Douro Valley Line Signalling (or lack of)

[matt]

I've just come back from a few days in the Douro Valley in Portugal. Once thing I noticed that further up the line there were no signals. How are the trains regulated. There appeared to be a station master with flag/baton to signal to the train. Do they radio the next station to check the line is clear? There were also pointsmen at some stations which seemed a very labour intensive way of working as I'm sure it is not a cheap line to operate.

 

[nwales58]

Probably telephone block signalling. Not my area of expertise so expert corrections welcome, but even 20 years ago it seemed to be surprisingly widespread on secondary lines in Italy and France even. The Bari-Barletta head-on about 10 years happened under telephone block. See

Signalling block system - Wikipedia

en.wikipedia.org

IP seem to wait until signalling is life-expired then somehow find the money for ETCS, e.g. Faro-Vila Real. According to Openrailwaymap, ETCS is being installed above Oliveira as far as Regua. @Giugiaro will know far more.

 

[Giugiaro]

From Caíde upwards, the railway line works under telephonic blocks. The legs between Caíde and Marco de Canavezes was meant to be under automatic block system, but that implementation is severely delayed.

Track improvement works are done in Portugal under several sub-contracts divided between track, overhead wire, traction transformers, radio telecommunications, signalling, earth work stabilisation, level crossing modernisation/closure, and some times stations, individual tunnels, individual bridges and particular rail yards.

So it is pretty common (in the 2010s/2020s) for a track improvement work to start and finish, and GSM-R, automatic block system, some bridges and tunnels (etc. etc.) to remain unbuilt or yet under construction.

 

[Flying_Turtle]

Telephone block with a WTT overlay and no radios at all. It works very well (altough well beyond its life expectancy) with two persons per station (a signalman and an handsignalman). It is also workable with one person per station but train crossings will take longer.
Station masters (SM) will usually be under the order of a regulator (like a line controller supervising signalboxes) which does not interfere in block working but only directs station masters regarding train order at open stations (drivers are aware of which stations are open or not). A SM will request to the next station SM, by telephone, permission to send train and, once granted, he may clear its own main station distant.
Now, stations usually only have distants which are interlocked with the hand operated points. For this reason, you seldomly have home signals as they are basically useless. Starters are also practically non existent as they have no use (they do not grant any authority for a train to proceed in Telephone Block).
If the distant is clear, assuming the train doesn t stop at the station, the train has a clear run through the station but the authority to proceed into the next block will be given by the presence of the SM presenting a raised furled red (yes, a furled red flag is the equivalent of a proceed signal in Portugal (and Spain also) as we do not use green flags).The absence of this signal will mean that the driver will have to stop the train, if possible, within station limits.
If the distant is on, it will present a red disc or a flashing red, which will tell the driver to be prepared to stop before the first point of the station, unless a yellow handsignal is presented there, which will allow the driver to proceed until the station platform.
If the station is not in service, a C will be displayed outside so the train crews know the station is not staffed.
Regarding the block working itself, overlayed to the SM exchanges, the WTT also plays an important role. It will have the booked train crossings and overtakings. Any alteration to this will leed to a form being delivered to train crews, for which reason, that while TB works very well when all is on time, despite its limitations, due to the WTT overlay, when delays happen, a complex set of bureaucratic procedures kicks in.
An example based on a typical Douro station:

Assuming a booked crossing in station D. Train 1 going from A to E, only stopping at D to cross with train 2 (the general rule is that both trains stop when crossing, although there is a small exception that I lwill not go into it). Train 2 is going from E to A, stopping at all stations.
Train 1 gets delayed, and the regulator informs the stations that the crossing between 1 and 2 is to be altered from D to C. So, train 2, when it reaches D, it will receive a form informing that the crossing with 1 was altered to C (the driver will not leave the station without the form).
Then train 2 will proceed to C.
In C, the SM will keep both distants on even with the first train to arrive in the loop. So trains will need a handsignalman to admit them into the station
Assuming train 2 arrives well before the train 1, and is placed in the loop, the SM of C still will receive train 1 with the distant on, and, as the station will not have home signals and the driver of train 1 is not informed of the crossing, the distant will need to be confirmed by detonators. Once in the station, train 1 will receive a form informing the driver that he crossed with train 2. Train 1 will still need to stop in D, unless an order cancelling the stop is given to the driver.
After this, they can all go on their merry way.

