Key takeaways
- HGe is a description, not a number: H for rack, G for narrow gauge, e for electric.
- 4/4 means full drive: all four axles of the locomotive work, with no purely carrying axles.
- Mixed drive is the special feature – the locomotive runs on adhesion on level ground and the rack engages on steep sections.
- The route reveals the vehicle type: wherever a rack rail lies in the track, rack vehicles are certain to run.
- Operators and areas of use change with timetables and vehicle procurement – check the current status.
Contents
Fact file
| Vehicle type | Electric narrow-gauge locomotive with rack-and-adhesion drive |
|---|---|
| Designation H | Rack drive |
| Designation G | Narrow-gauge vehicle |
| Designation e | Electric drive |
| Axle ratio 4/4 | all four axles are driven |
| Track gauge | Metre gauge (1,000 mm) |
| Typical operators | among others Matterhorn Gotthard Bahn and Zentralbahn – assignments change |
Identifying features
Is this really the class in front of you?
- Noticeably narrower gauge than standard-gauge vehicles – the locomotive looks tall and slender
- Rack rail down the centre of the track on the steep sections of the route worked
- Extra toothed wheel between the running wheels, often visible only from a low angle
- Four axles, all driven – no carrying axles running along
- Pantograph on the roof, usually of compact build for tight tunnel clearances
- Designation begins with HGe, not with Re, Ae or Ee
Updated: August 2026 – Three letters, one fraction – and the vehicle description is complete. The HGe 4/4 is an electric narrow-gauge locomotive with rack drive, at home in Switzerland’s mountain network. This page shows how to read the designation, what mixed rack-and-adhesion operation means in practice, and how to recognise such vehicles in the field.
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What is the HGe 4/4?
The HGe 4/4 is an electric locomotive for metre-gauge railways with rack drive, on which all four axles are driven. It’s thus a specialist vehicle for mountain routes with gradients that can no longer be handled safely by pure friction between wheel and rail.
The special feature is the mixed drive: on flat and moderately inclined sections, the locomotive runs like any other vehicle, on adhesion. Only where the route becomes steep does an additional toothed wheel engage a rack rail laid between the running rails. That way, not the whole route needs to be fitted with a rack – a compromise widely used in the Swiss mountain network.
Operationally, HGe locomotives are found among others around the Matterhorn Gotthard Bahn and the Zentralbahn. Which machine runs on which route is, however, not fixed and changes with timetables and vehicle procurement.
HGe decoded: every letter a statement
Swiss vehicle designations are built like a kit. Once you know the components, you can read any designation in the country – even one you’re seeing for the first time.
H – rack drive
The H at the front marks vehicles with rack drive. See it, and you know at once: this route has steep sections with a rack rail.
G – narrow gauge
The G marks a narrow-gauge vehicle. In Switzerland, that usually means metre gauge – 1,000 millimetres rather than the 1,435 millimetres of standard gauge.
e – electric
The lower-case letter describes the drive type. An e stands for electric, an m for a combustion engine. If it's missing entirely, it's a steam locomotive.
4/4 – the axle ratio
Numerator equals driven axles, denominator equals total axles. 4/4 means all four axles are driving axles. With 3/5, it would be three out of five.
For comparison: an ABeh 8/12 “Orion” is built on the same principle, except that it’s a multiple unit with passenger compartments rather than a locomotive. And the standard-gauge express locomotive Re 4/4 I shows what the same logic looks like without the rack and narrow-gauge marking. How to break down such systems in general is described in the guide to identifying locomotive classes.
Rack or adhesion: what you see in the track
At mountain railways, the fastest route to the right identification runs not via the vehicle, but via the route. The track reveals what can even run there. Metre-gauge networks without a rack, such as that of the Rhaetian Railway, handle their gradients purely by adhesion instead.
| Observation in the track | What follows | Typical vehicles |
|---|---|---|
| Two rails, nothing in between | pure adhesion operation | ordinary locomotives and multiple units |
| Rack rail only on steep sections | mixed operation | vehicles with H in the designation, such as HGe |
| Rack rail throughout | pure rack railway | specialist vehicles, often with their own fleet of coaches |
| Narrow gauge, tight radii | metre-gauge network | vehicles with G in the designation |
| Third rail or conductor rail | separate railway system | vehicles outside the classic scheme |
Route first, vehicle second
If you're standing at an unfamiliar route, look at the track first. Gauge and rack narrow down the possible vehicles so much that the rest of the identification almost takes care of itself.
Do you know what's running right now?
Community sightings show you which vehicles have most recently been reported on your route of choice.
Observing and photographing mountain routes
Different photographic rules apply on metre-gauge mountain railways than on a high-speed line. The trains are slow, the backdrop is half the picture, and access is often the hardest part. How much the backdrop matters is shown by the Landwasser Viaduct at Filisur. How such mountain routes came about is shown a few kilometres further on by the Bahnmuseum Albula in Bergün.
