Key takeaways
- FLIRT is a vehicle family from Stadler, not a single class – in Germany it is spread across several number blocks.
- The 428 block stands, in the German scheme, for the four-part FLIRT variant; the leading digit in 3428 marks a later allocation.
- Fastest way to identify it: short powered bogies right at the outer ends, Jacobs bogies in between, angular wraparound windscreen.
- Most likely to be confused with the Coradia Continental and Siemens Mireo – all three are aluminium-built articulated trains.
- Operator, network and livery change with each contract award and are no use for identification.
Contents
Fact file
| Vehicle type | Electric multiple unit (articulated train) for regional services |
|---|---|
| Vehicle family | Stadler FLIRT, FLIRT XL variant |
| UIC type code | 94 – electric multiple unit or railcar |
| Design | Articulated train with Jacobs bogies and short powered bogies at the train ends |
| Car body | Lightweight aluminium construction |
| Electrification system | 15 kV / 16.7 Hz AC |
| Number block | 428 block of the German class scheme, extended to four digits |
Identifying features
Is this really the class in front of you?
- Short, far-outboard powered bogie under each train end – the defining FLIRT trait
- Only a single, shared Jacobs bogie between each pair of car sections
- Angular-looking front with a strongly wraparound, deeply drawn-down windscreen
- Short, clearly set-off end sections behind the driver's cab
- Four-digit vehicle number from the 3428 block
- Interior walk-through the length of the train
Updated: August 2026 – Once you’ve learned where the bogies sit on a Stadler FLIRT, you can identify it as it passes. Class 3428 belongs to this family – and its four-digit number tells a story of its own about how the German class system grows once a number block fills up.
Spotted a FLIRT? Save the number.
You recognise the family by its running gear, but only the number tells the individual unit apart – Traintrack logs both, with place and date.
What is Class 3428?
Class 3428 denotes units of Stadler’s FLIRT family in the FLIRT XL variant – electric multiple units for regional services. They are built as articulated trains with aluminium car bodies: a single, shared Jacobs bogie runs between the car sections, while a short, far-outboard powered bogie sits under each train end. They run on 15 kV / 16.7 Hz AC; regional FLIRTs of this type are usually designed for 160 km/h.
The name is an acronym: Flinker Leichter Innovativer Regional-Triebzug (nimble, light, innovative regional multiple unit). Behind it lies a modular platform from which Stadler derives different configurations depending on the order. That’s exactly why the FLIRT is spread across several class numbers in Germany – besides 3428, among others Class 428 and Class 429.
Placing the 428 block correctly
The German multiple-unit scheme groups vehicles into blocks of tens and hundreds. The 42x range holds S-Bahn and regional multiple units, the 44x range the Coradia family, the 46x range double-deck and Talent vehicles. The FLIRT family occupies the area around 427, 428 and 429 – graded by the number of car sections.
Read the type code 94
The twelve-digit UIC number begins with 94 for electric multiple units. That's the coarsest but most reliable classification.
Recognise the class block
The final digits 428 place the train in the FLIRT area of the scheme. The number of car sections is the organising principle here.
Watch the leading digit
The 3 in 3428 doesn't mark different technology – it marks a later allocation, because the three-digit block was already taken.
Note the running number
Only that identifies the individual unit. Without it, a sighting stays a type note, not a proper record.
How the twelve-digit number is built is explained in the guide to the UIC vehicle number. The basic sequence for identifying classes is covered in the guide to identifying classes.
Where it fits into railway operations
Regional multiple units of this type have taken over services that used to run with locomotive-hauled stock. In Baden-Württemberg, the Go-Ahead Group operates units of this type in regional services. Traction is spread across the train, which improves acceleration from a stop – the decisive factor on local services with closely spaced stops. Among the electrified branch lines in this area is the Ammertalbahn, whose infrastructure belongs to the Zweckverband ÖPNV im Ammertal (Ammer Valley public transport association).
| Location | Chance of a sighting | Why |
|---|---|---|
| Electrified regional lines with a regular clock-face timetable | high | Core deployment area of the class |
| Terminus stations with a longer turnaround | high | The train stands still – ideal for a side view and the number |
| Junction stations with train splitting | high | Coupling and splitting make their own subjects |
| Large main stations | medium | Plenty of traffic, but short dwell times and difficult trainshed light |
| Non-electrified lines | very low | No overhead line, no electric multiple units |
Deployment details age fast
Which vehicles run in which network depends on service contracts with a fixed term. After a new award, entire fleets can change region, colour scheme and lettering. Treat network details as a snapshot, and check the current situation via real-time data and community sightings.
