The Stadler Citylink is a rail vehicle platform typically used for tram-trains manufactured by Stadler Rail. The design was introduced at Vossloh's Valencia factory in the 2000s before its sale to Stadler Rail in 2015. Stadler has continued to market the model since then. Most vehicles remain produced in Valencia, however vehicles for the US market are expected to be assembled at Stadler's Salt Lake City facility. Given its top speed of the Citylink mainly sees use in interurban-like applications as a tram, tram-train, or EMU. First introduced in a metre-gauge variant in Spain, the Citylink is currently also used in standard-gauge variants in Germany, Hungary, Mexico and the United Kingdom, and is on order for systems in Austria, Denmark, and the United States.
The largest operator of the Citylink, as well as its first standard-gauge operator, is the Verkehrsbetriebe Karlsruhe (VBK) of the Karlsruhe Stadtbahn. The Citylink has been the launch rolling-stock of numerous tram-train systems, most notably in Alicante, Sheffield, and Szeged. In 2022, the supply of Citylinks made Stadler's then-largest contract to date, the VDV Tram-Train project involving a consortium of six Austrian and German operators ordering 246 vehicles with an option for a further 258. The deal is worth €4 billion (£3.3 billion).
History
Beginnings in Spain
The Ferrocarrils de la Generalitat Valenciana (FGV), the operator of metre-gauge railway lines in the Community of Valencia in Spain, relaunched electric tram service in Alicante in 1999, initially on a trial basis on the right-of-way of the metre-gauge . The trial was successful and in 2001 a permanent tram network commenced construction and opened in 2003 using trams borrowed from Valencia. The initial line entirely used the right of way of the Alicante–Dénia railway line. The incorporation of more the pre-existing line into the tram network demanded interurban-style rolling stock more suitable for the expected from Alicante to Altea. As such, the first order for 9 units what would later become the Citylink was placed by the FGV from Alstom in April 2003, the vehicles were to seat 99 passengers over a length of and have a maximum speed of . The units were designated the 4100 series and entered service in July 2007. However, in the meantime, Alstom sold the Albuixech factory at which the units were slated to be produced, together with its orderbook, to Vossloh with the sale finalised in April 2005, resulting in Vossloh inheriting the product.
A second order for such trains would come from the Serveis Ferroviaris de Mallorca (SFM) in Mallorca for 6 units in 2009. These are considered largely similar to the trains produced earlier for Alicante, however are equipped to work with the island's railway electrification instead of Alicante's . Due to the cancellation of the project for which they were ordered and their boarding-height incompatibility with the significant portions of SFM's infrastructure, they have had a troubled service history and limited service.
The third order for the Citylink would also come from Spain, but would also be troubled. In 2011, FEVE ordered 4 diesel metre-gauge units for use in León. The order would be cancelled with the trains remaining undelivered. However, this is the first time that the Citylink, designed as modular platform, would be ordered with diesel traction.
"Citylink" branding By the time of its 2011 annual report, Vossloh was using the name "Citylink" to refer to its tram-train product, with earlier production retroactively designated into that product brand.
The Citylink would see its first large scale order in October 2011, when the Verkehrsbetriebe Karlsruhe (VBK) ordered 25 standard-gauge vehicles for use on the Karlsruhe Stadtbahn from Vossloh. The model type was named the NET-2012 and the order included options for a further 50 vehicles which were ultimately exercised in batches of 25 in 2015 and 2016. These vehicles retained the Citylink's basic 3-section, layout, but unlike previous versions are standard gauge, have a lower maximum speed of only and are unidirectional. The first dual-mode Citylinks were ordered by Verkehrsverbund Mittelsachsen (VMS) for Chemnitz in 2012. The order was for 8 vehicles with an option for a further 4, which was exercised in 2016. In addition to and operation, the vehicles are equipped with a two power packs each containing a diesel engine for a total off-wire power of .
The first Citylinks equipped for AC electrification were ordered from Vossloh by the South Yorkshire Passenger Transport Executive (SYPTE) in 2013 for the Sheffield Supertram. Making the Citylink to be the launch vehicle of the UK's first tram-train system. The vehicles are equipped for mainline railway electrification in addition to tram electrification. They were also the fastest Citylink vehicles until that time with Vossloh listing a design speed of , albeit a service speed of only .
Stadler production In November 2015, Vossloh announced it would sell its rail vehicles business to Stadler as part of a corporate reorganisation which involved divesting its transportation division, which also included Kiepe and MaK, to be sold later. As a result, Stadler inherited Citylink production and the Albuixech factory.
Stadler's first new sale of Citylinks, not including the exercise of options, was of 8 (with an option of 4) units for the Szeged-Hódmezővásárhely tram-train in May 2017, similar in characteristics to Chemnitz's. In September 2017 FGV of Alicante also ordered 6 additional units, but of a bimodal type.
The first high-floor Citylinks were ordered in January of 2019 by Transport for Wales (TfW), when an order for 36 units with a boarding height of was placed. The units are also the first Citylink units to be equipped for off-wire operation using batteries, rather than a diesel engine.
