Key takeaways
- SA135, SA136 and SA139 are diesel railcars in Polish regional service.
- Two manufacturers in one number block: the SA class tells you nothing about the builder – Newag and PESA share this range.
- The designation stays readable: S for diesel, A for railbus, digits for the class.
- Certain identification needs the markings – the shape alone doesn't reliably separate the classes.
- Operating areas shift with service contracts and regional procurements.
Contents
Fact file
| Vehicle type | Diesel railcar for regional services |
|---|---|
| Manufacturer | Newag (Nowy Sącz) and PESA (Bydgoszcz) |
| Designation | S = diesel traction, A = railbus, digits = class number |
| Traction | Diesel engines – operation independent of overhead line |
| Operating area | Non-electrified regional and branch lines in Poland |
| Special feature | One number block, two manufacturers – the class doesn't reveal the builder |
Identifying features
Is this really the class in front of you?
- No pantograph – a diesel vehicle with cooling equipment on the roof
- Compact railcar with few car sections
- Markings starting with SA and the class number
- Manufacturer's logo or builder's plate as an extra clue to Newag or PESA
- Operates on lines with no overhead line – a strong contextual clue
Updated: August 2026 – Three class numbers, two manufacturers, one vehicle type: the Polish diesel railcars SA135, SA136 and SA139 are a good example of why you should keep class and builder cleanly separate when identifying vehicles. This page shows what the designation reveals, what it doesn’t, and how to reach a solid sighting anyway.
Log class and manufacturer separately
For this vehicle group, the number says nothing about the builder – record both individually.
What are SA135, SA136 and SA139?
These are diesel railcars for Polish regional services on non-electrified lines. They belong to the modern generation that moved branch-line services in Poland on from ageing vehicles and short loco-hauled trains to dedicated railcars.
What sets this group apart isn’t the technology, but the attribution: this number range includes vehicles from Newag of Nowy Sącz and from PESA of Bydgoszcz. The SA number thus describes the vehicle type and class, not the builder. Anyone trying to deduce the manufacturer from the number alone will inevitably get it wrong here sooner or later.
What the designation says – and what it doesn’t
The system of Polskie Koleje Państwowe is built functionally. It describes what a vehicle does, not who built it.
| Level | Encoded in the designation? | Where do you find it? |
|---|---|---|
| Traction type (diesel/electric) | yes – first letter | S or E at the start of the code |
| Purpose | yes – second letter | A, N, U, T, P or M |
| Class number | yes – number block | e.g. 135, 136, 139 |
| Manufacturer | no | builder’s plate, manufacturer’s logo, vehicle list |
| Individual vehicle | partly | running number and UIC vehicle number |
As a reminder, here’s the letter logic in overview: E stands for electric traction, S for diesel. The second letter names the purpose – U universal, T freight, P passenger, M shunting, N railcar, plus A for the railbus. That turns abstract codes into readable statements: EU07 is an electric universal locomotive, ET22 an electric freight locomotive, SM42 a diesel shunting locomotive and SA139, well, a diesel railcar.
The Europe-wide unique identity, on the other hand, comes from the twelve-digit UIC vehicle number with the country code 51 for Poland. How this number is built is explained in the article on the UIC number and its check digit.
How to go about identification
Determine the vehicle type
No pantograph, no overhead line above the track: that settles it as a diesel vehicle.
Narrow down the category
Railcar or loco-hauled train? A railcar has the driving cab and passenger space in a single unit, with no separate machine at the front.
Read the class
The SA designation with running number sits on the side wall. Photograph it – for this group it's the decisive piece of evidence.
Check the manufacturer separately
A builder's plate or manufacturer's logo tells you whether it's Newag or PESA behind it. This information doesn't follow from the class number.
Practical tip: two fields instead of one
Keep separate fields for class and manufacturer in your logbook. For vehicle groups like this one, that saves the usability of your collection – afterwards, the builder often can no longer be reconstructed from an old entry.
Structured sightings instead of relying on memory
Class, number, manufacturer and location in a single entry – so the collection stays usable even years later.
Fitting it into operations
Diesel railcars are the backbone of services on lines without overhead line. They run where electrification was never economical, and enable tighter intervals than a loco-hauled train ever could.
In Poland, this category sits alongside two other worlds: the electric multiple units for the electrified network – such as the Newag Impuls – and diesel locomotives for heavier tasks. Within the diesel railcars, in turn, the SA132 to SA134 and the railcar marketed as the PESA LINK form their close relatives.
For spotters, the practical consequence is simple: if you want to see these vehicles, you have to seek out the non-electrified lines. At major, fully electrified hubs they’re the exception.
Why the effort pays off
Branch-line vehicles are structurally underrepresented in photo archives. There’s a simple reason: they run where few people travel, in small numbers, with few services per day. Spend a weekend on a branch line and you might end up with three or four usable shots – while thirty trains pass through a major station in the same time.
That’s exactly what makes such sightings valuable. They’re harder to get, they show vehicles that rarely appear in collections, and they document a type of service that’s particularly prone to change. Line closures, new service contracts and vehicle swaps hit branch lines noticeably faster than main lines.
A second point concerns planning: on branch lines, the timetable is your most important tool. Unlike at a hub station, where you can simply turn up and wait, here the right arrival time decides between success and an empty visit. Crossing stations are particularly rewarding, because two vehicles stand there at once – often the only realistic chance to get two different units in one shot.
