Super-fast broadband is arriving in Britain – but our roads won't be dug up to lay the cables. Rebecca Armstrong boldly goes where no hi-tech hardware has gone before

Crumbling Victorian tunnels full of effluent, rodents and the corpses of a thousand goldfish might not sound like the kind of place where a technological revolution is likely to take place. But sewers are the secret weapon of a company with a mission to create a nationwide network of hi-tech cables capable of delivering super-high-speed broadband.

The British firm H2O Networks has spent six years plotting its underground invasion and is now rolling out its network of fibre-optic lines across the country – through the UK's 360,000 miles of sewers.

If you imagine that the leaders of the techno revolution sit in gleaming, dust-free offices of steel and glass, then Lee Roberts, field engineer for H2O Networks, may cut a surprising figure. No one on his watch is allowed near a sewer without being properly suited and booted in a high-visibility neon-yellow outfit accessorised with a hard hat and a visor; well, you can imagine why that last item is necessary.

Having pulled on a harness and clipped myself to a hook attached to a sturdy tripod, it's time to venture down. "We use the tripod and the harness because we have to be able to self-rescue," Roberts says. "If someone down there gets injured, we can lift him out without getting into danger ourselves."

Sewers – a pungent cocktail of human waste, potentially lethal gases and confined dimensions – are hazardous working environments. So why, when there are so many more civilised options, would anyone want to use them for broadband cables?

"The cost of digging up the road to lay cables is huge," says Elfed Thomas, the managing director of H2O Networks. "It costs between £150 and £200 a metre, and it's massively disruptive for everyone. The combined cost of traffic disturbance from digging up the roads is already £4.5bn a year. Why add to it?"

Sewer-cam: a robot's-eye view
Courtesy of H2O Networks

But, companies being the money-making machines they are, there is also a financial carrot luring H2O 's engineers into the dank tunnels. Laying fibre-optic cables the traditional way is time-consuming; it can take up to 12 months to wire a 2km run. Thomas and team can cover that distance in four hours.

As we reach the sewer, there seem to be no hellish smells, no rats, just an inch of water lapping at our boots. Roberts points out the slim black cable snaking its way along the circular tunnel. It disappears into an off-shoot of the sewer that seems impossibly small, just a couple of feet across.

How does Roberts work out where a cable can safely be installed in tunnels this narrow? The answer is a remote-controlled pipe-crawling inspection device – a sewer-cam – that can be steered from the H2O van above the surface. This £110,000 piece of kit records any leaks, cracks or obstacles that could prevent the cables being laid. Nevertheless, when it comes to sewers, bigger is always better. "Larger sewers make installation easier," Roberts says.

The conventional method of laying cables – digging trenches beneath roads and pavements – puts the cables 45cm below the surface, but sewers reach depths of up to five metres. Down here, there is much less risk of them being severed, meaning that H2O's cables are more likely to be more reliable. Severed cables can be a huge headache for utilities companies and internet providers – as was shown earlier this month when fibre-optic cables on the sea-bottom were damaged, causing an online meltdown in the Middle East.

But it hasn't been easy to convince the water companies that their sewers the perfect place to lay cables, according to Thomas. "It's taken us six years to make this idea a reality, because we had to negotiate with the water companies. They were initially very sceptical because they are very risk-averse organisations."

Roberts adds: "Working with us wasn't really a priority for them but we showed them that the cables don't effect the sewer's performance. More importantly, we reassured them that the cables could benefit their monitoring of the sewers." Thanks to the sewer-cam, the water companies get a free CCTV record of the state of their sewers, which helps them to maintain standards and spot leaks.

Roberts checks that the gas levels in our pipe are safe. A few drowned snails are lying in the water by our feet, but I can't see any rats. Roberts says that whenever he tells people what he does, they ask "the rat question". He smiles the smile of a man who has seen a few grotesque rodents in his time but has lived to tell the tale. "The other thing I hear is, 'Have you ever found any gold?'" While he's notched up a fair number of Rattus norvegicus sightings, Roberts has yet to stumble on any lost treasures.

Instead, the sewers he visits are rich in technological booty. Most current broadband deals advertise speeds of between two megabits (Mb) and 8Mb per second. That's a measure of how fast information can pass along the cable. H2O Networks' customers can get connection speeds of up to 20 gigabits (Gb) per second. That's 20,000Mb per second, or up to 10,000 times faster than standard broadband. And that opens a whole world of possibilities. (You can check the speed of your own connection at home by visiting the website

Sewer-based fibre-optic cables are already a hit in Japan, and Paris has a network similar to the one we're inspecting today at H2O Networks' test site in St Asaph in North Wales. In the UK, the first people to benefit from these high-capacity but relatively low-cost cables are students and council workers. H2O Networks has created high-speed fibre connections for universities in Aberdeen, Bournemouth and Edinburgh after spotting the gap in the market; students need high-speed internet connections, and the universities that have to provide them are usually on a budget.

Napier University in Edinburgh paid about £80,000 for a 1.2km fibre network in its sewers; laying the same amount of cable under the roads would have cost up to £1.2m. When Bournemouth Borough Council signed up for a network from the company, it was completed in just over a week.

Thanks to the success of these projects, H2O Networks has launched Fibrecity, a plan to provide home and business users with its fibre-optic networks. At the end of April, the company will announce whether its first consumer network will be laid in Bournemouth, Dundee or Northampton. The infrastructure roll-out will start out in September, and mega-broadband will be ready for the first consumers around six months after that. The other cities will not be far behind. If all goes well, the rest of the country should follow.

Although the cables are laid by H2O Networks, consumers will have to pick up the service through an existing broadband provider. But H2O Networks expects that customers will get the faster speeds without paying any more for the service. "And once we've deployed fibres to an area, each home can get minimum of broadband speeds of 100Mb," Thomas says. UK broadband speeds lag behind those of other European countries, yet British consumers are paying up to 17 times more. Thomas thinks his company's cables could end this imbalance. "Costs will be low because the infrastructure the company is using is already there."

It's clear that sewers are the perfect place to lay cables. No one would want to come and disturb them, and there's plenty of room.

It's time for me to be hauled back out, and I head for the van to clean up. Sewers might be the answer to high-speed broadband on tap, but I feel – and smell – decidedly low-tech. If this is the future, it's best to experience it sat on your sofa with a laptop.

The high-speed revolution

Internet Protocol Television

Voice over internet protocol (VoIP) already lets us make phone calls over the internet. Internet protocol television (IPTV) does something similar for television. In order for internet TV to really work, connections have to be fast enough and the streamed data has to be reliable.


Do you want to know that your house is safe when you're on holiday? The next-generation of closed-circuit television cameras can be operated remotely and enable you to view live images through an internet connection. Just make sure that you have your local Neighbourhood Watch contacts on speed dial.

Home Automation

Control everything from radiators to radios, lighting levels to curtains remotely by connecting them up to a home computer network. With all that wireless winging its way around a residence, serious operating power is the order of the day.

Remote Medical Monitoring

High-density closed-circuit television within the home can help relatives and carers keep an eye out for people with disabilities, while medical monitoring for hospitals is already making waves across the Atlantic, allowing doctors and medical staff to monitor seriously ill patients remotely.

Remote storage

Apple's new MacBook Air does not have an internal DVD or CD drive – so is this an indication that soon we'll be backing up our data in remote servers, based in warehouses anywhere in the world, rather than using DVDs?

To make that process a reality, we'd need to have high-speed connections, and the next-generation of broadband could be the answer.

Watch the robots at work in the sewer at