WTT138

[Colin]

As most drivers will know, all you need is the set working book to do the job - don't get me wrong, the full timetable has it's uses - but the set working book can tell a lot all by itself.

I was issued with my WTT138 set working book this evening (the full WTT hasn't been delivered yet, apparently) and these are my observations from it to get the ball rolling....

Stock Balance (WTT137 in brackets):

Location	Mon - Fri	Sat	Sun
Ealing Common	32 (31)	25 (24)	24 (22)
Upminster	30 (29)	23 (22)	22 (21)
Barking	1 (1)	1 (1)	1 (1)
Richmond	1 (1)	1 (1)	1 (1)
Parsons Green (D Stock)	4 (5)	4 (5)	4 (5)
Parsons Green (C Stock)	4 (3)	4 (3)	4 (3)
Triangle Sidings	AM 2 (3) PM 4 (5)	AM 2 (3) PM 4 (5)	4 (5)
Hammersmith	AM 2 (4) PM 0 (2)	AM 2 (2) PM 0 (0)	N/A
Totals	C Stock 8 (10) D Stock 68 (67)	C Stock 8 (8) D Stock 54 (53)	C Stock 8 (8) D Stock 52 (49)

Now it could be that I've miscounted the D stocks (I so hope I haven't! ;D ;D), but looking at the above table, I hope somebody is on the ball when we change timetables (Sat 12 December is WTT137 and Sunday 13th December is WTT138) - otherwise the stock balance will be a little out....

Points to note are the increase of 1 to the D stocks on Mon - Sat, and 3 extra on Sundays! C stocks lose the two peak extra's on Mon - Fri's.

Additional observations from looking at the set working book:

• Upminster mid day stablers are up to 8, using set numbers 101-107, 110
  
• Ealing Common mid day stablers are down to 5, using set numbers 121-125
  
• Late night Richmond stabler is numbered set 117, and the train keeps that number in the mornings from Richmond on Sat & Sun. The train is changed over at Upminster in the evening on both Sat & Sun, the fresh train being numbered set 25 both days. On Mon - Fri, the train is set 105 and is thus now changed over during the day on all days as opposed to just at the weekends at present.
  
• Currently all D Stocks stabling at Parsons Green Mon-Fri are formed of mid day stablers - this practice ceases with WTT138 and all D Stock Parsons Green stablers are formed of all day runners.
  
• Only one Parsons Green starter on Mon-Fri is formed as a mid day stabler, that being set 122.
  
• Set numbers 151 & 152 remain as the Olympia trains at the weekends, but weekdays are somewhat different - essentially it is still set numbers 151 & 152, however set 152 still does it's first run from Upminster to Ealing before going onto the Olympia service; set 127 no longer exists (which currently does a couple of Olympia's towards the end of the AM peak) and so 151 is left to go it alone in the AM peak.
  
  For the PM peak, set 151 goes from Olympia to Tower Hill, then Wimbledon, Dagenham East and is booked to do a "rusty rail" move at Barking sidings before stabling at Upminster. Set 152 goes it alone through the evening peak before being joined by Set 50 for the rest of the evening. Set 50 stables at Upminster, so that opportunity still exists, along with the new direct Tower Hill service. As we know anyway, and the peak stand times certainly suggest it, the single Olympia's in the peaks will make use of stepping back at High St Ken, though drivers will only get 4 minutes to change ends at Olympia!!
  
• All first & last train numbers have changed.

I think that's about all for now - except to say that set 25 on Sundays is only one round trip (Upm-Rmd-Upm)........I bet it won't be a 'snip turn' ;D ;D

[Deleted]

Err... how can they promise a "more reliable" service on the T-Cup and the Wimblewares with two fewer trains?

[mrfs42]

As a pure guess, two less trains means greater stand time at termini.

Greater stand time gives more recovery time.

More recovery time gives Regulators (or whatever they're called these days) a bit more breathing space when it is needed to reform the service.

Just because there are more trains does not mean that the service levels are more reliable - less trains fighting for the same space means that the gaps between the service can be more even.

