Pneumatic Tube Mail

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Pneumatic tube canister

Networks of pneumatic tubes speeded mail along under city streets beginning in the 1890s. Mail was enclosed in pneumatic tube canisters that could hold up to 600 letters. The canisters traveled at an average of 35 miles per hour.

The first pneumatic tubes were introduced in 1893 in Philadelphia. Boston, Brooklyn, New York, Chicago and St. Louis also used the system. By 1915, these six cities had more than 56 miles of pneumatic tubes pulsing under the streets.

During World War I, the Post Office Department suspended the service to conserve funding for the war effort. After the war service was restored in New York and Boston. By the 1950s, it became clear that the end of pneumatic tubes was in sight as increasing mail volumes and changing urban landscapes made it impractical. While post offices and businesses moved with relative ease, the underground pneumatic system did not.

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Map of New York City pneumatic tube lines

Clerks working with a pneumatic tube system

Clerks working with the pneumatic tube system in a New York City post office building.

a group of people looking at a pneumatic tube system

Pneumatic tubes were placed in the basement facilities of post offices, where clerks worked around the clock to fill and send, open and empty the tube containers.

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In 1893 the Philadelphia post office tried a radically different and speedy way to transfer mail between post offices.

They installed a network of underground pneumatic tubes.

Cylinders like these carrying mail were pushed or pulled through the tubes by compressed air or vacuum suction.

Cylinders flew through the tubes as fast as 35 miles per hour.

Other cities followed the example.

In New York City, a forty-minute male wagon route was covered by the tubes in seven minutes.