UNISON members Jamie Butcher, Freddie Taylor, Steve Anderson and Mike Azzopardi. All images by Marcus Rose
The Thames Barrier is one of the most iconic and striking structures in London, a string of shimmering silver domes strung across the river. It’s also one of the most practical. For more than 40 years it has kept the city safe, a literal barrier against extreme tidal surges and the consequent flooding that, if left unchecked, would threaten lives, homes, businesses, the transport system, even the nation’s economy.
It’s a formidable feat of engineering that has stood the test of time. But it would be nothing without its people – a dedicated team of engineers, flood forecasters, advisors, electricians, cleaners and others who both operate and maintain it, around the clock. And many of these are UNISON members. U met with some of them, to discuss their roles in a most unusual workplace.
Wake-up call
In 1953, the North Sea Flood, caused by a huge tidal surge, overcame coastal defences and caused death and destruction in parts of the Netherlands, Belgium and the UK. People lost their lives in Scotland and down the East coast of England, including Canvey Island in the Thames Estuary, where 58 people were killed and 13,000 residents were temporarily evacuated. In London, where water spilled onto the streets of the East End, one person died and hundreds had to flee their homes.
The flood was a wake-up call. Until then, the flood defence for the capital relied solely on walls and earth embankments. Building these ever higher was impractical; there needed to be a long-term and more reliable solution. Research led to the 1972 Thames Barrier Act and, alongside raising the banks downstream, the structure we have today – one of the largest movable flood barriers in the world.
Construction began in 1974 and took eight years, the Queen officially opening the barrier in 1984. Eight miles downstream from central London, near Woolwich, its 10 steel gates span 520m across the Thames. Operated by hydraulic cylinders (housed in those dome-like ‘piers’), some of the gates sit flat on top of the river and are lowered into position when needed, while the larger, central ones are rotated upwards from the riverbed, standing as high as a five-storey building.
It takes around 90 minutes to close the whole of the barrier, in advance of an expected tidal surge. Each gate can withstand 9,000 tonnes of water.
Seeing off catastrophe
Operated and maintained by the Environment Agency, in its 42 years the barrier has been closed for flood defence 221 times. It helps to protect 48 square miles of central London, encompassing 1.42 million people, more than 4,000 listed buildings, 711 healthcare sites, 116 railway and tube stations and more than 300km of major roads. The value of residential property protected is estimated to be £321 billion.
“If the barrier failed there would be a catastrophe,” says control room duty engineer Mike Azzopardi. “The underground system would flood, the hospitals, the banking institutions.” In fact, the City of London and the financial district of Canary Wharf both hug the river – the latter clearly visible from the barrier itself. Thames Barrier duty officer and flood forecaster Steve Anderson adds: “London is the key economic centre of the country. If you knock that out, you knock out the economy. So, it’s imperative that we don’t let it flood.”
Steve and Mike work in the barrier’s control room, housed in a tall building on the south bank of the river, overlooking the piers. They are both barrier veterans – Steve having joined in 1992 and Mike in 2001. It feels apt that they’re sitting with me together, as they represent the two principal halves of the operation – flood forecasting and engineering.
As Steve puts it: “The flood forecasters are looking ahead to whether we need to operate the barrier. And these guys, our colleagues on the other side of the control room, are the nuts and bolts, who make sure it will work.”
Before coming to the barrier, Mike (above) worked for British Aerospace, on the Sea Harrier, running the development aircraft that would test modifications before they were rolled out to the fleet. “I’ve been fortunate throughout my career, because I’ve worked with some really good stuff. The Sea Harrier was a great icon of British engineering. And now I’m working on another.
“For its time, it’s absolutely amazing what they came up with for the barrier – the design, the actual engineering. Being able to dam the river and hold back that amount of water is an impressive feat.”
Mike’s role is essentially two-fold: to take part in the barrier closures from the control room – both for actual flood defence and the regular test closures – and to look after all of the plant and equipment on site, which he monitors from computer screens, firefighting any problems.
He explains that the barrier was “over-designed” to avoid failure, with a bewildering number of back-ups, notably for the hydraulics on each pier and the electricity supply; it can be powered by electricity networks on each side of the river – and should both fail, it has three diesel generators of it own.
“The barrier will work, whatever happens,” he says. “It’s like when Brunel designed the bridges. They were all over-designed to last, and they’re still standing. In fact, they’re probably better designed than some of the modern ones.”
UNISON across the operation
As a mechanical supervisor, Jamie Butcher (above) is one of those men working inside the barrier to ensure that nothing goes amiss, planning and resourcing the work of the mechanical maintenance team. In this case, “mechanical” primarily refers to the hydraulics that bring the massive gates into position.
“This is an electrically powered hydraulic operation. Each gate turns on two large hydraulic cylinders that sort of drag and push them into position. And anything that moves comes under the mechanical team,” he explains.
