re not pressing big red buttons?

‘I spend a lot of time looking after my grandkids. One of the little ones has just started telling his friends “Granddad works at Tower Bridge!”’

What do you think of tiny Tower Bridge?

‘I’ve seen a few models, but this one’s really good.’ Flo Wales Bonner

Read more from the Ministructures series.