Carousel prison
In US criminal law history, a carousel prison was a special type of prison in which the cells with the inmates were on a rotating plate, to which usually only one entrance led. This design enabled a larger number of prisoners to be looked after by the same number of guards. In contrast to a conventional prison, one entrance is sufficient for several cells.
The Carousel Prison was designed by William H. Brown and constructed by Haugh, Ketcham & Co and installed in various locations in the United States. However, most of these systems had technical problems, which is why they were converted into conventional prisons, for which new cell entrances had to be created.
On June 22, 1939, the last carousel prisons were closed. However, there are still 4 such systems available today, but only the one in Crawfordsville is still functional.