From above rather than below
Public footpaths above the route give a view of both train and landscape at once. From below, the train often disappears behind embankment and vegetation.
Make the gradient visible
A rack section only looks steep if there's a horizontal in the frame. Include houses, poles or the horizon – otherwise the gradient looks like nothing at all.
Plan for a longer focal length
Because you're keeping your distance and the vehicles are small, you need more focal length than in the lowlands. Slow trains make that technically easy.
Strictly avoid the track area
Tracks, rack sections, tunnel portals and operational installations are off-limits. In the mountains, there's the added issue that escape routes are missing – there's no grey area here.
Which focal length is realistic for this is covered by the guide to the best telephoto lens for railway photography. And if you want to know what’s currently running on a Swiss route, the guide to live-tracking trains in Switzerland helps.
Why rack railways are a chapter of their own
Friction has a limit. On a normal railway route, tractive effort is transmitted solely through the contact between steel wheel and steel rail, and that contact is small – roughly palm-sized per wheel on a heavy vehicle. It’s exactly this low friction that makes the railway so energy-efficient, and exactly this that becomes a problem on gradients.
Past a certain incline, an adhesion vehicle spins before it gets the train moving – and worse, it can no longer brake safely downhill. How far that limit can be pushed is shown by the Bernina Railway, which reaches its valley end at Tirano without any rack at all. The rack solves both problems at once. The toothed wheel engages positively, transmitting force not through friction but through the tooth flanks. That’s why the rack drive matters just as much going downhill as going uphill.
The price is effort: racks have to be laid, maintained and kept clear in winter, the vehicles need extra gearboxes and brakes, and entering and leaving the rack section only happens at low speed. The mixed operation the HGe 4/4 was built for limits that effort to the sections where it’s really needed. Other metre-gauge routes avoid it entirely: the Albula Railway at Bergün gains its height purely through spiral tunnels and adhesion.
The moment photographers wait for
At the transition between the adhesion and rack sections, the train slows noticeably. Whoever finds a publicly accessible spot within sight of such a point gets slow-moving vehicles and well-plannable compositions – a rare luxury in railway photography.
Common mix-ups
It suggests an HGe 4/4 when …
- the vehicle runs on metre gauge and carries a pantograph
- a rack rail lies in sections of the track
- it's a locomotive with no passenger compartment
- you count four axles, all driven
Look more closely when …
- the vehicle has windows for passengers – then it's a railcar, not a locomotive
- you can't see the rack because the section runs level
- two production batches stand side by side and you can't read the Roman numeral
It isn't an HGe 4/4 when …
- the vehicle stands on standard gauge
- the designation begins with Re, Ae, Ee or Am
- passengers get on and off – then you're looking for a multiple unit such as the Komet or Orion
The obvious neighbours in the metre-gauge network are the rack multiple unit ABDeh 4/8 “Komet” and the Gornergrat multiple unit Bhe 4/8 – both named under the same letter system, but with passenger compartments rather than a pure locomotive body.
Verdict
The HGe 4/4 is a textbook example of why the Swiss designation system pays off: three letters and a fraction tell you drive type, gauge, route profile and axle count, without ever having to look up a single list. In the field, the fastest route runs via the track: wherever a rack rail lies, rack vehicles run, and the rest follows from the markings on the vehicle.
Verdict in brief
H for rack, G for narrow gauge, e for electric, 4/4 for full drive: that's the HGe 4/4. A mountain vehicle you recognise faster from the route than from the vehicle itself – and whose areas of use shift with the timetable years.
Build your mountain-railway collection
Rack, metre gauge, special builds: Traintrack keeps you on top of things beyond the standard-gauge network too.
Summary
- The HGe 4/4 represents the Swiss speciality of mixed rack-and-adhesion railways in the metre-gauge network.
- Anyone who masters the letter system recognises rack vehicles from the designation before even seeing the drive.
- The Roman numeral after the fraction distinguishes successive production batches of the same basic type.
- Photographically, the class lives on its setting: gradient, spiral tunnels and mountain backdrop make the picture, not the locomotive alone.
Frequently asked questions
What does the designation HGe 4/4 mean?
It's made up of three statements: H stands for rack drive, G for a narrow-gauge vehicle and the lower-case e for electric drive. The fraction 4/4 means all four axles are driven. Put together, that gives: an electric narrow-gauge locomotive with rack drive and full drive on all axles.
What is mixed rack-and-adhesion operation?
On flat sections, the locomotive runs like any ordinary locomotive, via the friction between wheel and rail. On steep sections, an additional toothed wheel also engages a rack rail laid down the centre of the track. That makes it possible to handle gradients too steep for pure adhesion operation, without having to fit the whole route with a rack.
How do I recognise a rack railway?