VDV Tram-train In 2020, four German and two Austrian transit operators: the VBK and AVG of Karlsruhe, the Saarbahn, , the state of Salzburg, and the , banded for a joint procurement of up to 508 tram-train vehicles in order to leverage economies of scale. This tender became known as the VDV Tram-train. Stadler was announced as the winner of this tender with the Citylink platform in January 2022, by which time it had turned into 246 firm orders and 248 options with delivery schedules over the length of 10 years starting in 2024. The following contract, with its value of abot 4 billion Euros, became the largest in Stadler's history.
The vehicles are expected to share the same bogie configuration, vehicle size, and maximum speed but otherwise differ between manufacturer in terms of motor arrangements, seating arrangements, and voltages.
A full-scale mockup of the VDV Tram-train vehicle was presented in Karlruhe in December 2022.
In March 2022, VMS of Chemnitz ordered a second series of 19 Citylinks. These are considered similar to the VDV Tram-train specification, as Chemnitz was expected to take part in the tender but ultimately did not. Unlike Chemnitz's earlier series, these are equipped for instead of with a diesel engine, leading VMS to term them the series the "eCitylink".
Variable length In late 2024, Stadler announced its first sale of an electric tram in the United States. The Utah Transit Authority (UTA) ordered 20 Citylink units with an option for a further 40 from Stadler ahead of a Siemens bid for their S700. This would be the first time the Citylink would be produced to shorter than its typical length, as UTA opted for a length.
The first Citylink sets with a length longer than standard of four sections were announced separately within a week of each other in December 2025 for the Aarhus light rail and the Regionaltangente West project in Frankfurt.
Design During a rail vehicle conference at TU Graz in 2016, shortly after the product's acquisition by Stadler, the Citylink was presented in contrast to the Tramlink, the other tram platform in Vossloh's former portfolio, as a stadtbahn (light rail), as opposed to the Tramlink's presentation as a strassenbahn (streetcar). The Citylink differentiates from the Tramlink by having a higher operating speeds, a layout designed for seating comfort, and a higher clearance to comply with the German mainline rail (EBO) standards in addition to German tramway (BOStrab) standards.
Carbody The Citylink, being a modular platform, is available and has been produced in varied body-style configurations. In 2016, the "standard" version was considered to be long and wide over three segments. Though Stadler also presented the possibility of shorter and longer configurations at the time, up to in length with four segments. In 2025, Stadler presented a wider range of possible lengths, from to over between three and five segments. Acessible via Schienenfahrzeugtagung.at
The Citylink can also be produced to different track gauges, with models having been produced for metre-gauge networks in Mallorca, Alicante and León, and standard-gauge networks elsewhere.
In 2016, the "standard" version of the Citylink had 5 doors per side, the same as the NET-2012 in Karlsruhe. However, most versions produced to date have had only 4 doors per side, for example as for Mallorca or Sheffield. For the VDV Tram-train, all versions, except the one for the VBK in Karlsruhe, will have 4 doors per side, the version for the VBK will have 5.
Operation The Citylink was designed as an electric multiple unit tram-train, with power able to be drawn from overhead line equipment at or . Some Citylinks are fitted with transformers to provide dual-voltage capability, such as those used in Sheffield, which run at 750 V DC on the city's tram network, but with the ability to also use in the future, as is standard for British railways. In Chemnitz, Citylinks are fitted with a diesel engine as well as 750 V DC overhead power to provide hybrid-electric capability; while vehicles sold in Mexico are fitted with a diesel engine only due to a complete lack of railway electrification. Citylinks have a top speed of when operating on interurban routes under electric power.
Interior
Specifications vary depending on the operator; for example, the Citylinks operating in Sheffield are outfitted internally similarly to the city's existing trams, due to the relatively short length of the tram-train extension to Rotherham, while Citylinks that operate over longer distances can be equipped with facilities such as toilets and luggage racks. Depending on the internal layout, Citylinks can have a capacity of up to 250 passengers normally, though 4-section versions on order for Frankfurt and Aarhus are expected to have capacities of 352 and 360 passengers respectively.
Operations
As of mid-2026, the Stadler Citylink is operated in nine different systems across five different countries in Europe and North America, while a further seven systems in another four countries have the model on order or undergoing testing. +Orders and operations of the Stadler CitylinkCountryCity/SystemImageQuantityOrder dateServiceGaugeSectionsVoltageOff-wire capabilityRef.AustriaLinz (Lokalbahn)2020223Salzburg ()20202231000 V DCDenmarkAarhus (Letbane)8 (option for 12 more)202520294GermanyChemnitz (Chemnitz Bahn)8201220163 rowspan="2" 42015202019202220273Frankfurt (Regionaltangente West)27202520284Karlsruhe (tram-train)25201120143 rowspan="3" 2520152016252016201773202237520263Reutlingen3020223Saarbrücken (Saarbahn)28202220263HungarySzeged (tram-train)8201720213 rowspan="2" 420202022MexicoPuebla (Cholula tourist train)2201420173— rowspan="2" Tren Interoceánico2023SpainAlicante (tram-train)92003200736201720203León ()420103—Mallorca6200920123United KingdomSheffield (Supertram)7201320173Cardiff (South Wales Metro)36201820263United StatesAustin (Project Connect)212026Salt Lake City (TRAX)20202420283 rowspan="2" 202025
Austria Linz (future)