Military


Cable Ships

Telecommunications is an important area of growth in the global economy. With the explosion of world-wide communications, especially the Internet, the need for underwater communication cables has increased dramatically. Submarine cables provide highspeed broadband connectivity and capacity for large geographic areas that are often important centers of trade and communication. Submarine cables alleviate existing capacity constraints and meet the demand for future growth. With the world's increasing demand for better and faster Internet and telephone capacity, telecommunications companies are rushing to crisscross the oceans with thousands of miles of fiber optic cables. This technological boom is creating headaches for many coastal resource managers who are struggling to understand and address the environmental and economic impacts of laying cable along coastline.

Submarine cables carry heavy international communication traffic without the transmission delays associated with satellites. Submarine cables provide emergency routing alternatives to existing land-based telecommunication systems that are susceptible to earthquakes, flooding, storms, and other natural phenomena.

Minimizing restoration costs depends on 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 an overhead investment, which may not be economically viable for all operators.

The main reason that submarine cables rather than satellites are the dominant international communications infrastructure is that modern fiber-optic technology allows huge (and increasing) capacity per cable. For example, the trans-Pacific system permitted by one of NASCA's members to connect the U.S. West Coast with Japan has a capacity of over 5 terabits per second. That is equivalent to over 250 million simultaneous voice calls, or transmitting about 800,000 encyclopedia volumes every second. There literally is not enough room in the sky for satellites in the necessary geosynchronous orbiting positions to provide that much capacity.

Submarine fiber-optic cables typically have only the diameter of a garden hose (i.e., up to 1 inch). They typically are laid by a large specialized cable-laying ship, spooling the cable out of huge holding tanks.

Underwater telecommunication cables have in the past been laid by large purpose-built cable laying ships such as the cable ship Mercury owned and operated by Cable and Wireless, and Alert owned and operated by British Telecom. Both these ships are suited to laying cables in deep water up to the deepest ocean waters in the world. These cable laying ships require at least 20 fathoms of water and so where the cable approaches a land fall then the cable is usually held afloat by flotation devices and a manually-operated barge used to lay the cable to the shore.

A problem with such purpose-built cable laying ships is that they cannot work in very shallow water, particularly approaching landfalls, because they are large e.g. 11000 tons. They are also expensive to operate, not only because they are large but more importantly because they are only employed for cable laying on average for a small portion of the year. For the rest of the year they either lay idle or are "adapted" for other uses such as underwater surveys.

Smaller purpose-built cable laying ships exist but these vessels being purpose-built are still unecomonic unless they can be kept working for a substantial proportion of the year. There is no small e.g. 500-1000 deadweight tonnage purpose-built cable laying ship which is designed for burying cables.

In an attempt to economise it has been proposed to convert existing commercial vessels for cable laying and burying. The ship CABLE PROTECTOR has a deadweight tonnage just under 3000 tonnes is a flatback oil rig supply vessel previously used for carrying drill pipes, mud shifting and diver support functions. It has been converted to cable laying by the addition of a linear cable engine, cable tanks on deck, control cabin and using the existing accommodation for the cable laying crew, and in addition if there is the CIRRUS vehicles for ROV support, a central console cabin for the ploughing rig, with additional diesel engine power plant for providing hydraulic and electric power. It already has some of the other necessary hydraulic, pneumatic and electrical generation plants to provide for the cable laying and burial processes.

A flatback is not ideal because the cable is stored on deck and is therefore afforded little protection. Such an arrangement is less suited to bad weather conditions. Furthermore these vessels still suffer from a point of view of economy of operation because they are expensively equipped and they are not very suitable for deeper water applications and bad weather conditions.

A vessel such as a Platform Supply Vessel can be temporarily converted for cable laying and comprising in addition to its normal operational equipment an accommodation and power container providing accommodation needs for a cable laying crew including sleeping, bathing, eating and toilet facilities, and power for powering a stern thruster; a cable laying machine for laying a cable from the vessel; and control and deployment equipment for deploying the cable from the hold of the vessel via the laying machine and controlling laying of the cable; said container, laying machine and control and deployment equipment being removable from the vessel and re-useable.

The number of requests to lay cable has jumped significantly for many coastal states since the late 90s. In California alone, six projects were permitted from 1987 to 2001, and five of those were in 2001. The National Marine Sanctuary System evaluated the possibility of proposing new rules or policies regarding cables being laid in sanctuaries.

To connect states with countries half way across the globe, telecommunications companies lay thousands of miles of cable on the ocean floor. When they reach water depths where trawl fishing or anchoring occurs, a trenching system is used to bury the cable. When the cable reaches shallow water, directional drilling is typically employed to bring the cable under sensitive habitats to a small building, where it is connected with cables that may continue on land for thousands more miles.

Pursuant to the Submarine Cable Landing License Act (47 U.S.C. 34-39) the President must grant permission to any entity planning to land a submarine cable in the United States. This statute requires an entity to get permission before it is allowed to land and operate a submarine cable ''directly or indirectly connecting the United States with any foreign country, or connecting one portion of the United States with any other portion thereof'' * * * except for any submarine cable ''all of which, including both terminals, lie wholly within the continental United States.'' 47 U.S.C. 34.

