Crocodiles...

[IanStock]

Good evening all,

 

so much to know...so many questions... ;-)

 

Would appreciate it if some one could explain to me the purpose and positioning of those things called 'crocodiles' on French turnouts... and all those various bits they tend to paint white, as in the (hopefully) attached picture of Le Mont-Dore... Can't seem to find any English equivalent.

 

Many thanks for your patience in advance...

Ian S.

[The Stationmaster]

I can't see any crocodiles (contact ramps - for train control systems) in that picture and the things painted white are contre-rails (=check rails).

 

Illustrations of crocodiles can be found here (sorry it's Wiki but they are crocodiles)

 

https://fr.wikipedia.org/wiki/Crocodile_(signalisation_ferroviaire)

[IanStock]

Sorry, I  know there aren't any crocodiles in the picture - that was for all the other white things! I assume the check rails just use a different kind of support from British ones? (They look a bit like overkill...) I have also seen in other pictures something that looks like a clamp that closes over one rail. See below. I believe there was some British equivalent of this in the past...?

 

I assume also that the white lines are some kind of fouling marker?

 

Thanks for the link - should have thought of French wiki first. Just trying to work out what I need to put where when track laying begins in earnest - all these fittings are not really my forte...

 

Ian

 

 

[Fat Controller]

That's a dérailleur; used instead of the trap points we use in the UK. Some are interlocked with the points, as appears to be the case here. Others are put in place manually. They are very easy to fall over..

[IanStock]

Many thanks... intrigued how it works. Presumably the block is attached to a lever of some kind that lifts it out of place? Odd location too - the converging lines here lead to the headshunt of a run-round on the right and the diverging lines to the left are a platform road and its run-round loop. (At Tulle)

 

Good job I haven't built any catch points yet!

 

Thanks

Ian

[The Stationmaster]

Sorry, I  know there aren't any crocodiles in the picture - that was for all the other white things! I assume the check rails just use a different kind of support from British ones? (They look a bit like overkill...) I have also seen in other pictures something that looks like a clamp that closes over one rail. See below. I believe there was some British equivalent of this in the past...?

 

I assume also that the white lines are some kind of fouling marker?

 

Thanks for the link - should have thought of French wiki first. Just trying to work out what I need to put where when track laying begins in earnest - all these fittings are not really my forte...

 

Ian

The lever in this picture just works the derailer and is not connected to any points (odd location though!!).

 

And yes, some types of SNCF check rails use a very different method of fixing from ours.

[Edwin_m]

Many thanks... intrigued how it works. Presumably the block is attached to a lever of some kind that lifts it out of place? Odd location too - the converging lines here lead to the headshunt of a run-round on the right and the diverging lines to the left are a platform road and its run-round loop. (At Tulle)

 

Good job I haven't built any catch points yet!

 

Thanks

Ian

Possibly so something can be parked in the headshunt without rolling out into the passenger platform? 

[IanStock]

Possibly so something can be parked in the headshunt without rolling out into the passenger platform?

 

Possibly, but the only thing that ever needs to go in there is locos while running round. I think the track here was relaid not too long ago as well.

[Joseph_Pestell]

Going back to your previous thread, a nice piece of "pierre hexagonale" of the irregular kind in that shot of Le Mont Dore.

 

I remember when I built (in about a week) a BLT to exhibit at the local show in Perpignan. That had a catch point on the runround loop and just about every club member asked me about it. It had not occurred to me that they might not exist in France.

[IanStock]

Yes indeed - one of the reasons I was asking. There is a possibility I want to model that stretch of wall.

 

Interesting about the catch points - often the differences are in the least expected places. I guess it's errors of that sort (or not, as the case may be) that are the difference between a convincing model and not. As I think I said, my challenge is to build a French layout that does not look like it was made by an Englishman. Though how I'll ever know I've succeeded is another matter, being an Englishman! ;-)

[Fat Controller]

The lever in this picture just works the derailer and is not connected to any points (odd location though!!).

 

And yes, some types of SNCF check rails use a very different method of fixing from ours.

I wonder if it's some sort of training aid?

[Pacific231G]

The lever in this picture just works the derailer and is not connected to any points (odd location though!!).

 

And yes, some types of SNCF check rails use a very different method of fixing from ours.

I think these are stop blocks (taquets d'arrêt) rather than the more common derailer and assume they're to stop a runwaway vehicle, including a loco, from either of two sidings from getting any further. taquets d'arrêt seem to be used where you can be sure the runaway is moving very slowly which would be the case at the terminus end of Tulle station. 