[citysig]

Nov 17, 2009 3:29:19 GMT Colin said:

Now it could be that I've miscounted the D stocks (I so hope I haven't! ;D ;D), but looking at the above table, I hope somebody is on the ball when we change timetables (Sat 12 December is WTT137 and Sunday 13th December is WTT138) - otherwise the stock balance will be a little out....

I'm sure they have at least that part in hand and worked out - no doubt a couple of pages of alteration in the Traffic Circular. The H&C will of course have a few alterations of its own that evening.

I've never known that part of it to go wrong. It's the timetables themselves which tend to be the problem ;D

[citysig]

Nov 17, 2009 21:36:14 GMT @innocentabroad said:

Err... how can they promise a "more reliable" service on the T-Cup and the Wimblewares with two fewer trains?

It's the new (and indeed correct) way of thinking.
Much better to have fewer trains and run more reliably.

To basically repeat what mrfs42 has said:

Have 15 trains, running as close together as they can, constantly losing time as they queue up at termini or queue up en-route to the termini. Then because of the late-running they then have to be short-tripped or reformed to recover - providing an un-reliable service during the reformation / short-tripping.

On the other hand have 10 trains, with lower frequencies, but more space to breath. Termini operate better. Much less likelihood of queuing. Much more likelihood of keeping to time, and less need to reform or short-trip. All-in-all a much more reliable service.

Better to have a 5-minute service that works, than a 4-minute service that doesn't.

[Colin]

And I'm sure MetControl would agree, taking a couple of trains out when the job goes 'up the wall' is a well used method of service recovery precisely because it gives service control room for implementing all the other tools of service recovery.

[Deleted]

One thing was missed - penalties ;D It seems to me that due to ever tightning on penalty margin, it is better to run a service late than to cancel it all together.... At least they then meet more targets and have fewer fines to pay!

[Deleted]

Hope I can ask a general WTT question here. If not please redirect me.
I have been looking through some older WTTs that have graciously been provided to me - the first ones I have ever had. (Mostly Met.)

I noticed some have a row for "number of cars" while another has, in the place of that "trip number".
Do these rows alternate on releases of WTTs? Is "trip number" a replacement for the older "number of cars"?
Wouldn't the number of cars be pretty standard per line?

Just wondering.

[superteacher]

Trip number: Any move in one direction on the line is called a trip, this can even be a train coming out of a siding to a platform. Each change of direction, the trip number goes up by 1.

Number of cars is simply how many cars (carriages) the train is formed of.

[mrfs42]

Some will have a row for the number of cars as a hang-over from uncoupling/coupling.

If you look in the District & Piccadilly I sent over you should see something like Q6(4) - which means it is Q stock and 2 cars are uncoupled en route. Terminal uncoupling is shewn with a † in the arrival time.

The number of cars is nowadays standard per line - except in the case of Metropolitan WTTs that have a comment with Train 407 - the Chesham shuttle is made up of 4 cars.

I can't remember OTTOMH if the earlier Met. still had uncoupling going on - it wasn't a lot anyway and it would have been at Watford and Uxbridge in that sort of era.

Anyway, I digress:

I've forgotten what 'snip turn' and 'on the bounce' mean - enlightenment, please?

[Deleted]

Snip turn - short duty (e.g. book on 07.00, book off 15.00 but with only a few hour's work - and certainly nothing like 8 hours!!).

On the bounce - a continuous stretch (e.g. "four days on the bounce").

;D ;D ;D

[mrfs42]

Ta.

[Deleted]

Nov 17, 2009 22:01:56 GMT mrfs42 said:

As a pure guess, two less trains means greater stand time at termini.

Greater stand time gives more recovery time.

More recovery time gives Regulators (or whatever they're called these days) a bit more breathing space when it is needed to reform the service.

Just because there are more trains does not mean that the service levels are more reliable - less trains fighting for the same space means that the gaps between the service can be more even.

[Deleted]

Nov 17, 2009 22:01:56 GMT mrfs42 said:

As a pure guess, two less trains means greater stand time at termini.

