Cable-laying works on the second submarine link to Sicily owned by Malta’s quad-play communications provider GO started at St Paul’s Bay after the Italian vessel, Teliri – commissioned to carry out these works – gave the green light for commencement. Works originally scheduled to start last week had to be postponed in view of strong gale-force winds that hit the Maltese Islands over the weekend.
The Teliri was moored around 600 metres away from the landing station at St Paul’s Bay as the cable was slowly fed from its storage tanks, through the conveyor machinery down to sea while it was tied to buoys to keep it afloat. Divers located all along the cable route in large dinghies guided the cable to the landing point during the process of its unloading from the vessel.
Once the cable reached shore, it was pulled and anchored to the shoreline manhole from where initial tests were carried out to confirm that the operation was successfully. Following these tests, the buoys were gradually released and the cable slowly sunk to the bottom of the sea under its own weight.
When all buoys were removed and recovered on board, the Teliri started moving away from shore towards Sicily in the direction of the cable route. Once the ship reached the position where the cable could be buried, the mechanical plough system was lowered into the sea to start what is known as ‘the burial operation’.
Meanwhile, at the shoreline manhole, cable jointers spent the afternoon splicing the submarine cable to the land cable. Further tests were subsequently carried out from the telecom exchange in St Paul’s Bay to the ship.
Concurrently, in shallow areas, where the optic fibre cable requires a higher level of protection, divers will apply cast-iron shells, called articulated pipes and cable anchorages. Where the cable is suspended between rocks, bedding in geocem is applied.
In cases where posidonia – better known as sea grass – is present, screws will be driven into the seabed close to the cable – typically every 10m. The cables are then anchored to the screws, and thus fastened to the seabed. The risk of possible shifting of the cable on the seabed is thus avoided. As the posidonia grows, the cable will tend to become caught within the “mattes” it generates, thereby producing a further locking-in effect and a certain degree of protection – without causing any damage whatsoever to the posidonia.
A total of 290 km length of cable will be lowered on the seabed – with maximum depths reaching 900 metres – between Malta and Sicily. In Malta, the cable lands at GO’s existing premises at St. Paul’s exchange whereas in Sicily it will terminate in a landing station provided by Interoute in Via Abetone at Mazara Del Vallo. From there the cable will be backhauled through Interoute’s PoP in Mazara to the rest of their pan-European network.
In Sicily the cable landing station will be operated and maintained by Interoute. The process of laying the cable between St Paul’s Bay and Mazara Del Vallo, south of Palermo, will last around two weeks and the new cable system is expected to be functioning by early 2009.