Photos: Telstra's undersea fibre optic cable
This is the Ile de Sein — and as you can see — it's a massive ship. It sports a crew of 60, who work in shifts to lay cable twenty four hours a day, seven days a week.
The cable that runs between Australian and Hawaii isn't straight; it needs to run around under-sea mountains, past crevasses and follows the rugged terrain of the sea floor. Many months of planning were involved in plotting the best undersea route for the cable. A member of the project commented the undersea cables can reach depths of 5,000 metres or more.
Telstra expects the cable to be active by the fourth quarter this year. Bandwidth on the cable will be available to both Telstra retail and wholesale customers.
This is the view from the front windscreen for the Ile de Sein, giving you an idea of the size of the ship. The Ile de Sein has just completed a 9,120km journey from Hawaii, and the cable will connect the Australian mainland tomorrow.
Telstra said around 65 percent of the Internet content accessed by Australians comes out of the US, and IP traffic has been doubling every two years, a trend that is expected to continue into the future.
Telstra was not willing to comment on the cost of the cable, but Kate McKenzie from Telstra Wholesale, said the company is "very confident of recovering cost".
This is the fibre optic cable that gets run under the sea — separated into different layers. The functional part of the cable is only 17mm thick. This is coated in a flexible white plastic, which forms the outer layer.
The cable is dropped straight to the sea floor without any weights or additional protection. The only additional baggage is the optical signal amplifiers, of which 121 were used in the connection from Sydney to Hawaii, one every 75km.
The inner most layer is the fibre optic cable, which is surrounded by a steel sheath. This is in turn coated in a copper sheet, which carries 12 kilovolts of charge to power the optical amplifiers.
The final lay is the white plastic insulation that protects the cable. Telstra claims the cables have a 25 year lifespan.
The entire undersea cable comes down to this — four tiny fibre optic cables. Between them these cables carry up to 1.28 terabits of data, which Telstra says is equivalent to 160,000 concurrent high definition television channels.
The cables transmit at an optical wavelength of around 1500nm, according to David Piltz from Telstra. That's the infrared region, and so it would not be visible to the naked eye. In a manner similar to tuning in a TV, the fibre optic system uses 64 unique frequencies within this range to transmit high volumes of data.
This is the cable spool where the massive amounts of undersea cable necessary make the Sydney-Hawaii connection are stored. It's seven metres deep and around 15 metres in diameter. All the cable is laid in the spool by hand.
The cable is run live from the ship — data is continuously being sent down the cable — even as it drops to the ocean floor. This gives an indication of the performance of the cable and allows it to be continuously monitored.
The Ile de Sein has two cable spools, this is the second. The cable is a different colour because it is the non-reinforced white cable pictured earlier. Reinforced black cable is used near the shore to stop damage from fishing boats and other vessels.
Here you can see the reinforced and non-reinforced cable in cross section side by side. You can see that the undersea cable — the white one on the right — is quite thin.
This dial displays the rate the cable is being run out from the ship, and the force on the cable, shown here in kilonewtons.
This is the machine that runs the cable out to sea. In particularly deep oceans, the cable may not touch the ocean floor until it is 20 kilometres behind the ship or more. Thus it is important to carefully monitor the stresses on the cable.
A giant hydraulic machine sits on the back of the Ile de Sein. We don't know what it's for, but it's impressive.
This is a deck from which the cable is laid — and gives you an idea how big the Ile de Sein is.