Going underground with Geo Networks

Russell Sewer

Going underground with Geo Networks

An agreement with Thames Water has allowed Geo Networks to deploy its London fibre optic network through its sewer system. NCN’s Russell Drury donned his overalls to take a look.

An opportunity to go down a sewer is perhaps the strangest press trip I have been invited to while working for NCN. But it was one I couldn’t miss, so I agreed to join a Geo Networks tour group at the Wick Lane Drainage Depot in East London, just a stone’s throw from the Olympic Stadium.

After our safety briefing we were kitted up in sturdy boots that came up to our waste, a hard hat, white overalls and a harness. It looked like we were going on a caving expedition.

We then squeezed down a tight manhole on a ladder, with the assistance of a safety winch, and into the dark (and rather smelly) space below.

The network

Geo Networks’ agreement with Thames Water to deploy its London fibre optic network through the London sewer system allows its network to run up to 12m below ground, rather than just below the surface.

The deeper position of the cable means that it does not suffer from surface disruption. Every time a utility provider, or other telecoms supplier, needs to access their infrastructure, they must navigate through the intricate and crowded web of cables just below the pavement.

Geo’s London network is buried so deep that it has only suffered one cable cut since the company began operating it in 2005. It also means that getting Geo’s network around London involves minimum digging or fuss – which is great news for fellow Londoners and the environment.

Geo’s routes follow the large main sewers which are high enough to walk through. The cables are secured at shoulder height in the sewer using the company’s own developed clips, not lying loose on the floor, to keep them safe from the trampling feet of the occasional engineer. Geo is also developing an innovative sewer lining to house the fibre, which has the added advantage of protecting the longevity of the sewers for Thames Water.


After wading around in six inch deep water for 20 minutes it was time to head back up to civilisation. As we waited in turn to ascend the ladder members of the group passed the time by scanning the floor for objects of interest. Three spoons and a small gold crucifix was the extent of our findings, while one group member dropped her glove (at least it wasn’t her camera). After changing out of my overalls (and a good spray of deodorant) I left the depot with a greater appreciation of the complexities involved in making our capital tick – not to mention for the individuals who have to work in the sewers on a daily basis!


  • Show Comments

Your email address will not be published. Required fields are marked *

comment *

  • name *

  • email *

  • website *