Tatra T3
The T3 is a type of Czech tramcar produced by ČKD Tatra. A late-2000s study conducted on the Prague tram system has shown 98.9% reliability, the best of the Prague tram system fleet. During its period of production between 1960 and 1999, 13,991 powered units and 122 unpowered trailers were sold worldwide.
It became the most dominant tramcar model in Eastern Bloc countries, except for Poland, where locally produced trams from Konstal factory are still the mainstay in tram systems there, and Hungary, where ČKD only made inroads to the country's tram market during the late 1970s. Together with Soviet KTM-5 it is among the most produced trams, as of 2022, it is still the most widespread tram car in the world.
Initial design
The design of the T3 follows the US PCC streetcar design, with two bogies, level floor and a single segment, able to run unidirectionally, as a solo unit or in a pair. It was specified to have the same capacity as its predecessor, but be lighter and easier to build. Some of the things that were done to meet this goal were making the walls thinner for lower weight, and after the first series, fitting the cars with laminate seats instead of cushioned leatherette seats such as the T2 used.Just as with the T2, the T3's outer appearance was designed by František Kardaus. The lower part of the tram is made of a lightweight welded steel profile and sheet metal. The tram body consists of columns, which are additionally reinforced in their lower part by longitudinal struts. The cladding of this structure is made of steel sheets. Self-extinguishing fiberglass is used on the front walls of the tram. The floor of the car is made of reinforced moisture-resistant plywood, on which a grooved rubber carpet with a non-slip surface is also glued. The side glass windows of the tram are mounted in rubber profiles, while the upper parts of the windows on both sides of the tram are sliding. The walls in the tram saloon are covered in the lower parts under the windows with a layer of. Above it, they are protected by paint. The car was accessed through three four-part folding doors, whose width reached.
Power was provided by a pantograph, usually lowered and raised manually. The tram is powered by four TE 022 series-wound traction motors, each with an output of 44 kW, manufactured by the ČKD Praha company. Each pair on a bogie is connected in series, while both groups are connected in paralel. The motors are placed lengthwise, powering the wheels via a bevel gear, in order to reduce noise. Power was regulated by a set of resistors with a TR37 accelerator. A dead man's switch was left out compared to the T2. Braking was conducted in two stages, using the rear bogie's brakes in the first stage and all brakes in the second.
There were three roof flaps in the tram. In addition to these, it was also possible to ventilate by opening the sliding parts of the windows. In the driver's cabin, ventilation is provided by slots located above the windshield. Heating is provided by electric heaters installed in the seat posts. The driver's seat is heated by its own unit located under the tram. Internal lighting is via fluorescent lamps, using the same voltage as the trolley. Initially, the layout was configured such that passengers would move around a conductor's station, which was later removed during conversion to ticket self-service operations.
The length of the tram over the couplers is, while the car body itself is long. Its width is and the height of the roof above the rails is. Inside the car there were 25 seats and 75 standing places, with the seats having an alternating red and grey color scheme.
The T3 was delivered to all tramway companies in the former Czechoslovakia. It was most numerous in Prague, where over 1,000 vehicles were delivered. The T3 still forms the backbone of the Czech tram fleet.
Derivatives
T3SU
As with the T2SU, the first T3SU was delivered with the modification of removing the middle door and replacing it with seats. Later cars, however, were delivered with the third door in place. Again, the vehicles had a closed operator's compartment and were adapted for the harsh climate. Altogether 11,368 T3SU were delivered, making it the largest production of a single type of streetcar worldwide. But because so many of one type were made, their replacement by more modern cars was slow.The T3SU was delivered from 1963, first to Moscow and later to 33 further Soviet cities.
