Steepest adhesion railway


Chris Wood
 

At present, the English language version of Wikipedia's article on the Uetlibergbahn states that it is the steepest standard gauge adhesion only railway in Switzerland. Another editor has suggested that the words 'standard gauge' can be removed from this statement, as there are no steeper adhesion worked railways of any gauge in Switzerland.


A quick search of the literature suggests the Basel tram line 3 is slightly steeper at 7.96% (as against the Uetliberg's 7.9%). But that is, of course, a tramway, which may or may not count. And it might be no more than a rounding difference.


Does anybody know of any other Swiss adhesion railways steeper than the Uetliberg?.


OL.Guerbetal
 

Am 13.06.2016 um 15:31 schrieb chris_j_wood@... [SwissRail]:
A quick search of the literature suggests the Basel tram line 3 is
slightly steeper at 7.96% (as against the Uetliberg's 7.9%). But that
is, of course, a tramway, which may or may not count. And it might be
no more than a rounding difference.

Does anybody know of any other Swiss adhesion railways steeper than
the Uetliberg?.
Ufff, all this hunting for records...

Now the steepest standard gauge railway in Switzerland without rack is the TL M2 in Lausanne with 120�! Sure, they have rubbers...

Then, BVB tram infrastructure has a railway concession, so it counts.

In a few years AB will be at the top of the list with 80� in the new Rieth�sli tunnel in St. Gallen.

Finally, the 79� at the Uetliberg are a geometrical reality. But they don't count for traction and braking questions, because it is a too short bit.

Uncheck the boxes you don't like ... :-)

Markus, G�rbetal


Simon
 

[Top posting and full quote repaired by the moderator]
Basel tram line 3 is essentially flat from one end to the other so I'd be interested to know where the 7.96% came from ? As an aside, the extension of line 3 into France and St Loius railway station is under way. There's a lot of digging going on along the French route and the strengthening of the bridge over the Swiss airport road is now complete. The Swiss side is all but complete with track laid and catenary posts up.


Martin Baumann
 

That 7.96 gradient is on the Kohlenberg hill which is served by lines 15/16 not 3


Chris Wood
 

That 7.96 gradient is on the Kohlenberg hill which is served by lines 15/16 not 3
I stand corrected. I took the reference from this:

Gemäss Eisenbahnverordnung sind bei Neubaustrecken Steigungen bis 4% zulässig, unter
besonderen Bedingungen auch solche bis 7% . In Basel gibt es auf der Linie 3 am Kohlenberg
einen kurzen Abschnitt mit 7,96% Steigung. Dort dürfen nur stark motorisierte Tramzüge verkehren.
which comes from http://www.tram8.info/index.php?id=tramlexikon, which I believe to be the official web site of the project to extend the Basel trams to Weil. Certainly the site has an impressive list of sponsors on its home page, included the Swiss Government, the canton of Basel-Stadt and the BVB, so I took it as being authoritative. You live and learn.


George Raymond
 

That 7.96 gradient is on the Kohlenberg hill which is served by lines
15/16 not 3
The street named Kohlenberg in Basel rises steeply from Barfüsserplatz to Musik-Akademie on line 3. I understand that when a coupled set of three non-articulated trams climb this grade, two of them must be powered.

George


Guerbetaler
 

Am 15.06.2016 um 15:19 schrieb 'George Raymond':
The street named Kohlenberg in Basel rises steeply from
Barfüsserplatz to Musik-Akademie on line 3.
<https://commons.wikimedia.org/wiki/File:Basel_2012-09-28_Mattes_(61).JPG>

<https://map.geo.admin.ch/?zoom=12&X=267068&Y=611263&layers=ch.bav.haltestellen-oev,ch.swisstopo-vd.ortschaftenverzeichnis_plz,ch.swisstopo.swissboundaries3d-gemeinde-flaeche.fill&layers_visibility=true,false,false&lang=de&topic=ech&bgLayer=ch.swisstopo.swissimage&layers_opacity=1,0.75,1&crosshair=marker>


Martin Baumann
 

My apologies, I am not overly familiar with Basel street etc names despite having travelled on the whole system.


The gradient on 15/16 is fairly steep though, maximum 6.90


Simon
 

The Kohlenberg hill on Line 3 is about 100m long, so the stats obviously apply to the maximum incline on the line and not an average.
The other steep section that I’m aware of is on the 16 route as it climbs from Leimgrubenweg to Jakobsberg and on to Hechtliacker.


Chris Wood
 

Markus writes:

Ufff, all this hunting for records...
Tend to agree, but I'm afraid it is part of the baggage that comes with Wikipedia.

