No Plastic No Internet!

Current Undersea Cable System
Current Undersea Cable System


Many scientists have put forth the concept of internet even before its discovery; such as by Nikola Tesla: world wireless system and JCR Licklider (MIT professor): Intergalactic Network. However, the first working prototype of internet was demonstrated by ARPANET (Advanced Research Projects Agency Network), via a project funded by the US Department of Defence, in 1960s; wherein, the communication was established between two computers of which one was placed in UCLA (University of California, Los Angeles) and another at Stanford. Thereafter, the technology has grown tremendously and has become an indispensable part of our lives today.

Table below provides the dates when internet started in some of the countries:

Sr. No.Country NameInternet Start Year
7New Zealand1978

How are countries connected?

I was really interested to understand how we are connected through internet even when we are countries apart! Although we are using wireless internet network, we do need some extremely lengthy undersea cables connecting countries. Can you imagine China and USA being connected by undersea cables!

Some Figures:

  • Total number of undersea cables: 436 as of early 2021
  • Total length of the undersea cables: As of 2021 1.3 billion km
  • First undersea cable: Transatlantic No. 1 laid in 1956
  • They can be as deep as 25,000 ft below the ocean’s surface
  • Longest undersea cable: Fibre-optic Link around the Globe (FLAG) – 28,000 kilometre long connecting the United Kingdom, Japan, India, and many places in between. The cable has 39 landing points.
  • Market: 17.3 billion USD in 2019 and expected to reach ~35 billion USD in 2027, CAGR of 9%
  • Largest market share: Asia Pacific (~36%)
  • Smallest market share: Middle East and Africa (~5%)
  • Major players: Alcatel Submarine Networks, SubCom, LLC, ABB, Huawei Marine Networks Co., Ltd., NEC Corporation, NEXANS NORWAY AS, FUJITSU, Prysmian Group, Saudi Ericsson, HENGTONG GROUP CO., LTD., ZTT, Corning Incorporated, NKT A/S, Hellenic Cables Group
  • These are faster and cheaper than the satellites
  • Lifespan: About 25 years

Below YouTube video provides an overview of how all countries are inter-connected by the undersea internet cables (As the video is from 2017, the numeric details would have updated and should be taken only for reference)

Overview of how all countries are inter-connected by the undersea internet cables

These cables are fiber optic based cables connecting countries with cables laid on the floor of the ocean, and transmit huge amounts of data every minute. Laying of the cables is performed using specially-made ships. Video below provides details on how these cables are laid.

How undersea cables are laid?

What are cables made up of? There are many types of cables used in the undersea application. Photos of some of which are shown below:

Types of cables used in the undersea application
Schematic of the general type of the undersea cable

General details of the cable:

  • Diameter: ~25 mm
  • Weigh: ~1.4 tonnes per kilometre

The optical fibers are coated with petroleum jelly and put inside a copper tubing (carrying electricity); which is surrounded by a plastic tube. This assembly is further covered by an aluminium barrier and stranded steel wires, and is additionally protected Mylar tape. This all is finally covered with a polyethylene plastic coating sealing the above mentioned materials.

One can observe that three types of plastic materials are used in making an undersea cable:

  • Polycarbonate
    • Very good temperature resistance: -40 to 120oC
    • Excellent chemical resistance
    • UV-resistant
    • Light weight
    • Virtually unbreakable and vandal-proof
    • Has B1 rating of fire resistance. It’s a self-extinguishing polymer
  • Mylar tape
    • Mainly used as an insulation material
    • Very good temperature resistance: -70 to 150 C
    • Mylar is  a brand from DuPont
    • It’s made of polyester film tape having one side coated with acrylic adhesive
    • Best in class resistance to:           
      • Hydrolysis
      • UV protection
      • Salt water
    • Very good barrier properties
    • Largely used as cable insulation material
  • Polyethylene
    • Hydrophobic polyethylene provides best in class water resistance to the cable
    • This high dielectric (can be upto 500 kV) polymer has ability to take high ocean bottom water pressures
    • Can be a medium density polyethylene or cross-linked polyethylene (XLPE). However, largely its XLPE

Thus, we can see that polymer materials are required for safeguarding the optical fibers and other metal structures inside the cable; without the presence of which the life of the materials under the sea condition would be very low. So we can truly say: No Plastic No Internet! Video below provides information on how the undersea cables are made:

How undersea cables are made?

Some challenges with the undersea cables:

  • Sharks and undersea creatures try to bite &/eat these cables
  • Vulnerability to natural disasters
  • Spying on information by other countries
  •  Difficulty in repairing

Dear Readers, do go through the above content on ‘No Plastic No Internet’ and let me know your viewpoints in the Comments section.

Thanks for Reading!

I put up a new post whenever I come across an interesting topic, so follow my blog and stay updated about the developments in the polymer industry.


One thought on “No Plastic No Internet!

  1. Amazing….

    As I understand huge amount of plastic is required for this application.

    It will be interesting to know if there is any scope for use of recycled plastic in this field, inspite of stringent performance requirements.

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