20th century, whereby the core competence – flow devices (ejector pumps, nozzles, and industrial burners) – became ever more sophisticated. In contrast, the motor- and turbine-engineering declined and were ultimately abandoned. The Körting Double-Acting Gas Engine In 1900 Ernst Körting filed patents for a novel design of gas engine. This engine had a single water cooled piston that was double acting, i.e. the cylinder had combustion chambers at either end. As the engine was a 2-stroke this gave it continuous power strokes, much as a double acting steam engine. The lack of continuous power strokes in internal combustion engines was perceived by those used to steam as having the potential for mechanical problems due to the intermittent power strokes. The Körting design was quite successful in a range of applications particularly large installations powered by blast furnace gas. The prototype 350bhp engine was tested in June 1900 and the results presented in the 1900 annual meeting of the "Verein von Gas-und Wassefach Männern". published by the German Gas Lighting Journal, and reproduced in The Engineer. This article states that a four-stroke version of the double acting design was introduced two year before which also had both piston and rod cooled by water. Other Körting Engines Although Körting were known for their unusual double acting two-stroke, they made a range of more conventional engines over a long period. The 1909 Gross-Basenach experimental M III airship was equipped with two Körting V8 engines. Körting engines (initially paraffin engines and later diesel engines) were used extensively in early German submarines. The 6 cylinder 2-stroke submarine engine was reviewed in The Engineer magazine in August 1906. This utilised crankcase compression, with the piston controlling all the ports. It was referred to as using petroleum, though this was almost certainly the less volatile paraffin/kerosene type, as it had exhaust heaters for the carburetors, and electric pre-heating of both cylinders and vaporisers, with the engine being turned over for some time by electrical power before being put to work. This allowing the engine to be started after 5 minutes. The engine was rated at 200bhp at 500rpm, and two were installed per submarine. References Literature Wolfgang Leonhardt: List und Vahrenwald, zwei prägende Stadtteile von Hannover, Hamburg 2005, 125 Jahre Körting Hannover history of Körting AG for the 125th anniversary, 1996 External links Manufacturing companies based in Hanover Engineering companies of Germany 1871 establishments in Germany Companies