Appenzeller Bahnen AG (AB)

Updated: August 2026 – At first glance, “ABeh 8/12” looks like a typo. In fact it’s one of the most information-dense codes in European rolling-stock studies: it reveals classes of accommodation, type of traction, rack capability and the ratio of powered to existing axles. This page introduces the Appenzeller Bahnen AG (AB) and uses it as an example to explain the Swiss designation system, which applies throughout Switzerland.

What are the Appenzeller Bahnen?

The Appenzeller Bahnen AG is a regional railway company in Appenzellerland, in north-eastern Switzerland. The company name follows a common Swiss pattern: a region plus the plural “Bahnen” (railways). The plural is no coincidence – it indicates that several lines have been brought together under one corporate roof.

Like many Swiss railway companies, it’s a public limited company (AG); public shareholdings are the rule in Switzerland and no contradiction of the legal form. For identification in the field, though, that’s secondary. What matters is what’s written on the vehicle – and for that you need the Swiss designation system.

The Swiss designation system: letters and axle fraction

German class numbers are catalogue numbers: you have to look them up. Swiss vehicle designations, on the other hand, are descriptive. They consist of two parts: a group of letters and a fraction.

The fraction gives the powered axles in the numerator and total axles in the denominator. “Re 4/4” means: all four axles are powered. “Ee 3/3” means: three out of three axles powered. “ABeh 8/12” means: eight out of twelve axles powered, the rest are carrying axles.

Character	Meaning	Example
A, B, C, D (locomotive)	Speed class, A the fastest	Re, Be, Ce
A, B, D (coach/railcar)	1st class, 2nd class, luggage	ABeh = both classes
E	Shunting locomotive	Ee 3/3
R	increased speed through curves or special braking equipment	Re 4/4
e	electric traction	Re, Ee, Beh
m	internal combustion engine	Am, Bm
a	accumulator (battery)	Ea
h	rack equipment	HGe, ABeh
g	narrow gauge	Ge, HGe

To work through a real example: ABeh 8/12 is a multiple unit with first and second class (A and B), electric (e), rack-capable (h) and with eight out of twelve powered axles (8/12). You’ll find a vehicle of this design family in the database as the ABeh 8/12 (Orion). The rack electric locomotive HGe 4/4 reads according to the same pattern – rack, narrow gauge, electric, all four axles powered – as does the rack multiple unit Bhe 4/8, with second class and four out of eight axles powered.

Identification in the field: step by step

Context within rail operations

Regional railways in hilly and alpine terrain work under different conditions from lowland lines: sharp curves, steep sections, stops close together. It’s exactly these conditions that are reflected in the vehicle designations – an “h” for rack or a high proportion of powered axles aren’t quirks but technical answers to the topography. Metre-gauge and rack vehicles like these are mostly built by Stadler Rail, which covers much of this segment in Switzerland.

You’ll find similar conditions at other railways in the Alpine and pre-Alpine region, such as the Rhaetian Railway, the Matterhorn Gotthard Bahn or the Zentralbahn. Which vehicles an individual company actually uses changes with procurement and diagrams – the logic of the designations, however, stays the same.

If you want to identify unfamiliar vehicles systematically, you’ll find the general approach in the guide to identifying rolling-stock classes. For shots in narrow valleys with difficult light, it’s also worth looking at the guide How to take good photos of trains.

Exercise: decoding three designations

The system only sticks once you apply it to unfamiliar examples. Three short run-throughs to work along with.

Ee 3/3: The capital letter E stands for a shunting locomotive. The second letter, written in lower case, is an e – electric traction. The fraction 3/3 says: three out of three axles powered, so no carrying axle. Result: a three-axle electric shunting locomotive.

Re 4/4: R stands for increased speed through curves or special braking equipment, e for electric, 4/4 for four out of four powered axles. Result: a four-axle main-line locomotive with full traction – one of the most common designs in Switzerland.

HGe 4/4: H refers to the rack equipment, the G to narrow gauge – depending on the type of vehicle you’ll come across this character in upper or lower case – e stands for electric traction and 4/4 again for full traction. Result: a narrow-gauge rack electric locomotive, a vehicle type that would make no sense without mountains.

With these three examples in your head, you can decode almost any Swiss designation. The rest is practice: fraction first, then the capital letters, then the lower-case letters.

Documenting sightings

Common mix-ups

• Fraction read as a class number – “4/4” isn’t a type number but the axle ratio.
• A and B as speed on railcars – on coaches and railcars they mean classes of accommodation, not speed.
• “e” confused with “electric locomotive” – the lower-case letter only describes the traction; the type of vehicle follows from the capital letters.
• h ignored – the rack “h” is the clearest clue that the line includes steep sections.
• Classic designation played off against the modern number – both often appear side by side on the vehicle and complement each other.

Conclusion

The Appenzeller Bahnen are a regional railway company with several lines – and an ideal practice subject for the most important piece of Swiss explanation there is. If you can read letters and the axle fraction, you’ll understand every Swiss vehicle designation without a reference book.