Tuesday, July 28, 2020

Connection Across the Pond—Cable Under the Atlantic

A contemporaneity promotional map showed the route of the cable.

On July 28, 1866 permanent telegraphic connection between North America and Europe was established when a new Trans-Atlantic Cable was completed. It was the fifth attempt to make the connection.  The first in 1857 failed.  
The second attempt in 1858 did establish a connection.  Queen Victoria wired her congratulations to American President James Buchannan.  Despite this engineering triumph for the company launched and guided by Cyrus West Field, that cable failed within a month when excessive voltage was applied while attempting to achieve faster telegraph operation.  A second attempt that year to lay a replacement also failed. 

A shore-end cross section of the innovative  cable that made thie connection possible.  The copper wire was wound and insulated with hemp.        
Although the brief operation proved the project was feasible, the great expense and technical challenges—and the intervening crisis of the American Civil War—delayed further attempts until 1865.  By that year successful underwater cables in the Mediterranean and elsewhere led to the development of enduring and well insulated cable.  According to Wikipedia the new cable…

…core consisted of seven twisted strands of very pure copper weighing 300 lb per nautical mile (73 kg/km), coated with Chatterton's compound, then covered with four layers of gutta-percha, alternating with four thin layers of the compound cementing the whole, and bringing the weight of the insulator to 400 lb/nmi (98 kg/km). This core was covered with hemp saturated in a preservative solution, and on the hemp were spirally wound eighteen single wires of soft steel, each covered with fine strands of manila yarn steeped in the preservative. The weight of the new cable was 35.75 long hundredweight (4000 lb) per nautical mile (980 kg/km), or nearly twice the weight of the old.
Advocates of modern commercial hemp can use that in their campaigns for legalization.

The SS Great Eastern was one of the largest and most celebrated steam packets plying the Atlantic  before she was converted to a cable layer and sailed to even greater fame.
In 1865 S.S.Great Eastern captained by Sir James Anderson began laying the improved cable heading west from Foilhommerum Bay, Valentia Island, in western Ireland.  After 1,062 miles the cable snapped and the end was lost to the bottom of the sea.  Anderson had to return to Britain and Field had to scramble to raise new capital for another attempt the following year.  He formed the Anglo-American Telegraph Company, to lay a new cable and complete the broken one and sold enough stock to try again in 1866. 
This time the Great Eastern completed its task bringing the cable to its western terminus at Heart’s Content in eastern Newfoundland.  Displaying its usefulness the first message from the continent in addition to praise from The Times contained word that a peace had been signed between warring Prussia and Austria. 
After a few days in port, Anderson turned the Great Eastern back to sea to try and locate the lost end of the 1855 cable and restore it to operation.  It was an epic search conducted by dragging a grappling hook over the sea bed a mile and a half below.  The cable was snagged and lost once before it was finally recovered and spliced to new cable in the ship’s hold.  On September 7the ship returned to Heart’s Content and two cable connections were soon functioning. 
When the Transcontinental telegraph between California and the America East coast was completed on one end and Russian telegraphy stretched to the Pacific on the other, much of the world was connected.  And London was the hub of world communications.

The completion of the cable was celebrated on both sides of the Atlantic.
Messages over the vast distance were not instantaneous.  Only eight words in a minute in Morse Code could move and took several minutes to cross the ocean.  None the less, connection was made and valuable information—especially commercial news and stock quotations, were quickly going back and forth. 
In the next few years seven other cables were laid by companies from Britain, the U.S., France, and Germany.  By the 1870’s improved technology allowed duplex and quadruplex transmission and receiving systems to relay multiple messages over the cable.  It was then literally possible to have  a conversation with questions and answers across the ocean in hours. 

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