Ordering of fast trains out of Paddington to Reading

[whole diary]

[Boppy]

Hi,

My experience from last night getting home to Reading (and then missing my connecting bus) has led me to once again post a question concerning the ordering of trains leaving from Paddington or more relevantly when to put fast turbo trains on the relief line instead.

I certainly don't want to make this a moan - I'm much more genuinely interested to know more about the decision making process that occurs when several fast trains leave Paddington within a few minutes and how signallers decide the optimal order of those trains.

So what happened last night?

Because of delays to the incoming services (due to trespassers on the line) the 19.45 (to Plymouth) and the 19.48 (to Cheltenham Spa) HST^▸ (High Speed Train) services were delayed by a few minutes leaving.  However the 19.50 fast service to Oxford left on time.  A couple of minutes before the 19.50 left the screens popped up with platforms for both the 19.45 & 19.48 so I had to decide which train would get to Reading first out of those 3 choices.

I checked from the bridge which out of the 19.45 and 19.48 was dispatched first and so ended up taking the 19.48 service hoping that it would not be held up behind the slower 19.50 service.  Unfortunately, that is what happened - the train order was the slower Turbo 19.50 which stopped at Slough followed by the 19.48 and then the 19.45.

So the 19.48 travelled at reduced speed slowing before Slough and I got to Reading at 20.30 after a few minutes wait outside Reading as well.

My question is this:

Is it worth delaying 2 trains more so just to keep 1 on time?  I would have thought that the 19.48 would have got to Reading almost on time if ordered first (it left a minute or 2 late from what I recall).  The 19.45 could then also have followed at a higher speed and possibly made up time further along it's journey form any slack available.

As I say I'm just pretty interested to know how the order is decided - and whether there is scope for signallers to put the 19.50 on the relief line at the start to let HSTs overtake?

Plus I would have though FGW^▸ (First Great Western) would rather 1 of their trains was officially late rather than having 2 that were.

Any feedback over how such decisions are made would be much appreciated!

Thanks,

Boppy.

[devon_metro]

I would imagine that the signallers were not sure when the 1945 and 1948 service were to depart, as TRTS^▸ (Train Ready To Start. A plunger/switch pressed by platform dispatch staff that informs the signaller that a train is ready to depart.) hadn't been called.

[IndustryInsider]

I would imagine that the signallers were not sure when the 1945 and 1948 service were to depart, as TRTS^▸ (Train Ready To Start. A plunger/switch pressed by platform dispatch staff that informs the signaller that a train is ready to depart.) hadn't been called.

That's probably about right. TRTS being 'Train Ready To Start' which is a button or plunger that despatch staff press when the train is all set to go (i.e. there's a driver and guard, the train is prepared, and the last of the passengers is boarding).

The signallers at Slough will (in conjunction with the Automatic Route Setting system) decide which gets preference based mainly on that, and once committed it can take a few minutes for a set route to 'die out' and another to be set, so it's more trouble than it's worth. There is also a good chance that the Slough signallers would not have the time to check that it's a Turbo and make a decision based on that - though if stopping at Slough it only adds a couple of minutes to the through timings anyway.

Though sometimes I've witnessed some decidedly sloppy signalling, so it's possible that was the case for the trains your describe too.

[devon_metro]

If Paddington is controlled by ARS^▸ (Automatic Route Setting), then it is possible that ARS set the route, and the signallers were not happy filling out many hundreds of forms upon cancelling a route. (120seconds before the signal is useable again) plus the miffed driver who would be on the phone to the bobby etc.

[Boppy]

Hi,

Cheers for your replies which have answered some of the things I was wondering about.  It sounds pretty automated then!

Thanks again,

Boppy.

[Tim]

It main weakness of the signalling system is that the Automatic Route setting circuits are very slow and take a minute or so to set, cancel or change a route.  This means that Signallers are often loathed to change things once they are set

[eightf48544]

There is also the problem that the despatch stafff at Padd are FGW^▸ (First Great Western) whilst the signalmen at Slough are Networkrail. Therefore all communication has to go via Swindon. Although FGW/Networkrail have a joint control it still takes time.

That's why you need a fat controller and all staff working for the same company (BR^▸ (British Rail(ways))?). In BR days the duty manager at Padd would have  decided what order to let the trains out and TELL OOC^▸ (Old Oak Common (depot)) box that's what was going to happen.

