turn replaced by Otto's four-stroke engine. The changeover to four-stroke engines was remarkably rapid, with the last atmospheric engines being made in 1877. Liquid-fuelled engines soon followed using Diesel (around 1898) or gasoline (around 1900). Crossley The best-known builder of gas engines in the United Kingdom was Crossley of Manchester, who in 1869 acquired the United Kingdom and world (except German) rights to the patents of Otto and Langden for the new gas-fuelled atmospheric engine. In 1876 they acquired the rights to the more efficient Otto four-stroke cycle engine. Tangye There were several other firms based in the Manchester area as well. Tangye Ltd., of Smethwick, near Birmingham, sold its first gas engine, a 1 nominal horsepower two-cycle type, in 1881, and in 1890 the firm commenced manufacture of the four-cycle gas engine. Preservation The Anson Engine Museum in Poynton, near Stockport, England, has a collection of engines that includes several working gas engines, including the largest running Crossley atmospheric engine ever made. Current manufacturers Manufacturers of gas engines include Hyundai Heavy Industries, Rolls-Royce with the Bergen-Engines AS, Kawasaki Heavy Industries, Liebherr, MTU Friedrichshafen, INNIO Jenbacher, Caterpillar Inc., Perkins Engines, MWM, Cummins, Wärtsilä, INNIO Waukesha, Guascor Power, Deutz, MTU, MAN, Scania AB, Fairbanks-Morse, Doosan, and Yanmar. Output ranges from about micro combined heat and power (CHP) to . Generally speaking, the modern high-speed gas engine is very competitive with gas turbines up to about depending on circumstances, and the best ones are much more fuel efficient than the gas turbines. Rolls-Royce with the Bergen Engines, Caterpillar and many other manufacturers base their products on a Diesel engine block and crankshaft. INNIO Jenbacher and Waukesha are the only two companies whose engines are designed and dedicated to gas alone. Typical applications Stationary Typical applications are base load or high-hour generation schemes, including combined heat and power (for typical performance figures see), landfill gas, mines gas, well-head gas and biogas, where the waste heat from the engine may be used to warm the digesters. For typical biogas engine installation parameters see. For parameters of a large gas engine CHP system, as fitted in a factory, see. Gas engines are rarely used for standby applications, which remain largely the province of Diesel engines. One exception to this is the small (<150 kW) emergency generator often installed by farms, museums, small businesses, and residences. Connected to either natural gas from the public utility or