Key takeaways
- Bi-mode, not hybrid: the locomotive runs electrically under the wire and switches to the diesel engine where there's no overhead line.
- The number gives it all away: 90 80 at the start stands for “other traction type” – which is exactly where bi-mode locomotives are classified.
- Identification feature number one is the combination of pantograph and diesel module, including the roof fans.
- The “light” variant is aimed at lines with a lower permitted axle load – it's the lighter sister of the Vectron Dual Mode.
- Areas of operation change with contract awards, leasing agreements and timetable years – always check the current situation.
Contents
Fact file
| Vehicle type | Bi-mode locomotive – electric under the wire, diesel-electric without overhead line |
|---|---|
| Platform | Siemens Vectron |
| Wheel arrangement | Bo'Bo' (four axles in two bogies) |
| Design | lighter variant of the Vectron Dual Mode for lines with a lower permitted axle load |
| Electrification system on the German network | 15 kV / 16.7 Hz AC |
| Vehicle number | NVR number starts with 90 80 – code for “other” traction type |
Identifying features
Is this really the class in front of you?
- Four axles in two bogies – not a six-axle design
- Typical Vectron front with a narrow window band, but fan grilles and exhaust outlet on the roof
- Pantograph present and a diesel module – the combination is the key feature
- Vehicle number starts with 90 80, not with 91 80 (electric locomotive) or 92 80 (diesel locomotive)
- Mostly at the head of freight trains, often in single-wagonload traffic to sidings without overhead wire
Updated: August 2026 – A locomotive with a pantograph on the roof that still puffs out exhaust: that’s confusing the first time you see it. The Siemens Vectron Dual Mode light is built for exactly that – it runs electrically under the wire and covers the rest of the route with a diesel engine. This page shows you how to recognise it, what its vehicle number reveals and what to pay attention to when documenting it.
Spotted a bi-mode loco? Secure the number.
Especially with young, rare classes, the full vehicle number is the most important piece of information – recorded in seconds in Traintrack.
What is the Siemens Vectron Dual Mode light?
The Vectron Dual Mode light is a four-axle bi-mode locomotive from the Vectron family by Siemens Mobility. Bi-mode means the locomotive has two full-fledged power sources – the pantograph for electric operation under the overhead line and a diesel engine for everything without wire. The suffix “light” denotes the lighter design compared with the Siemens Vectron Dual Mode; it’s aimed at lines with a lower permitted axle load.
The operational reasoning behind it is simple: on many freight routes the main line is electrified, but the last stretch to the factory, port or siding is not. In the past, that required either a locomotive change or a pure diesel locomotive over the entire route. A bi-mode locomotive does both in one diagram – without any shunting at the system boundary.
Why the vehicle number starts with 90
This is the most instructive detail of this vehicle and at the same time the most reliable way of identifying it. For traction units, the European vehicle number starts with a two-digit code for the vehicle type:
| Code | Vehicle type | Example |
|---|---|---|
| 90 | other traction type | bi-mode locomotives, steam locomotives, special drives |
| 91 | electric locomotive | classic main-line electric locomotive |
| 92 | diesel locomotive | main-line diesel locomotive |
| 94 | electric multiple unit | regional and S-Bahn multiple units |
| 95 | diesel railcar | railcars on branch lines |
| 98 | diesel shunting locomotive | shunting and small locomotives |
A bi-mode locomotive fits neither 91 nor 92 – so it ends up in the catch-all group 90. That’s exactly why it’s in the same category as steam locomotives in this database: both share the code for “everything else”. How the full number is structured and what the check digit at the end is for is explained in the guide to reading the UIC number on the vehicle.
How to recognise the locomotive in the field
Count the axles
Four axles in two bogies. That immediately rules out six-axle bi-mode locomotives such as the Eurodual or the Euro 9000.
Look at the roof
A pantograph alone isn't enough. Also look for an exhaust outlet and large fan grilles – that's the signature of the diesel module.
