Key takeaways
- The 4020 is a three-part electric commuter EMU – built from the late 1970s for dense suburban traffic.
- The number system explains the train: 4020 is the power car, 7020 the intermediate car, 6020 the driving trailer – the leading digit encodes vehicle type in the ÖBB system.
- Fastest feature: high-floor boarding with steps and the angular 1970s body shape.
- Clearly distinguishable from newer classes such as the 4024 or 4744/4746, which have low-floor boarding.
- The fleet is changing: deployment areas and numbers are not a permanent state – check the current status.
Contents
Fact file
| Vehicle type | Electric commuter multiple unit for suburban and S-Bahn services |
|---|---|
| Designation system | ÖBB Class 4020 – the leading 4 stands for electric railcar |
| Train formation | Three-part unit made up of power car 4020, intermediate car 7020 and driving trailer 6020 |
| Electrification system | 15 kV / 16.7 Hz AC |
| Years built | From the late 1970s |
| Service profile | Dense commuter service with many stops, high-floor boarding |
| Status | Fleet strongly in decline, being replaced by newer EMU families – check the current status |
Identifying features
Is this really the class in front of you?
- Three-part unit that is not split during operation
- Boxy 1970s/80s body with high-floor boarding and steps
- Pantograph only above the power car, not above every car
- At the end of the train a driving trailer without a pantograph, class number beginning with 6020
- Large, rectangular front windows and a flat, barely styled nose
- Runs in commuter service with a dense stopping pattern, not in long-distance service
Updated: August 2026 – An angular body, high steps, three permanently coupled cars: the Class 4020 is the commuter EMU that generations of Austrian passengers have ridden. This page shows you how to spot it, why a single train carries three different class numbers, and how to tell it apart from the newer EMU families.
Seen a 4020? Log it now.
Older commuter vehicles disappear from everyday service quickly – note the number, place and date while you can still see them.
What is the ÖBB Class 4020?
The Class 4020 is a three-part electric commuter EMU of the Austrian Federal Railways, built from the late 1970s for dense traffic in conurbations. It runs on 15 kV at 16.7 Hz, boards at high-floor level, and is designed for many stops, short dwell times and high passenger turnover.
Operationally, it therefore sits at the opposite end of the spectrum from long-distance stock: no claim to comfort over long distances, but acceleration, door capacity and robustness instead. The difference between these two worlds – and what it means for spotters – is covered in detail in the article Local versus long-distance services compared.
One train, three class numbers: understanding the ÖBB system
Anyone reading the markings on a 4020 set for the first time pauses: the three cars carry three different four-digit numbers. That’s not a mistake – it’s the Austrian system.
The ÖBB designate powered vehicles with “class” plus a four-digit number, and the leading digit encodes the vehicle type. For a 4020 unit, that produces a very readable breakdown:
| Vehicle | Class | Leading digit means | Role in the train |
|---|---|---|---|
| Power car | 4020 | 4 = electric railcar | Carries traction and pantograph |
| Intermediate car | 7020 | 7 = intermediate car | Pure passenger space, no traction |
| Driving trailer | 6020 | 6 = driving trailer | Cab, no traction |
This logic runs through the entire Austrian fleet: 1 stands for electric locomotives, 2 for diesel locomotives, 5 for diesel railcars. Once you’ve internalised it, you can roughly place even unfamiliar vehicles before reading a single data sheet.
Then there’s the twelve-digit European vehicle number. It begins with the vehicle type code, followed by the country code – 81 stands for Austria. How to find this number on the vehicle and decode it block by block is explained in the guide to the ÖBB number and UIC vehicle number.
How to identify a 4020 in the field
Step 1: Check the doors
Doors with steps and a high-set floor point to the 4020. Newer commuter EMUs board largely step-free.
Step 2: Assess the body
Angular, flat, barely styled – the design language of the 1970s and 80s is unmistakable once you put it next to a modern EMU.
Step 3: Scan the roof
Only one of the three cars carries a pantograph. If the roof is fitted the same way over every car, it's a different type.
Step 4: Read the numbers
4020, 7020 and 6020 on the three cars confirm the identification for good.
Practical tip for the first glance
Check the doors first. You can see the boarding height even in poor light and from a great distance – you can check the shape details and numbers afterwards at your leisure.
Where does a 4020 still run today?
Community sightings show you which older commuter vehicles were last reported.
Where and how you’ll realistically encounter the class
Commuter EMUs don’t follow a spectacular route – they follow the timetable interval. For your search that means: stations with a dense service in conurbations beat lonely spots on the line. Where trains run every ten or fifteen minutes, you’ll see more vehicles in an hour than elsewhere in half a day.
Fleet and deployment area keep changing
Older EMU classes are gradually being replaced by newer families. Which diagrams are currently still worked by the 4020 shifts with timetable changes and vehicle deliveries. Check the status via real-time information and current community reports, rather than relying on lists found online.
The fastest way to find out which departures are actually due at a given station is through regional information systems. How to use them properly is described in the guide to regional transport associations and live departures.
Why the class is especially worth it right now
Vehicles in the final phase of their service life are interesting to spotters for a simple reason: their numbers only move in one direction. With the 4020, there’s the added factor that it represents a vehicle generation that won’t exist again – high-floor, angular, with clearly separated roles per car.
In practice, that means three things:
- Completeness beats quantity. One vehicle properly documented with number, date and location is worth more than ten vague notes.
