Maintenance of submarine cables
Ever since the very first submarine cable was laid, it has been necessary to be able to repair faulty cables. In the early days of the submarine cable business, knowledge about how to locate, recover, repair and re-lay a cable was limited, and those operations were always a challenge for the engineers and crew onboard a cable ship. The requirement of getting a faulty cable back in service forced the cable owners to invest in the development of a technology and working practice, which have been proven to be effective and have practically remained unchanged over nearly a century. In the past few decades, the cable technology has moved from heavy copper/lead/steel cables towards lighter or smaller cable design based on fibre technology. These new cables combined with more aggressive fishing technology (moving into deeper waters) will normally require additional protection. This will normally be achieved by burial either during installation using a cable plough or during repair where ROV and jetting techniques are used.

If a buried cable has been previously fouled and pulled up out of the seabed, it becomes even more vulnerable even if it wasn't damaged. Most of the cable faults occur, not in deep ocean water but, near coasts. Major cause for cable faults can be related to fishing activities and use of anchors.

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Marine Maintenance Centre (MMC)
The Marine Maintenance Centre (MMC) is based in Greenwich, London and manages the maintenance of submarine cable systems through Marine Maintenance Service Agreements (MMSA). Such agreements bring together cable system owners/operators and the maintenance service provider (Alcatel-Lucent) to repair and maintain cable systems. Key factors determining the terms of a maintenance agreement will include, but are not limited to: cable system length, capacity, complexity of the system, response time, etc.

Availability
Managing and maintaining a submarine cable system at the lowest operating cost, whilst delivering the highest level of performance, is a key objective of system operators. The operator who guarantees availability of service ensures that end-user confidence remains high and revenue streams are secure. In the highly competitive telecommunications market, experience and expertise are crucial but they are not always available in-house. Recognising these needs, Alcatel-Lucent has developed a range of services to support operators from initial planning to maintenance of installed submarine cable networks.

The Maintenance solutions may include:

• Private dedicated or private shared maintenance services
• All-inclusive contracts in connection with system purchase
• Single or multiple maintenance vessels on continuous stand-by anywhere in the world
• Call-out maintenance agreements
• Maintenance on live submarine cable systems (In service repairs)
• Chromatic Dispersion Management
• Guard vessel services
• Near shore maintenance (shore to approximately 12m water depth)
• Cable recovery/deployment and burial
• Jointing, testing and transmission
• Logistics management of shore based cable spares, joints and repeaters
• Logistics management of onboard vessel cable spares, joints and repeaters
• Post repair burial services
• Reporting and charting
• Cable awareness services
• Periodic inspection and cable protection improvement services
• Shore-end landings or replacement
• Post lay, inspection and burial services
• UJ kits supply and replenishment

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Asia-Pacific Private Maintenance Agreement
Alcatel-Lucent Submarine Networks manages a number of Private Marine Maintenance Service Agreements in the Asia Pacific region. We have a joint venture with Tyco SubCom, each providing one vessel into the service.

Coverage is presently provided by two state-of-the-art cable ships capable of carrying out all aspects of cable maintenance and related services. The vessels are powerful, enabling them to operate in severe adverse weather conditions.

The vessels are up to 150 meters long, deadweight is up to 70,000 tonnes and the vessels can proceed at a speed of up to 16 knots. The vessels are fitted with advanced Dynamic Positioning Systems enabling them to maintain station and perform a cable repair in severe weather conditions.

A dedicated jetting Remotely Operated Vehicle (ROV) with a horsepower of 300kW, capable of operating to a maximum depth of 2500m is placed onboard each vessel.

The capabilities cover all marine sections from beach manhole to beach manhole and include shore-end repair/reinstatement, buried sections to 2000m water depth and surface laid abyssal sections.