Check the side wall
The body is divided up differently from the pure electric locomotive, because the engine, cooling system and fuel supply need space. Large fan areas are a strong indication.
Read the number
If it starts with 90 80, the traction type is settled. The class and serial number that follow identify the specific series and locomotive.
The quickest test from a distance
Number of axles first, then the roof. You can make out both even in mediocre light. Check the details of the side wall and the number at your leisure when the locomotive is stationary or when you look at the photo on your computer later.
Context within railway operations
Bi-mode locomotives are tools for a very specific task: freight routes with mixed electrification. From that you can work out where it’s worth looking.
| Setting | Chance of a sighting | Why |
|---|---|---|
| Electrified main line with non-electrified sidings | high | Exactly the design’s operating profile |
| Industrial and port railways with an end of overhead wire | high | No system change needed, a locomotive change is saved |
| Pure long-distance hub without freight traffic | low | Other vehicle types dominate |
| Fully electrified freight corridor | medium | Possible, but makes little economic sense |
| Heritage railways and special services | very low | Young production vehicles in commercial service |
Areas of operation aren't permanent
Who runs which locomotive depends on leasing agreements, contract awards and timetable years. Lists on the internet go out of date quickly. Rely on current community sightings and your own observation rather than a snapshot from three years ago.
If you want to understand the difference between freight and passenger vehicles systematically, you’ll find the basics in the article on local and long-distance services from a spotter’s perspective.
See which bi-mode locos are being reported right now
Community sightings show you what's actually out and about at the moment – before you set off.
Spotting and photography
Because these locomotives work freight, different rules apply than with long-distance passenger services. There’s no regular-interval timetable to hold on to, and dwell times are often short.
- Freight hubs rather than passenger stations. Marshalling yards and the associated public platforms are the more realistic locations. Practical advice on this is collected in the guide to spotting at marshalling yards.
- Ends of overhead wire make great subjects. The point where the overhead line ends is exactly where a bi-mode locomotive shows its purpose – provided you find a publicly accessible location with a clear view.
- Get the roof in the picture. A slightly elevated viewpoint makes the difference from the pure electric locomotive visible. Photographed head-on, a Vectron looks like any other Vectron.
- Capture the whole side wall. Only then will the vehicle number be legible later – and without it, the sighting is only half the information.
For choosing a focal length and dealing with distance at such locations, the guide to the best telephoto lens for railway photography will help. And the crucial ground rule: tracks, operational railway land and depots are off-limits. They’re private land; entering them is prohibited and potentially fatal. Photograph from publicly accessible areas – the rules are summarised in the article on safe distance from the track.
Common mix-ups
It points to a Vectron Dual Mode light if …
- you count four axles
- a pantograph and an exhaust outlet are present at the same time
- the vehicle number starts with 90 80
- a freight train or a trip working is attached
Look more closely if …
- you only see the locomotive head-on – the Vectron front is similar across the family
- a leasing livery makes it harder to place
- you're not sure whether it's the standard or the lighter variant
It's not a Vectron Dual Mode light if …
- you count six axles – then the Eurodual or Euro 9000 are candidates
- there's no pantograph
- the number starts with 91 80 or 92 80
To distinguish it from the purely electric platform, it’s worth comparing it with the Siemens Vectron; the six-axle competition is described on the page about the Stadler Eurodual. How to work through such chains of features in general is shown in the guide to identifying classes.
Conclusion
The Vectron Dual Mode light isn’t a vehicle you recognise by a spectacular shape – it’s a Vectron with a second drive. That’s precisely the route to identifying it: number of axles, roof with pantograph and exhaust outlet, then the number. Because the fleet and its duties shift with every contract year, careful documentation is more valuable here than with any older locomotive.
In short
Four axles, pantograph plus diesel module, number starting 90 80: that's a bi-mode Vectron. Whether it's the standard or the “light” variant is ultimately decided by the full vehicle number – always note it down.
