Making Up For Lost Time

[RichmondCommu]

G'day everyone,

A few weeks a go I caught an afternoon train from Newcastle back to Kings Cross and we left Tyneside a fair few minutes down. However this is a good news story as we arrived into the 'Smoke on time. In order to avoid the possibility of getting career railway staff into trouble I don't wish to disclose any specific details of my journey but I have to say that I was very impressed.

All this has left me wondering how this was achieved? Now I've no doubt that efficient platform dispatch certainly helped along with smart thinking in the various signaling centres. However, knowing the route reasonably well we seemed to accelerate much harder away from stations then is usually the case; in particular Darlington. In essence I'm interested to know whether any slack is built into the timetable to allow drivers to make up for lost time.

Your thoughts on this would be very welcome.

Richmond Commuter.

 

[MidnightFlyer]

Yep, most timetables (certainly over that distance) will have a few mins built in over the course of the journey for engineering or pathing purposes, as well as some for performance IIRC. In addition to that, there's usually 5 mins added to the arrival time at the final destination in passenger timetables (i.e. booked to arrive at 1053, passengers see it as 1058), though this might be what performance time is. But in brief - yes, there's certainly time built in timetables!

 

[heart-of-wessex]

Always padding at the end maybe for PPM reasons, even for short distances. When the Gospel Oak - Barking was only doing Gospel Oak - South Tottenham shuttles (morning engineering work saw the line closed to Barking), it was given a minute and a half for the 1 mile outward journey from South Tottenham to Harringay Green Lanes, yet on the return, the terminators were given 6 minutes to do Harringay Green Lanes to South Tottenham (1 mile 8 chain to be exact)!

 

[Eagle]

Yep, most timetables (certainly over that distance) will have a few mins built in over the course of the journey for engineering or pathing purposes, as well as some for performance IIRC. In addition to that, there's usually 5 mins added to the arrival time at the final destination in passenger timetables (i.e. booked to arrive at 1053, passengers see it as 1058), though this might be what performance time is. But in brief - yes, there's certainly time built in timetables!

There's usually a bit of both (extra minutes sprinkled throughout the journey and a big chunk added to the end). I'm all for it as it improves reliability and decreases the chance of trains missing their slots, which is certainly worth the loss of 10 minutes or so on a longer journey.

 

[RichmondCommu]

Thanks for your replies. Can I assume that on leaving a station a train is always accelerated as hard as possible?

 

[306024]

At the risk of repeating some of the above, train planning computer software holds all the data for how long it takes for various traction to get from A to B. A lot of work goes on to make these as accurate as possible, and while this is improving, there are no doubt examples where they are not correct.

There are then various allowances that are added to a schedule as follows:

Engineering allowance, otherwise known as recovery time. This is an agreed allowance that is mandatory to add to the schedule at key timing locations, and is to cater for temporary speed restrictions.

Pathing allowance. Added to a schedule to avoid trains hitting each other on paper. Usually to keep trains headway apart, maintain agreed timing margins at junctions, or maintain agreed platform re-occupation times.

Performance allowance. This one is more subjective, and not always used. It is the closest you get to what could be perceived as padding, but is usually used where the workings are very time critical, say at a certain junction, to ensure the train passes precisely at that time.

Advertised differential. This is where trains are advertised in the public timetable to arrive later than the working timetable. Usually to improve performance statistics, a personal view is that it is beginning to be abused in some cases. But that is the time quoted to the public, only enthusiasts really get excited by it.

So there are various ways a train can make up time:

1) Less temporary speed restrictions on the network than are allowed for in the schedule
2) Pathing time not used because the train that would be a schedule clash simply isn't there in practice
3) Not needing the performance allowance
4) Smart station work in less than the timetabled dwell time
5) Superior traction being used to what the train is timed for
6) Skill of the driver to know where time may be regained

There are subtle differences in different parts of the country, but those are the basics from the horses mouth.
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Thanks for your replies. Can I assume that on leaving a station a train is always accelerated as hard as possible?

