AEG 12X, ABB Eco2000 platform

In the early 1990s, West German federal railway Deutsche Bundesbahn (DB) sought to replace its ageing electric locomotive fleet with a single type. In the previous decade, DB introduced its first universal locomotives with three-phase asynchronous induction motors and two bogies with two powered axles each, the DB Class 120, which had been successful. In 1991, DB requested bids^[8] for about 1000 more universal locomotives with an improved design and increased power, the planned DB Class 121. The railway industry began developing new locomotives, but in October 1992, DB cancelled the tender^[9] due to the high price of the offers and the changed situation.^[8] In 1994, Deutsche Bundesbahn merged with the former East German Deutsche Reichsbahn, creating Deutsche Bahn, bringing over 600 modern DR Class 243 locomotives into the joint locomotive fleet. In addition, the merger coincided with a railway reform, dividing the rolling stock of Deutsche Bahn between its regional passenger, long-distance passenger and freight business areas, making the universal locomotive plans obsolete.^[9] From late 1993, the business areas of Deutsche Bahn and their predecessors called new bids for electric locomotives tailored for their specific needs.^[8][10]

The competitors for the DB Class 121 included two of the forerunners of Bombardier Transportation: German locomotive manufacturer AEG Schienenfahrzeuge, a part of AEG which was controlled by Daimler-Benz at the time; and ABB Henschel, a German locomotive manufacturing branch of Swedish-Swiss company ABB. Components of both the AEG and ABB concepts were built into the prototypes of the DB Class 120 for trials from late 1991.^[9][11] AEG followed up its development effort by building an experimental universal locomotive, the 12X.^[12] This locomotive can be considered the predecessor of the TRAXX family. The 12X was delivered in June 1994^[13] and, although owned by AEG, was designated Class 128 by DB. The 12X featured several innovations compared to the Class 120,^[13] including water-cooled inverters based on GTO thyristors, a new final drive concept with pivot axle bearings on both sides,^[14] and a new bogie concept with a short wheelbase of 2,600 mm (102.4 in).^[15] The locomotive also had a modular design, allowing the derivation of different versions for different operational needs,^[13] and thus it formed AEG's basis to compete for the new orders of Deutsche Bahn's business areas.^[8][10] Meanwhile, ABB developed its own design of a modular electric locomotive platform, the Eco2000 concept.^[8] ABB's concept included a version of its Flexifloat high-speed bogie family with a wheelbase of 2,650 mm (104.3 in); and biodegradable ester cooled inverters with GTO thyristors and an also ester cooled main transformer,^[11] which can be considered the origin of the inverters and transformer of the first generation of TRAXX locomotives.^{[improper synthesis?]}

The 12X was later used as testbed for new technologies, becoming the first locomotive in the world with IGBT based converters in 1997^[16][17] and testing the MITRAC traction control electronics from 1998.^[16] Both of these technologies would later find their commercial application in TRAXX locomotives.

DBAG Class 145 family, Adtranz Octeon platform

In November 1994, Deutsche Bahn chose ABB and AEG for two of its orders: ABB was to deliver 145 express locomotives for DB's long-distance business area DB Fernverkehr, the DB Class 101, while AEG was to supply DB's freight business area DB Cargo with eighty locomotives for medium-weight freight trains, the DBAG Class 145.^[18]

The original Class 145 design was a cheaper derivative of the 12X, omitting components for higher speeds, including hollow-shaft drives, which were replaced by simpler axle hung drives.^[19] In January 1996, ABB and Daimler-Benz merged their railway business areas into a joint venture, ADtranz.^[20] The final design of the locomotive was adapted for more commonalities with the DBAG Class 101.^[19] The biodegradable^[18] ester cooled inverters with GTO thyristors and the also ester cooled main transformer of the DBAG Class 145 was derived from those of the DBAG Class 101, but with less components for the lower maximum power, providing for individual bogie control rather than individual axle control.^[19] The bogie design was also adapted and merged into the ABB-originated Flexifloat family, with wheelbase increased to 2,650 mm (104.3 in).^[19] Due to the shared features, the Class 145 was sometimes described as a member of the Eco2000 family.^[19]

