Trivia: PIS/CIS oddities...

[Surreytraveller]

Most of the CIS screens on the Uckfield Line also have the problem that even a slight delay to the train will result in it vanishing from the boards before it arrives, as the number of minutes of any delay always gets calculated rather "optimistically".

Probably because most of the track circuits on the Uckfield Line do not coincide with the station platforms, so the system is just set up to clear when a train should have left, rather than when it has really left.

 

[swt class 450]

Also another major error is that the Atos Mike automated announcements at Hastings always announce:

... Polegate , Berwick Upon Tweed , Glynde ...

I have no idea how this has happened. I really thought whoever is in charge of programming the automated announcements would of realised. Maybe they dont have very good geographical knowledge and got Berwick and Berwick Upon Tweed confused with each other when programming them.

 

[Joe Paxton]

The screens on Platform 2 at Gatwick Airport (but none of the other platforms) still display all GTR "Thameslink" branded trains as "First Capital Connect".

How very helpful, for those who have a Thameslink-only ticket (and are happy to go along with it) !

 

[Surreytraveller]

Also another major error is that the Atos Mike automated announcements at Hastings always announce:

... Polegate , Berwick Upon Tweed , Glynde ...

I have no idea how this has happened. I really thought whoever is in charge of programming the automated announcements would of realised. Maybe they dont have very good geographical knowledge and got Berwick and Berwick Upon Tweed confused with each other when programming them.

More likely someone with a degree and two months' experience has been put in charge rather than someone who knows what they are doing.

 

[tsr]

Re. Gatwick Airport, I believe the CIS board above the main bank of TVMs on the main concourse still occasionally shows "Welcome to Waterloo East".

Probably because most of the track circuits on the Uckfield Line do not coincide with the station platforms, so the system is just set up to clear when a train should have left, rather than when it has really left.

This will be a factor at a couple of stations, but the resolution of the data from the track circuits would mean that with sufficient allowances made for the real-life timings (eg. based on acceleration) of the trains, more accurate CIS displays would be possible without the need for further tracking equipment of any sort.

The problem is more that the CIS system is very optimistic about how quickly each train can reach each station once it enters the given track circuit. On a good day you might just reach some of the stations as the boards change over to show the next train; other days, you can see them clearing on approach. Occasionally, during the half-hourly morning and evening service periods with different calling patterns for various trains, you do occasionally need to clear up the confusion and make sure people aren't expecting the wrong train, though off-peak it's much easier (and, all that said, the "contra-peak" workings are usually empty anyway).

Fortunately, the Uckfield Line is one of those "rationalised" local branches where the TCs do at least correspond to the vicinity of each station, and there's roughly one per station, so although their geographical limits are somewhat different from the specific areas of the station, you could calculate realistic estimates of arrivals/departures based on when each train hits each track circuit. The main sticking point here is at Buxted on the Up, really, and possibly Hever on the Down, though Hever has so few passengers boarding Uckfield-bound trains that it rarely ever matters.

 

[sk688]

Dont know if its odd or not , but all the LM 350s say 00:00 London Midland quite often on their services .

Also Not in Service , despite being in service . I was on one recently from Euston to Watford , which was going to Milton Keynes or Northampton , and the thing just said Not In Service the whole time . The guard was making all the announcements

 

[Wilts Wanderer]

The CIS at Swindon P4 regularly announces 'stand back, the next train is not scheduled to stop' and then nothing appears. I have a suspicion it is caused by a freight going into the Down Goods Loop to the east of the station.

 

[Paul Kelly]

Here's a picture of the SWT express service from London Waterloo to Poole, Leaving Waterloo at 18:54 and getting to Poole 1hr and 1min later!

Interesting; 1854 is the time the train left Southampton Central. It seems to be getting confused because the portion that terminates at Poole divides from the through Waterloo to Weymouth portion at Southampton: http://www.brtimes.com/#!train?uid=W35205

It's just poor programming and lack of attention to detail on the part of the information system vendor really; there should be no excuses for it. On the other hand you could say that the TOCs should hold their suppliers to account and not put up stuff like that.

 

[louis97]

Track circuits control the signals​ If the train has fully passed the next signal then it would be clear of the previous track circuit and the PIS would then realise it's left

A track circuit alone tells the CIS nothing, it is the passing of the signal and therefore movement of the train describer from the berth of that signal that alerts the CIS to the departure.

