powered Peterson. The Detrick was constructed by Detrick, William H Mehrling, and Lee Gaeke who designed the engine based on a Stanley. Charles Keen began constructing a steam car in 1940 with the intention of restarting steam car manufacturing. Keen's family had a long history of involvement with steam propulsion going back to his great-great-grandfather in the 1830s, who helped build early steam locomotives. His first car, a Plymouth Coupe, used a Stanley engine. In 1948 and 1949, Keen employed Abner Doble to create a more powerful steam engine, a V4. He used this in La Dawri Victress S4 bodied sports car. Both these cars are still in existence. Keen died in 1969 before completing a further car. His papers and patterns were destroyed at that time. In the 1950s, the only manufacturer to investigate steam cars was Paxton. Abner Doble developed the Doble Ultimax engine for the Paxton Phoenix steam car, built by the Paxton Engineering Division of McCulloch Motors Corporation, Los Angeles. The engine's sustained maximum power was . A Ford Coupe was used as a test-bed for the engine. The project was eventually dropped in 1954. In 1957, Williams Engine Company Incorporated of Ambler began offering steam engine conversions for existing production cars. When air pollution became a significant issue for California in the mid-1960s the state encouraged investigation into the use of steam-powered cars. The fuel crises of the early 1970s prompted further work. None of this resulted in renewed steam car manufacturing. Steam cars remain the domain of enthusiasts, occasional experimentation by manufacturers, and those wishing to establish steam-powered land speed records. Impact of Californian legislation In 1967, California established the California Air Resources Board and began to implement legislation to dramatically reduce exhaust emissions. This prompted renewed interest in alternative fuels for motor vehicles and a resurgence of interest in steam-powered cars in the state. The idea for having patrol cars fitted with steam engines stemmed from an informal meeting in March 1968 of members of the California Assembly Transportation Committee. In the discussion, Karsten Vieg, a lawyer attached to the Committee, suggested that six cars be fitted with steam engines for testing by California District Police Chiefs. A bill was passed by the legislature to fund the trial. In 1969, the California Highway Patrol initiated the project under Inspector David S Luethje to investigate the feasibility of using steam engined cars. Initially General