Adtranz rolled out the first Class 145 in July 1997.^[19] In addition, 17 identical locomotives were built for lease to private railways. A further six locomotives were built for the Swiss railway MittelThurgauBahn.^[21]

In March 1998, Adtranz announced its intent to consolidate its product range into seven modular product platforms.^[22][23] The electric locomotive platform with the brand name "Octeon" was to be based on Adtranz's newest types for Germany (the Class 145 and Class 101).^[22] Adtranz originally intended to introduce Octeon types alongside existing products,^[22] and applied the name to its new products outside Germany at the end of the nineties, like the FS Class E464^[24] or the heavy-haul locomotive Iore.^[25] The GTO thyristor based converters of these locomotives were from the water-cooled Camilla family,^[24] which was developed by ABB as successor for the oil-cooled converters in the SBB-CFF-FFS Re 460.^[26] The Octeon brand name did not catch on and was abandoned when Bombardier acquired Adtranz in 2001.

Between 2000 and 2002, a version of the DBAG Class 145 for passenger trains, with hollow shaft final drive and a higher top speed of 160 km/h, was produced for DB's regional business area DB Regio.^[3] The top of the front of the carbodies was modified to provide space for a flip-disc display.^[27] These locomotives were given the designation DBAG Class 146.0.

Although the production of the DBAG Class 145 ended by the time Bombardier bought Adtranz in 2001, and even the production of the Class 146.0 locomotives ended by the time the TRAXX brand name was introduced in 2003, in Bombardier's own publications, the Class 145 was included in the TRAXX F140 AC,^[28] the Class 146.0 in the TRAXX P160 AC type.^[29] The still in-production FS Class E464 got the designation TRAXX P160 DCP,^[30] while TRAXX H80 AC was applicable to the Iore class,^[31] however, these then still in production types were excluded from the TRAXX family in publications after 2007.^[32]

DBAG Class 185 family, Bombardier TRAXX platform

In July 1998, Adtranz received a follow-on order for 400 more locomotives for medium-weight freight trains, the DBAG Class 185.^[33] The double voltage Class 185 was meant for international operation, and was also dubbed Europalok.^[33] The basic concept of the running gear, the axle hung motors, the ester cooled inverters and transformer was maintained from the Class 145.^[34] In addition to the electronics for double voltage operation, modifications included the provision for the installation of the full variety of train protection systems in use in Europe, and the lowering of the roof by 105 mm to fit the vehicle in the international UIC 505-1 loading gauge.^[34][35]

In 2001 Bombardier bought Adtranz, thus acquiring locomotive building technology. Under Bombardier, the Class 185 was developed into a family like that of the Class 145, with private railway and passenger (DBAG Class 146.1) versions. In May 2003, Bombardier also received an order for a quadruple system version from the Swiss Federal Railways (SBB).^[36]

In September 2003, Bombardier gave the Class 185 family a brand name, TRAXX, intended to allude to the terms 'traction', 'track' and 'attraction'.^[37] The acronym stands for Transnational Railway Applications with eXtreme fleXibility.^[6] The first letter of TRAXX type designations provides for differentiation according to the area of application, with F for freight and P for passenger.^[31] The original system also tentatively included H for heavy-haul and S for high-speed,^[31] but no actual vehicles were delivered under this designation. The number following the first letter indicates the top speed of the locomotive in kilometers per hour.^[31] The next two letters indicate the supply system, with AC for alternating current electric locomotives, DC for direct current electric locomotives, MS for multi-system locomotives capable of operating both under AC and DC overhead wires, and DE was foreseen from the start for an eventual Diesel-electric version.^[31] An extra P letter at the end was to designate powerheads (traction heads), that is locomotives with one driving cabin for push-pull operation.^[31] An also optional number at the end designates different versions,^[31] later used for the designation of generations.