- Liveries are timestamps. Colour schemes and markings change over the years. A photo can later be dated purely from its livery.
- Details disappear first. Markings, interior fittings and data panels often change long before the vehicle itself does.
Anyone working systematically therefore photographs not just the front, but also the side with the full marking. That costs ten extra seconds and makes the difference between a memory and a verifiable record.
Photo tips for commuter EMUs
A 4020 at the platform is a tricky subject: a short dwell time, often backlit, little room to step back. These points help.
Use the end of the platform
At the end of the platform you get more distance and a freer angle on the front – naturally, within the accessible area and behind the safety line.
Think in terms of the whole unit
Three cars is a lot of length. A slightly angled view gets the complete set into the frame more easily than a front-on position.
Photograph the number separately
An additional detail shot of the vehicle marking makes the sighting clearly verifiable later.
Watch your safety
Tracks, operational railway land and stabling areas are off-limits. Every usable photo can be taken from the platform.
The basics of choosing a spot, light and composition are covered in the guide to railway photography.
Common mix-ups
It points to the 4020 when …
- the train consists of exactly three permanently coupled cars
- the doors have steps
- only one car carries a pantograph
- the markings show 4020, 7020 and 6020
Look more closely when …
- you only see the train from the side without a marking
- two units are coupled together and the number of cars looks unclear
- the livery is unfamiliar – colour schemes change over the years
It's not a 4020 when …
- the boarding is low-floor and step-free
- a separate locomotive is hauling the train
- the class number begins with 4024, 4744 or 4746
The most obvious candidates for confusion are the low-floor Class 4024 (Talent) and the newer Cityjet EMUs of Classes 4744 and 4746. Anyone looking at an unpowered driving cab should also consider the ÖBB CityShuttle driving trailer – it looks similar at the front but belongs to a locomotive-hauled push-pull train.
Verdict
The Class 4020 is a lesson in Austrian rolling-stock knowledge: a single train explains how the ÖBB’s class system works, what a driving trailer is for, and how to recognise a vehicle generation. Body shape and boarding height lead to the right answer in seconds, and the markings provide the confirmation.
Quick verdict
Three cars, high-floor boarding, an angular body and the numbers 4020, 7020, 6020: this is Austria's classic commuter EMU. Because the fleet is shrinking, every documented sighting is worth more than it was ten years ago.
All your commuter sightings in one place
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Summary
- The Class 4020 shaped electric commuter services in Austrian conurbations for decades.
- It consists of three permanently coupled vehicles with clearly separated roles: traction, intermediate car, driving cab.
- Body shape, boarding height and the four-digit class number are enough to identify it.
- As the class is increasingly replaced by newer EMUs, documented sightings gain in value.
Frequently asked questions
What is the ÖBB Class 4020?
A three-part electric commuter EMU of the ÖBB, built from the late 1970s for dense suburban and S-Bahn traffic. The unit consists of a power car, an intermediate car and a driving trailer, and is not split during operation.
Why does one train carry three different class numbers?
Because the ÖBB designate every vehicle individually. The powered car runs as 4020, the unpowered intermediate car as 7020, the driving trailer as 6020. The leading digit indicates the vehicle type: 4 for electric railcars, 6 for driving trailers, 7 for intermediate cars.
How do I tell the 4020 apart from the Class 4024?
By the boarding and the shape. The 4020 is a high-floor vehicle with steps and an angular 1970s body. The 4024 is a low-floor EMU with a distinctly rounder shape and low-set doors. When in doubt, the class number on the side of the vehicle settles it.
Is the Class 4020 still running?
The fleet is shrinking because newer EMU families are taking over its duties. How many units are actually in service at any given time, and on which lines, keeps changing. So don't rely on older lists – rely on current sightings and timetable data instead.
How do I recognise the Class 4020's driving trailer?
It has a cab with large front windows but no pantograph on the roof and no powered bogies. Its number begins with 6020. When the train pulls away it stays audibly quiet – the engine noise comes from the power car at the other end of the train.
Where was the Class 4020 typically used?
On electrified commuter routes with a dense stopping pattern – so in conurbations and on S-Bahn-style services. Specific lines change with contract awards and timetable years, but the vehicle type reliably tells you which service segment to look in.
What does the 4 in the class number mean?
It encodes the vehicle type. The ÖBB designate powered vehicles with "class" plus a four-digit number: 1 stands for electric locomotives, 2 for diesel locomotives, 4 for electric railcars and multiple units, 5 for diesel railcars. This system runs right through the fleet and is the fastest way into Austrian rolling-stock knowledge.
Is it worth documenting sightings of the Class 4020?
Yes, especially now. Vehicles nearing the end of their service life often disappear from everyday operation faster than expected. Anyone who logs number, date, location and livery ends up with a solid record instead of vague memories.
Log your sighting of the ÖBB Class 4020
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
ÖBB Class 4024 (Talent)
The Class 4024 is the ÖBB's low-floor Talent EMU. Here's how to recognise it by its bogies and boarding – and how to tell it apart from the Cityjet and the 4020.
EMUÖBB Class 4744 / 4746 (Cityjet / Desiro ML)
Cityjet is the product name, 4744 and 4746 are the classes: here's how to recognise the ÖBB's Desiro ML EMUs and tell them apart from older commuter classes.
Driving trailerÖBB CityShuttle Control Car
A control car has a driving cab but no motor. Here's how push-pull operation works on the ÖBB CityShuttle – and how to spot the control car for sure.
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