Misplaced Pages

#590409

25-531: Five cable-laying ships have been named CS Monarch , or, after the nationalisation of British telegraph companies, HMTS Monarch : Cable layer 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

50-464: 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. 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

75-433: A cable repair ship. 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

100-407: 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

125-608: 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. 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

150-732: A recent invention of unknown longevity. The agreement to make the connection was announced by the Postmaster General on December 1, 1953. The project was a joint one between the General Post Office of the UK, the American Telephone and Telegraph company, and the Canadian Overseas Telecommunications Corporation . The share split in the scheme was 40% British, 50% American, and 10% Canadian. The total cost

175-469: A total of 51 repeaters in the central section. The armored cables were manufactured southeast of London , at a factory in Erith , Kent , owned by Submarine Cables Ltd. (owned jointly by Siemens Brothers & Co, Ltd , and The Telegraph Construction & Maintenance Company, Ltd). The cables were laid over the summers of 1955 and 1956, with the majority of the work done by the cable ship HMTS Monarch . At

200-411: A year. Although a telephone cable was discussed at that time, it was not practical until a number of technological advances arrived in the 1940s. The developments that made TAT-1 possible were coaxial cable , polyethylene insulation (replacing gutta-percha ), very reliable vacuum tubes for the submerged repeaters and a general improvement in carrier equipment. Transistors were not used, being

225-408: 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

250-590: The American and Soviet heads of state, although using a teleprinter rather than voice calls as written communications were regarded as less likely to be misinterpreted. The link became operational on 13 July 1963 and was principally motivated as a result of the Cuban Missile Crisis where it took the US, for example, nearly 12 hours to receive and decode the initial settlement message that contained approx. 3,000 words. By

275-559: 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

SECTION 10

#1732851906591

300-403: The cable (which can take some time to reach the bottom) and keep the cable straight, the repeaters are fitted with parachutes. TAT-1 TAT-1 (Transatlantic No. 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

325-526: The communications traffic was routed to the US border by a microwave radio relay link, and in Brunswick, Maine the route joined the main US network and branched to Montreal to connect with the Canadian network. Opened on September 25, 1956, TAT-1 carried 588 London-US calls and 119 London-Canada calls in the first 24 hours of public service. The original 36 channels were 4 kHz. The increase to 48 channels

350-510: 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. 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

375-536: The hard way that there is another way to sing". The 15 minute connection, which required a music quality circuit, cost £300 (~£6,500 as of 2015). Robeson performed this way again in October 1957 when he linked up to the Grand Pavilion, Porthcawl , Wales, fulfilling an invitation to the eistedfodd there. A 10-inch record featuring selections from the event entitled Transatlantic Exchange was issued by South Wales area of

400-685: The land-end in Gallanach Bay near Oban , Scotland, the cable was connected to coaxial (and then 24-circuit carrier lines) carrying the transatlantic circuits via Glasgow and Inverness to the International Exchange at Faraday Building in London . At the cable landing point in Newfoundland the cable joined at Clarenville , then crossed the 300-mile (480 km) Cabot Strait by another submarine cable to Sydney Mines , Nova Scotia . From there

425-526: 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

450-502: The sea floor, which prevents fishing vessels from snagging cables as thrall their nets. HMTS Monarch (renamed CS Sentinel 13 October 1970) completed the first transatlantic telephone cable , TAT-1 , in 1956 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

475-650: The time the message was decoded and interpreted, and an answer had been prepared, another – more aggressive – message had been received. In May 1957, TAT-1 was used to transmit a concert by the singer and civil rights activist, Paul Robeson performing in New York to St Pancras Town Hall in London. Due to McCarthyism , Robeson's passport had been withdrawn by the United States authorities in 1950. Unable to accept numerous invitations to perform abroad, he stated "We have to learn

500-469: 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. The most common laying engine in use is the Linear Cable Engine (LCE). The LCE is used to feed the cable down to

525-519: 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: 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

SECTION 20

#1732851906591

550-514: Was about £120 million. There were to be two main cables, one for each direction of transmission. Each cable was produced and laid in three sections, two shallow-water armored sections, and one continuous central section 1,500 nautical miles (2,800 km) long. The electronic repeaters were designed by the Bell Telephone Laboratories of the United States and they were inserted into the cable at 37-nautical-mile (69 km) intervals –

575-554: Was accomplished by narrowing the bandwidth to 3 kHz. Later, an additional three channels were added by use of C Carrier equipment. Time-assignment speech interpolation (TASI) was implemented on the TAT-1 cable in June 1960 and effectively increased the cable's capacity from 37 (out of 51 available channels) to 72 speech circuits. TAT-1 carried the Moscow-Washington hotline between

600-523: 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. The first transatlantic telegraph cable had been laid in 1858 (see Cyrus West Field ). It only operated for a month, but was replaced with a successful connection in 1866. A radio-based transatlantic telephone service was started in 1927, charging £9 (about US$ 45, or roughly $ 550 in 2010 dollars) for three minutes and handling around 300,000 calls

625-450: Was normally necessary for the ship to slow down while the repeater was being laid. 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. Another issue with coaxial repeaters is that they are much heavier than the cable. To ensure that they sink at the same rate as

#590409