A cable layer or cable ship is a deep-sea vessel designed and used to lay underwater cables for telecommunications, for electric power transmission, military, or other purposes. Cable ships are distinguished by large cable sheaves [1] for guiding cable over bow or stern or both. Bow sheaves, [2] some very large, were characteristic of all cable ships in the past, but newer ships are tending toward having stern sheaves only, as seen in the photo of CS Cable Innovator at the Port of Astoria on this page. The names of cable ships are often preceded by "C.S." as in CS Long Lines. [3]
The first transatlantic telegraph cable was laid by cable layers in 1857 to 1858. It briefly enabled telecommunication between Europe and North America before misuse resulted in failure of the line. In 1866 the SS Great Eastern successfully laid two transatlantic cables, securing future communication between the continents.
Cable ships have unique requirements related to having long idle periods in port between cable laying or repairs, operation at low speeds or stopped at sea during cable operations, long periods running astern (less frequent as stern layers are now common), high maneuverability, and a fair speed to reach operation areas. [4]
Modern cable ships differ greatly from their predecessors. There are two main types of cable ships: cable repair ships and cable-laying ships. Cable repair ships, like the Japanese Tsugaru Maru, tend to be smaller and more maneuverable; they are capable of laying cable, but their primary job is fixing or repairing broken sections of cable. A cable-laying ship, like Long Lines, is designed to lay new cables. Such ships are bigger than repair ships and less maneuverable; their cable storage drums are also larger and are set in parallel so one drum can feed into another, allowing them to lay cable much faster. These ships are also generally equipped with a linear cable engine (LCE) that helps them lay cable quickly. By locating the manufacturing plant near a harbor, cable can be loaded into the ship's hold as it is being manufactured. [5]
The newest design of cable layers, though, is a combination of cable-laying and repair ships. An example is USNS Zeus (T-ARC-7) the only U.S. naval cable layer-repair ship. Zeus uses two diesel-electric engines that produce 5,000 horsepower (3,700 kW ) each and can carry her up to 15 knots (28 km/h; 17 mph). She can lay about 1,000 miles (1,600 km) of telecommunications cable to a depth of 9,000 feet (2,700 m). The purpose of Zeus was to be a cable ship that could do anything required of it, so the ship was built to be able to lay and retrieve cable from either the bow or the stern with ease. This design was similar to that of the first cable ship, Great Eastern. Zeus was built to be as maneuverable as possible so that it could fulfill both roles: as a cable layer or a cable repair ship. [6]
To ensure that cable is laid and retrieved properly, specially designed equipment must be used. Different equipment is used on cable-laying ships depending on what their job requires. In order to retrieve damaged or mislaid cable, a grapple system is used to gather cable from the ocean floor. There are several types of grapples, each with certain advantages or disadvantages. These grapples are attached to the vessel via a grapple rope, originally a mix of steel and manila lines, but now made from synthetic materials. This ensures that the line is strong, yet can flex and strain under the weight of the grapple. The line is pulled up by reversing the Linear Cable Engine used to lay the cable. [7]
The most common laying engine in use is the Linear Cable Engine (LCE). The LCE is used to feed the cable down to the ocean floor, but this device can also be reversed and used to bring back up cable needing repair. These engines can feed 800 feet (240 m) of cable a minute. Ships are limited to a speed of eight knots (15 km/h) while laying cable to ensure the cable lies on the sea floor properly and to compensate for any small adjustments in course that might affect the cables' position, which must be carefully mapped so that they can be found again if they need to be repaired. Linear Cable Engines are also equipped with a brake system that allows the flow of cable to be controlled or stopped if a problem arises. A common system used is a fleeting drum, a mechanical drum fitted with eoduldes (raised surfaces on the drum face) that help slow and guide the cable into the LCE. [7] Cable ships also use “plows” that are suspended under the vessel. These plows use jets of high-pressure water to bury cable three feet (0.91 m) under the sea floor, which prevents fishing vessels from snagging cables as thrall their nets. [8]
HMTS Monarch [9] (renamed CS Sentinel 13 October 1970) [1] completed the first transatlantic telephone cable, TAT-1, in 1956 [10] from Scotland to Nova Scotia for Britain's General Post Office (GPO).
The Ocean Marine System Group used a cable laying software designed by Makai Ocean Engineering Inc., in five of their cable installation and repair vessels. The MakaiLay software has been used by 90% of the worlds' global fleet of cable ships. These five OMS vessels were installed with this software on August 23, 2023, to reduce failures during installation and increase reliability, safety, speed, and accuracy: [11]
When coaxial cables were introduced as submarine cables, a new issue with cable-laying was encountered. These cables had periodic repeaters inline with the cable and powered through it. Repeaters overcame significant transmission problems on submarine cables. The difficulty with laying repeaters is that there is a bulge where they are spliced in to the cable and this causes problems passing through the sheave. British ships, such as HMTS Monarch and HMTS Alert solved the problem by providing a trough for the repeater to bypass the sheave. A rope connected in parallel to the repeater went through the sheave which pulled the cable back in to the sheave after the repeater had passed. It was normally necessary for the ship to slow down while the repeater was being laid. [12] American ships, for a time, tried using flexible repeaters which passed through the sheave. However, by the 1960s they were also using rigid repeaters similar to the British system. [13]
Another issue with coaxial repeaters is that they are much heavier than the cable. To ensure that they sink at the same rate as the cable (which can take some time to reach the bottom) and keep the cable straight, the repeaters are fitted with parachutes. [13] [12] : 212
TAT-1 was the first submarine transatlantic telephone cable system. It was laid between Kerrera, Oban, Scotland and Clarenville, Newfoundland. Two cables were laid between 1955 and 1956 with one cable for each direction. It was inaugurated on September 25, 1956. The cable was able to carry 35 simultaneous telephone calls. A 36th channel was used to carry up to 22 telegraph lines.
