For anyone who is interested (
), the fibre-optic cables are usually threaded through small-bore ducts fastened to the soffit (roof) of the sewer by stainless steel clips. In smaller diameter sewers this can be done by robotic devices which are monitored by on-board CCTV cameras.
Alternatively an armoured cable can be fixed directly, and this is a robot for doing that...
Any other useless info you need, just give me a shout.