During the gate closures, there are members of both the mechanical and electrical teams in position within each of the piers. “You each take a pier, and you liaise with the control room. Some of the mechanical operations need visual confirmation and checks that the equipment’s running correctly. Electrical do the same role. And if a fault occurs, we would be there to fix any mechanical faults, and electrical would be there to fix any electrical or control faults.”
While the gate closure is usually activated from the control room, if for some reason that fails, mechanical can take over locally. Mirroring Mike’s comments, Jamie says: ‘Basically, the gates can’t not close, so you have to have everything covered and a certain level of redundancy.”
Jamie has been at the barrier for about 10 years, where he also the UNISON steward. The union represents around a third of the 90-strong workforce, in a broad range of roles.
Another of these is Freddie Taylor (above), who’s been on the maintenance team for around 18 months. “We clean and maintain all the piers. That could be from mopping the floors, polishing, emptying the bins. The main issue is bird poop,” he smiles. “A lot of pigeons nest out on the piers, and they’ll find any way to get inside. It can clog things up, but it’s more from a health and safety point of view. Pigeon poo is really infectious.”
They also clean the long tunnel spanning the river beneath the barrier, allowing access to the piers. Freddie laughs. “They say there’s light at the end of the tunnel, but it doesn’t always feel like it.”
Other tasks include office and kitchen refurbs, basically keeping the place shipshape. “The structure’s 40 years old now, so you need to give it a bit of TLC.” And, like seemingly everyone on the barrier, his team has a role when it is operated, with their own list of checks before it’s decided that the gates are ready to be moved.
Mike says that a full barrier closure, which he will oversee from the control room – and yes, he presses the button – has a special excitement. “What you’ll find is that the morale on site is completely different, because everyone’s got a role, everyone is gelling together, and they want to do it to the best of their ability. And they’re doing something that you can actually, physically see.”
Watching the weather
The person who decides whether the barrier will close, or not, is the duty controller; but that is only after ample advice from forecasters like Steve (above). So, when does that happen? In the Fifties, flood forecasting was virtually non-existent. Instead, Londoners made do with the adage, “When the lions drink, London will sink”, referring to the decorative bronze lion heads lining the Embankment. Today, thankfully, forecasting has become somewhat more sophisticated.
The barrier sometimes helps during times of extreme fluvial flows from upstream, caused by rainfall. This was the reason for, arguably, its finest hour, in the winter of 2013/14, when the UK was battered by devastating storms and the barrier was closed 50 times in 13 weeks, completely protecting London from flooding.
But its primary purpose is to combat surge tides, otherwise known as storm tides. As Steve explains: “If you watch the weather forecast and they talk about deep lows bringing all this horrible, rainy, windy weather we’ve had recently, well it’s those low pressures that literally lift the sea, raise the tide. That’s the surge element. And that’s what we’re monitoring for, 24/7, 365 days a year. Because if you’ve got that on top of a spring tide, you’ve got a much higher tide to contend with.”
The forecasters run their models twice a day, based on data from weather satellites, oil rigs, weather ships and coastal stations. “Ultimately, it’s the combination of three factors – the tide, the surge, the fluvial flow coming downstream – that will determine whether we need to operate the barrier or not.”
Steve’s role also includes providing flood warnings and alerts, and liaison with the Port of London Authority, which is responsible for river traffic on the Thames. “Whether we’re having a full closure and taking the river, or move one gate for a trial, we will have an impact on navigation. So, we don’t do anything without direct involvement with the PLA.” All told, he says, “the control room is a real hub of communication.”
According to the Environment Agency’s Thames Estuary 2100 plan, over the coming decades climate change will make average sea levels rise. As a result, high tides will be higher and storm tides bigger and more frequent – increasing the risk. Steve predicts that one consequence will be the need to close the barrier more often.
The plan is for all of the estuary’s defences to be raised or upgraded, to take place in phases throughout the rest of this century. As for the barrier, it was originally designed to last to 2030 but has endured so well that it will remain the city’s primary defence until 2070; what happens then, whether it’s replaced or upgraded, is still to be decided.
For now, its role in keeping London safe is taken for granted. “The barrier provides reassurance for people, it is that insurance policy against disaster,” says Steve. “But most people won’t hear about our work, because we’re just getting on with it.”
UNISON members and climate change
Andy Theaker (above) is the chair of the Environment Agency UNISON Thames branch, who currently works, himself, in field operations in the west Thames. He’s aware of a whole other army of UNISON members working the length and breadth of the estuary, keeping communities safe.
“Speaking of Thames Estuary 2100 he says: “The need to improve tidal defences creates opportunities to rebuild the riverside and create a life-enhancing environment for the people who live and work there.
“As summers get hotter, residents and workers will need more green space cooled by river breezes, with well-designed walking and cycling routes along the Thames to encourage sustainable transport – reducing carbon emissions and air pollution. This will benefit local economies and the businesses that operate in the estuary and create better habitats for wildlife to thrive.
“We must do this in a sustainable way, so that we can reduce the environmental impact and help tackle the climate crisis. Each and every one of us has a duty to do our bit and taking part in UNISON’s Year of Green Activity is just the start.”
