The Mercedes-Benz O305 was a single deck, double deck and articulated bus manufactured by Mercedes-Benz in Mannheim, West Germany from 1968 until 1988. It was built as either a complete bus or a bus chassis and was the Mercedes-Benz adaptation of the unified German VöV-Standard-Bus design, that was produced by many different bus manufacturers including Büssing, Magirus-Deutz, MAN, Ikarus, Gräf/Steyr, Heuliez, Renault, and Pegaso. The O305 was designed for use as a single-decker bus, however it was later redesigned to accommodate double-decker bodies. Germany Mercedes-Benz unveiled the O305 prototype in 1967, production in Mannheim started in 1969. A slightly elongated Standard-Überlandbus suburban model (11.3m) followed in 1970, replaced by the O307 class in 1972. From 1974 the O305 received a more powerful engine and an epicyclic gear rear axle plainly audible by its distinctive singing noise. An articulated version was named the O305G. In the mid 1970s, the Falkenried rolling stock manufacturer had developed a transmission concept with the engine and the power train placed in the rear part. After Mercedes-Benz had acquired the patent, a 1977 prototype was deployed by the Hamburger Hochbahn public transport operator. Production began in 1978. After a first converted trolleybus version named the O305T was deployed in Kaiserslautern, Daimler-Benz built five articulated buses with a BBC-Sécheron electrical equipment (O305GT) which served the public transport in Kaiserslautern and the Bergen trolleybus system, from 1985 in Basel, and finally in Brașov, Romania. Four dual-mode bus types were built in 1983 and deployed in Esslingen and Essen. Twenty hybrid electric variants were used by the Stuttgarter Straßenbahnen public transport company and in Wesel. In 1979, the CMTC in Brazil imported one O305T for test until 1980. From 1984 onwards, the O305 was replaced by the second generation of the German Standard-Linienbus Mercedes-Benz O405. Production of the O305 ceased in early 1987. Hong Kong In Hong Kong, the O305 was the first bus model from outside United Kingdom and countries of Commonwealth of Nations to be purchased. A total of 41 buses were introduced, with the prototype in 1983 and the others in 1985. All were withdrawn and subsequently scrapped in 2001/02 except three, which are preserved by groups of bus enthusiasts in Hong Kong and Australia. Background and history For a long period of time, Hong Kong franchised bus operators were required by law to purchase double-decker buses produced in Commonwealth countries. After repealing the requirement in