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09/07/2019

What methods are used to lay cables under the ocean?

What methods are used to lay cables under the ocean?

Submarine cables are laid down by using specially-modified ships that carry the submarine cable on board and slowly lay it out on the seabed as per the plans given by the cable operator. The ships can carry with them up to 2,000km-length of cable.

How subsea cables are laid?

A plough is used to lay the cable inside a trench instead of leaving it on the sea bed. In case an obstruction occurs while laying cables on the seabed, a length of cable can be recovered and re-laid on a separate route to avoid blockage.

What are subsea cables used for?

Subsea or submarine cables are fiber optic cables that connect countries across the world via cables laid on the ocean floor. These cables – often thousands of miles in length – are able to transmit huge amounts of data rapidly from one point to another.

How were telegraph cables laid in the sea?

In 1854, Cyrus West Field conceived the idea of the telegraph cable and secured a charter to lay a well-insulated line across the floor of the Atlantic Ocean. In 1866, the British ship Great Eastern succeeded in laying the first permanent telegraph line across the Atlantic Ocean.

Do cables run under the ocean?

Today, more than 99% of international communications are carried over fiber optic cables, most of them undersea, according to TeleGeography. The easiest way of doing so is not by tapping the cable, but the point where it connects to land.

Why do we need undersea cables?

Undersea cables make instant communications possible, transporting some 95 percent of the data and voice traffic that crosses international boundaries. They also form the backbone of the global economy — roughly $10 trillion in financial transactions are transmitted via these cables each day.

What is a subsea power cable?

A submarine power cable is a 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.)

How were telegrams sent across the ocean?

Transatlantic telegraph cables were undersea cables running under the Atlantic Ocean for telegraph communications. The first cable was laid in the 1850s from Valentia in western Ireland to Bay of Bulls, Trinity Bay, Newfoundland.

How did telegraph work on ships?

Communication between ship and shore was by Morse code, as it was for conventional telegraphy. The equipment only transmitted messages for about 300 miles in daylight, although that figure doubled or tripled after dark thanks to the refraction of long-wave radiation in the ionosphere.

Is the Internet under the sea?

Close to shore, in water shallower than 1,500 metres, the cables are buried to protect them – but in deep water they lie on the seabed. The American end of cabling carrying the internet between Europe and North America. ‘More than 2.5 quintillion bytes of information are created and shared every day,’ notes Shinkle.

What are the steps in installing a submarine cable?

Installing a submarine transmission cable involves a series of actions: Selection of the provisional path; Obtaining permission from the relevant authorities; Survey of the path; Designing the cable system in order to meet the conditions of the selected path; Laying the cable, including burial in appropriate areas;

How are submarine cables buried in the sea?

Cables are buried in the seabed in shallow waters in order to minimize the risks for damages. The trenches in which the cables are placed are dug by a submarine plough and covered by sediment or rocks.

Can a submarine cable be installed on the High Seas?

United Nations Convention on Law of the Sea – UNCLOS (1982). The freedom to install submarine cables on the high seas beyond the continental shelf and to repair existing cables without impediment or prejudice;

What are the threats to a submarine transmission cable?

The main threats to a submarine transmission cable are external impacts due to predominantly anchors and fishing gears. In order to minimize the risk of a cable tear due to a vessels’ anchoring, a “Cable protection zone” or CPZ is established along the cable’s path. These zones are legally defined and marked on nautical charts.