How a Telephone Switchboard Works — 1911

by Paula Bosse

I have a lot of weird interests — one of them is a fascination with telephone switchboards. I’ve never really known how they worked, back in the days when operators had to assist with all calls, completing them by plugging things (“plugs”) into holes (“jacks”) in a large board filled with lots and lots of holes. How did they possibly know where those plugs went? This photo essay from the January, 1911 issue of New England Telephone Topics is very helpful. (All images are larger when clicked.)

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THE PANELS BELOW ILLUSTRATE “THE MAKING OF A LOCAL CALL THAT ORIGINATES AND TERMINATES IN THE SAME EXCHANGE”

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THE PANELS BELOW ILLUSTRATE “THE MAKING OF A TRUNKED CALL; THAT IS, ONE THAT ORIGINATES IN ONE EXCHANGE AND TERMINATES IN ANOTHER”

And there you have it.

In these early days, I always assumed an operator knew a line was busy by listening in on the line to hear if people were talking — I’ve never heard of holding the metal plug to the jack and waiting to hear clicks which would indicate the line is in use.

I hope this information will come in handy to those studying for a possible “Early 19th-Century Telephone Switchboard Procedure” category on Jeopardy. (You’re welcome.)

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Sources & Notes

Text and photos from the January, 1911 issue of the trade publication New England Telephone Topics. As stated in the article, the photographs were taken at the School For Operating in Boston.