 

[louis97]

This will be a factor at a couple of stations, but the resolution of the data from the track circuits would mean that with sufficient allowances made for the real-life timings (eg. based on acceleration) of the trains, more accurate CIS displays would be possible without the need for further tracking equipment of any sort.

The problem is more that the CIS system is very optimistic about how quickly each train can reach each station once it enters the given track circuit. On a good day you might just reach some of the stations as the boards change over to show the next train; other days, you can see them clearing on approach. Occasionally, during the half-hourly morning and evening service periods with different calling patterns for various trains, you do occasionally need to clear up the confusion and make sure people aren't expecting the wrong train, though off-peak it's much easier (and, all that said, the "contra-peak" workings are usually empty anyway).

Fortunately, the Uckfield Line is one of those "rationalised" local branches where the TCs do at least correspond to the vicinity of each station, and there's roughly one per station, so although their geographical limits are somewhat different from the specific areas of the station, you could calculate realistic estimates of arrivals/departures based on when each train hits each track circuit. The main sticking point here is at Buxted on the Up, really, and possibly Hever on the Down, though Hever has so few passengers boarding Uckfield-bound trains that it rarely ever matters.

You mean Train Describer data? This is what Realtime Trains uses, track circuit "data" is meaningless as there is no way to identify what the train is.

The Uckfield is a funny line in respect of Train Describers, it has additional describer berths at certain repeater signals (normally repeater signals don't have berths). In the up direction there is two stations that fall in the same describer 'section' - Cowden and Hever, this meaning that once you arrive at Cowden, you don't know if you have left Cowden until you have departed Hever. In the down direction there is also two stations that fall in the same describer 'section' Edenbridge Town and Hever, therefore in this case you don't know if the train has left Edenbridge Town until it has also left Hever.

All other stations on the branch have a describer 'section' to themselves, and therefore there should be no reason for the trains to need to drop off the screen before a departure is reported. If this is the case then this is the setup by Southern to reduce the time between the train departing and it remaining on the screen. If the trains are dropping off the screens before the train has arrived then this suggests the 'offsets' (the time it takes between moving between describer berths and arriving/departing a station) is incorrect.

 

[Muzer]

You mean Train Describer data? This is what Realtime Trains uses, track circuit "data" is meaningless as there is no way to identify what the train is.

The Uckfield is a funny line in respect of Train Describers, it has additional describer berths at certain repeater signals (normally repeater signals don't have berths). In the up direction there is two stations that fall in the same describer 'section' - Cowden and Hever, this meaning that once you arrive at Cowden, you don't know if you have left Cowden until you have departed Hever. In the down direction there is also two stations that fall in the same describer 'section' Edenbridge Town and Hever, therefore in this case you don't know if the train has left Edenbridge Town until it has also left Hever.

All other stations on the branch have a describer 'section' to themselves, and therefore there should be no reason for the trains to need to drop off the screen before a departure is reported. If this is the case then this is the setup by Southern to reduce the time between the train departing and it remaining on the screen. If the trains are dropping off the screens before the train has arrived then this suggests the 'offsets' (the time it takes between moving between describer berths and arriving/departing a station) is incorrect.

Track circuit data isn't meaningless at all if you know which TDs correspond to which track circuits. After all (outside of a possession or permissive working at least), no more than one train can be in one signalling block at a time. So you can look at both the TD data and the data on track circuit occupancy to get a bigger picture.

 

[Frothy]

For reasons that evade me, the PIS at Burley Park only identifies the 1842 to Selby once it is pulling into the station, whereupon it magically appears on the screen.
Before 1842, the screen shows the next train as 1854...

Sent from my SM-G920F using Tapatalk

 

[bluegoblin7]

It seemed like an oddity to me, as I used to ride along the SSL to Upminster and only Stepney Green blatantly showed wrong destinations.

Harrow is certainly an oddity and will have come from a problem with the train descriptions (TDs) that are passed along the line from signal cabin to signal cabin. That said, there are occasionally trains that run to Harrow (out of service), before reversing and running to Wembley Park to stable in the sidings there - in many places with DMI screens it's possible that this TD has been altered to show 'Not in service', but perhaps not at Stepney Green and its light boxes. But, it's equally possible that it could either be a problem in the TD system between Barking and Whitechapel cabins or an incorrect TD set up by the Barking signaller. Not my patch, though, so I couldn't give a more conclusive answer.

