| The Southern Cross Cable has been in the spotlight recently because of damage to the cable 20 km off the coast of Sydney on Sunday July 29th. This caused a 15 hour disruption of service, but was resolved quickly. But what is the Southern Cross Cable?
In November 2000, the PacRim cable linking Australasia and the United States was superseded by the Southern Cross Cable, a cable network almost 30,500 kilometres long. There is a station every 40 kilometres along the cable to boost the signal, ensuring that it is received clearly at the other end.
The current capacity of the network is 120 gigabits per second. That’s 120,000,000 kbps… compare that to your 56kbps modem!! It has the capacity to transfer a stack of typed documents nearly a kilometre high every second, or two full-length movies.
The cable goes to a maximum depth of 7.5 kilometres, and this depth is reached in an oceanic trench between New Zealand and Hawaii. There are two separate cables, buried an average of 90cm below the sand to avoid damage by shipping. The cables are encased in jelly and then in a steel tube, then it is covered in high-strength steel wires and a copper coating, then covered in a high density plastic. All together this makes up a cable that is about 2cm wide. The actual optical fibre itself is smaller in diameter than the full stop at the end of this sentence. |
