Key takeaways
- ICM stands for InterCity Materieel: the NS names its multiple units after their purpose, not after a class number.
- The nickname explains the design: the train is called Koploper because you could originally walk through the front into the coupled neighbouring unit.
- Three- and four-car: ICM-III and ICM-IV differ in the number of car sections, not in the basic concept.
- 1.5 kV DC ties the ICM to the Dutch network – you won't come across it in Germany.
- Deployment and fleet numbers change with every timetable year and as newer vehicle generations arrive.
Contents
Fact file
| Vehicle type | Electric multiple unit for intercity services |
|---|---|
| Meaning of the abbreviation | ICM = InterCity Materieel, i.e. vehicle stock for the intercity |
| Nickname | Koploper – Dutch for roughly "the one that walks at the front" |
| Variants | three- and four-car units (ICM-III, ICM-IV) |
| Electrification system | 1.5 kV DC – the standard system of the Dutch network |
| Operator | Nederlandse Spoorwegen (NS) |
| Country of operation | Netherlands |
Identifying features
Is this really the class in front of you?
- High-set cab, with the zone of the former front gangway below it
- Rounded front section drawn well upwards, with a large windscreen
- Fixed units of three or four car sections, often coupled together in service
- Only one pantograph type for 1.5 kV DC – not a multi-system vehicle
- Yellow-and-blue NS base livery with intercity markings
- Vehicle number in the Dutch scheme, UIC country code 84
Updated: August 2026 – A yellow-and-blue multiple unit with a strikingly high-set cab, and below it a front that looks as though you could walk right through the middle of it: that’s the NS ICM, which in the Netherlands practically everyone just calls “Koploper”. This page explains what the abbreviation means, how to identify the type in seconds, and why you won’t come across it on the German side of the border.
Spotted a Koploper? Log the unit.
Number, location and date documented in a few seconds – Traintrack keeps you on top of foreign vehicles too.
What is the NS ICM (Koploper)?
The ICM is an electric multiple unit of the Nederlandse Spoorwegen (NS) for intercity services. The abbreviation stands for InterCity Materieel, roughly “vehicle stock for the intercity”. It exists in three- and four-car versions, usually written as ICM-III and ICM-IV – the appended digit simply states the number of car sections.
That already contains the most important lesson for anyone wanting to identify Dutch vehicles: the NS doesn’t assign class numbers the way DB does, but descriptive codes drawn from the vehicle concept. Once you’ve understood this logic, you can read half the fleet without looking anything up. VIRM stands for Verlengd InterRegio Materieel, SGM for Stadsgewestelijk Materieel, SLT for Sprinter Lighttrain – each code describes the purpose, not the order in which it was procured.
Why the train is called Koploper
The nickname isn’t an accident, but the exact description of a design idea. The ICM’s cab sits on a raised level. The space below or beside it was built as a gangway: when two units were coupled together, you could walk right through the whole train formation on foot – past the driver’s workplace.
These front gangways were taken out of use in the course of modernisations. The shape stayed: the characteristically tall, rounded front section with the set-off cab window. That’s exactly what lets you recognise the ICM even if you know nothing about its history.
Check the height of the cab
Does the cab window sit noticeably above the level of the passenger windows? That's the most striking feature of the ICM and hardly as pronounced on any other Dutch multiple unit.
Check the coupling level
Below the cab lies the zone of the former gangway. As a result, the front looks deeply structured rather than smooth – unlike modern local-service multiple units.
Count the car sections
Three or four sections per unit. If several units are coupled, you'll count another front section between the formations each time – that's the dividing line.
If you’re unsure of the general approach, the guide to identifying rolling-stock classes helps: it explains in which order to work through features so you don’t get lost in details.
The ICM in Dutch railway operation
The Dutch line network is run predominantly on 1.5 kV DC. This historically grown decision still shapes the entire vehicle fleet today: anything that can only handle 1.5 kV stays within the country. It was only the high-speed line that brought 25 kV AC into the network – and with it the need for multi-system vehicles.