As mentioned, 'Check front of train' is much more common, and happens when there is no TD attached to a train. Not much can be done about this until the resignalling is completed - for example, on the Hammersmith branch TDs don't get sent in either direction between Hammersmith and Edgware Road cabins, as there's only one place the trains can go*. If there's any changes then they'll get communicated verbally between the signallers via telephone. On the westbound this isn't really a problem - the fancy new DMIs (installed for the resignalling) will accurately show the time until the next train and its destination (Hammersmith). But, on the eastbound, all it can show is 'Check front of train', as there's no data sent by the signalling system as to what that train will do when it reaches Edgware Road. Is it a Barking? A Circle line? Or a short-trip somewhere? (Bonus points to anyone who knows all the possible eastbound trips...) This train is then prescribed a TD by Edgware Road cabin, which should then be passed to Baker Street and beyond.

Hopefully that gives a brief overview... it's very easy to get into the nitty gritty of how TDs work on the Tube, but it's moving away from the general question.

(*Okay, there's technically two, as you can run trains into 24rd siding at Hammersmith. As it's a non-passenger move, it means that such trains have to be terminated and detrained at Goldhawk Road, and so ideally would be described as such on DMIs. However, there's nothing timetabled to do this in passenger service, and often when it does happen with a train it's a last minute decision during disruption to get the signaller out of a pickle. )

 

[najaB]

If the next track circuit is three to five minutes down the line, that is when the PIS system knows the train has left the station. Not all track curcuits coincide with station platforms.

Given the location of Dundee station that is unlikely - especially since it happened in both directions (Dundee Central junction and Camperdown junction are each no more that a few hundred metres away).

 

[louis97]

Track circuit data isn't meaningless at all if you know which TDs correspond to which track circuits. After all (outside of a possession or permissive working at least), no more than one train can be in one signalling block at a time. So you can look at both the TD data and the data on track circuit occupancy to get a bigger picture.

You do have a good point, certainly possible, however I doubt it would offer much additional information on a passenger information basis. It is certainly useful from a map perspective (the GWR staff map screens show this actually), but as track circuit on basic railway tends to be limited to 1 or 2 (overlap and the rest) between any signals its benefits are limited.

Generally you are better off just adding additional Train Describer berths to track circuits, something which already happens in various locations where stations are awkwardly placed in relation to signal or there are long signal sections. This has two key benefits, firstly you don't have to put together a system to bring together the train describer data and track circuit data (where available) and secondly this method would work in areas where track circuit data output isn't available (which is quite a few!).

This all then comes down to how the track circuits are actually designed into the network, generally this would be most useful on lines with long distances between signals. However on such lines the track circuits tend to be limited to 1 or 2 sections between each signal, this of course is no use if you have 2 or more stations between two signals. So more infrastructure would be required to break up the track circuit in sections relative to each station.

 

[Kneedown]

Back in Central days when we used to work the Birminghams, if you were first stop Wilnecote or Tamworth it was always good for a trouser filling moment when the 170's PIS flashed up "Next stop Water Orton", while approaching at speed!

 

[Envy123]

Harrow is certainly an oddity and will have come from a problem with the train descriptions (TDs) that are passed along the line from signal cabin to signal cabin. That said, there are occasionally trains that run to Harrow (out of service), before reversing and running to Wembley Park to stable in the sidings there - in many places with DMI screens it's possible that this TD has been altered to show 'Not in service', but perhaps not at Stepney Green and its light boxes. But, it's equally possible that it could either be a problem in the TD system between Barking and Whitechapel cabins or an incorrect TD set up by the Barking signaller. Not my patch, though, so I couldn't give a more conclusive answer.

Well, the "Harrow-on-the-Hill (semi-fast)" trains turned out to be District Line trains, so I think the TDs got confused.

 

[rebmcr]

Well, the "Harrow-on-the-Hill (semi-fast)" trains turned out to be District Line trains, so I think the TDs got confused.

No, that's what bluegoblin7 meant. Districts stabling along the Metropolitan route.

