Australia - South Australia/Northern Territory.
The Overland Telegraph Line - Early international cables.

From almost the start of telegraphic communications, visionaries dreamt of extending the technology to reach distant shores. Submarine cables became the focus of considerable manufacturing activity - at first highly unsuccessful.

First ideas for submarine cables.

In 1843, Samuel Morse coated a wire with rubber and then inserted that into a lead pipe. He then laid this wire between Castle Garden and Governors Island in New York Harbour. A telegraphic message was communicated through the wire over that short distance but it was impractible over a longer distance.

Attention then changed to laying a cable across the English Channel. Europe was by then criss-crossed with long telegraph wires - but England was isolated. As lead pipe could not be used over such distances, technicians experimented with rubber coverings around the telegraph wires but soon discovered rubber quickly deteriorated in sea water.


At that time, Victorians used a product called gutta-percha to make a range of products such as dolls, small ornaments, items of furniture, etc. Gutta percha was a rigid natural latex from the sap of gutta-percha tree found in South-East Asia. It was hard at room temperature but very malleable in hot water and it could be easily molded. Although gutta-percha was expensive:

  1. it provided an ideal coating of submarine cables because of it being biologically inert, resilient and a good electrical insulator with a high dielectric strength.
  2. it is useful in dentistry for root canal therapy;
  3. it was used to make pistol hand grips and rifle shoulder pads before bakelite was invented;
  4. it was used to make golf balls by providing a solid core and that design revolutionised the game.

Indeed gutta-percha became so much in demand that the trees were harvested in unsustainable numbers and the supply collapsed.

The first cable across the English Channel.

Gutta-percha was used for the first attempt to lay a submarine cable across the English Channel. The Brett brothers obtained the necessary permissions and embarked on their project. John was a retired antique dealer whilr his younger brother Jacob was an engineer.

They contacted the newly established Gutta-Percha Company in London and ordered a wire coated with a quarter of an inch of gutta-percha - which made it about as thick as a power cord used today.

On 28 August 1850, they loaded the cable wrapped around a steel drum on the back of a small tug boat called the Goliath and set sail for Cap Gris-Nez near Calais in France. It was not long before they realised that the cable was so light that it floated. They solved that problem by adding weights at regular intervals to force it to the bottom.

After arrival, they attached the latest technology to the cable and sent the first test message. Unfortunately it was indecipherable because the water around the cable changed the electrical properties and the dots and dashes of the morse code were smoothed out. They then used an older-style machine to slow the transmission speed and did achieve some success. Their happiness in this qualified success sank the following day when a French fisherman caught the cable in his net abd dragged it to the surface. As Standage (1998, 72) describes "he hacked off a piece to see what it was. Deciding that it was a hitherto unknown form of seaweed with a gold centre, he took it to show his friends in Boulogne".

The Brett brothers developed their ideas further and achieved success in September 1851 by installing an armored cable between Dover and Calais that lasted for many years under the name of their company Submarine Telegraph Company between France and England (see elsewhere also).

The Atlantic Cable.

Once a cable across the English Channel worked successfully, ambitions were turned to crossing the Atlantic. Four major attempts made for this crossing - in 1857, 1858, 1865 and finally the first successful crossing in 1866 organised by John Pender. There are many descriptions of these efforts and some of these can be referenced elsewhere.