The (), known in official records as , or sometimes known as , is a series of tramcars which was manufactured by Hungarian companies ("Ganz-MÁVAG Locomotive, Carriage and Machine Factory") and ("Ganz Electric Factory"). The tramcars have three main variants, which are all eight axle rail motor coaches with a Bo'2'2'Bo'tr axle arrangement, the last variant being capable of operating as electric multiple units. The cars were manufactured in Budapest between 1964 and 1978, and in overall 152 regular units and two prototypes were made. The official designation resolves to ("Articulated Motor Coach, Ganz"), this was changed to in and records, and the semi-official resolves to ("Industrial Articulated"), because it was the first articulated tram design in Hungary which was produced by a regular manufacturing company instead of an in-house workshop of a transit company. The final production variant of the series is capable of controlling another unit of its type through proprietary 50-wire cables, though traction current isn't shared between units. The trams are also capable of sensing the breakup of the tramset with a proprietary system implemented along the couplers. Two prototypes, sometimes referred to as , were made before mass production started, these cars originally had a single articulated joint instead of two, but later these were extended. The production variants , and were unified over the years and now they are referred to as . One damaged car was rebuilt with experimental features, and its type is referred to as . Partly based on the operating experiences of this car, in the 1990s 20 cars were refurbished, their type is referred to as . The was intended to replace the lower capacity and obsolete, in-house trams. tramcars are still in active service in Budapest, whereas – with the exception of the two prototypes – the first scrapping took place only in 2009, when the only car was taken out of service owing to maintenance difficulties. The first tramcar entered passenger service in 1965, thus the series is now in continuous service for years. The series also carries the distinction of having one of the cars take Diana, Princess of Wales on a ride along the city's scenic Line 2 on the Danube's bank. tramcars are nicknamed as or ("industrial articulated"), ("Ganz articulated"), or when running in multiple unit pairs, ("Goliath"). Design and manufacturing The CSMG series was Ganz's, and thus the Hungarian machine industry's first foray