After the Jumo 004 had entered serial production, the Technical Department of the RLM requested Junkers to build a much larger engine capable of powering the heavy jet bombers then under development for the Luftwaffe.
However, these variants were rejected as they were not powerful enough, and Junkers began to design the 109-012.
[1] The engine was to feature an 11-stage axial compressor enclosed in a sheet-steel casing and a 2-stage, air-cooled turbine.
The RLM ordered ten pre-production examples of the 109-012 to be built at Dessau for testing, where several parts for the engines including nine exhaust cones were already completed.
[1] Data from [citation needed]An episode of The Antiques Roadshow filmed at Powis Castle in summer 2022 featured a blueprint of the Junkers 0-12.