Submarine power cable

A submarine power cable is a major transmission cable for carrying electric power below the surface of the water. These are called "submarine" because they usually carry electric power beneath salt water (arms of the ocean, seas, straits, etc.) but it is also possible to use submarine power cables beneath fresh water (large lakes and rivers). Examples of the latter exist that connect the mainland with large islands in the St. Lawrence River.

Design Technologies

Most power systems use alternating current (AC). This is due mostly to the ease with which AC voltages may be stepped up and down, by means of a transformer. When the voltage is stepped up, current through the line is reduced, and since resistive losses in the line are proportional to the square of the current, stepping up the voltage significantly reduces the resistive line losses. The lack of a similarly simple and efficient system to perform the same function for DC made DC systems impractical in the late 19th and early 20th centuries. (Available devices, such as the rotary converter, were less efficient and required considerably more maintenance.) As technology improved, it became practical to step DC voltages up or down, though even today the process is much more complex than for AC systems. A DC voltage converter often consists of an inverter - essentially a high-power oscillator - to convert the DC to AC, a transformer to do the actual voltage stepping, and then a rectifier and filter stage to convert the AC back to DC.

Cable

An electrical cable is made of two or more wires running side by side and bonded, twisted, or braided together to form a single assembly, the ends of which can be connected to two devices, enabling the transfer of electrical signals from one device to the other. Cables are used for a wide range of purposes, and each must be tailored for that purpose. Cables are used extensively in electronic devices for power and signal circuits. Long-distance communication takes place over undersea cables. Power cables are used for bulk transmission of alternating and direct current power, especially using high-voltage cable. Electrical cables are extensively used in building wiring for lighting, power and control circuits permanently installed in buildings. Since all the circuit conductors required can be installed in a cable at one time, installation labor is saved compared to certain other wiring methods.

The term originally referred to a nautical line of specific length where multiple ropes, each laid clockwise, are then laid together anti-clockwise and shackled to produce a strong thick line, resistant to water absorption, that was used to anchor large ships. In mechanics, cables, otherwise known as wire ropes, are used for lifting, hauling, and towing or conveying force through tension. In electrical engineering cables are used to carry electric currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers.

Cable length

A cable length or length of cable is a nautical unit of measure equal to one tenth of a nautical mile or approximately 100 fathoms. The unit is named after the length of a ship's anchor cable in the age of sail. The definition varies:

References

See also

Cable (British band)

Cable were a British indie rock band originally from Derby, UK who released 3 albums in the late '90s: Down-Lift the Up-Trodden ('96), When Animals Attack ('97), and Sub-Lingual ('99), on Infectious Records. The band split up in 1999.

Formed in 1992 by Matt Bagguley and Darius Hinks, Cable were initially inspired by the art-rock leanings of indie-labels such as Touch and Go, Dischord, Blast First, Southern Records and Shimmy Disc, and also UK artists such as Spacemen 3 & My Bloody Valentine. The first settled line-up was Matt Bagguley (vocals/guitar), Darius Hinks (guitar), Pete Darrington (bass), Neil Cooper (drums) and throughout 1993 the band played regularly with underground acts from the U.S (such as Medicine, Polvo, Truman's Water, Rocket From The Crypt..) In early '94 their debut single "Sale of the Century" was released on 7", by Derby-based indie-label Krunch! Records. Radio 1 DJ John Peel played it immediately on his show saying it was the best thing he'd heard that week and phoned the band during the show to invite them to record a session. John Peel remained a loyal fan from that moment on, and altogether the band recorded 4 Peel Sessions.