European Railroad Discussion > The third-rail electric way across the mountains (Part 1)

With apologies to the late Richard Steinheimer for adapting the title to his fine book about the electrified Milwaukee Road route across the mountain ranges of the northwestern United States.

Electrification of mountain railways is not unusual in Europe, but delivering the electric current via a third rail is rare outside of urban settings, with overhead power supply being the norm.

One of the exceptions – and the only one to cross an international border --  is the 58-km metre-gauge route between Martigny, Switzerland, and St. Gervais-Le Fayet in France, which is operated jointly by the Swiss regional operator Transports de Martigny et Régions (TMR) and SNCF Voyageurs, the passenger rail arm of the French national railway.  TMR runs the trains between  Martigny and Vallorcine in France, the first station across the Swiss-French border, a distance of 21 km.  SNCF’s regional  Auvergne-Rhône-Alpes operation handles the trains from Vallorcine to St. Gervais-Le Fayet.

The full route opened in 1908, when a short connection across the border was completed.  It was wholly third-rail at that point, the system having been chosen for the French section from St. Gervais to Chamonix that opened in 1901, one year before work started on the Swiss section.

But now,  on the Swiss side, a long-term conversion to overhead supply is under way, and I wanted to see the third-rail system while it’s still in operation there.  So I made it a priority to visit during my  vacation last year,  and spent  September 24-25 riding and photographing trains between Martigny and Chamonix-Mont Blanc.

Services are branded as Mont-Blanc Express, although there is nothing  express about it, with trains taking 51 minutes southbound and 56 northbound for the 21 km between Martigny and Vallorcine, where through passengers have to transfer.  Trains between Vallorcine and St. Gervais-Le Fayet are scheduled at 90 minutes southbound  and 93 northbound.

 I’ve read of trains running the whole distance in the past, but there are no through runs in the current timetable. The transfer time at Vallorcine is five minutes southbound and 12 minutes northbound.  In general, the co-ordinated services covering both sections run hourly on a clockface timetable.

Now, on with the show.

(1) TMR BDeh 4/8 set 21 is seen at the Martigny terminus.  This is one of five sets delivered in 1997, with three owned by SNCF (numbered  1 to 3, classified as Z800) and two by TMR (21-22). These can operate anywhere along the whole route, being equipped for both third-rail in either country and for catenary current collection and rack operation in Switzerland.

On any given day, units of this type owned by either operator can be used strictly on the SNCF section between St. Gervais and Vallorcine or the TMR-operated section from Vallorcine to Martigny.  But their days are numbered, as I’ll show in Part 2.

(2) The flat 4-km section between Martigny and Vernayaz uses overhead catenary. But at the south end of the station, beneath a road overpass, the transition is made to both third-rail supply and a Strub rack system, as this marks the start of a 3.4-km climb up a ruling gradient of 20%.

(3) In the transition zone, the rare combination of third-rail power supply, metre-gauge track and a rack system can be seen up close from the property of a neighbouring tourist attraction, the Gorges du Trient.  That was worth the price of admission in itself, but the unexpected rail photo opportunities were a bonus.


   
 



Edited 3 time(s). Last edit at 07/07/26 06:43 by railsmith.

---

---

---

(4) From the same spot  as in photo 3, TMR set 21 is seen emerging from the north portal of the 83-metre Buvette tunnel, en route to Martigny.  The catenary is already in place here. 

(5) Riding the 20% grade beyond the tunnel  opens up vistas of the broad Rhône valley, which stretches all the way west to the east end of Lake Geneva.  The town of Vernayaz is directly below.  In the centre of the photo, an SBB train on a service between Brig and Geneva can be seen at the standard-gauge mainline station.

(6) The view from a train on the valley floor captures a sign promoting the Mont-Blanc Express alongside the 20% grade, a graphic illustration of why a rack is needed.  No such double-digit  grade exists in French territory, but there is a 9% grade near the southern end of the route, one of the steepest anywhere to be operated purely by adhesion.
 



Edited 4 time(s). Last edit at 07/07/26 08:58 by railsmith.

---

---

---

(7) The rack section just before Salvan (7.4 km from Martigny), the largest town between Vernayaz and the French border.  It sits at an elevation of  934 metres after the climb from the base at 457 metres.  We’re now in the valley of the Trient river, flanked by steep slopes.

(8) Nearing Les Marécottes at 8.9 km, the line has been fully converted to overhead supply.  From my observations, it seems that priority has been given to converting the line where it passes through stations, with an obvious safety benefit for passengers.
  