Portuguese telephone block is a mainline block system designed to handle high traffic volumes as safely as possible (there are single track lines with CTV today that see 1/3 of the traffic they saw in the times of telephone block). As much as I like as is, I still fail to understand why they don t place a kind of tokeless block overlay (which is quite simple to add).
Any further doubts just ask!

 

[matt]

Thank you, very interesting to see how it works. It looked quite labour intensive compared to the UK for example.

 

[Flying_Turtle]

Thank you, very interesting to see how it works. It looked quite labour intensive compared to the UK for example.

In terms of productivity or person/train movement it certainly it is not very productive but it is a very cheap and rather safe setup for its time and age.

Similar setups in France can much more efficient, with trailable points equiped with FPL (obviously you don't use the FPL when they are to be trailed ), 3 aspects distants (deferred stop, caution and all clear) and no requirement for one train at a time into the station (which is also a rule in Portuguese railways, unless you have a full set of signals and 150 meter to waste beyond the signal). I believe they just put both distants into caution and let both trains enter the station without the need of an handsignalman. Then, they just trail the points at the end of the station. Simple, quick and effective!

 

[Giugiaro]

In the Douro line staff has been lost to only two staff members per station. One station master, and one shunter*.
The station master coordinates the arrival and departure of trains with the next station and central command at Contumil (CCO Porto).

The shunter signals the safe entry to the station to arriving trains, sets points and also do coupling/decoupling if necessary.

A train can only pass the first point if:

1. The Advanced Signal 1000m before the first point was set to Clear and the station is unstaffed (eclipsed);
2. The Advanced Signal 1000m before the first point was set to Deferred Danger, and the shunter is at the point signalling either a green light/green flag/raised furled red flag for a non-stopping train, or yellow light/yellow flag for a stopping train.

If the shunter isn't present at the point, or anywhere visible with a clear signal, then it basically means there is a phantom Absolute Danger signal at the first point.

*Shunting, signalling and point manoeuvre has been merged into a single task in Portugal.

 

[30907]

Thanks both for clear detailed explanations.

 

[AdamWW]

Fascinating. I wish I'd paid attention when I went on the line a few years ago.

 

[ainsworth74]

Fascinating. I wish I'd paid attention when I went on the line a few years ago.

Yes I was just thinking that! All this completely passed me by but then again I suppose I was so taken by the traction, rolling stock and scenery that the nitty gritty operational matters were missed.

 

[Flying_Turtle]

In the Douro line staff has been lost to only two staff members per station. One station master, and one shunter*.
The station master coordinates the arrival and departure of trains with the next station and central command at Contumil (CCO Porto).

The shunter signals the safe entry to the station to arriving trains, sets points and also do coupling/decoupling if necessary.

A train can only pass the first point if:

1. The Advanced Signal 1000m before the first point was set to Clear and the station is unstaffed (eclipsed);
2. The Advanced Signal 1000m before the first point was set to Deferred Danger, and the shunter is at the point signalling either a green light/green flag/raised furled red flag for a non-stopping train, or yellow light/yellow flag for a stopping train.

If the shunter isn't present at the point, or anywhere visible with a clear signal, then it basically means there is a phantom Absolute Danger signal at the first point.

*Shunting, signalling and point manoeuvre has been merged into a single task in Portugal.

A few bits and bobs there...

The distant (which is the british designation for the advanced signal)will usually be at around 1000 meters from the station but it will vary according to the line speed (Rede, however, indeed has both distants at exactly 1000 meters but in Ermida is 844 meters from the Porto side and 896 meters from Régua side...)

Regarding the point 2, when you get a distant at deferred stop (Paragem Diferida, Deferred Danger), you will never get a green flag at the point... As I said, not only they don't exist in the Portuguese railways as the shunter giving entry to a train into a station comming from deferred stop, assuming the train is to be admited into the station, is only allowed to caution the train by showing show a yellow flag, allowing the train to proceed into the station. There, if the station master shows the train a furled red flag (and not a green flag) the train is allowed to resume normal speed.
A curiosity: If a train is to be cautioned through all the station (for example, due to the need of passing a non stopping train through a loop) the station master will display a yellow flag, allowing the train to proceed into the next block but with a 30 km/h speed restriction until the train clears the last point.

To help you clear any imprecisions and doubts you might have, please check the IMT website, where it has the relevant regulations

https://www.imt-ip.pt/ferroviario/caminho-de-ferro/regulamentacao-de-seguranca/