Accelerate a class 360 as hard as possible and standing passengers will fall over. It depends on the line speed and time due at the next location, it may not be necessary to accelerate hard at all if there is pathing time ahead.

 

[Searle]

There is also usually some padding in the middle of a journey, especially around the Birmingham area of Cross Country.

To show the effects of padding and delays, I've gathered together the delay minutes for Cross Country's 08:20 Aberdeen to Penzance, and put them into a neat bar chart :P


1V60 Bar Chart by Mikez2605, on Flickr

You can definitely see the effects of padding around Edinburgh and Exeter :P

 

[306024]

I wonder what is happenning around Inverkeithing ?

This sort of data is really useful to planners to see if there is a timetabling reason why a train is losing time, or whether it is other circumstances outside their control.

 

[Searle]

I wonder what is happenning around Inverkeithing ?

This sort of data is really useful to planners to see if there is a timetabling reason why a train is losing time, or whether it is other circumstances outside their control.

Just seems to lose two or three minutes a day. I think it sometimes takes long to dispatch because of the curvy platform and SDO. Can take up to four minutes when it's only scheduled for one.

 

[yorkie]

My train today departed York 11 minutes late. 1 hour & 33 minutes later, we were on time passing Potters Bar. In fact, we caught up with a preceding FCC train so the final run into Kings Cross wasn't particularly quick, but we still arrived 2 minutes early. There was good regulation at Peterborough, as we overtook a Leeds - London train that called there (which we were booked to overtake near Doncaster), no delay was caused to that train either, which also arrived early.

 

[306024]

Excellent. Before I upset the siggies on here, I should also have included

7) Skill of the signaller to make correct regulating decisions

 

[The Planner]

At the risk of repeating some of the above, train planning computer software holds all the data for how long it takes for various traction to get from A to B. A lot of work goes on to make these as accurate as possible, and while this is improving, there are no doubt examples where they are not correct.

There are LOTS of examples where they are not correct. However without the agreement of the TOC/FOC, getting them changed is not an easy process, especially if an increase is required. It doesn't help when TRATIM tables (running time calculations produced by the now defunct AEA technology) are considered the most valid source of data!

Performance allowance. This one is more subjective, and not always used. It is the closest you get to what could be perceived as padding, but is usually used where the workings are very time critical, say at a certain junction, to ensure the train passes precisely at that time.

Which is dictated by the TOC mostly, I have rarely seen this proposed by NR in all my years (Dec 08 VHF is the only time)

The biggest issue there is now is where TOCs drive to the timetable, not to what is capable. Seeing as the most reliable way to capture data is via stopwatching in conjunction with the TOC, what you tend to find are SRTs that cannot be reduced. Modelling software can suggest that shorter times are possible, but unless you can prove so the TOC/FOC is under no obligation to accept them. New traction or traction being used on a route it hasn't used before will have timings based upon modelling and then validated by real time runs. TRUST is useless in this process due to its rounding technique, CCF is also a bit ropey....
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There is also usually some padding in the middle of a journey, especially around the Birmingham area of Cross Country.

There will be due to the complexity of the area and mixed traffic. There is normally some around Kingsbury/Water Orton/Landor St to cater for freight moves that may or may not be there and on the Southern side to cater for Cross City trains.

 

[306024]

I'd agree with a lot of that, in fact I wish I had £1 for the number of times I've said some of it !

Stop watch timings are the best way to get the timings accurate, but these are best done from the driving cab with the driver being fully aware of what data you are trying to capture. Driving standards and eco-driving policies inevitably mean the train should be driven to the timetable, but if you are trying to measure the art of what is possible then this has to be done with the full co-operation of the driver managers and standards teams. And you need to pick a representative driver, as individual driver technique does vary within the standards. This will enable you to build up a large spreadsheet of detailed timings, which is good evidence.