In the new system, the factory designation of the DBAG Class 185 and its sisters with other railways became TRAXX F140 AC, that of the DBAG Class 146.1 TRAXX P160 AC, and that of the planned quadruple voltage SBB locomotive TRAXX F140 MS.

When Bombardier introduced the first TRAXX 2 types, the original family was also designated TRAXX 1,^[6] and the number 1 was added at the end of the type designation of first-generation locomotives still in delivery.

TRAXX 2 and TRAXX 2E platforms

In 2004, the basic TRAXX design was subjected to a major overhaul, with the carbody and the front redesigned to suit current crashworthiness standards, and the replacement of GTO thyristor based inverters with IGBT based inverters.^[38] The option of individual axle control in place of individual bogie control was also introduced.^[27] The coolant of the inverters and the main transformer was also changed from ester to water.^[27] The carbody design was completely standardised, by default providing a space for the mounting of a flip-disc display above the windshield, which is covered by a non-structural hood in freight versions.^[27] The bogie frame was strengthened, to allow an increase of axle loads to 22 tons.^[27] This generation of the family is also referred to as the TRAXX 2 platform,^[6][39] and is sometimes also indicated with a number 2 at the end of the type designations.^[40]

The TRAXX carbody design and internal configuration was modified again in 2006 when the first actual Diesel-electric version was built, to provide the same layout for Diesel and electric versions.^[38] In the electric versions, the central location of the diesel engine was used for the AC transformer or the DC chokes. The weight of the component at the central location is supported on a horizontal mounting plate that fits onto the main frame using the same fixtures.^[38] This generation of the family is also referred to as the TRAXX 2E platform,^[6] the type designations themselves didn't change.^[41] The TRAXX 2E generation also included the first actual deliveries of the DC versions of the TRAXX platform.^[41] The AC version of the TRAXX 2 remained in production in parallel with the 2E versions of other types.^[42]

Traxx Africa

In March 2014 Transnet ordered 240 dual-voltage 1,067 mm (3 ft 6 in) Traxx Africa locomotives, to be built in South Africa.^[7] The first locomotive was handed over to Transnet in December 2017, with revenue service planned to begin early in 2018.^[43] As of December 2020^[update], Transnet is in possession of 56 Traxx Africa locomotives.^[44]

TRAXX F140 AC

The TRAXX F140 AC operates on AC overhead lines. They can work under both the 15 kV/16.7 Hz and the 25 kV/50 Hz AC systems. As built they are configured for future ETCS / ERTMS train control and safety systems.^[1]

The 200 units built between 2001 and 2003 for Deutsche Bahn were classified as DBAG Class 185, or DBAG Class 185.1 once production switched to the TRAXX F140 AC2 design.^[48] A further 57 units were built for various European leasing companies, and were classified in Germany as Class 185.5.

Another 35 units were produced for the freight business area of the Swiss Federal Railways, SBB Cargo (SBB Re482), and 20 units for Swiss private railway BLS AG (BLS Re485). The Swiss locomotives differ from the German versions in details such as pantographs (2 more, with smaller contacts for running under Swiss catenary (not because of tunnels)) and Switzerland specific safety systems in addition to the German systems.^[49][50]

TRAXX P140 AC

In Luxembourg CFL operates 20 locomotives.

TRAXX P160 AC

The TRAXX P160 AC is the passenger version of this class, with a correspondingly higher top speed of 160 km/h. A lower unsprung mass was achieved by using hollow shaft final drives instead of the axle hung motor arrangement of the 140 km/h maximum speed versions. The bogies and drive unit are the same as used in the DBAG Class 146.0.^[3]

In Germany, DB Regio acquired 32 units between 2003 and 2005, where they are designated DBAG Class 146.1.