In a related Executive Order (E.O. 10530) the President delegated authority to the Federal Communications Commission (FCC) to grant, deny, or condition submarine cable landing licenses, except that no license can be granted or revoked without the FCC first obtaining approval from the Secretary of State and advice from any executive department of the Government as the Commission may deem necessary. The National Telecommunications and Information Administration (NTIA), an agency within DOC, advises the Department of State and the FCC on all submarine cable landing license applications.

Changes in the construction of undersea cables, especially the use of optical fibers in place of copper, have resulted in cables having smaller diameters and increased unrepeatered lengths. Existing equipment is often ship-specific and not interchangeable or flexible, so that a major change of cable diameter often forces a change of laying system. Further, repeaters in their relatively bulky housings can only be laid during a period of much reduced speed of travel of the laying vessel.

Cable laying and repair requires accurate knowledge of the ocean circulation to minimize the impact of strong currents on the activities of the cable ship as it tends the cable and on underwater remotely operated vehicles working on the cable. The all-weather capability of altimeter data have been used to identify regions of strong currents along the edges of oceanic eddies near cable laying and repair operations, a monitoring capability that is especially important when thermal imagery is not available because of cloud cover.

The Ile de R is a 469-foot (143-m), dynamically positioned ocean-going cable lay and repair vessel, which enables it to maintain position without the use of anchors. The vessel has twin main engines and propellers, two rudders, and full redundancy of equipment, allowing it to hold position or to continue working even in the event of an equipment failure. The vessel can remain at sea for approximately 32 days and is capable of operating in sea and weather conditions up to Beaufort 7. Sea and weather conditions defined as Beaufort 7 include winds between 28 to 33 knots with wave heights between 13.5 to 19.0 feet (4.1 to 5.8 m). The vessel is also equipped with a ROV to assist cable laying activities with a safe working depth of 8,202 feet (2,500 m).

Tyco Telecommunications restructured its fleet by constructing six new Reliance Class ships. This provides Tyco with one of the most flexible and cost effective fleets in the industry. Tyco Telecommunications' newest Reliance Class cable ship, the 12,184 gross ton Tyco Dependable was delivered at Keppel Hitachi Shipyard, Singapore on November 19, 2002. Tyco Telecommunications has one of the youngest and most capable cable ship fleets in the world.

Reliance Class vessels feature dynamic positioning, cable automation, and a State of the Art bridge, engine room, and many other features available. These features enable Reliance Class vessels to operate faster, with improved fuel economy, and reduced crews, resulting in overall lower operating costs. In addition, Tyco Dependable is the fourth of six new Reliance Class cable ships specifically designed, constructed and outfitted to provide our customers with the highest quality marine services for both undersea cable maintenance and new cable installations.

With the completion of the Reliance Class cable ships and subsequent retirement of older vessels, Tyco shore side operations, engineering and logistics will be more efficient with six robust vessels of the same design.

The six Reliance Class vessels have been designed and built under Tyco Telecommunications' supervision and are engineered to provide both installation and maintenance services for undersea communications systems. Successfully combining proven cable ship design elements with the latest available technology, these cable ships are large, fast and extremely seaworthy vehicles. The design of these ships has allowed for dramatic improvements in fuel consumption and crew size; these improvements as well as the standardization of the fleet ensure Tyco's competitiveness.

With a total of 9,800 kW of thruster power available (2 fixed bow, 1 drop down bow, and 2 azimuthing stern thrusters) and a state-of-the-art duplex dynamic positioning system, the Reliance Class cable ships are capable of maintaining station during cable repair operations under the most severe conditions. These ships are among the best designed and operated ships in the world, and are a vital piece of Tyco Telecommunications' capability to provide world class cable installation and repair services.

The Solitaire of Allseas Engineering is the largest pipelay vessel in the world. The Solitaire project saw the conversion of a 120,000 ton bulk carrier into the world's largest and most sophisticated pipelaying vessel for the Allseas Group, the leading international offshore pipelaying contractor. The initial hull conversion commenced in Singapore but due to extreme delays, the partly completed vessel was brought to Swan Hunter for major hull completion, overall outfitting, testing, commissioning and sea trials. The vessel was over 285m long (excluding stinger) with a breadth of 40.6m and a displacement at sailaway of 70,250 tons. It was powered by eight diesel engines producing over 51 mw of power and had eight large computer controlled azimuthing thrusters for propulsion and station-keeping. Swan Hunter was responsible for installing the majority of all cabling and pipework, including much pipework replacement, and completely outfitted the 420 man accommodation to a very high standard.

On May 22, 2003 C.S. Long Lines L. P., Baltimore, MD, received approval to sell the 11,326-gross-ton cable ship LONG LINES to Sea Lion Marine Ltd., a St. Vincent and The Grenadines corporation, for resale to Priyank Shipbreaking Co., Pvt. Ltd., an Indian corporation, for scrapping in India. The vessel was built in 1963 in Hamburg, Germany.




NEWSLETTER
Join the GlobalSecurity.org mailing list


 

privacy policy