ZiU-9

ZiU-9, or ZIU-9 (Cyrillic: ЗиУ-9) is a Soviet (and later Russian) trolleybus vehicle. Other names and indexes for the same vehicle include ZiU-682 and HTI-682 (Cyrillic: ЗиУ-682 and ХТИ-682). The ZiU acronym stands for Zavod imeni Uritskogo, which is a plant named after Moisei Uritsky, the Russian revolutionary. Before 1996 this acronym was also a trademark of the vehicle manufacturer. It has been changed to Trolza. The ZiU-9 was put in mass production in 1971 and it is still assembled along with other more advanced trolleybus vehicles in the Trolza (former ZiU) factory. The total number of produced ZiU-9s exceeds 42,000 vehicles. In addition, many copies of ZiU-9 were made in other factories of the former Soviet bloc. This model is the most numerous trolleybus vehicle in the world.

History and development

The explosion-like development of trolleybus systems in the Soviet Union in the 1960s required a large number of trolleybus vehicles. The mainstay of the contemporary Soviet trolley fleet, the ZiU-5, was not sufficient for huge urban passenger transfers. It was more suited for medium-size cities rather than large megapolises such as Moscow or Saint Petersburg. In addition the ZiU-5 had an aluminium hull, which was expensive and complicated from a technological point of view. The two doors in the ZiU-5 hull ends did not work well in overcrowded situations which were quite common in Soviet public transportation.