Map of 100 year old Capital Hill Steam Tunnels – Dashed lines show the original tunnels, solid lines mark the 1950 expansion.
Who knows what lurks beneath the streets of Washington, DC? Rats, explosions waiting to take out unsuspecting manhole covers, Metro, policy wonks, cables, aging water pipes? Around the buildings of Congress, there are also pedestrian passages that let Congressmen, Senators, staffers, and other associated hangers-on to scurry beneath the often grid-locked streets above.
There used to also be the Library of Congress Book Conveyor Tunnel. Designed by then Library of Congress Superintendent, Bernard Green, it was intended to transport books from the Jefferson Building of the Library of Congress, back to the House of Representatives chamber at 600 feet per minute, when the Jefferson Building was constructed in 1898 to replace the previous library in the Senate wing of the Capital.
At the time it was an engineering marvel with pneumatic tubes to send the book request to the Library. “Handwritten requests for documents would come in via pneumatic tube, and the text would make its way to the central desk on an intra-library system. From there it was walked down into the basement and whisked through the tunnel conveyor at 600 feet per minute. This whole literary orchestra took just five minutes, likely less time than it would take your average contemporary congressman to pull up an arcane PDF through”
The book tunnel was demolished in 2000 to make way for the underground Capital Visitor Center. However, it is still possible to walk some of the underground pedestrian terminals around the Library of Congress.
For more information and photographs, check out this Gizmodo article.