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Today, our entire planet is tightly shrouded in wired and wireless networks for various
purposes.
And a very large share in this entire web falls on submarine cables.
The importance of submarine cables today can hardly be overestimated.
For decades, they have been used to provide much-needed power and telecommunications connectivity
to islands, remote locations, offshore platforms, and other areas without their own power sources.
Today, with the advent of offshore wind farms and other natural energy power plants, many
of these cables are also streaming towards them.
They carry the energy received in the sea.
These cables are expected to meet very high standards.
This is due not only to the fact that they need to pass a huge amount of energy, but
also to the fact that they will have to withstand many threats emanating from the ocean floor.
From conductor manufacturing to insulation and reinforcement processes, these cables
are a true masterpiece of cutting-edge technology.
According to experts, more than 850,000 kilometers of submarine cable have been laid around the
world.
And although they vary greatly in diameter and type, they are usually used either for
communication or for power supply.
When you consider the hundreds of thousands of kilometers of these cables currently traversing
the seabed, it's not hard to see the huge amount of investment that both private and
public companies are putting into equipment for transporting and distributing energy.
Whereas in the past two cables were required to complete a particular task, now the same
task can be accomplished using only one cable of the same power.
This means that such work will be done much more economically.
The huge demand for cable has led to significant price increases for many of the cable designs.
The manufacturing process for high-power submarine cables varies greatly, depending on the electrical
power and the distance over which the electricity must be transmitted.
The cross-section of each cable shows that inside it consists of many high-quality strands
braided with galvanized steel.
The cable consists of an outer plastic tube with a copper sheath and a small amount of
vaseline inside for insulation.
In addition to cores and insulation, the cable may contain a screen, core, filler, steel
or wire armor, metal sheath, outer sheath.
Each structural element is needed for the cable to work in certain environmental conditions.
All of them are aimed at protecting and shaping the cable.
Typically, cable production begins with a series of thick wires.
The section of cable is then passed through a machine that wraps it in a protective sheath.
Later, this single piece of wire would be included in a much larger package of wires
and cables that would be carefully insulated to maximize its lifespan.
The first cable for laying at sea was created in 1850.
It did not have a shell, the insulation of the cores was resistant to moisture, and armor
was used for protection.
The submarine cable also includes lead or aluminum water armor, stranded steel wires,
mylar tape and a final polyethylene film to protect the entire cable from damage and corrosion.
To facilitate cable installation, most manufacturing plants lay the cable directly on large metal
rollers that allow the cable to be easily transferred to the laying vessel.
To connect separate offshore installations, these special cable-laying vessels first conduct
an underwater inspection of the route being laid to ensure that there are no barriers
in the way.
Therefore, at the beginning of the laying process, a cable is pulled to the vessel,
to which one end of the cable is attached.
This is done using a remotely controlled underwater vehicle that moves along the carrying cable
of the offshore installation.
This carrier cable is then pulled aboard the vessel and connected to the cable head.
When the ship approaches the shore where the cable will be brought out, a special winch
is lowered from its side and the end of the cable is pulled through the pylon at the top
of the ship.
In this case, the operator checks each section when it comes into contact with the bottom.
In this case, the cable always remains afloat, for which several small pontoons or other
floating facilities located along the entire length (from ship to shore) of the cable line
can be used.
As the cable is laid, workers determine exactly where it should be cut.
The same process is repeated at the opposite end of the cable, on the shore.
To secure the cable on the shore, a special cable-laying plow is used.
This plow is pulled ashore with a winch.
The same winch pulls the cable through the plow.
Then a special remote-controlled trenching robot digs in the newly laid cable.
Offshore wind farms are among the most important developments in recent history.
They provide much more energy than their terrestrial counterparts.
For transmission, they require high-tech cables.
These submarine cables are extremely complex and are also placed in extremely harsh and
corrosive environments.
For this reason, submarine power cables tend to be well insulated and much more durable
than communications or land-based power cables.
Submarine cables have a service life of up to 25 years.
A decommissioned cable may remain inactive on the ocean floor or be retrieved for further
processing.
