Tatra KT4 is the name of an articulated tramcar developed by the Czech firm ČKD Tatra. The first pre-production vehicles entered service in Potsdam

Potsdam

Potsdam is the capital city of the German federal state of Brandenburg and part of the Berlin/Brandenburg Metropolitan Region. It is situated on the River Havel, southwest of Berlin city centre....

 in 1975, with the first production vehicles in 1977. A total of 1747 units were built, with initial deliveries to East Germany (DDR) and later The USSR and SFR Yugoslavia. KT4 variants were built for both standard gauge

Standard gauge

The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...

 and meter gauge tramways. Production of the KT4 tramcar was halted in 1991 due to worldwide economic and political changes at the time.
The production was shortly resumed in 1997 to produce last 20 models for Belgrade

Belgrade tram system

The Belgrade tram system is a large network with 12 lines totalling 127.3 route km. It is operated with around 200 trams, including ČKD Tatra KT4, CAF Urbos, and DUEWAG Be 4/6 vehicles. The first tram line was introduced in October 1892...

, Serbia

Serbia

Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...

.


Since the start of the 1990s many of the earliest production tramcars have gone through extensive refurbishment and rebuilding, including the replacement of folding doors and the installation of low floor

Low-floor tram

A low-floor tram is a tram that has no stair steps between one or more entrances and part or all of the passenger cabin. The low-floor design improves the accessibility of the tram for the public, and also may provide larger windows and more airspace....

 center sections.

History

The KT4 was originally designed to demands set out by the needs of the GDR, who found bogie cars too expensive and needed a solution to their aging fleet of two-axle vehicles. The first steps into the KT4s design were made when ČKD Tatra modified a six-axle K2

Tatra K2

The Tatra K2 was the first production articulated tramcar built by ČKD Tatra between 1966 and 1983, following the failure of the experimental K1 which never entered production. It was noted that the main problem with the K1 was with the new electrical equipment, and therefore the same electrical...

 tramcar, to a four-axle suspended articulation formation which later presented itself in the KT4. The KT4 has identical pedal control systems and bogies as the Tatra T3

Tatra T3

The T3 is a type of tramcar produced by Tatra. During its period of production, between 1960 and 1989, 13,991 multiple units and 122 sidecars were sold worldwide, mostly in Central and Eastern Europe and the Soviet Union...

 bogie tramcar. As production continued the design was improved, noted particularly in 1983 with the addition of thyristor control

Thyristor drive

A thyristor drive is a motor drive circuit where AC supply current is regulated by a thyristor phase control to provide variable voltage to a DC motor.-Applications:Thyristor drives are very simple and were first introduced in the 1960s...

Variations

Variations of the KT4 exist, though they are generally subtle and focused around seat layout and pantograph

Pantograph (rail)

A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...

 type.

• KT4D - German Model
• KT4SU - Soviet Union Model
• KT4YU - Yugoslavian Model

KT4D

The KT4D Model, was delivered to the following DDR cities;

City	Delivery Years	Number Delivered
Berlin Berlin Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...	1976-1988	574
Brandenburg Brandenburg Brandenburg is one of the sixteen federal-states of Germany. It lies in the east of the country and is one of the new federal states that were re-created in 1990 upon the reunification of the former West Germany and East Germany. The capital is Potsdam...	1979-1983	16
Cottbus Cottbus Cottbus is a city in Brandenburg, Germany, situated around southeast of Berlin, on the River Spree. As of , its population was .- History :...	1978-1990	65
Erfurt Erfurt Erfurt is the capital city of Thuringia and the main city nearest to the geographical centre of Germany, located 100 km SW of Leipzig, 150 km N of Nuremberg and 180 km SE of Hannover. Erfurt Airport can be reached by plane via Munich. It lies in the southern part of the Thuringian...	1976-1990	156
Frankfurt (Oder) Frankfurt (Oder) Frankfurt is a town in Brandenburg, Germany, located on the Oder River, on the German-Polish border directly opposite the town of Słubice which was a part of Frankfurt until 1945. At the end of the 1980s it reached a population peak with more than 87,000 inhabitants...	1987-1990	34
Gera Gera Gera, the third-largest city in the German state of Thuringia , lies in east Thuringia on the river Weiße Elster, approximately 60 kilometres to the south of the city of Leipzig and 80 kilometres to the east of Erfurt...	1978-1990	60
Görlitz Görlitz Görlitz is a town in Germany. It is the easternmost town in the country, located on the Lusatian Neisse River in the Bundesland of Saxony. It is opposite the Polish town of Zgorzelec, which was a part of Görlitz until 1945. Historically, Görlitz was in the region of Upper Lusatia...	1987-1990	11
Gotha Gotha (town) Gotha is a town in Thuringia, within the central core of Germany. It is the capital of the district of Gotha.- History :The town has existed at least since the 8th century, when it was mentioned in a document signed by Charlemagne as Villa Gotaha . Its importance derives from having been chosen in...	1981-1982	6
Leipzig Leipzig Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...	1976	8
Potsdam Potsdam Potsdam is the capital city of the German federal state of Brandenburg and part of the Berlin/Brandenburg Metropolitan Region. It is situated on the River Havel, southwest of Berlin city centre....	1974-1987	45
Plauen Plauen Plauen is a town in the Free State of Saxony, east-central Germany.It is the capital of the Vogtlandkreis. The town is situated near the border of Bavaria and the Czech Republic.Plauen's slogan is Plauen - echt Spitze.-History:...	1976-1988	45
Zwickau Zwickau Zwickau in Germany, former seat of the government of the south-western region of the Free State of Saxony, belongs to an industrial and economical core region. Nowadays it is the capital city of the district of Zwickau...	1987-1988	22
TOTAL	1974-1990	1042