 

[Skoodle]

Dalston Junction Platforms 2 and 3, when a train is forming ECS after terminating at the buffer stops, the screens display "Not In Service....please stand clear, this train is not scheduled to stop at this station". I should hope it would!

 

[jbg]

Not strictly PIS (though it is a system intended to give information to passengers) but I spotted this peculiarity at Huddersfield a few weeks ago:

Here's an impossibility at Huddersfield too:


Victoria stopper from P5.

 

[jbg]

....-.

 

[Chris M]

A few years ago I was on a Birmingham New Street to Liverpool class 350. The train however thought it was going from Liverpool to Birmingham. It announced all the stations correctly but Birmingham as the destination and then listed the stations we been to as the next stations.
At least one person got on and then hurridly got off again thinking the train was going to Birmingham.

 

[Envy123]

No, that's what bluegoblin7 meant. Districts stabling along the Metropolitan route.

bluegoblin7 put forward 3 suggestions on why Harrow trains appeared on the TD. The actual trains which came, were not Not In Service, and the TDs showed them during the day.

Hence, the 2nd suggestion was most likely.

 

[Steddenm]

Strangest couple i heard were at Basingstoke a few years ago:

"Platform 1 for the x Virgin Pandolino service to Bournemouth. Calling at Winchester, Southampton Airport Parkway, Southampton Central, Brockenhurst and Bournemouth. A shop is available on this train. This train is formed of 11 coaches."

"Platform 5 for the x Anglia Railways service to London Waterloo. Calling at Woking and London Waterloo. This is the service from Ilford and has 3 coaches."

They were of course a CrossCountry 5 car voyager and South West Trains 159 from Exeter respectively. I'm guessing station staff were having a "play"

Oh and the Talking Clock sometimes gets a playout at Nuneaton.

Here in Ireland it's common for some of the automated announcements at Connolly Station to announce all services as Translink Northern Ireland Railways rather y than Iarnród Éireann.

 

[prod_pep]

At Glasgow Central, the replacement bus departure point seems to be missing. I've heard a couple of times: "The next bus to depart from *pause* will be the..."

 

[Joe Paxton]

On some PIS displays at CLJ...

Special notice

Welcome to Clapham Junction

Erm, yes, such a very special notice!

 

[GW43125]

On an SWT Weybridge-Waterloo 458 last week, upon leaving Chertsey she told us that "This train is for London Waterloo calling at: and London Waterloo". No intermediate stations, just "and London Waterloo". She did it leaving VW too.

 

[Chris M]

On an SWT Weybridge-Waterloo 458 last week, upon leaving Chertsey she told us that "This train is for London Waterloo calling at: and London Waterloo". No intermediate stations, just "and London Waterloo". She did it leaving VW too.

I think it was a District line train a couple of weeks ago that was announcing simply "This is a .... train to .... . The next station is ...."

Wandering off topic, but the iBus announcements in London are composed of "<route> to <destination>", e.g. "277 to Crossharbour" and individual stop names, but sometimes they go a bit wrong and substitute a random sound file for one of the words, which is sometimes quite amusing. A while back I was on a bus that had substituted "Henleys Corner/Addison Way" for the word "to" so we got "94 Henleys Corner/Addison Way Acton Green" repeatedly.

 

[wls1]

c2c used to have a rogue announcement that said "premier class accommodation is available in coach A" probably denoting the quiet zone as premier accommodation.

also sometimes 357s can burst out saying random things, like "all trains are disrupted due to a broken down freight train" confusing the passengers and breaking the on board PIS.

 

[swt class 450]

On an SWT Weybridge-Waterloo 458 last week, upon leaving Chertsey she told us that "This train is for London Waterloo calling at: and London Waterloo". No intermediate stations, just "and London Waterloo". She did it leaving VW too.

Although i have never seen that happen when the final destination is not the next stop she has been saying "calling at and" on approach to all final stops ever since the 458/0 units were converted to the 458/5 units.

For example:

When approaching London Waterloo she says: "This train is for London Waterloo. Calling at and London Waterloo."

When approaching Weybridge she says: "This train is for Weybridge. Calling at and Weybridge."

When approaching Windsor & Eton Riverside she says: "This train is for Windsor & Eton Riverside. Calling at and Windsor & Eton Riverside."

When approaching Woking she says: "This train is for Woking. Calling at and Woking".

I presume this was just an error when the automated announcements were programmed.