After the cables are decommissioned and removed from the ocean, they are recycled at a dedicated
cable recycling plant.
First, the cables are cut into manageable sections, usually about 60 or 90 centimeters
long.
They are then fed into a special machine that cuts the cable and exposes each component.
The insulation is removed and vital metal and electronic parts are stored for reuse.
These old cables still contain millions of dollars worth of materials that can be reused
in production for a variety of purposes.
Despite all the impressive technology that is used in the manufacture of cable today,
in fact, submarine cables have been around for over 150 years.
And the very first transatlantic telegraph cable was laid between 1853 and 1858.
He was able to send entire messages from Ireland to Newfoundland in a matter of minutes.
Of course, in those days these cables were haphazardly laid by low-speed steamers.
Today, this work is carried out by specialized vessels with unique swivel sections for cable
storage and deployment.
A special rotating turntable for cable laying can hold a weight of 5,000 tons.
With the help of a tensioner, he lays the cable on the seabed at the same speed as the
ship moves along a predetermined route.
This route is designed in such a way as to avoid any major natural obstacles that could
cause the cable to break or fail.
Vessels also have special mooring systems and flat bottoms that allow for reduced movement
when operating in both shallow and deep waters without risk to crew and equipment.
The interior of these unique ships is intriguing.
Most notably, the entire center of the ship is adapted for the cable-laying process.
Here you can see thousands of meters of rope for an underwater robot, which is used for
auxiliary work when laying an underwater cable.
Extensive areas of the vessel are completely reserved for storage facilities.
The vessel also has specially equipped sections from which the movements of the ship's cable-laying
devices and tractors can be coordinated using remote control.
As demand for marine power grows everywhere, there is no doubt that these massive cable-laying
vessels will continue to be used more often in the seas and oceans around the world.
Offshore wind turbines are becoming more and more popular.
Therefore, the role of companies that ensure the transfer of energy generated by wind turbines
to the shore is greater than ever.
As the sea portion of the cable reaches the shore, a team of onshore cable-layers step
in.
She is ready to stretch kilometers of cable to connect to the substation.
However, this process is still subject to many different unique challenges and problems.
To somehow reduce some of these dangers, the seabed is plowed and the cable is buried.
However, fishing boats and anchorages still pose a risk to even the deepest cable structures.
Only one violation, such as, for example, the inept use of an anchor, can leave entire
island states without electricity and communications for several days.
These places include the Aran Islands, located off the west coast of Ireland.
Due to its small size, most of its power, such as the Internet and other communications,
is brought here from the mainland via submarine cables.
In 2016, one of these submarine cables broke, essentially cutting off power to the entire
archipelago.
The repair company ESB International was sent to repair the damaged cable.
It was necessary to send divers to the bottom of the ocean to make repairs without removing
the 500-megawatt plugs to the surface.
To accomplish this task, the company has prepared a special installation for the repair of the
habitat.
It took years of training in swimming pools and other simulated environments to master
it.
Despite this decision, the repair process was still quite complicated.
The repair chamber had to be lowered into place so that its two halves passed above
and below the cable.
The chamber is then evacuated to allow divers to make repairs in a dry environment using
gloves built into the side of the repair chamber.
In addition to simply laying thousands of miles of cable, the company was required to
implement various innovative methods and engineering solutions.
The complexity of the repair is also affected by the depth at which the cable is located.
Trained divers can reach depths of up to 30 meters quite easily, but deeper depths require
special equipment.
It
allows divers to work at a depth of several hundred meters.
Divers prepare for operations at such depths in advance.
But it's not
just seawater that destroys cables, there are also reports of sharks and other marine
predators biting underwater cables.
This creates holes in the insulation, which can later lead to corrosion on the line.
Since cable repair involves dredging the damaged area and meticulous replacement of the cable
at sea, one can only hope that technology will find a way to make these threats much
less damaging.
Ultimately, it should be noted that the ocean is the enemy of everything that is created
by human hands.
Thousands of kilometers of cables, docks for boats and ships, wind turbine platforms - all
this is subject to corrosion.
This is a constant force that must be kept under control in order to reduce costly damage.
That's all.
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