Trolza, formerly known as the Uritsky factory or simply Uritsky, was a trolleybus manufacturer in Russia, located in Engels, Saratov oblast. In the Soviet era it was known as ZiU or Uritsky factory. ZiU/Trolza has built over 65,000 trolleybuses. Historically, the most numerous models of ZiU production were the MTB-82, the ZiU-5 and the ZiU-9. The ZiU-9 is the most widely produced trolleybus in history. The factory has exported its production to various countries, including Argentina, Bulgaria, Colombia, Greece, Mongolia, Hungary, Serbiaetc.
History
The enterprise was founded in Imperial Russia in 1868, but it began producing trolleybuses in 1951. Trolleybus production by the Uritsky factory began in 1951, but the company's first model, the MTB-82d, was a refinement of a design first developed several years earlier, by the national government in Moscow in 1945–46, the MTB-82m. A prototype MTB-82m was built in February 1946 at a military factory. Following the construction of 77 additional MTB-82 trolleybuses in 1946–47, improvements in the design led to the introduction of the MTB-82d. Production of the improved model continued at military factories as well as at MTRZ, a small trolleybus repair plant in Moscow, until 1951, when the Uritsky factory was established in Engels to take over all trolleybus production from the various smaller facilities. ZiU's production of the MTB-82d lasted from 1951 to 1961, and a total of 3,746 were built. In the 1980s, ZiU was building more than 2,000 trolleybuses per year, mostly for domestic use but up to 160 per year for export outside the USSR. For many years until at least the early 1990s, ZiU was the world's largest manufacturer of trolleybuses. Around 1996, it was renamed Trolza, short for AO Trolleybusnyi Zavod. In 2016, Trolza announced that it would begin production of trolleybuses and electric buses in Juárez Celman, Córdoba Province, Argentina. The company intends to supply and modernise existing systems in Rosario, Córdoba and Mendoza while also supplying new potential networks. In 2020 due to continuous financial difficulties, Trolza declared bankruptcy. The trolleybus factory was leased to PCTransport Systems who launched their own line of trolleybuses called "Admiral".
