by Horst Zoeller, 1996 - 2020, 67th Edition, 22 Nov 2020

Junkers M12

Research Oil Engine, Feb. 1908
initialy 74 kW, after conversion to Tandem Engine 147kW
by Hugo Junkers and

Tandem Engine M12 in 1910 at Aachen

Historical Data:
The M12 design was started in 1905 by Junkers, Scheller and Wagenseil. The M12 was the first oil engine of Hugo Junkers. It was a horizontal double piston, two stroke engine. The Versuchsanstalt prepared the principle calculation and layout drawings. The engine itself was built by Soest + Co. at Dusseldorf. In February 1908 the 74kW M12 ran for the first time. For test purposes the engine was converted for gas fluids in March 1909.

In September 1909 the M12 was converted into a Tandem engine and in December 1909 the converted M12 reached 147kW power. In 1910 the M12 engine was exhibited at the St. Petersburg Engine Exhibition with great success.

During the following years the M12 was used for several experiments at Aachen. At least in 1919 the engine was still in use, before it probably was transfered to Dessau. Later this engine was stored at the Junkers facilities in Munich-Allach, where it was still available in 1997. By then the engine was handed over to the Hugo Junkers Museum at Dessau, where it is now under public display.


introduced Nov 1996, transfered Nov 2017
contents last updated 24 Jun 2004