Tatra T6B5

Tatra T6B5 (also known T-3M) is a Czechoslovak high-floor four-axle tram car with pulse control electrical equipment, mass-produced by ČKD Prague JSC from 1983 to 1998. After the bankruptcy of the manufacturer, the Inekon Group enterprise carried out the additional assembly of previously laid down cars and their sale to customers until 2007 inclusive; the last four cars were delivered to Ufa at the end of 2007.

Tramcars of this type are used in cities of Russia, Ukraine, Latvia, Bulgaria and the DPRK.

In the 1990s, the Ukrainian enterprise Tatra-Yug built 38 cars of this type at the facilities of the Yuzhmash plant under a license purchased from the Czechs based on the T6B5 car, and also produces new modernized cars based on this model, which were called K-1. The Uraltransmash plant also produced several models of trams (71-401, 71-402 and 71-403), using the T6B5 as a basis. In fact, they differed from the original only in the modification of the body and the use of Russian electrical equipment.

Tram car type T6B5 is a four-axle motorized tram car designed for one-way traffic.

Tram cars can be operated independently or coupled into trains of two or three cars, controlled from one control station (CME). Their operation with trailer cars is not allowed. Operation of a two-car train is possible with one raised pantograph (for a three-car train – with at least two). Control of the second car from the remote control of the first is possible even if the traction electrical equipment of the first car is faulty.

The design of the bogie ensures reliable operation of the car over the entire range of speeds and loading, as well as smooth running from the point of view of passengers and the driver. The basis of the trolley is a frame welded from hollow load-bearing beams and cast end seals. The cart contains two traction motors suspended on crossbars, the axis of which is parallel to the longitudinal axis of the cart. The engine torque is transmitted to the gearbox by a telescopic cardan shaft. The load between the bogie and the car body is transmitted by a cradle, which is sprung by a combination of two steel coil springs. Its vibrations are damped by a telescopic shock absorber. The bogie includes a mechanical disc brake located on the motor shaft and an electromagnetic rail brake. The bogies are available in two gauges: 1435 mm and 1524 mm.

The car body is welded from pressed and rolled steel profiles. The crossbars and longitudinal fastening of the cantilever parts are created from closed load-bearing elements. In the upper part of the base there are distribution channels for cable connections and the supply of cooling air to the traction motors; in the lower part of the base there are electrical cabinets and auxiliary devices. The end parts, sidewall and roof are lined with steel sheet, the surfaces of which are coated with shock-absorbing paint. The floor of the car is made of waterproof plywood, onto which a non-slip rubber floor covering is glued.

In order to access the cables placed in the cable channel, the middle part of the floor is removable. Internal lining made of malt or wood fiber boards. The carriage is equipped with three four-leaf screen doors. The doors are controlled electromechanically; the control mechanism is located above the doors, in the cabinet. The clear distance at the open doors is 1300 mm, which allows two passengers to enter or exit at the same time. The door mechanism is equipped with a safety friction clutch.

All car windows are made of safety glass and are mounted in rubber profiles. The windows in the front parts of the car are stable; most of the other windows, including the driver’s left side window, open in their upper part. The seats for passengers are upholstered. In order to more conveniently clean the car, the space under the seats is free (except for the sandboxes and battery disconnector).

Ventilation of the passenger compartment is natural, using three hatches in the roof of the car, opening windows and entrance doors that open when passengers enter and exit. The cabin is heated by electric heating casings placed in the side channels of the car body and powered from the mains. Heating power regulation is two-stage.

The passenger compartment lighting is fluorescent, powered from a battery using individual transistor converters. Emergency lighting is provided by three lampshades located near the entrance doors. External lighting of the carriage using incandescent lamps.

The driver’s seat is an enclosed cabin located in the front of the car. The upper part of the cabin is glazed and equipped with movable locking doors. Large front windows guarantee good visibility from the driver’s seat. The upholstered driver’s seat can be adjusted both lengthwise and heightwise. The placement of control and monitoring elements, as well as measuring instruments at the driver’s seat, was proposed taking into account ergonomic requirements. In order to provide a wide visibility area, two electrically driven wipers and a washer are placed on the front frontal part of the car. At the top of the cabin there is a frontal rewound banner and a sun screen. Ventilation of the driver’s seat is natural with the help of an opening side window and forced with a heater fan. The cabin is heated with warm air from a heater.

Electrical equipment

The tram car is equipped with a TV3 type traction drive using self-ventilated TE-023 type traction motors. The motors on each of the trolleys are connected in series and controlled by their own thyristor pulse converter, which, together with the traction-to-brake switch, reversing contactors and the input inductive-capacitive filter, are located in a self-ventilated compartment. Since contactors turn power circuits on and off without current, their service life increases. To power low-voltage circuits and recharge the battery, a static converter is installed on the car, which ensures higher operational reliability and efficiency of the converter. The electric drive includes a system of protection against slipping and skidding, which, thanks to the ideal regulatory capabilities of the thyristor pulse converter, ensures rapid equalization of the difference in wheel speeds. This not only guarantees operational reliability when braking, but also reduces wear on the tires. The traction characteristics of the car are set by an electronic regulator, which receives signals with information from the car control devices and the traction drive.


The Tatra T6B5 car has only three factory modifications:

  • T6B5SU – for the USSR with a track gauge of 1524 mm
  • T6B5B – for Bulgaria with a track gauge of 1435 mm
  • T6B5K – for the DPRK with a track gauge of 1435 mm

Assembly: Prague (Czechoslovakia/Czech Republic) + Dnipro (Ukraine)

Years of production: 1983—2007

Production: 1324 units

Length: 15300 mm

Width: 2500 mm

Height: 3145 mm

Track gauge: 1435 mm/1524 mm 

Capacity: 120 passengers (40 seats)

Powerplant: TE 023

Power: 4× 45 kW

Type of current: 600 V (DC)

Max speed: 75 km/h

Empty weight: 18.9 t

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