ⓘ Tatra T6A5

                                     

ⓘ Tatra T6A5

Tatra T6A5 is a unidirectional high-floor Czech streetcar made for public transport in Europe and is one sub-type of T6 standard trams made by Czech light rail supplier Tatra ČKD in Prague. Five cities, namely Bratislava, Kosice in Slovakia and Brno, Prague and Ostrava in Czech Republic operate them in various configurations and amounts. The vehicle was designed as successor to Tatra T3 which has been operated in Europe for more than three decades at the time T6A5 was launched. The launch customer was Dopravny podnik Bratislava which received the first set of two vehicles in 1991. Apart from four units which were severely damaged in accidents and were withdrawn from the service, full fleet remains in operation as of today. They are commonly called "Irons" by general public and operator employees because their design resembles the triangular surface of clothing irons when seen from larger height.

Although T6A5 is operated exclusively in Czech Republic and Slovakia, there are several different versions operated in other states in Continental Europe and some efforts had been made also to operate these vehicles in North America.

                                     

1. History

During the early 1980s, new requirements were set by European light rail operators for new vehicles, which would feature lower operating costs and easier maintenance. At the time, Tatra ČKD engineers were already working on new concepts of design and controls that would replace almost 30-year-old Tatra T3 dominating the tram fleet in many European cities.

The T6 model range was introduced with T6B5 in 1983, which has been made mostly for Russian and Ukrainian operators. Tatra T6B5 featured electronic controls and completely new design. Tatra T6A2 launched in 1985 was redesigned to meet requirements for German and Hungarian operators. Vehicle remained technically same but was made considerably smaller to better suit the operation in Germany due to their much narrower streets and less space between rails. To bridge the differences between the two, Tatra T6A5 was developed which was not as large and heavy as T6B5 but not as small as T6A2. German cities Schwerin, Chemnitz were considering T6A5 for fleet restoration.

The last order for T6A5 was filled in 1998, although vehicle remained in offering until ČKD ceased operations in 2002. 296 vehicles and one replacement chassis were made since 1991.

On 27 December 2005, two vehicles were sold to Bratislava. These two trams were manufactured in 1997 and were used for testing purposes in Prague where they remained until 11 May 2004 when they were acquired by rail engineering company Pars Nova a.s. in Sumperk, where they undergone major refurbishment and re-painting to new livery used by third revision vehicles in Bratislava. Continuous service began on 13 December 2006 and both vehicles are coupled into one set. They now carry registration numbers #7957 and #7958 and slightly differ from rest of the fleet due to different front and rear coupler.

                                     

2. Design and construction

Vehicle has angular steel construction with large windows, 3 collapsible doors on the right side and is painted with red-cream livery.

Interior was fitted with leather seats, rubber anti-slide floor and was universally made with cream window frames and gray roof and floor.

Chassis is mounted on two bogies, has four axles and every axle is connected to one traction motor. Traction motors are controlled via pulse converters. Current collection from trolley wire is done via pantograph. Construction of bogies used for T6A5 is based on North American PCC standard.

                                     

3. Operation

T6A5 can drive as solo vehicle or can be coupled in to train set from two or three cars. Two-car sets and solo vehicles are always used, Three-car sets are used very rarely, mostly for testing purposes. Tram sets are connected with electric couplers and only one pantograph is used for powering the entire set.

Maximum design speed is 65 km/h40 mph. At the start of operation in Bratislava and Kosice, speeds as high as 115 km/h71 mph were achieved during special tests. But due to poor track maintenance and condition, they dont drive faster than 50 km/h31 mph. Only exception is light rail line to U.S. Steel factory in the outskirts of Kosice, where all trams, not just T6A5, drive at 60 km/h37 mph which is maximum speed for this area.

Information system contains front, side, back and internal panel.

                                     

4. Development

Since its debut, T6A5 was made in three versions, most changes made were minor and were mostly visual as vehicles electronics and mechanics remained unchanged.

First revision

The First revision noted as T6A5/I is the oldest revision, featuring red-cream livery and classic gray-cream colored interior.

Second revision

Second revision noted as T6A5/II is minor revision and only featured improved wheel slide protection, different pantograph and tilt sash windows.

Third revision

Third revision noted as T6A5/III saw renewed livery, redesigned interior, doors, drivers air conditioning, plastic seats with textile coating, new pantograph and electronic information displays.

T6A5.3

The T6A5.3 is modification of classic Tatra T3 to T6A5 using new replacement chassis and old parts and bogies from T3. This was an experiment in Prague made to find a cheaper ways to restore fleet. Only one vehicle of this kind was built in 1998, but due to its atypical origin, it is not operated in regular service because of low reliability.



                                     

5. Operation in North America

ČKD attempted to enter United States market when New Orleans Regional Transit Authority, public transport operator in New Orleans, Louisiana proven interest in T6A5 in the late 1990s, but due to several atypical properties of New Orleans streetcar system, such as rail gauge, trolley wires and customers requirements, T6A5 had to be heavily modified to meet them. As a result, Tatra T6C5 was developed which was bi-directional, had pair of doors on both sides, air conditioning and alongside pantograph, the pair of trolley poles installed on both ends of the vehicle. Only one unit was built in 1998 and has been tested in New Orleans between 1999 and 2001. American operators were satisfied with the vehicle but due to upcoming bankruptcy of ČKD they canceled the order and returned the vehicle to Europe. In 2003, T6C5 was sold to Strausberg, Germany where it remains in operation as of today.

                                     

6. Accidents and incidents

On 19 January 2009 in Kosice, the two-car set #618+619 had an accident with rigid truck on railway crossing followed with derailment and hitting several utility poles, the vehicle has been heavily damaged and has been withdrawn from the service, few passengers were injured. Vehicle No. 619 was repaired and returned to service.

On 1 September 2008 in Prague, #8671 was hit by an ambulance when entering the light rail depot, there were no injuries and vehicle was withdrawn from the service since then.

On 19 September 2011 in Prague, the two-car set #8697+8698 crashed in high speed to Skoda 14 T standing at the tram stop. All three vehicles were removed from the service and accident left one fatality, the driver of T6A5. Investigation shown that drivers health problems were most likely to cause the accident.