By the rack rail between the running rails. It starts and ends at marked transition points and runs continuously on steep sections. Wherever it lies, vehicles with rack drive are certain to run – a very reliable clue to the vehicle type, even before anything actually arrives.
What does the Roman numeral in HGe 4/4 II mean?
It distinguishes successive production batches of the same basic type. An HGe 4/4 II is the second generation of the HGe 4/4 family, technically modernised compared with the first batch but comparable in basic principle. You find the same principle on standard-gauge locomotives such as the Re 4/4 II.
Where do HGe locomotives run?
On metre-gauge mountain railways, among others around the Matterhorn Gotthard Bahn and the Zentralbahn. Which vehicles run on which route shifts, however, with timetable years, new procurements and rebuilds. Current assignments are best checked via live data and community sightings.
What's the difference between HGe and Re?
Everything except the electric drive. Re denotes a standard-gauge adhesion locomotive with a higher permitted curve speed, HGe a narrow-gauge locomotive with rack drive. They run on different networks, aren't interchangeable, and meet at most at interchange stations serving both gauges.
Why are narrow-gauge locomotives so slender and tall?
Because the one-metre gauge limits the vehicle's cross-section. At the same overall height, a metre-gauge vehicle therefore looks considerably more slender than a standard-gauge locomotive. On top of that, tight tunnel and curve radii in the mountains force compact bodies and short vehicle lengths.
What's the best way to photograph vehicles on mountain routes?
With distance, and with the mountain in the frame. Metre-gauge railways run slowly, which allows longer focal lengths and careful composition. Look for publicly accessible footpaths or viewpoints above the route – track areas, tunnel portals and operational installations aren't a photo spot.
Log your sighting of the HGe 4/4
Date, location and vehicle number logged in seconds – and visible to the community.
Related classes
MGB ABeh 8/12 (Orion)
ABeh 8/12 means: first and second class, electric, rack drive, eight of twelve axles powered. Here's how to read the designation of the Stadler-built Orion.
EMUMGB ABDeh 4/8 (Komet)
ABDeh 4/8 means: first and second class, luggage compartment, rack drive, electric, four of eight axles powered. Here's how to read the Komet's designation.
EMUBhe 4/8
Bhe 4/8 means: second class, rack-and-pinion drive, electric, four of eight axles powered. Here's how to read the Swiss designation and spot the unit in the field.
Electric locoSBB Re 465 (BLS)
The Re 465 is the BLS variant of the Lok 2000 family and is easily mistaken for the Re 460. This page shows you how to tell the two apart with confidence.
Electric locoSBB Re 474 (Vectron CH)
The Re 474 is a four-axle multi-system freight locomotive for the Switzerland–Italy corridor. This page explains electrification systems, naming and recognition features.
Electric locoRe 4/4I
The Re 4/4 I was the first series of the Swiss Re 4/4 family: a light four-axle express engine. Today you mostly meet it at private railways and heritage societies.
Who is behind it
Groups, brands, manufacturers and operators – who owns whom and how to recognise them out in the field.
Bahnmuseum Albula
The Bahnmuseum Albula in Bergün is an exception among heritage railways: it owns no line of its own and runs no trains of its own. The attraction is outside – the metre-gauge Albula line of the Rhaetian Railway runs past the building to a regular timetable, UNESCO World Heritage status included.
Heritage railwayMuseumsbahn Blonay–Chamby
The Blonay–Chamby museum railway links two active metre-gauge networks over the slopes above Lake Geneva across just a few kilometres. The association runs steam and electric traction on its own line – and alongside that maintains one of the most extensive collections of historic narrow-gauge vehicles in Switzerland.
GroupRhätische Bahn (RhB)
The Rhaetian Railway is one of the few railways in Europe where network, operations and brand sit in a single hand. It combines several originally independent lines, runs on metre gauge with no rack, and operates two completely different electrification systems on the same network.
Where to see the HGe 4/4
Specific viewpoints with lighting times, coordinates and an honest verdict on whether the trip is worth it.
Albula line near Bergün
Between Bergün and Preda, the metre-gauge Albula line climbs over 400 metres – with spiral tunnels, loops and viaducts packed into a tight space. A railway trail runs right through the middle, and in winter the closed pass road becomes a sledging run.
Photo spotLandwasser Viaduct near Filisur
A curved limestone viaduct that leads, without warning, into a rock tunnel 65 metres up: the Landwasser Viaduct on the Rhaetian Railway is Switzerland's best-known railway subject. An official platform makes it one of the few Alpine subjects that even beginners can get right.
Narrow gaugeTirano and the Bernina Railway
Two stations stand side by side in Tirano: the Italian standard-gauge station and the terminus of the Swiss Bernina Railway. Between them the metre-gauge line runs street-level through town – no rack system, but full UNESCO World Heritage status.
Related guides from the blog
