A telecommunications operator can reduce the visual intrusion of its network by laying all cables underground. Nothing could be simpler...
Generally, only up to a point. It's expensive to bury cables underground - and very difficult to reach them for repair, maintenance and replacement once they're there. Also, laying cables underground is quite an involved and complex business.
Today laying telephone cable underground is still a strenuous job with the methods used surprisingly not changing much from those used in early days.
Originally a channel was dug into the ground along the route of a pre-planned network where a four-inch earthenware pipe would be laid. Depending on the needs of the network, either a wide or thin cable would be pulled through the pipe by rope, leaving some spare space for future use. A large gang of men would have to pull the cable, as it was so heavy.
Spare rope was left in the ducts for future cables, which today are frequently fibre optic. In fact the only differences now are that the gangs can use machinery to help pull the cables through and if rope is missing or broken, automatic duct motors are used to worm through the pipes threading new lengths.
Below the surface of Britain is a complex network of tunnels, pipes and cables, belonging not only to BT but also to all of the other utility companies such as the gas and electricity companies.
Under the pavement of every town and city lie the pipes and ducts that carry the local distribution network. Footways are peppered with small manhole covers that provide access to the system. Deeper down, closer to the phone exchanges, the network tunnels are wider but again can be accessed by manhole covers and usually need a ladder to climb the six feet to the bottom.
Blocked cable ducts can be a problem, especially if the blockage is 60 feet away from an opening. The best way to shift the obstruction is to attack the duct like a blocked drain with a very long pole.
A missing or broken draw rope can cause another major headache. In this case a duct motor is used to feed a replacement through. The motor looks like a barbell with two balloons at either end of a short pole. Twine is tied to the pole and the balloons are alternatively inflated inching the mechanism down the duct.
But the motor can take its time, and according to 'cable layers legend', it's said that the more enterprising engineers have tied string around the neck of a ferret and sent it chasing a rat along the duct to speed things up!
If none of these methods work the only answer might be to dig up the duct and start again from scratch.
As soon as you sink a spade into the ground in a busy city centre the chances are it won't be far away from an underground cable and potential danger. The truth is, it's very crowded under the surface. There are cables of all varieties: telephone, electricity, and cable television as well as pipes from the gas and water companies, not forgetting underground walkways, drains, sewers, tunnels and underground trains.
Although all utility companies should have their cables mapped out, not every map is totally accurate, and not everyone checks the maps before they start digging. To try to reduce the impact of broken cables, BT launched a helpline for contractors to ring before they started work, so they could be on site to identify cables in advance, before they could be damaged. Not only was prevention cheaper than cure, but it meant that customers would not have their essential connections interrupted unnecessarily.
Alec Bonsall was attracted to telecoms as a schoolboy during the Second World War, when he drove around in his uncle's van, who was a maintenance engineer for the PO Telephones.
His interest was spurred on by his hobby as a radio pirate working on RAF surplus equipment sold off cheaply after the war. He joined the GPO as a Special Faults Investigation Officer during the late 1940s.
He remembers that some of the faults he had to investigate had nothing to do with the phone but were caused by other domestic appliances with some shocking results.
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