All spares, including spare cable, a number of cable bodies and jointing kits are stored onboard each of the two vessels, enabling the vessels to leave port within 12 hours notice, when receiving a callout, or move from one repair to another without having to return to the depot

Presently more than 80,000km of submarine cable is serviced under the Private Maintenance in the ASIA Pacific region.

Earthquakes and similar underwater activity frequently hit the Asia Pacific region. Combined with areas of intense fishing activity the region calls for deep-sea as well as shallow water repairs, requiring multi-skilled personnel and equipment.

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Atlantic Private Maintenance Agreement
 Alcatel-Lucent Submarine Networks is providing maintenance and related services in support of submarine cables in the Atlantic Region, using two advanced cable maintenance vessels supported by depot facilities in Calais and Halifax.

The Atlantic Private Maintenance Agreement provides a unique solution for our customers. It provides a cost effective maintenance service for the vast majority of underwater telecom cables with more than 97,000km of cables being currently maintained in APMA.

Alcatel-Lucent provide two dedicated vessels to APMA, the IT Interceptor and Peter Faber and can call upon its fleet of three installation vessels and the IT Intrepid in times of need.

APMA has a distinct advantage by carrying strategic spares onboard, as this allows the vessels to move from one repair to another without having to return to the depot to load cable. This allows greater flexibility and cost saving to our customers.

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South Pacific Maintenance Agreement
Alcatel-Lucent Submarine Networks is providing maintenance and related services in support of submarine cables in the South Pacific region, using an advanced cable maintenance vessel supported by depot facilities in Suva, Fiji.

The South Pacific Maintenance Agreement provides a unique solution for our customers. It provides a cost effective maintenance service for the vast majority of underwater telecom cables in the region, with more than 31,000km of cables currently maintained in SPMA.

Alcatel-Lucent provide a dedicated vessel based in Noumea, New Caledonia to SPMA, the Ile de Re.

SPMA has a distinct advantage by carrying strategic spares onboard as this allows the vessels to move from one repair to another without having to return to the depot to load cable. This allows greater flexibility and cost saving to our customers.

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Cable Maintenance Vessels
Minimising restoration costs depends on a rapid response services deployment of competent marine personnel to deal with external aggression faults, however infrequently these may occur. Efficient repairs and maintenance of submerged plant demand experienced and skilled personnel who are continuously qualified and familiar with cable repair techniques. Establishing and managing a team with up-to-date jointing and transmission skills together with equipment and materials requires time, experience and capital and overhead investment, which may not be economically viable for all operators. Alcatel-Lucent can offer the services of experienced, fully trained and certified (where required) specialist personnel onboard the vessels for all kind of cable repair and maintenance.

All maintenance vessels are manned with qualified and experienced crew. Each maintenance vessel has a ROV (Remotely Operated Vehicle) system onboard in order to locate, inspect or to carry out post lay burial as required, down to water depths of 2500m and up to 3m burial into the seabed.

The vessels are strategically located to suit maintenance requirements from our customer worldwide.

The Alcatel-Lucent Marine Maintenance Centre (MMC) is manned 24 hours a day. When a cable fails, the top priority is to get it repaired as quickly as possible. Each cable ship base is organised to ensure that a repair vessel can set sail normally within 24 hours of receiving a repair call from a maintenance authority or client.

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ROV Systems
Alcatel-Lucent Submarine Networks is using powerful work class ROV (Remotely Operated Vehicle) systems for submarine cable maintenance on each maintenance vessel.

All ROV systems are fitted with a burial tool system, manipulators, sonar system, echo sounder (altimeter), cable tracker, acoustic positioning, surveillance cameras (colour, SIT and monochrome) suited for work down to a maximum 2500m. Furthermore, special ROV tools such as cable cutter and cable clamp are available.

Free Fly mode is optimum for cable repair, survey, and burial. Tracked mode, for bottom crawling trenching, requires significantly less hydraulic power for propulsion, allowing operation for increased burial speed or soil strength. Post-Repair inspection and Burial (PRIB) is performed using the ROVJET.

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