In 1984 Leipzig

Leipzig

Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...

 handed over their 8 trams to Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

. Since the early 2000s the Tatra tramcars in the former GDR are being replaced and sold to other countries in Central and Eastern Europe.

KT4SU

The Soviet Union ordered the KT4SU for their meter gauge tramways, the following cities received deliveries;

City	Delivery Years	Number Delivered
Yevpatoria	1987-1990	18
Kaliningrad Kaliningrad Kaliningrad is a seaport and the administrative center of Kaliningrad Oblast, the Russian exclave between Poland and Lithuania on the Baltic Sea...	1987-1990	30
Liepāja Liepaja Liepāja ; ), is a republican city in western Latvia, located on the Baltic Sea directly at 21°E. It is the largest city in the Kurzeme Region of Latvia, the third largest city in Latvia after Riga and Daugavpils and an important ice-free port...	1983-1988	22
Lviv Lviv Lviv is a city in western Ukraine. The city is regarded as one of the main cultural centres of today's Ukraine and historically has also been a major Polish and Jewish cultural center, as Poles and Jews were the two main ethnicities of the city until the outbreak of World War II and the following...	1976-1988	145
Pyatigorsk Pyatigorsk Pyatigorsk is a city in Stavropol Krai on the Podkumok River, about from Mineralnye Vody. Since January 19, 2010 it has been the administrative center of the North Caucasian Federal District of Russia...	1988-1990	25
Zhytomir	1981-1988	20
Tallinn Tallinn Tallinn is the capital and largest city of Estonia. It occupies an area of with a population of 414,940. It is situated on the northern coast of the country, on the banks of the Gulf of Finland, south of Helsinki, east of Stockholm and west of Saint Petersburg. Tallinn's Old Town is in the list...	1980-1988	74
Vinnytsia Vinnytsia Vinnytsia is a city located on the banks of the Southern Bug, in central Ukraine. It is the administrative center of Vinnytsia Oblast.-Names:...	1980-1990	81
TOTAL	1976-1990	415

KT4YU

The KT4YU, is the Yugoslav variant of the tramcar, these were delivered to the now Serbian and Croatian capitals. The last KT4s ever produced were delivered to Belgrade in 1997, these tramcars were equipped with IGBT-modules and named KT4M-YUB (where B stands for Belgrade to be distinguished from Zagreb model). In 2002. 30 Belgrade tramcars were modernized in Goša / Inekon, and marked as KT4-YUBM.

City	Delivery Years	Number Delivered
Belgrade Belgrade Belgrade is the capital and largest city of Serbia. It is located at the confluence of the Sava and Danube rivers, where the Pannonian Plain meets the Balkans. According to official results of Census 2011, the city has a population of 1,639,121. It is one of the 15 largest cities in Europe...	1980-1997	220
Zagreb Zagreb Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...	1985-1986	51
TOTAL	1980-1997	271

Other variations of the KT4

A series of KT4 trams were also produced for Pyongyang, North Korea

Pyongyang Tram

Pyongyang Tram is a tram system in Pyongyang, North Korea.In the pre-war era, there were three tramways in Korea, in Seoul, Busan, and Pyongyang. However, the system in Pyongyang was discontinued after the Korean War of 1950 to 1953...

, but have subsequently had their articulation removed.