CD 242 / 243

Updated: August 2026 – A four-axle electric locomotive with a rounded, conspicuously smooth front, a Czech train in front of it, and a number on the side starting with 242: then you’re looking at one of the Škoda AC locomotives that enthusiasts have called “Laminátka” for decades. This page explains what’s behind the class number, why the same locomotive used to be called S 499.02, and how to identify it reliably in the field.

What are Classes 242 and 243?

Classes 242 and 243 are four-axle electric locomotives from Škoda in Plzeň, designed for the AC system at 25 kV and 50 Hz. They have the wheel arrangement Bo’Bo’ on two two-axle bogies and belong to the classic general-purpose locomotives of the Czech network.

Operationally, that creates a hard boundary: these machines can only run where AC runs through the overhead line – that is, in the south and east of the country. Wherever the line switches over to the DC network, that’s where they stop. That’s exactly why dual-system locomotives such as Classes 362 and 363, which can handle both systems, were developed later.

Why the same locomotive has two designations

Czech vehicle designations can seem confusing to German spotters at first, because many classes are known under two names. The reason is a system changeover.

Before 1988, ČSD vehicles carried designations made up of a letter and a number group. A leading S marked an AC locomotive, a T a diesel locomotive. Class 242 was called S 499.02 in this system.

Since 1988, a purely numeric class system has applied. S 499.02 became Class 242, and the class number has since been lettered on the vehicle together with the running number. Older books, photo archives and forum posts, though, still use the old designation – anyone who knows both finds considerably more material.

Identification in three steps

For a reliable classification you don’t need detailed knowledge of the production series. Three observations are enough, and they work from the platform too.

How to read such numbers systematically, and which digits are actually informative, is explained in the article on the UIC number and its check digit. Anyone who wants a generally structured approach to unfamiliar vehicles will find the right sequence in the guide to identifying classes.

Where the AC locomotives run – and where they don’t

The mixed electrification system is the key to understanding Czech operations. The same applies to freight trains as to passenger trains: ČD Cargo has to break its diagrams at the system boundaries or deploy dual-system machines straight away. The table below shows what that means for your chances of a sighting.

Situation	Chance of a 242 / 243	Reason
AC network in southern and eastern Czechia	high	The matching system runs through the overhead line here
DC network in northern Czechia	very low	The locomotive can’t run there under its own power
System-changeover points inland	medium	Locomotive changes and waiting times make vehicles clearly visible
Border stations towards Germany	very low	Germany runs on 15 kV / 16.7 Hz, which these classes aren’t equipped for
Transfer runs and special workings	unpredictable	It happens, but follows no timetable pattern

Spotting and photo tips

The smooth laminate front is demanding to photograph: it has little texture and reflects in harsh light. Four points help.

• A three-quarter view instead of a front-on shot. An angle of roughly 30 to 45 degrees shows the front and side at the same time and gives the rounded shape some depth.
• Prefer flat light. In the morning and late afternoon, the curves stand out; midday light makes the front look flat.
• Get the number in the frame. Without a legible vehicle number, the sighting stays imprecise – frame the shot so the side lettering is included.
• Work from publicly accessible locations. Platforms, paths and bridges yes, track areas, operational railway land and stabling sidings no.

A simple rule applies to your search strategy: go where the matching electrification system runs. That sounds obvious, but it saves whole days. Anyone waiting in the Czech north for an AC locomotive waits in vain, no matter how much traffic there is. Conversely, on the AC network, even a medium-sized junction station is enough to see several vehicles of this class within a short time. Combine that with dwell times: at stations with locomotive changes, turnaround times or longer stops, you have the calm to read the number properly and take a second, closer shot of the side lettering.

Tracks, operational railway land and shunting areas are never a photo spot – that applies abroad just as much as at home. The basic rules are summed up in the article on safe distance from the track. For research ahead of a trip to Czechia, the guide to Czech sighting and photo-spot sources is worth a look.

Common mix-ups

The most common mix-up happens within the Škoda family itself. The more angular Classes 162 and 163 look similarly proportioned at a quick glance, but belong on the DC network. And anyone who sees a modern, considerably flatter-drawn locomotive has more likely come across the Class 380.

Verdict

Classes 242 and 243 are a good entry point for anyone wanting to learn about Czech vehicles: they explain the country’s electrification system, numbering system and nickname culture all in one vehicle. Anyone who puts together axle count, front shape and the first three digits gets it right almost every time.