(9) A few hamlets dot the slopes, this one being Le Trétien, served by a request stop some 10.5 km from Martigny, which is half-an-hour away by train.  The elevation is now 1059 metres.

About midway between the houses and the upper right corner, a concrete snowshed can be glimpsed, giving an indicating of the course of the right-of-way. The view is looking southward.

Also of note is the substantial electricity transmission line to the left of the houses. This carries power generated at a facility directly beside Le Châtelard VS station, operated by the Swiss federal railway (SBB CFF FFS) to power its substantially electrified network.  SBB produces 90% of its power requirements and I’ll cover the Le Châtelard  operation in a later post.


 



Edited 4 time(s). Last edit at 07/07/26 08:57 by railsmith.

---

---

---

(10)  At the 11.5-km mark, both third-rail and catenary infrastructure are in place. This view was only possible because the driver had the cab door open briefly. 

(11)  The third rail has been removed from this stone-arched viaduct (Viaduc des Torrents) just south of Finhaut station (14 km). The view is to the north.

(12)  The last station in Switzerland before the border crossing is Le Châtelard-Frontière (18.1 km), with catenary in place.
 



Edited 2 time(s). Last edit at 07/07/26 06:42 by railsmith.

---

---

---

(13) The SNCF station in Vallorcine presents a contrast.  We’re now in France and this is strictly third-rail territory. That rail is very close to the passenger on the platform, albeit protected by a shield. This is where passenger transfers take place and trains turn around, in less than 10 minutes.  The train at left will run from here to St. Gervais-Le Fayet, timed at 90 minutes. The train at right will return to Martigny.

These sets are cousins, built by Stadler.  SNCF 56 at left is one of six (51-56), delivered from 2006 to 2008, and classified Z850. The Swiss-owned set at right is TMR 72 and was delivered with sister 71 in 2009 (Z870 in the French classification).  But the SNCF type is not equipped for rack operation (although they do have pantographs) and thus is restricted to France, whereas the two TMR units could run the full distance.

(14) A detailed view of the third-rail at Vallorcine.  The trains use top-contact collector shoes.

(15) A substantial concrete snowshed protects the track just north of Argentière, about midway between Vallorcine and Chamonix.



 

---

---

---

(16) At the major station of Chamonix-Mont Blanc, on this day Swiss-owned TMR set 21 is working the Vallorcine-St. Gervais service, all in France.  It will dwell here for five minutes.

As at Vallorcine, walking between platforms involves a paved foot crossing over the tracks, which I’m standing on for this view.  As a child, I lived in Southern Electric territory in Britain and have been used to third-rail trains since my earliest memories (our house bordered the Brighton mainline), but have never felt so close to live power rails as I did on this day.

(17)  The view as seen from the foot crossing, looking south.  
 
(18)  The dangers posed by 800 volts DC are elaborated in this adjacent warning sign, which reads:  “800V electrified track. Do not throw anything away.  Do not leave anything lying around or drop anything.  Do not stand on the third rail or on the safety barriers.”


 



Edited 1 time(s). Last edit at 07/07/26 02:16 by railsmith.

---

---

---

(19)  Another sign emphasizes the message in four languages, with a threatening graphic that should be understood by anyone.  It notes the electric supply as being 850 volts but most of the written sources I’ve consulted put it at 800.

(20)  As befits a world-renowned skiing resort, Chamonix boasts an impressive station that fronts a main street.

(21)  At the mid-point of its journey, TMR 21 departs Chamonix  for St. Gervais-Le Fayet, 45 minutes away.

I’ll continue the story with a post tomorrow, looking at the change in rolling stock which began two weeks ago. If you've liked this, stay tuned.
 



Edited 1 time(s). Last edit at 07/07/26 05:53 by railsmith.

---

---

---

Thanks for the pictures and the detailed information.  I look forward to your next post.  I'll be there two weeks from today.  Gerry

when, how do they work on the track?

dan Wrote:
-------------------------------------------------------
> when, how do they work on the track?

Presumably, as with other European operators with busy schedules, a lot of work is done at night and using non-electric vehicles so the juice can be shut off.

TMR has two cars like the one shown here, converted from passenger units, to power work trains. It's classified as Xemh: X = work use, em = electric and diesel powered, h = rack-equipped.  It can run off its diesel engine.



Edited 1 time(s). Last edit at 07/07/26 07:15 by railsmith.

---

Great report!  

thanks railsmith ! for taking us with