DB Class 151

Updated: August 2026 – A long, hefty locomotive body, six axles and a freight train that seems to have no end: the Class 151 is one of the few German electric locomotives you recognise from the silhouette alone, before you’ve seen a single detail. This page shows how to identify it, how to tell it apart from its six-axle sister, and where you’ll realistically find it.

What is the Class 151?

The Class 151 is a six-axle electric locomotive for heavy freight trains, built between 1972 and 1978 in 170 examples with numbers 151 001 to 151 170. It delivers around 6,300 kW and is rated for 120 km/h – an unusually high speed for its size.

That was exactly the point of its design. The heavy freight locomotives of the previous generation had plenty of tractive effort but were slow. The 151 was meant to do both: pull large loads while running fast enough not to hold up traffic on mixed-use main lines. That makes it the logical further development of the freight locomotive line that began with the four-axle Class 140.

Where the 151 sits in the numbering system

The number 151 is no coincidence, but the result of a clear system.

• Since the 1968 renumbering, the leading 1 has marked the electric locomotive. Before that these vehicles carried an E: E 10, E 40, E 41, E 50.
• The number range places the intended use: 101 to 128 stand for passenger and general-purpose locomotives, 139 to 155 for freight locomotives, from 180 upwards come multi-system and cross-border locomotives.
• The 151 superseded the 150, which had previously been the Bundesbahn’s heavy freight locomotive as the E 50 – making it, in numbering terms, the direct successor.
• After reunification, the Reichsbahn classes moved into the same range: the Reichsbahn’s Class 250 became the Class 155, which thus came to stand directly next to the 151.

Once you understand this logic, you can work out the original purpose of any German electric locomotive from the number alone. The systematic approach to this is explained in the guide to identifying classes.

How to identify a 151 in the field

Where it fits into railway operations

The 151 is a main-line locomotive for heavy trains. Anyone looking for it needs different locations than for passenger traffic – and different expectations, because there’s no clockface timetable. A large marshalling yard like Maschen south of Hamburg is therefore the obvious starting point. Preserved museum machines of the class, meanwhile, can be found at collections such as the Südwestfälisches Eisenbahnmuseum in Siegen.

Setting	Chance of a sighting	Why
Electrified freight corridors	high	Core territory for heavy trains
Marshalling yards and train formation facilities	high	Trains are made up and taken over there
Industrial and port connections with overhead wire	medium	Heavy block trains, but irregular
Timetabled passenger routes	very low	Wrong duty profile
Non-electrified lines	ruled out	Electric locomotive with no on-board power source

How to observe freight traffic in a planned way at all is described in the article on the freight train radar for Germany; choosing a location and approach at a marshalling yard is covered by the guide to spotting at a marshalling yard – exclusively from publicly accessible locations. In the Ruhr area, that applies for instance to Hagen-Vorhalle.

Photo tips for a six-axle freight locomotive

• Plan for more picture width. The 151 is noticeably longer than a four-axle locomotive. A crop that works for a 143 cuts off the bogies here.
• Keep the bogies visible. The six axles are the main feature – a lower viewpoint or a slightly oblique angle shows them best.
• Include the start of the train. With a freight locomotive, what it’s pulling is part of the story. A few wagons in the frame make the sighting comprehensible – at a freight hub like Duisburg-Hochfeld Süd you get both together.
• Look for flat light. The large, smooth side surfaces need raking light, otherwise they look empty.

Exposure, composition and depth of field are covered in the guide taking good photos of trains. Photography happens exclusively from the platform or from publicly accessible land; tracks, operational railway land and sidings are off limits.

Six axles: what the wheel arrangement means operationally

The axle count isn’t just a recognition feature, but a technical decision with clear consequences. Anyone who understands it can better judge what any unfamiliar locomotive was built for.

• More axles spread the weight. A heavy locomotive with only four axles would exceed the permitted axle load. Six axles allow a higher total mass – and mass is exactly what a locomotive needs to put tractive effort onto the rail.
• More powered axles mean more usable friction. Transmittable tractive effort depends on the friction coefficient between wheel and rail. Six powered axles put the power down better than four, especially on wet rail and on gradients.
• The price is cornering ability. Three-axle bogies are longer and run worse through tight curves. That’s why six-axle locomotives are almost always main-line machines and rarely found in tight shunting areas.
• That’s why they exist almost exclusively in freight service. Passenger locomotives don’t need extreme tractive effort, but speed and smooth running – four axles are enough. In Germany, six axles are practically a reliable sign of a freight locomotive.

For identification purposes that’s a valuable shortcut: anyone counting six axles can immediately rule out the entire passenger and local-service sector and only has to decide between a few candidates.

Common mix-ups

The only genuinely dangerous candidate is the Class 155: also six-axle, also a freight locomotive, but of Reichsbahn origin and with a flatter, more evenly panelled body. From a greater distance, the hefty-looking but four-axle Class 120 can also cause confusion – a look at the bogies settles it immediately.

Verdict

The Class 151 is the locomotive that teaches you that counting axles is the most reliable identification method of all. Six axles, hefty body, heavy freight train: nothing more is needed for the right group. The number then only has to decide between two candidates.