Siemens Vectron Dual Mode

Updated: August 2026 – A locomotive with a pantograph on the roof and a cooling system for a diesel engine on the side: the Siemens Vectron Dual Mode is a bi-mode locomotive that keeps going exactly where the overhead line ends. This page explains how the concept works, why the vehicle runs as Class 248 in Germany and how to recognise it with certainty.

What is the Siemens Vectron Dual Mode?

The Vectron Dual Mode is a four-axle bi-mode locomotive from Siemens Mobility. It belongs to the Vectron platform, can run electrically under the overhead line and switches to a diesel engine on non-electrified sections. The wheel arrangement is Bo’Bo’, the top speed 160 km/h, and the electrification system is Germany’s 15 kV / 16.7 Hz.

In Germany it carries the class number 248. Operationally, it solves a very specific problem: many freight services run over electrified main lines but end on sidings without overhead wires. Until now that required a second locomotive – with a bi-mode machine, this change is no longer necessary.

Why the number starts with 2

Since 1968, Deutsche Bahn’s computerised (EDV) numbering scheme has grouped traction units by type of traction. This system explains at a glance why a vehicle that runs electrically most of the time still ends up in the diesel block.

Number range	Vehicle type	Examples
1xx	Electric locomotives	Class 101, Siemens Vectron
2xx	Locomotives with a combustion engine	Class 248, Class 218
3xx	Small locomotives and shunting vehicles	Class 361
4xx–6xx	Railcars and multiple units	Class 423, Class 612
7xx	Departmental vehicles	Class 711

So what matters is not what the locomotive mostly runs on, but that it has a combustion engine on board at all. That’s why the Dual Mode machine sits in the 2xx block, while the purely electric Siemens Vectron is listed in the 1xx block. The same logic applies to the lighter sister variant Vectron Dual Mode light and to multi-mode concepts from other manufacturers such as the Stadler Eurodual.

How to work through numbering systems like this in general is shown in the guide to identifying classes.

How to recognise the locomotive in the field

Bi-mode, multi-system, hybrid: keeping the terms apart

Several terms are in circulation around modern locomotives, and they are easily confused. They describe different things – and if you keep them apart, you’ll classify vehicles far more reliably.

Bi-mode or dual-mode locomotive means: two different energy sources on board, here the overhead line and a diesel engine. The vehicle can haul trains at full capacity in both operating modes.

Multi-system locomotive, by contrast, means: several railway electrification systems, but always electric operation from the overhead line. Such machines run across borders, but need overhead wires everywhere.

Hybrid vehicle refers to the combination of a main energy source and an energy storage unit, such as diesel plus battery. The storage unit helps when pulling away and absorbs braking energy, but does not replace the main source.

Last-mile equipment, finally, describes a small auxiliary diesel on an electric locomotive, intended only for slow shunting movements without overhead wires – not for mainline service.

The Vectron Dual Mode clearly belongs in the first category: it is not an electric locomotive with an auxiliary engine but a locomotive that can work mainline duties in both operating modes. That’s exactly the difference from vehicles with a pure last-mile function, and exactly why the vehicle looks considerably bulkier from the outside than a purely electric locomotive of the same platform.

Where you’ll find Class 248

The operating profile follows directly from the concept: bi-mode locomotives pay off where electrified and non-electrified infrastructure meet.

Typical situations are:

• Freight trains serving sidings, whose last kilometres have no overhead wires.
• Ports and industrial areas, where the overhead line ends at the works boundary.
• Transfer and feeder runs between marshalling yards and siding customers.
• Engineering and special trains, where the overhead line is switched off or not present.

On top of that come combined-transport terminals such as those operated by CargoBeamer. Marshalling yards and the lines around them are therefore a sensible starting point for your search. How to observe there legally and effectively is described in the guide to spotting at a marshalling yard.

One special feature makes these vehicles even more interesting for observers: the change of operating mode takes place at a specific point on the line, usually where the overhead line ends or a section without wires begins. Such places are appealing for photos, because that’s where the pantograph comes down and the diesel engine takes over – a process you won’t see in quite this way with any other type of locomotive.

At the same time: exactly where the changeover happens depends on the infrastructure and operational rules and is not something you can derive from a map. If you’re after subjects like this, work with your own observation and community reports – and choose your vantage point exclusively on publicly accessible ground.

For clear identification of the individual machine, the vehicle number remains decisive. The full system behind the twelve-digit identifier with check digit is explained in the article on the UIC number.

Common mix-ups

Verdict

The Vectron Dual Mode is one of the few locomotives you can pin down with a single observation: a pantograph and diesel technology on the same vehicle. Four axles, 160 km/h, Class 248 in Germany – and an operating profile that begins exactly at the limit of electrification. Where individual machines run changes with contracts and fleet build-up, which is why keeping your own, continuously updated records is worthwhile.