T3SUCS
Originally, the production of the T3 was stopped in 1976 and focus shifted to newer vehicles. The Slovak city Košice, however, ordered two motor coaches as an exception. The production of the replacement type KT8D5 was slated to begin in 1985, but this model was by then obsolete. Further production of the T3 would have been too expensive, so instead vehicles of the type T3SU were re-imported and adapted. The closed operator's cab was maintained, the vehicles had all three doors in place, and differed from the original T3 only in a few details.T3SU Evolution
Over time, the T3SU has had minor changes in both exterior appearance and interior design.Exterior details:<1966: Narrow passenger windows disappeared
- ~1969: Narrow window route designators
- 1980s: Illuminated route indicator on top
- ~1985: Oval turn indicator at the front became two rectangular lights. The same lamps began to be fitted to the rear
- 1983 onwards: Small grid in the forward section of the tram on the left side
- ~1985: Two small red lamps near the tramcar-to-tramcar "control circuit port", both front and rear
- Additional red horizontal lamps from behind
- Early 1960s to early 1970s: Sofa-style seats
- Early 1970s to mid-1980s: "Toilet"-like seats
- 1977–1978: Cream-coloured saloon
T3D
In East Germany the first three T3D cars started operation in 1964 and the city of Dresden got its first delivery in 1965. The cars were used in part due to their width of. They operated as single cars or as multiple units and/or as mini trams. The use of trailer cars was due to the use of original Czech T3 electrical equipment, which had enough power to support trailer cars, and was only present in Germany and Yugoslavia. However, due to reduced available power, the maximum speed of the streetcar reached only 55 km/h instead of the usual. Today, only Chemnitz still maintains T3s as backups for regular service, which are designated as T3D-M.T3YU
From 1967 onwards, vehicles supplied to Yugoslavia differed from the standard type T3 by having different pantographs and trucks. In addition, trailer cars were used, as in East Germany. Uncommonly, the network used narrow-profile vehicles, two of which could be found in Czechoslovakia and one in the Soviet Union.T3R
At the end of the 1960s, Romania ordered RA cars as part of an agreement in the Comecon. The first vehicles came in 1970 to the city of Galați and had different electrical equipment from the Czechoslovak vehicles, to use the network's 750 V DC voltage. Since the carbodies were built too wide for use elsewhere, they remained in Galați. Only 50 units were delivered. Romania then opted for the narrower Tatra T4, which had more success, being still used in Bucharest as of 2025.A few more of the same type were manufactured in 1997.
T3RF
Four Tatra T3RF were the very last T3 trams built. They were made for Samara and Izhevsk, but only Samara bought them. In 2002 the two others were sold to Brno and modernized.Modernized Tatra-T3 trams
In most Czech cities and in some others such as Bratislava, Moscow, Riga, and Odesa, Tatra-T3 trams became very common. As a result, service and maintenance workers became very experienced at servicing them. This was one reason for modifying existing trams rather than replacing them with newer stock. Many of these modifications bear the designation T3R, whereby the 'R' stands for Czech word rekonstrukce or T3M, with 'M' standing for 'modified'.Modernization normally includes:
- Restoration of the car body
- Digital/Electronic destination sign installation
- Audio information system
- Installation of new traction motors
- Thyristor-controlled motor traction system
- Refurbishing of the interior, which varies by city and transport authority
- Pantograph replacement
- Tatra T3R.P – IGBT Transistors by TV Progress
- Tatra T3R.E - TV Europulse electrical equipment
- Tatra T3G – TV-8 thyristors
- Tatra T3M.3 – TV-14 electrical equipment
- Tatra T3S – Body changes and TV-14 electrical equipment
- Tatra T3M.2-DVC – added the ability to open doors by buttons for passengers
- Tatra T3.04 - Škoda electrical equipment with IGBT transistors
- Tatra T3Mod - EVPÚ Nová Dubnica electrical equipment
- Tatra T3AS - Body changes and EVPÚ Nová Dubnica electrical equipment
- Tatra T3R.PV - PV Progress electrical equipment
- Tatra T3R.PVO – Changed front and back mask, same electrical equipment as T3R.P
- Tatra T3R – Body changes and TV-8 thyristors