13 - US Machines
The Americans built 145 machines, mainly four-wheel Naval versions, at the National Cash Register Company at Dayton, Ohio.
They also built special additional machinery such as the Autoscritcher, Superscritcher and Duenna: These machines were used to break traffic using the pluggable Reflector D. The Autoscritcher was electro-mechanical and used relay technology while the Superscritcher was fully electronic and contained about 3,500 valves. The Duenna was used for breaking Enigma keys on a crib when the wiring of Reflector D was unknown.
Note: there were other attachments used which are not referred to here.
(c) John Jackson