Now the steepest standard gauge railway in Switzerland without rack is
the TL M2 in Lausanne with 120‰! Sure, they have rubbers...
I think you mean pneumatic tyres. Rubbers means something quite different - at least to anybody versed in US English. :-)

My understanding is that M2 uses a system not dissimilar to the Paris Metro, where the standard gauge steel wheels and rails come into play in the event of a tyre puncture. I'm guessing that such punctures are pretty unlikely in these days (tyre technology was much more primitive back when Paris invented the system), but this does seem to imply that the steel to steel contact must be able to cope with the gradient if the worst happens. Does anybody know more?.


Andrew Moglestue
 

[message repaired by the moderator - as far as possible]
According to physics, the friction coefficient of steel on steel is 0.4 to 0.8 (I guess depending on the surface properties.For a greasy or lubricated surface this degrades to about 0.15 In order to prevent the wheels from losing their adhesion, the tractive effort per axle must remain below the product of the axle load x the friction coefficient. On a gradient, part of the tractive effort is required to prevent the train rolling downhill, so if you actually want to accelerate, the tractive effort must exceed the weight of the train x the friction coefficient. So as you increase the gradient you must keep the tractive effort between these two rapidly converging values. So this means a steel wheel on steel rail can under optimal conditions climb a gradient of 80% but if you allow for the rail getting dirty and have no counter strategy, it is only 15%. So I assume that in Lausanne if you have a tyre failure, you can maybe continue going on the other tyres but if all tyres fail you can at best stop safely and wait to be rescued.


OL.Guerbetal
 

Am 16.06.2016 um 15:31 schrieb chris_j_wood@... [SwissRail]:
Now the steepest standard gauge railway in Switzerland without rack is
the TL M2 in Lausanne with 120‰! Sure, they have rubbers...
I think you mean pneumatic tyres.
I meant rubber tyred.
<https://en.wikipedia.org/wiki/Rubber-tyred_metro>

As you can read in the article mentioned, the standard gauge rails are not only for emergencies but also for normal guidance, especially through points, or switches, if your prefer American English.

The emergency isn't thought to occur in a way that all tyres are punctured at the same time.

For the rest the system is exactly the same as in Paris or Lille.

Markus, Gürbetal


George Raymond
 

I would like to thank group owner Markus for his tireless efforts to provide so much of the information requested by and available to members this group.

George


Guerbetaler
 

Am 16.06.2016 um 18:49 schrieb Andrew Moglestue:
So this means a steel wheel on steel rail can under optimal
conditions climb a gradient of 80%
You didn't want to say 8%, did you?

Markus


Barry Emmott <barry.emmott@...>
 

There are also rubber-tyred lines on the Santiago Metro, Chile.
Barry Emmott


OL.Guerbetal
 

Am 17.06.2016 um 10:45 schrieb 'Barry Emmott':
There are also rubber-tyred lines on the Santiago Metro, Chile.
There are many more, but this wasn't the question here. My point was, that the Lausanne M2 is of the same make as Paris and Lille. The same system was installed elsewhere.

Markus, G�rbetal


gordonwis
 

Rode the Lausanne metro two days ago, and watched the pneumatic tyres in operation...


Chris Wood
 

Hi Markus.

When you wrote:

> My point was, that the Lausanne M2 is of the same make as Paris and Lille.

did you perhaps mean to say Paris and Lyon.

I've not visited Lausanne since the M2 opened, but my understanding is that it based on the Paris Metro rubber tyred system, as also used in Lyon and other places. However the only rubber tyre system I've ever heard of in Lille is a VAL (Véhicule Automatique Léger) system.

If I'm wrong and the M2 is a VAL or VAL-like system, then my question doesn't arise as there are no steel wheels or rails involved in that system. Whilst there are a lot of similarities, VAL cars run on rubber tyres at all times, and are exclusively guided by horizontal guide-wheels.



Chris.


OL.Guerbetal
 

Am 21.06.2016 um 11:55 schrieb chris_j_wood@... [SwissRail]:
[...] However the only rubber tyre system I've ever heard of in Lille
is a VAL (Véhicule Automatique Léger) system. If I'm wrong and the M2
is a VAL or VAL-like system, then my question doesn't arise as there
are no steel wheels or rails involved in that system. Whilst there
are a lot of similarities, VAL cars run on rubber tyres at all times,
and are exclusively guided by horizontal guide-wheels.
The truth is somewhere in between. You are right in that Lille doesnt't have a standard gauge guide rail (an I stand corrected). But then again you are wrong in saying that the VAL /only/ works on rubber tyres as the VAL has a central guide rail for points or switches.

<https://commons.wikimedia.org/wiki/File:Ligne_2_du_m%C3%A9tro_de_Lille_M%C3%A9tropole_-_Garage-atelier_du_Grand_But_(06).JPG>

:-)
Markus