You then need a TOC/FOC who is prepared to accept that not all the results will work in their favour, and will meet different vested interests within your own company. Commercial teams will be interested in journey time in areas where TOCs are in competition with each other as this can have a big effect on revenue allocation. As an operator my view is accurate timings are paramount, but if you are going to cost your company money you need a strong case to get it agreed internally.

Use of theoretical timings does not in my experience always take account of the latest driving standards. This is an area where TOC/FOC and NR need to communicate with each other better to understand each others perspective.

Finally down here performance time e.g.<1> is only used with NR agreement, to use a well worn phrase Network Rail are the custodians of the timetable. Advertised differential on the other hand is determined by the TOC, unless NR suggest its use to avoid iffy connections being advertised.

 

[Bald Rick]

Believe it or not this is the most testing part of the whole Thameslink Programme.

Rebuilding London Bridge and installing the world's first ATO system over ETCS are chickenfeed compared to rewriting a timetable that affects a third of the trains on the national network. And keeping everyone happy while doing it!

Currently TL trains have some allowance approaching the core and within it, either in 'official' allownces or some long dwell times. However with trains runnign at 2 1/2 min headways in the core you can't put any allowances or long dwells in as the trains would then queue up behind. And with 24tph, that queue could get long.

So, how do you allow for inevitable minor delays without screwing performance of a fair chunk of the network? There's quite a bit of headscratching going on right now about it.

 

[asylumxl]

So from this thread it's fair to say driver skill doesn't have a huge effect on making up time?

I realise that different companies will have their own policies on how the trains should be driven, but I would have thought it'd have at least a small effect?

I think this is sort of what the OP was trying to ask.

 

[455driver]

So from this thread it's fair to say driver skill doesn't have a huge effect on making up time?

So next time my train is late I wont bother pushing it to the maximum to try and make the time up, I will just sit there all relaxed pushing buttons and sod the passengers that will be late!

 

[306024]

Not sure how you drew that conclusion. Without the skill of the driver the train doesn't move! The OP was asking about scheduling, which deserves a full answer as it isn't as simplistic as some may think. However the manner in which a driver drives can of course have a big effect on timekeeping, especially when it comes to making up time, so I wouldn't discount it at all.

Meanwhile at Thameslink yes I'd believe it. Presenting trains on time to go through the core section is vital.

 

[asylumxl]

So next time my train is late I wont bother pushing it to the maximum to try and make the time up, I will just sit there all relaxed pushing buttons and sod the passengers that will be late!

Not sure how you drew that conclusion. Without the skill of the driver the train doesn't move! The OP was asking about scheduling, which deserves a full answer as it isn't as simplistic as some may think. However the manner in which a driver drives can of course have a big effect on timekeeping, especially when it comes to making up time, so I wouldn't discount it at all.

Seems you two have never heard of sarcasm .

Of all the reasons it was only briefly mentioned.

And please do 455driver, couldn't give two ****s since I never use your services .

 

[455driver]

And please do 455driver, couldn't give two ****s since I never use your services .

I am moving TOCs soon, so are you sure I wont be driving you in the future?

You are obviously a "f##k you Jack I am alright" sort of person!

 

[306024]

Perhaps you should have put your winking smiley after your first post

I've been mis-interpreted in the past as well so no harm done. Trouble is the written word doesn't always come across with the right effect. I mentioned driver skill as one of the factors, in no particular order, but in providing a logical answer to scheduling it just appeared further down the list. Nothing more sinister than that

 

[asylumxl]

Perhaps you should have put your winking smiley after your first post

I've been mis-interpreted in the past as well so no harm done. Trouble is the written word doesn't always come across with the right effect. I mentioned driver skill as one of the factors, in no particular order, but in providing a logical answer to scheduling it just appeared further down the list. Nothing more sinister than that

Perhaps, but I thought it was obvious enough. In future I will attempt to make my sarcasm clearer .

I am moving TOCs soon, so are you sure I wont be driving you in the future?

You are obviously a "f##k you Jack I am alright" sort of person!

Then I will walk . Given that you'll still be pushing buttons at the origin station I'll probably arrive first .