Your bi-mode sightings in one place
Number, date, location and photo in one app – over the years that builds up a collection no online list can replace.
Summary
- The Vectron Dual Mode light belongs to the bi-mode family of the Vectron platform and combines electric operation with a diesel drive for lines without overhead wire.
- For identification in the field, the number of axles, the roof with pantograph plus exhaust outlet and the number starting 90 80 are enough.
- Operationally it's a freight locomotive for routes with mixed electrification – the classic locomotive change is no longer needed.
- Because the fleet and its duties change quickly, it's worth recording every sighting with the full vehicle number and the date.
Frequently asked questions
What is a Vectron Dual Mode light?
It's a bi-mode locomotive from the Siemens Vectron family: it runs electrically under the overhead line and uses a diesel engine on non-electrified sections. The suffix “light” stands for a lighter design that can also work lines with a lower permitted axle load.
Why does the vehicle number start with 90 and not 91?
The first two digits of the vehicle number indicate the vehicle type. 91 stands for pure electric locomotives, 92 for pure diesel locomotives. Vehicles that fit neither pigeonhole get group 90 for “other” – which is where bi-mode locomotives end up, just like steam locomotives.
How do I tell it apart from a normal Vectron?
Look at the roof and the side wall. A pure electric locomotive has pantographs, but no exhaust outlet and no large engine fans. On the bi-mode variant you'll find both. The body is also divided up differently, because the diesel module needs space.
Where does the Vectron Dual Mode light run?
Typical are freight duties on routes that are partly electrified and partly not – for example runs from a main line to a siding without overhead wire. Which diagrams are actually worked depends on leasing agreements and contract awards, and changes all the time.
How many axles does the locomotive have?
Four, spread over two bogies – wheel arrangement Bo'Bo'. That clearly distinguishes it from six-axle bi-mode locomotives such as the Stadler Eurodual, which are designed for higher tractive effort with heavy trains.
Is the locomotive a hybrid with a battery?
No. Bi-mode means two full-fledged energy sources: overhead wire and diesel engine. A hybrid vehicle in the narrower sense stores energy in batteries and releases it again. Both exist on the market, but technically they're not the same thing.
How do I recognise the exact locomotive?
By the full NVR number on the side wall. It contains the vehicle type, country code, class and serial number plus a check digit. Only with it can a sighting be clearly assigned later – the class designation alone isn't enough.
Why is this locomotive listed in the steam locomotive category?
Because the database sorts by the vehicle-type code 90. This group brings together all traction units that are neither pure electric nor pure diesel locomotives – historically mostly steam locomotives, today also modern bi-mode and special drives.
Log your sighting of the Siemens Vectron Dual Mode light
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
Siemens Vectron Dual Mode
The Vectron Dual Mode is a bi-mode locomotive: it runs electrically under the wires and with a diesel engine on non-electrified sections. In Germany it is Class 248.
Electric locoSiemens Vectron
The Vectron is Siemens's modular locomotive platform and shapes European freight services. Here's how to identify the variants and read the number correctly.
Steam/specialStadler Eurodual
The Eurodual is a six-axle dual-power locomotive from Stadler, running in Germany as Class 159. Here's how to identify it and tell it apart from the Euro 9000.
Steam/specialDR Class 42
The Class 42 was the heavy war locomotive KDL 3: 1,061 built, 1'E wheel arrangement, constructed from 1943. Today it survives only as a preserved museum vehicle.
Steam/specialDR/DB Class 44
The Class 44 was the heavy freight locomotive of the standard-design classes: five coupled axles, three cylinders, around 1,989 built. The "Jumbo" now only runs in preservation.
Steam/specialClass 50
Class 50 is the most successful German freight steam locomotive: over 3,000 built, five coupled axles, low axle load. Today it only runs in heritage service.
Who is behind it
Groups, brands, manufacturers and operators – who owns whom and how to recognise them out in the field.
Related guides from the blog
