Flashback Friday: An Underwater Cable of 1939


By Jayne MillerNov 18, 2016


When it comes to undersea cables, we've come a long way.

Take this 1939 Bell Systems reel, which showcases scenes from the San Francisco Harbor, as workmen ready submarine telephone cable that is to live at the bottom of the San Francisco Bay, winding beneath the Bay Bridge.

We watch the workmen carefully and artfully protect the cables from water, employing paper, lead, and several layers of woven fiber and protective armor. The narrator boasts the use of 1,056 wires, each separately insulated.

At 2:50 an anonymous workman handles hot lead, binding the protective layer to the smooth metal coat. A few moments later, around 3:15, an "extremely unromantic substance" comes into use: soap suds. The household item was used to check for any holes in the brand new cable coating.

Aw, shucks. This video seems to have disappeared from the internet. 
We hope our description of the action paints a picture for you. (If you feel robbed of video content, this reel from 1958 is also pretty good.) 

The first submarine communications cables were laid in the 1850s and have been evolving ever since. Later generations of cables carried telephone traffic - like the cable shown in this video - and then data. Modern cables have been upgraded to optical fiber technology to carry digital data.

Plus, in the last 80 years, the sheer amount of cables has seen a sharp uptick.

While cable installation remains tedious and expensive – as true as it was in 1939 – about 99% of all international telecoms traffic is transmitted via these cables beneath the sea.

However, the cables of today have leveled up from paper and lead coatings to polyethylene and aluminum water barriers, among other things.

And it’s safe to say the cable-laying process looks a little different.


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