CANTAT-1 was the first Canadian transatlantic telephone cable, between Hampden, Newfoundland and eventually Grosses-Roches, Quebec and Oban, United Kingdom, which followed on from the success of TAT-1. It was conceived and approved as stage one of a proposed commonwealth round the world cable and was done at a cost of $8,500,000. The system was jointly owned by Cable & Wireless and the Canadian Overseas Telecommunication Corporation (COTC).
A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables were laid beginning in the 1850s and carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858.
Transatlantic telegraph cables were undersea cables running under the Atlantic Ocean for telegraph communications. Telegraphy is an obsolete form of communication, and the cables have long since been decommissioned, but telephone and data are still carried on other transatlantic telecommunications cables.
The Hooper's Telegraph Works Ltd was established by William Hooper in 1870 to manufacture and lay submarine communications cable using his patented vulcanized rubber core. Before the company was formed to produce finished submarine cable Hooper had furnished core for other companies, particularly that of William Thomas Henley, to armor and sheathe. The original core works were located at Mitcham, London with the later complete cable, core with external sheathing, production located and later consolidated at Millwall and the company renamed Hooper's Telegraph Works.
The Cable Ship Mackay-Bennett was a transatlantic cable-laying and cable-repair ship registered at Lloyd's of London as a Glasgow vessel but owned by the American Commercial Cable Company. She is notable for being the ship that recovered the majority of the bodies after the sinking of the Titanic.
Alcatel–Lucent S.A. was a multinational telecommunications equipment company, headquartered in Boulogne-Billancourt, Paris France. It was formed in 2006 by the merger of France-based Alcatel SA and U.S.-based Lucent Technologies, the latter being a successor of AT&T's Western Electric and a holding company of Bell Labs.
The second CS Faraday was a cable ship built by Palmers Shipbuilding and Iron Company, Hebburn-on-Tyne, in 1922–23, as a replacement for the ageing CS Faraday built in 1874. Design of the new ship was influenced by long experience with the original ship.
USS Kailua (IX-71) was originally CS Dickenson, a civilian supply and personnel transport cable-repair ship of the Commercial Pacific Cable Company that was based in Honolulu serving the island cable stations at Midway and Fanning Island.
CS Telconia was a British cable ship used in the early 20th century to lay and repair submarine communications cables. She was built in 1909 by Swan Hunter & Wigham Richardson for the Telegraph Construction and Maintenance Company and remained in service until late 1934.
USS Nashawena (AG-142/YAG-35) was a United States Navy cable layer constructed during World War II for the Army as the wooden-hulled self-propelled barge BSP 2008. The barge was completed converted to cable work for U.S. Army Signal Corps as the cable ship Col. William. A. Glassford supporting the Alaska Communications System in the shallow island waters of Alaska. She was transferred to the United States Navy in 1947 as a miscellaneous auxiliary and assigned to cable-laying duties for the U.S. Pacific Fleet.
HAW-1 was the first submarine telephone cable laid between Hawaii and the mainland United States. HAW-1 was laid in 1957, and consisted of two cables, each transmitting in one direction over 36 channels, with an individual length of 2,625 Nmi (4,862 km). The cable spans between Hanauma Bay, Oahu, Hawaii and Point Arena, California.
AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies.
COMPAC, the Commonwealth Pacific Cable System, was an undersea telephone cable system connecting Canada with New Zealand and Australia. It was completed by closing the last gap in Honolulu Harbor, Hawaii, at 6:25 a.m. B.S.T. on October 10, 1963. Public service of the cable commenced early in December 1963.
C.S. Sovereign is a class DP2 type cable ship used for subsea cable installation and repair works. The ship was designed by BT Marine with Hart Fenton & Company as Naval Architects and built by Van der Giessen de Noord in 1991.
CS Pacific was a cable ship registered in Copenhagen, Denmark, owned by the Great Northern Telegraph Company. The steel vessel was built in 1903 in the shipyards of Burmeister & Wain and delivered that year for the purpose of laying and repairing submarine cable in the Far East networks. Historical records of this cable ship are kept in the National Maritime Museum of Denmark. Pictorial records of the ship are available through the DieselHouse interactive initiative.
CS Alert, or HMTS Alert, was a cable-laying ship that had a significant role in World War I. She was launched in 1871 for the Submarine Telegraph Company with the name The Lady Carmichael. In 1890 the ship was acquired by the General Post Office (GPO) as part of the nationalisation of the British telegraph network. At the outbreak of World War I, Alert was immediately dispatched to cut German telegraph cables in the English Channel, seriously damaging Germany's ability to securely communicate with the rest of the world. Alert was taken out of service as a cable ship in 1915 but her cable-handling gear was retained for fitting on her replacement. After the war, she worked as a merchant ship under various names, finally being wrecked at Redcar under the name Norham in 1932.
The India Rubber, Gutta Percha and Telegraph Works Company was a London-based company based in Silvertown, East London. It was founded by Stephen William Silver in March 1864 as Silver's Indiarubber Works and Telegraph Cable Company Ltd. However in July that year the name was changed to the India Rubber, Gutta Percha and Telegraph Works Company.
HMTS Monarch, launched on 8 August 1945 and completed during February 1946, was the fourth cable ship with that name. The ship was built for the General Post Office (GPO) for the laying and repair of submarine communications cable and was the largest cable ship in the world when completed and the first cable ship to have all electric cable machinery.
Five cable-laying ships have been named CS Monarch, or, after the nationalisation of British telegraph companies, HMTS Monarch:
The ship Seine laying the land end of the Brazilian submarine telegraph cable at Madeira, illustration from the magazine The Illustrated London News, volume LXIII, November 1, 1873.