Going underground

CRN's intrepid reporter Hannah Breeze took a tour of London's sewers to investigate the innovative way in which a telecoms firm is putting them to good use

The "Great Stink" of London in the summer of 1858 prompted the engineering of the city's first ever sewage system. Now, more than 150 years later, the very same waste-disposal network has found another use, but this time with a technological edge.

Enhanced security and the ability to provision technology quickly are high on the list of priorities for channel businesses, and telecoms firm Geo Networks claims it has managed to do both by tracking its network cables in an unusual location: within the fully functioning tunnels of the Victorian sewer network.

But while the location - about 12 metres below ground and accessible only by climbing down a manhole and wading through sewage - may not act as the most glamorous setting for the cables, Geo says the business benefits outweigh the insalubrious setting.

The company inherited the unusually located cabling (pictured) from Urband, a telecoms outfit it acquired in 2005, one year after Geo's launch. Since the acquisition, Geo has continued to work with Thames Water to add to the network, contracting engineers to delve below the surface to add to the growing sprawl of cabling, which now runs for 120km along the London sewer tunnels.

Access to the sewer can be dangerous, and those with no experience are required to have emergency breathing apparatus with them at all times. Visitors gain access by clambering down 12 metres of scaffolding-style ladders in full safety gear while strapped into a harness.

Andy Tipping, Geo's sales director, explained that the uninviting nature of
the sewer, together with the difficulty of access, act as additional security features
to the network, meaning that the cabling is virtually inaccessible to unauthorised personnel.

On top of the access requirements, having the cables so deep under the ground means that the network is almost completely undisturbed by roadworks and maintenance to gas, electricity and water pipes, which sit above the sewers.

Tipping said: "Having the network deep within the sewers is ideal for us. We do not have to dig up the roads to gain access, which saves us time and money. As the sewers are so far under the road, we are in line with Transport for London and the Mayor's plans for reducing congestion caused by road digs."

On average, telecoms fibre and traffic cameras sit about 45cms below the road surface, while gas, electricity and water mains rest lower, at a depth of between 55cm and 60cm. Tipping claimed that no Geo cables have ever been cut by mistake, and they are simply not open to the threat of exposed cabling during road digs.

"The network is very secure in the sewers, partly because it is so hard to get into, but it is very rarely affected by roadworks because of [how deep] it is, and this gives us something completely unparalleled to our competition." added Tipping.

As Geo's network is pinned to the walls of fully functioning sewers, Thames Water staff regularly work within the tunnels, adding an additional level of security, said Geo. The cameras used by the drainage company to monitor and survey the levels of flow and waste are able to flag up any potential network problems, according to Tipping, who added that the companies have a "true partnership".

The firm's fibre optic technology, which tracks the London sewers and gas mains outside the city, takes the form of four multi-coloured pipes, which each contain 432 individual fibres and are attached along the top half of the sewer tunnels.

Geo claimed that the high concentration of fibres within the pipes means that, as new customers sign up, it can simply switch on new fibre which is already pre-provisioned, saving customers money.

Tipping said: "For me, the main benefit is that we are able to provision the [cables] very quickly. There are huge capacities in those pipes already, which mean new services can be [established] quickly as the fibres are already provisioned, and simply need to be lit up."

From a marketing perspective, having something different makes Geo stand out from the crowd, and the novelty value can complement the technical and security benefits, said Tipping: curious existing and prospective customers are keen to throw on some overalls and see the pipes for themselves.

But while an afternoon in the sewer and the promise of secure, high-performance technology can be enough to entice some customers, the cost involved of tracking new cabling within the sewer can mean customer investment is designed for the long term.

Tipping added: "For a one-year contract, for example, it can be costly. But for high-data transfer, it is a very good and secure solution. We believe that we can offer significant savings in the long term. We look at the total cost of ownership for a customer, and that is important.

"Time wise, we have the potential to put new services up in days, instead of six to nine months, and this is enticing for [prospective customers]."

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