For you as an observer, that means: the ICM is a purely domestic vehicle. Cross-border trains towards Germany need either multi-system vehicles or diesel railcars. So anyone standing at a German border station waiting for a Koploper is waiting in vain.
| Observation location | Chance of a sighting | Why |
|---|---|---|
| Large Dutch interchange stations | high | Intercity traffic concentrates there, with long dwell times at the platform |
| Dutch long-distance lines | high | Scheduled area of operation for the type |
| German border stations | very low | 1.5 kV DC ends at the system boundary |
| German domestic lines | excluded | No regular deployment outside the Netherlands |
| Purely local-transport hubs | low | Sprinter vehicles dominate there |
Fleet and deployment are subject to change
Which diagrams are worked by which vehicle family shifts with timetable years, modernisations and the arrival of newer generations. Check the current status before a trip instead of relying on older lists.
In the double-deck sector, the NS VIRM takes on comparable duties, and in fast services the NS ICNG. The counterpart in local services is the NS SLT as a Sprinter vehicle, built completely differently in front and door layout. Anyone generally interested in vehicles beyond the German border will find a good starting point in the article on sightings and research abroad. Historical stock, meanwhile, is shown by the Museum Buurt Spoorweg in Twente. Entirely focused on steam operation is the Museumstoomtram Hoorn-Medemblik in North Holland.
Log sightings abroad properly
A logbook that also understands Dutch unit numbers – so your finds stay comparable.
Spotting and photography: what matters with the ICM
The ICM is a rewarding subject because its front is unusual – and a difficult one, because that very front easily looks dull if the light doesn’t cooperate. Four points make the difference.
Make the front structure visible
A three-quarter view of about 30 to 45 degrees shows the raised cab and the gangway zone at once. Shot head-on, the train loses exactly the feature that defines it.
Use flat light
In the morning and late afternoon, the edges of the front section stand out. Harsh midday light makes the rounded surfaces look flat and featureless.
Include the coupling point
With several units coupled together, the join between two front sections is the strongest image narratively – that's where the design principle actually becomes visible.
Document the number
Also photograph the markings. Without a number, a sighting can hardly be matched up later, especially with a large, similar-looking vehicle family.
For composition and exposure, it’s worth looking at the guide good train photos. How to read the full vehicle number and correctly interpret country code 84 is explained in the article on the UIC number and its system.
Safety applies unchanged
Tracks, operational railway land and stabling sidings are off limits. Photograph from publicly accessible areas, behind the platform edge, and never in disregard of barriers – abroad just as much as in Germany.
Common mix-ups
It points to the ICM if …
- the cab sits noticeably raised above the passenger windows
- the front below the cab looks structured rather than smooth
- the unit consists of three or four car sections
- the train is running in Dutch intercity services
Look more closely if …
- you only see the side view – then the door layout helps further
- several units are coupled and you're looking for the formation boundaries
- the vehicle carries a different advertising or special wrap
It's not an ICM if …
- the train is double-decked – then you're looking at a VIRM or DDZ
- the front looks flat and low with many doors in the local-service style
- the vehicle runs in Germany under 15 kV AC
Conclusion
The ICM is one of the few vehicles whose nickname fully explains the design. Raised cab, gangway zone in the front, three or four car sections – that’s all you need to identify it with confidence. And because it’s tied to the Dutch network as a pure DC vehicle, it belongs to the trains you have to visit deliberately.
In short
High cab, structured front section, three or four car sections: that's the Koploper. It stays in the Netherlands – anyone wanting to document it plans the sighting there and always notes the unit number.
Your Dutch sightings in one place
Unit, location, date and photo filed together – so you immediately see which vehicle families you're still missing.
Summary
- For decades the ICM was the face of Dutch intercity services and carries one of the most distinctive front-end designs in Europe.
- Three observations are enough to identify it: a raised cab, a rounded front section with a gangway zone, and the number of car sections.
- Anyone wanting to see the ICM has to go to the Netherlands – the pure DC vehicle doesn't leave the country's network.
- Document the unit number and the condition of the front section: both change with modernisations and withdrawals.
Frequently asked questions
What does the abbreviation ICM stand for?
ICM stands for InterCity Materieel, roughly "vehicle stock for the intercity". The Dutch state railway NS traditionally names its multiple units after their purpose or vehicle concept rather than a number. The same logic produced codes such as VIRM for Verlengd InterRegio Materieel or SGM for Stadsgewestelijk Materieel.
Why is the ICM called Koploper?
Because you could walk through the front on this train. The cab sits on a raised level, and below or beside it a gangway led into the coupled neighbouring unit. Passengers could therefore walk through the whole train formation without having to get off – in Dutch usage this became the name Koploper.
What's the difference between ICM-III and ICM-IV?