For anyone wanting to build some there are drawings here

http://forum.e-train.fr/album_mod/upload/c71ba11621e14e10c77b0b610e2115ee.jpg

http://forum.e-train.fr/album_mod/upload/09adb317d35ee23dfd7a39d74e951fa1.jpg

http://forum.e-train.fr/album_mod/upload/788156205079bc34251a7ec2db32d769.jpg

http://forum.e-train.fr/album_mod/upload/59487d8d412d9fecba6dbe4e1630504c.jpg

the final drawing is for a "unified" SNCF trap point so they do or did exist.

If anyone knows an effective way of representing taquets in H0 I'd like to know as they seem far harder to model than a Britsh trap/catch point. There was an article in RMF a few years ago but it involved a lot of pieces of plasticard and making it work especially remotely was fairly fiendish.

 

 

 

Ian, to try to answer some of your questions.

 

French practice makes a distinction between voies principales (running lines more or less) and voies de service (sidings, run rounds* etc) Vehicles parked on the latter must be prevented from rolling onto the voies principales either by stop blocks, derailers or the track layout with headshunts etc). Passenger trains are normally only permitted to use voies principales which must not be fitted with derailers. Rolling stock isn't supposed to be left parked on Voies Principales though there are exceptions to this such as coaching stock parked between runs- often overnight- at station platforms.

 

Although the lever isn't physically interlocked, French railways have made extensive use of local levers that can only be unlocked by keys that can only be released from an interlocked board when the relevant signals are closed. It's a bit like the British use of Annet keys on single line tokens (which the French rarely used) but often far more complicated.

 

The white markers between some of the tracks are indeed fouling markers and known as "bornes de garage franc" They're usually concrete castings and some are of the right length that when placed between converging tracks will give the appropriate separation (either enough to keep vehicles a safe distance apart or to leave enough gap for a shunter on a vehicle not to be knocked off) .

They don't have to be broken though several of those in the north sidings at Noyelles seem to be but this does show the standard casting pretty clearly. White painted sleepers or even white paint on the sides of rails can be used instead but SNCF seem very keen on these so they're a good thing to help give an authentic French atmosphere. 

 

 

Update - I've just realised that there's an unbroken garage franc in my avatar picture; here it is in close up

This picture taken on the same very wet day in 2006 shows two of them end to end (presumably to give a greater clearance for the main line) at Noyelles-sur-Mer in 2006 with a typical taquet (in this case a  taquet dérailleur) in the foreground.

 

 

This taquet is remotely operated and would be interlocked so the main line signals on the Boulogne-Paris line behind can't be cleared unless it's closed. Here is a close up and you can also see in more detail the angle iron that helps ensure that the runaway goes where it's supposed to and  the strip of metal bolted between the rails presumably to stop the other wheel from destoying the sleepers.

 

 

With less use of separate signalboxes, particuiarly at local stations, French operational staff probably spent more time running around on the ground changing points, flagging moves etc. so it was normal practice for anything a railway worker might trip over or walk into, especially in the dark, to be painted white. That included the ends of check rails and wing rails, local point levers and their guard rails, and often even the corners of buildings so again that'll help with authenticity. (I've noticed at places like White City that London Underground  do the same with the ends of conductor rails where a mistake could all too easily lead to an electrocution)

 

I assume you by now know that crocodiles perform a similar function to  AWS ramps though they work slightly differently making an electrical contact with a wire brush on the loco and passing a +20V or -20V signal depending on whether the signal they indicated was open or closed.   

 

*update. Some run rounds only used for that purpose weren't protected as they'd only be used by a loco under control.

[IanStock]

Pacific 231G  many thanks for that information - I've been away from the board for a few days and have only just caught up. All very helpful and will no doubt come in useful when the track building gets fully underway. As expected, there's a lot more to know different from the U.K. scene than perhaps meets the eye. I'm still trying to get my brain round the signalling systems, which seem more like Morse code than anything else!

[Pacific231G]

Pacific 231G  many thanks for that information - I've been away from the board for a few days and have only just caught up. All very helpful and will no doubt come in useful when the track building gets fully underway. As expected, there's a lot more to know different from the U.K. scene than perhaps meets the eye. I'm still trying to get my brain round the signalling systems, which seem more like Morse code than anything else!

Although the basic indications are fairly straightforward (though there are rather more of them than in Britain) figuring out what signals went where is far more complex and seemingly inconsistent. The mistake would be to try to map French signals onto British equivalents because, though the purpose is the same, there are fairly fundamental differences in principle. One major difference was that in Britain it is the signals that give a train permission to proceed whereas in France the train order authorises a train and the signals restrict it; operation on main lines was generally by "open block".