Additionally, (Landesnahverkehrsgesellschaft Niedersachsen mbH (LVNG), (Hannover) ) has 10 units which are leased to the railway company metronom (operating as ME146).^[51]

TRAXX F140 AC2

The first AC member of the TRAXX 2 family, which featured carbodies with improved crashworthiness and water-cooled IGBT-based inverters, was the demonstrator loco 185 561, delivered in May 2004. It was produced ahead of the main tranche of TRAXX F140 AC2 locomotives for homologation of the class in Germany.

Another demonstrator TRAXX F140 AC2, 185 568 was used for tests on the then new HSL-Zuid in 2006. Subsequently, it was used for tests of the ETCS system.

Both demonstrator locomotives were eventually sold to private operators for normal use.

The remaining 200 of the 400 Class 185 freight locomotives ordered for DB Cargo were to be of this type, and the new versions were given the subclass designation DBAG Class 185.2. Since this large order represented the main body of production at Bombardier's Kassel plant, any further private orders for the AC locomotives would be included into the F140AC2 production line - thus the original F140 AC type effectively ceased production when the production of DB Cargo's (by then renamed Railion) Class 185.2 began.

The locomotives operated by SBB Cargo are designated Re482.2.

TRAXX P160 AC2

Alongside the F140 AC2 locomotives, the passenger versions received the same improvements. DB Regio received 47 units between 2005 and 2006; as with the freight version the '.2' subclass was used to distinguish these new versions - the Deutsche Bahn locomotives being classified as Class 146.2, following on from the Class 146. A number of smaller orders have been received, including more units for the metronom railway - procured via LNVG. DB Fernverkehr, the German Railways branch which operates Intercity services, ordered 27 more Class 146.2 locos on 12 January 2011. The locos will start service in December 2013.^[52]

Operators and leasing companies

This article needs to be updated. (November 2013)

As of 2010, production of the AC2 versions is still ongoing, with the DB Schenker order expected to be completed in late 2009. Along with German companies the AC locomotives have orders from Scandinavian countries and from Hungary – where the Hungarian State railways (MÁV) (Magyar Államvasutak) has placed an order for 25 (and optional 25) P160 AC2 machines.

TRAXX F140 MS

The first multi-system TRAXX unit that could operate under AC and DC electrified catenaries, SBB Re484 001, was introduced at the same time 185 561 was introduced as demonstrator locomotive for the F140 AC2 type. In addition to the 15 kV/16.7 Hz and 25 kV/50 Hz AC supplies, the new model could also be operated under 3 kV DC overhead electrification.^[27] Later models also supported a 1.5 kV DC supply. This locomotive for SBB was also the first TRAXX variant with individual axle control in place of individual bogie control.^[27] The general type name given by Bombardier was TRAXX F140 MS.^[62]

Apart from the different pantographs, electrical systems for DC operation, the F140 MS types are identical to the contemporary dual voltage versions. However, under 1.5 kV DC, the maximum available power is limited to 4.0 MW, although this does not affect the maximum tractive effort, which is limited by other factors. As a consequence of the additional equipment required, the locomotives weigh approximately 1 tonne more than their dual voltage relatives.^{[note 1]}

The locomotives are designed for cross border operations; the addition of 1.5 kV and 3 kV DC operability potentially allows the locomotives to operate in Poland and Italy. In practice the delivered locomotives were used for work into Switzerland and Italy, and equipped with either the Italian safety system SCMT or ETCS.

Post 2006 many more of these multi-system locomotives were produced, this time with some for use in the Benelux countries, as well as France and Poland, with further units being produced for Swiss/Italian traffic. In Poland, locomotives used by PKP Cargo have been designated as the EU43 class (this designation was originally meant for what is now known as the FS Class E.412, which was initially intended for Poland but now mainly operated by Italy). Units hired from Alpha Trains cargo to SNCB (Belgium) have also received the class number SNCB Class 28

In July 2018, Bombardier introduced the third generation of TRAXX multi-system locomotives, named the MS3, which in addition to carrying over compatibility with the four electrification systems introduced an onboard engine to enable travel over short distances of non-electrified track.^[64]