The number states the number of car sections: the ICM-III is three-car, the ICM-IV four-car. Basic concept, front and technology are the same. In service, several units are coupled together, so the overall train length results from the combination – the NS uses the same system for other vehicle families too.
Can I see the ICM in Germany?
No, not in regular service. The ICM is designed for 1.5 kV DC, while the German network runs on 15 kV AC. Cross-border services therefore run with multi-system vehicles or diesel railcars. Anyone wanting to see the Koploper travels to the Netherlands.
Are the front gangways still in use?
The walk-through front gangways were taken out of use in the course of modernisations. The characteristic shape of the front section, however, was kept and still makes the vehicle unmistakable today. Whether the unit in front of you still shows traces of the gangway technology is best seen right at the coupling level.
How do I tell the ICM apart from a Sprinter?
By purpose and shape. Sprinter vehicles such as the SLT and SNG are local-service trains with many doors, a low entry and a plain, flat front. The ICM has the noticeably taller, rounded front section with a raised cab and is designed as an intercity vehicle for longer runs.
Is the ICM still running to schedule?
Scope of deployment and fleet numbers keep changing, because newer vehicle generations are arriving and older units are being withdrawn. Don't rely on older lists – check the current status via real-time data and community sightings before planning a trip.
How do I tell exactly which unit is standing in front of me?
By the unit number, marked on the front and side sections. Together with the full UIC number, it's the unambiguous identifier. The country code 84 confirms the vehicle is registered in the Netherlands – a quick check if you're unsure about its origin.
Log your sighting of the NS ICM (Koploper)
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
NS VIRM
The VIRM is the double-deck workhorse of Dutch rail traffic. Its abbreviation stands for Verlengd InterRegio Materieel – extended InterRegio stock.
EMUNS SLT (Sprinter Lighttrain)
The SLT is one of the multiple units that defines Dutch regional services. Its abbreviation stands for Sprinter Lighttrain, and the number gives the count of car sets.
High-speedNS ICNG (Intercity Nieuwe Generatie)
The ICNG is the NS's Intercity Nieuwe Generatie – an Alstom Coradia Stream for 200 km/h. Here's how to read the abbreviation and recognise the multiple unit.
EMUNS SNG (Sprinter Nieuwe Generatie)
The SNG is the newest Sprinter generation at NS. Its abbreviation stands for Sprinter Nieuwe Generatie, and technically it's built on CAF's Civity platform.
EMURET Alstom Citadis (Rotterdam)
The Citadis is Alstom's low-floor tram platform. In Rotterdam it runs for RET – and follows different rules from any railway vehicle.
EMUConnexxion Protos
The Protos is a rare small-series multiple unit that ran for Connexxion on the Valleilijn. Here's how to place it and how to document it.
Who is behind it
Groups, brands, manufacturers and operators – who owns whom and how to recognise them out in the field.
Museum Buurt Spoorweg
The Museum Buurt Spoorweg runs between Haaksbergen and Boekelo in the Dutch region of Twente. It's considered the oldest heritage railway in the country – and shows a phenomenon that surprises many: Dutch heritage tracks are mostly worked by German steam locomotives.
Heritage railwayMuseumstoomtram Hoorn-Medemblik
The Museumstoomtram between Hoorn and Medemblik isn't a heritage railway in the usual sense, but a preserved steam tramway. You can tell at a glance: the locomotives' running gear is skirted, because these vehicles once ran through streets and villages.
State railwayNederlandse Spoorwegen (NS)
The Nederlandse Spoorwegen run the core network of the Netherlands, but by no means everything moving on Dutch rails. Freight, regional lines and infrastructure sit with other companies – and the yellow livery only tells you which part you're looking at.
Where to see the NS ICM (Koploper)
Specific viewpoints with lighting times, coordinates and an honest verdict on whether the trip is worth it.
Amsterdam Centraal
Amsterdam Centraal stands on three artificial islands in the IJ, has one of the best-known station façades in Europe, and channels all of the Netherlands' international traffic. For spotters it's also the country's most difficult major station – because of the crowds.
Junction stationUtrecht Centraal
Utrecht Centraal is the point where the Dutch network comes together. Over twenty platform tracks, a pattern that repeats exactly every thirty minutes, and a concourse that swallows more light than it looks like it would. Once you've understood the rhythm, you can work here extremely efficiently.
Related guides from the blog