 

In principal, most (but not all) mechanical signals give no indication when open and show a board of various shapes when closed and a lot more movements were controlled by hand signals or by following a standard "evolution" for example when running round a train. 

 

There are also different "regimes" of signalling for different situations, nowadays usually marked by plates on the signal posts. Some single line branches and almost all light raiways had/have no signals apart from fixed markers.  They also very rarely used single line tokens and permission to enter a single line section was given by the "chef" (and nobody else)  There was also some distinction between signals that controlled speed (over points for example), absolute and deferred stop signals that protected against conflicting moves, and "semaphore" signals that controlled entry to blocks but in many instances could be passed by a train at slow speed or when shunting. There were also significant regional differences even though signalling was standardised in 1930 (by the "Code Verlant") 

Far more than in Britain, colour light signals corresponded with their mechanical predecessors and both generally display the same lights though CLS has added some new indications using flashing lights.

 

Unfortunately, the rule books and most descriptions of French signalling are fine on what each signal means to a driver but far less clear on where, when and why they're actually deployed.

[IanStock]

Many thanks once again. Something is telling me that railways regs. betray far more of the national mind set than might have been expected. In Britain, you stop unless you're told to go; in France you go unless you're told to stop. I like that ;-)

[Patrick]

Looking forward to following your progress, Ian. I'm slowly developing a plan for a HO scale layout based somewhere roughly halfway along Le Cévenol. Glaciers seem to progress than me, though...

 

 

Taquet d'Arret Noyelles 2006.jpg

Taquet d'Arret T6 Noyelles 2006.jpg

 

Just out of curiosity, I can only find one company which markets taquet dérailleurs in HO scale (Regions et Compagnies). Are there any more options? I'm surprised Decapod don't seem to carry suitable accessories in their range...

[Pacific231G]

Looking forward to following your progress, Ian. I'm slowly developing a plan for a HO scale layout based somewhere roughly halfway along Le Cévenol. Glaciers seem to progress than me, though...

 

 

Just out of curiosity, I can only find one company which markets taquet dérailleurs in HO scale (Regions et Compagnies). Are there any more options? I'm surprised Decapod don't seem to carry suitable accessories in their range...

RMF did an article on scratchbuilding them from plasticard and Evergreen section a few years ago. They didn't look too difficult to build hough making them functional looked a bit more involved. I don't recall seeing them on (m)any French H0 layouts but then how many British layouts include trap points?

[IanStock]

Thanks Patrick. This isn't going to be a quick build either!  Nothing wrong with taking your time...

 

I may have a go at non-working derailleurs but the problem is, unlike a catch point, there is little point in modelling them for purely aesthetic reasons as they will very obviously look wrong if modelled in the open position but would give serious operational problems if modelled closed!

 

Best,

Ian

[Pacific231G]

Thanks Patrick. This isn't going to be a quick build either!  Nothing wrong with taking your time...

 

I may have a go at non-working derailleurs but the problem is, unlike a catch point, there is little point in modelling them for purely aesthetic reasons as they will very obviously look wrong if modelled in the open position but would give serious operational problems if modelled closed!

 

Best,

Ian

That's what's been worrying me and I suppose the answer would be something that looked like a closed derailer but moved aside when a wheel went past it.

I did though find this http://www.ptitrain.com/reportages2006/rosny/index3.htm

just over half way down is an animated GIF showing a working model and it looks fairly simple - well simpleish. The caption though that I roughly translate as "Yes, it really is a working derail in 1/87 scale" indicating just how rare these are on layouts though not, unfortunately for us, in real life where their brght white colour serves only to show up their absence. 

[IanStock]

Hmm. Amusing but not sure how realistic that is. I'm wondering whether wire in tube might have potential. But as with many things, better to leave them out thst do them badly.

 

 

That's what's been worrying me and I suppose the answer would be something that looked like a closed derailer but moved aside when a wheel went past it.

I did though find this http://www.ptitrain.com/reportages2006/rosny/index3.htm

just over half way down is an animated GIF showing a working model and it looks fairly simple - well simpleish. The caption though that I roughly translate as "Yes, it really is a working derail in 1/87 scale" indicating just how rare these are on layouts though not, unfortunately for us, in real life where their brght white colour serves only to show up their absence.

 

[marklin181]

Is the operating mechanism for the derailer in the galvanised tin cover with the handle  ?   From looking at the photo there is no other elect cables or pull wires visible . In Australia the motor for these are usually similar to point motors or connected to ground frames  by channel iron for operation . We also use both  derailers & catch points to protect main lines  from runaways .

 

 Cheers  Tom in Oz