Check first, then travel
Live-reported sightings show you which units are currently out and about – saving you waiting time at the wrong spot.
Spotting and photo tips
The most interesting feature of this train sits low down. Anyone who only shoots head-on portraits ends up with pictures from which the class can no longer be worked out afterwards.
Plan for a side view
Only from the side do you see the bogie arrangement – short powered bogies outboard, Jacobs bogies in between. That is the most documentarily valuable shot.
Three-quarter view as the default
30 to 45 degrees to the vehicle axis show front and side wall together. For flat multiple-unit fronts, this is the perspective that creates depth.
Match shutter speed to the situation
A sharp still of a train passing through requires a short shutter speed. For trains pulling into the station, much less is needed – but framing matters more there.
Take the number as evidence too
A second, tight shot of the side lettering makes every sighting verifiable – even weeks later when sorting through your photos.
Platform edge, safety distance, track area
Even for the perfect side view, the safety line is never crossed. Track areas, operational railway land and stabling sidings are off-limits – no exceptions, no discussion.
Anyone wanting to keep their sightings usable long-term will find a workable structure for number, place, date and extra notes in the guide to the sighting logbook.
Why the FLIRT’s running gear looks the way it does
The striking bogie arrangement is not a styling choice but the result of an engineering decision. An articulated train saves weight and length because neighbouring car sections share a bogie. That works well at the intermediate joints – but not at the train ends, where there is no neighbour to share with.
Stadler solves this with short, separate powered bogies under the driver’s cabs. They carry the traction equipment and sit much further outboard than you’d expect from conventional vehicles. Exactly this picture – a tiny end section behind the cab, with a short bogie underneath – is the identifying feature found in no other widespread family in quite the same way.
The design has operational consequences you can observe trackside. The unit is inseparable: individual cars cannot be swapped out or removed. Extra capacity is therefore created solely by coupling several units together, which leads to double and triple formations at peak times. And because traction is spread over several axles, the train accelerates from a stop noticeably better than a locomotive-hauled train of comparable length – the real reason multiple units have taken over local services.
Practical tip: log formations too
With coupled units, two vehicle numbers run together. Note both – otherwise you won't be able to reconstruct later which units were travelling together. The coupling point between two fronts is also a subject you don't get with a single train.
Common mix-ups
The FLIRT shares its size class with two equally widespread families: the Coradia Continental as Class 1440 and the Siemens Mireo as Class 1463. All three are aluminium-built articulated trains, all three run in the same service segment.
It points to a FLIRT if …
- a short, far-outboard powered bogie runs under each train end
- only a single, shared bogie sits between the car sections
- the windscreen looks angular and wraps well around the corner
- the vehicle number comes from a 427, 428 or 429 block
Look more closely if …
- you only see the train head-on – then you're missing the running-gear tell
- the front looks very flat and smoothly rounded – a hint towards Mireo or Coradia
- the number is four digits and you want to place the group, not just the family
It is not a FLIRT if …
- the middle cars are double-deck – then you're in Desiro HC or KISS territory
- a separate locomotive is moving the train
- two separate bogies sit between the car sections
Conclusion
Class 3428 shows two things at once: how a FLIRT is built, and how the German class system grows once a number block is full. The running gear and front shape lead you to the family, the four-digit number to the group, the running number to the specific unit. Applied in that order, identification is a matter of seconds.
In short
Short powered bogies outboard, Jacobs bogies in between, angular wraparound windscreen: that's a FLIRT. The 3428 additionally tells you that the three-digit 428 block had already been allocated.
Keep track of your units
Traintrack shows you which numbers you've already logged – and which ones you're still missing from this family.
Summary
- Class 3428 is one of the number groups under which the Stadler FLIRT runs in Germany.
- Its most reliable feature is the short, outboard powered bogies under the train ends.
- The four-digit number follows the same logic as 1440, 1463 or 3462: the three-digit base block was already taken.
- For a solid sighting, what counts is the full vehicle number, not the colour scheme or destination display.
