In 1930, the 22-million-pound Indiana Bell building was rotated 90 degrees without interrupting work or services, and employees never felt a thing

In November 1930, engineers in Indiana, USA, accomplished an astounding engineering marvel by moving an 11,000-ton telephone exchange building. This building, which housed 600 employees, was shifted 16 meters and rotated 90 degrees over 34 days, all while maintaining full operational capacity, including gas, water, electricity, and phone services.

The project was masterminded by the engineering firm Bevington, Taggert & Fowler, with the execution handled by John Eichlea Co. The method involved lifting the seven-story structure with hydraulic jacks and then using hydraulic rollers placed on specially laid 75-ton spruce beams to move it. The building was maneuvered at a slow pace of 40 centimeters per hour, with workers continuously setting up the next roller as the building advanced.

To ensure that the building remained accessible, a mobile entrance walkway was used, allowing access even as the building rotated. Remarkably, according to the Telephone Collectors International, many of the 600 employees inside didn’t even realize the building was being moved.