Photo tips and safety on branch lines
| Situation | Chance | What to watch for |
|---|---|---|
| Terminus of a branch line | high | Long dwell time, clear view, no tangle of overhead line |
| Small rural station with a crossing | high | Two vehicles in one shot possible |
| Public path alongside the line | medium | Only outside the track area, keep your distance |
| Major electrified hub | low | Mostly electric vehicles run there |
| Operational facilities, stabling sidings, workshops | none | Operational railway land – no access, no shot |
Even on quiet lines, tracks are off limits
The fact that only a few trains run on a branch line changes nothing about the rules. Track areas, level crossings as a vantage point and operational facilities aren't a photo spot. Stay on publicly accessible paths and behind the platform edge.
How to turn your observations into a system that still holds up after years is shown in the guide to a sighting logbook. And if you want to learn how to identify unfamiliar vehicles methodically, the guide to identifying classes helps.
Common mix-ups
It points to these SA classes if …
- there's no pantograph present
- the line has no overhead line
- it's a railcar with no locomotive coupled ahead
- the markings read SA135, SA136 or SA139
Take a closer look if …
- you couldn't read the class number in full
- you're trying to deduce the manufacturer from the shape – that doesn't work here
- several units are running coupled together
They aren't SA railcars if …
- a pantograph sits on the roof
- the designation starts with SM, ST or SU – those are diesel locomotives
- a locomotive is hauling carriages rather than a railcar running under its own power
Verdict
This vehicle group teaches a rule that applies far beyond Poland: class designation and manufacturer are two separate pieces of information, and a naming system that describes the function simply cannot also deliver the builder. Record both separately, and you build an archive that’s genuinely usable later – avoiding the most common attribution error with modern regional vehicles.
In short
SA means diesel railcar, the digits name the class – the manufacturer is a separate matter. Photograph the markings, check the builder separately, and the sighting checks out.
Document Polish branch lines
Class, number, manufacturer, line and date in one place – so individual finds become a real collection.
Summary
- The SA135, SA136 and SA139 classes belong to the modern generation of Polish diesel railcars for branch lines.
- Notably, this number block contains vehicles from two manufacturers – a detail that trips up many identification attempts.
- A solid sighting needs the full markings including the running number.
- Where the vehicles run depends on service contracts and changes over the years.
Frequently asked questions
What are SA135, SA136 and SA139?
They are diesel railcars for Polish regional services on non-electrified lines. They belong to the modern generation that renewed branch-line services in Poland. Unlike many other class groups, the vehicles in this number block don't all come from the same manufacturer.
Who builds these railcars?
Polish rolling-stock manufacturers – specifically Newag, based in Nowy Sącz, and PESA in Bydgoszcz. Both manufacturers are represented in this number range. The SA number alone therefore doesn't tell you the builder; for that you need the builder's plate or the manufacturer's marking on the vehicle.
What does the code SA stand for?
Diesel traction and railbus. In the PKP system, the first letter names the traction type – S for diesel, E for electric – and the second the purpose. Alongside A for the railbus, there's U for universal, T for freight, P for passenger, M for shunting and N for railcar.
How do I tell the classes apart in the field?
Via the full markings on the side wall. The classes are similar to one another in size and basic concept, which is why silhouette comparisons quickly go wrong. A tight photo of the markings is practically essential for this vehicle group if the sighting is to hold up.
Do these railcars run to Germany?
Not in scheduled service. They're procured for Polish regional services. From Polish railcar manufacturing, German railfans are most likely to encounter the PESA LINK domestically, which runs here as Class 633. For the SA classes, the route leads onto Polish branch lines.
How do I reliably recognise a diesel vehicle?
By the missing pantograph and the radiator and exhaust equipment on the roof. The second, often even quicker way is to look at the line: where no overhead line is strung, no purely electric vehicle can run – which settles the vehicle type before you've even checked the first detail.
Why does Poland assign class numbers across manufacturer boundaries?
Because the system describes the function, not the builder. Traction type and purpose sit in the code, and the digits are a running class number. That's consistent from an operational standpoint – but for spotters it means manufacturer and class have to be recorded separately.
What belongs in a good sighting of these classes?
Class designation, running number, date, location, operator and, if identifiable, the manufacturer. That last point in particular is the interesting extra piece of information for this group, because it can't be derived from the number and is barely reconstructable afterwards.
Log your sighting of the PKP SA135 / SA136 / SA139
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
PKP SA132 / SA133 / SA134
SA132, SA133 and SA134 are Polish diesel railcars from PESA's range. This page explains the SA designation system and how to identify them in the field.
DMUPESA LINK
The PESA LINK is a low-floor diesel railcar from Poland – and one of the few Polish railcars that also run in regular service in Germany.
EMUNewag Impuls (EN76 / EN96)
The Impuls is Newag's electric multiple-unit family from Nowy Sącz. Its product name and PKP class codes such as EN76 or EN96 describe two different levels.
Who is behind it
Groups, brands, manufacturers and operators – who owns whom and how to recognise them out in the field.
PESA Bydgoszcz
PESA Bydgoszcz grew out of a railway workshop and is today Poland's best-known rolling-stock builder. Elf, Link, Dart and the tram families shape the picture across the whole country – and with Class 633, a PESA railcar even appears on German vehicle lists.
State railwayPolskie Koleje Państwowe (PKP)
Polish locomotive designations are the most clear-cut numbering system in Central Europe: two letters tell you the traction and purpose before you've even read the number. The group structure behind them is considerably less clear – a lot of what's called PKP no longer belongs to it.
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