Throw in the delays ARS^▸ (Automatic Route Setting) imposes changing order then it's more than likely the wrong decision about order of despatch will be made.

[willc]

It's also worth bearing in mind that an Oxford Turbo is working pretty hard to keep to time and has precious little recovery time in hand, whereas the other two trains were going a lot further and have recovery allowances built in down the line. Not great if you're only going to Reading, I will concede, but the odds are other trains were right time at the end of their journeys.

Does anyone know whether the transfer from Slough to the new signal centre at Didcot at the end of next year will have any implications for the operation of the route-setting equipment? Presumably this is dependent on the kit in the signal centre.

[eightf48544]

Does anyone know whether the transfer from Slough to the new signal centre at Didcot at the end of next year will have any implications for the operation of the route-setting equipment? Presumably this is dependent on the kit in the signal centre.

A very interesting question. I think it comes under the Chinese curse of "May you live in interesting times". Current "new" siganalling schemes, Portsmaouth, Manchester South etc. have not gone very well, so the omens are not good for a smooth change over.

I'm not sure how much physical equipment is to be replaced in the Slough area but basically Didcot will be the new signalbox for Slough and will operate with VDUs,  ARS^▸ (Automatic Route Setting) and SSSI interlocking, whereas Slough is currently relay locking and NX push buttons (strictly turn and push).

[devon_metro]

I could have sworn Slough was an IECC^▸ (Integrated Electronic Control Centre)?

[inspector_blakey]

My memory may be failing me but I'm pretty sure Slough has (or at the very least had) both a panel box and an IECC^▸ (Integrated Electronic Control Centre) seperately, controlling different areas.

[Hafren]

My understanding is that Slough is a panel, and Slough New (covering Paddington-Hayes/Heathrow area) is an IECC^▸ (Integrated Electronic Control Centre). Similar to Swindon having two boxes, with Swindon B being the IECC covering Didcot.

[willc]

Does anyone know whether the transfer from Slough to the new signal centre at Didcot at the end of next year will have any implications for the operation of the route-setting equipment? Presumably this is dependent on the kit in the signal centre.

A very interesting question. I think it comes under the Chinese curse of "May you live in interesting times". Current "new" siganalling schemes, Portsmaouth, Manchester South etc. have not gone very well, so the omens are not good for a smooth change over.

I'm not sure how much physical equipment is to be replaced in the Slough area but basically Didcot will be the new signalbox for Slough and will operate with VDUs,  ARS^▸ (Automatic Route Setting) and SSSI interlocking, whereas Slough is currently relay locking and NX push buttons (strictly turn and push).

But in both cases you cite, the suppliers of the kit were new to the UK^▸ (United Kingdom) network - Siemens at Portsmouth and Ansaldo at Manchester - a result of the unlamented Railtrack trying to put pressure on their existing suppliers, I think. Didcot will be a Westinghouse installation and they know what they're doing in UK conditions and are locally based, Chippenham to be precise.

[signalandtelegraph]

My understanding is that Slough is a panel, and Slough New (covering Paddington-Hayes/Heathrow area) is an IECC^▸ (Integrated Electronic Control Centre). Similar to Swindon having two boxes, with Swindon B being the IECC covering Didcot.

Correct 

[Boppy]

You all make some interesting points:

• willc - The Oxford Turbo having less slack over it's entire route is something I hadn't considered.  You're right that I'm obviously aggrieved that my train gets to Reading late but I agree that the HSTs^▸ (High Speed Train) may well have caught up their 15mins delay by the end of their journeys.  For statistics at what part of a train's journey is recording it's time done - is it just the end stop?  Does a train get recorded as late if it arrives at Reading 15mins late but arrives at Plymouth on time?
  
• Everybody's points about the various signalling panels and the modernisation of things moving from Slough to Didcot have shown me just how complicated the setup is.  Are these new signalling schemes designed to control larger areas from one location and if so will this improve things signalling wise in people's opinions?
  
• eightf48544 - Your point about having just one person in control of dispatch (like back in the BR^▸ (British Rail(ways)) days) is interesting as it seems to me there is an issue here.  The current joint control for dispatch sounds very bad for FGW^▸ (First Great Western) to me as whilst they have an incentive to dispatch the trains as optimally as possible I just don't see how or why this would also be the case for Network Rail - is there some benefit they gain by re-ordering the trains that get delayed?  From the sounds of it the effort needed to sign off changing routes actually makes it a disincentive!
  

Cheers,

Boppy.

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