Frequently asked questions
What does the acronym FLIRT stand for?
FLIRT is a Stadler acronym for Flinker Leichter Innovativer Regional-Triebzug (nimble, light, innovative regional multiple unit). It refers to a lightweight aluminium articulated train for regional services. The family comes in different car counts and several drive variants, which is why it is spread across several class blocks in Germany.
How do I reliably identify a FLIRT?
By the running gear. Under each train end sits a short, far-outboard powered bogie, while only a single, shared Jacobs bogie runs between the car sections. This pattern is distinctive and can be spotted even from some distance once you see the train from the side.
What does the 3 in front of the 428 mean?
It marks a later allocation within the same number block. The German class scheme works with three digits; once a block is full, a digit is prefixed. That's how classes like 3428, 1440 or 3462 come about – technically it remains the same vehicle family.
What is a FLIRT XL?
A variant of the FLIRT family with larger dimensions. Stadler builds the FLIRT as a modular platform, from which different lengths, car counts and fit-outs can be derived depending on the order. The basic design as an articulated train with Jacobs bogies is retained throughout.
What does UIC type code 94 mean?
The twelve-digit vehicle number begins with the type code. 94 stands for electric multiple units and railcars. It says nothing about manufacturer, length or area of operation – a FLIRT, an S-Bahn train and a double-deck multiple unit all carry the same 94.
How do I tell FLIRT and Coradia Continental apart?
Both are articulated trains with Jacobs bogies. The FLIRT has the characteristic short powered bogies right at the outer ends and a more angular windscreen that wraps well around the corner. The Coradia looks flatter and smoother. In the end, only the vehicle number gives you certainty.
Where does Class 3428 run?
Electric regional multiple units are deployed under time-limited service contracts. Network, operator and livery can change with every new award without the vehicle itself changing technically. So check the current situation via real-time data and recent sightings.
Why do Jacobs bogies matter for spotters?
Because they allow a quick, reliable first sort. If there is only one bogie between two car sections, it's an articulated train – which immediately rules out conventionally built trains and locomotive-hauled carriage sets. Only then is it worth looking at the front and the number.
Log your sighting of the Class 3428 (Stadler FLIRT XL)
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
Class 428 (Stadler FLIRT)
Class 428 is the four-part Stadler FLIRT. Count the car sections, check the gangways, read the number – and you'll reliably tell it apart from 427, 429 and the four-digit FLIRT variants.
EMUClass 429 (Stadler FLIRT)
Class 429 is the longest version of the Stadler FLIRT, with five car sections. Car count and gangway design lead you reliably to the right answer.
EMUStadler FLIRT
The FLIRT is Stadler's most widespread regional multiple unit in Germany. Class 427, 428 or 429 – the number tells you straight away how many cars the train has.
EMUClass 445 / 446 (Bombardier Twindexx Express)
The Class 445 is a double-deck multiple unit: double-deck cars with their own drive and no separate locomotive. Its intermediate cars run as Class 446.
EMUClass 4462 (Siemens Desiro HC)
The Class 4462 is a Siemens Desiro HC: single-deck end cars, double-deck intermediate cars. The step in height behind the head is unmistakable.
EMUClass 450
The Class 450 isn't a number you meet every day. This page shows you how to classify such a class properly by build type and UIC number, instead of guessing.
Who is behind it
Groups, brands, manufacturers and operators – who owns whom and how to recognise them out in the field.
Go-Ahead Group
The Go-Ahead Group is a British transport group that wins regional network contracts on the European mainland and runs them through national subsidiaries. That's why its trains almost never carry the name "Go-Ahead" – instead they carry the name of the network, the commissioning body, or a joint venture.
InfrastructureNahverkehrsgesellschaft Baden-Württemberg (NVBW)
The NVBW is a company owned by the state of Baden-Württemberg. It owns no lines and runs no trains, but shapes the appearance of almost every regional train in the south-west. Anyone who takes bwegt colours for an operator is misfiling their sighting.
InfrastructureZweckverband ÖPNV im Ammertal (Ammertalbahn)
The Ammertalbahn between Tübingen and Herrenberg doesn't belong to a large group, but to a municipal special-purpose association. It owns the line but doesn't run any trains – a textbook case of the split between infrastructure and operations, in miniature.
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