Disruption of access to the Internet can cause, at least, frustration and more seriously can have significant economic and welfare consequences.

A large proportion of Internet traffic is carried over optical fibre cables. But because of the environment they inhabit, cables are particularly vulnerable.

Some of the more well-known causes of disruption to communications include construction workers drilling through cable ducts and boats dragging their anchors over submarine cables.

But other causes of disruption are more surprising. Thousands of people in the UK recently had their broadband restored after it failed because rats chewed through cables. Engineers discovered nesting rats had chewed through ducting, outer casing and multiple cables – equipment which usually needed a drill to get through.

Talking of wildlife, there also have been reports of sharks biting through submarine cables leading to changes in cable design to inhibit their appetite.

But the unpredictability of the effect of human activities on online access surpass wildlife any day:

For 18 months, at precisely 7am every day, the broadband signal in a tiny Welsh village simply vanished. Engineers were sent to the remote settlement to investigate the problem. They spent days testing connections and replacing cables until they finally got to the root of the problem – one villager’s old television. The resident turned his second-hand television on each day at 7am. It created a burst of “electrical noise” that brought down the neighbourhood’s broadband.

Wireless signals aren’t immune to unintended consequences either. Mobile network operators have reported an increasing problem of trees planted near base stations obstructing mobile signals. These trees were planted as part of the planning conditions to ameliorate the environmental impact of new mobile sites. An operator was recently quoted as saying: “Trees grow but mobile antennae don’t!”

PTT doesn’t provide courses on rats, sharks, old televisions, or trees. But we do offer a range of telecoms related courses including those covering cable installation and protection and finding faults.