Greater stand time gives more recovery time.

More recovery time gives Regulators (or whatever they're called these days) a bit more breathing space when it is needed to reform the service.

Just because there are more trains does not mean that the service levels are more reliable - less trains fighting for the same space means that the gaps between the service can be more even.

Not so sure it will all be in the termini layovers, I think you will witness revised (additional) running times in WTT138, particularly in the peaks, in a similar (although I doubt as extensive) way in which running times were revised on a large scale for Picc WTT 44 (Oct 08)

[mrfs42]

Nov 18, 2009 23:08:43 GMT @shedcompnodosh said:

Not so sure it will all be in the termini layovers, I think you will witness revised (additional) running times in WTT138, particularly in the peaks, in a similar (although I doubt as extensive) way in which running times were revised on a large scale for Picc WTT 44 (Oct 08)

They are - aspect has already commented on this here.

The timing revisions for Picc 44 are indeed very interesting, but belong in another thread.

I was using terminal stand time as it is the easiest variable to calculate and to a certain extent is is also the most controllable variable in TT structure.

Intermediate stand time is a bit of a black art by comparison.

[Deleted]

Nov 17, 2009 22:01:56 GMT mrfs42 said:

As a pure guess, two less trains means greater stand time at termini.

Greater stand time gives more recovery time.

Interesting reversal, less trains gives more time at terminals purely becuase of the single platform at Barking or Plaistow, but at the expense of headway.
To maintain headway, as on the District, you need more trains to give more stand time at termini if you are to maintain headways (so +1 for the Richmond runers).

As it was buried in a different thread, I re-post my observations on WTT 138

Nov 15, 2009 22:27:39 GMT @aspect said:

In the new WTT 138 stand time at Wimbledon reduces from, on average, 15 - 18 mins to 8 - 11 mins. Ealing increases slightly from (average) 8 - 10 mins to 10 - 12 mins. Richmond increases notably from, on average, 11 - 13 to 17 - 19 mins.
All of which is actually rather sensible as extended dwell times reduces the need to short trip a late train and curtailing or diverting an Ealing or Richmond service is more critical than a Wimbledon service where there is twice the frequency and where the point of origin (generally) alternates between Upminster and Edgware Road, hence any delay causing late running is generally only going to affect alternate trains.

Having examined the running timings a bit closer now, they aren't as grim as it first looked, it would appear the off peak running times to Richmond and Wimbledon are the same. The Ealing service gains an average of 6 mins running time off peak and 10 mins peak. Richmond an Wimbledon gain about 6 mins extra running time peaks only. One assumes the additional times on the Ealing service are attributable to the delays caused by the Piccadilly Line service at Acton Town and Hanger Lane Junct.

Only other note is that whilst the peak service will continue to change from the off peak Upminster - Wimbledon, Tower - Ealing pattern, instead of going to the present Tower/Barking/Dagenham - Wimbledon and Upminster - Ealing, it appears to go to Tower/Barking/Upminster - Wimbledon and Dagenham/Upminster - Ealing. As before there are odd trains that "buck the trend"

[mrfs42]

Nov 18, 2009 23:36:05 GMT @aspect said:

Interesting reversal, less trains gives more time at terminals purely becuase of the single platform at Barking or Plaistow, but at the expense of headway.

Surely not - less trains means a greater headway between them; would it not be at the expense of service density?

I might be wrong in this, so I'm open to correction, but 'the single platform at Barking or Plaistow' just doesn't really wash with me - by that token every individual platform is a 'single platform'.

Plaistow is a red herring as the platform occupancy is away from the main and successive trains; on book there isn't a consecutive stream of trains turning back in Plaistow; likewise platform 3 at Barking. Now, if you were talking of either platforms 6 or 1/2 at Barking I would concede that there would need to be a minimum time of 5 booked minutes between consecutive moves (if tipping out).

Likewise with the reversals I'd guess at 1 - 2 minutes clear space needed behind/around reversing trains, depending on track circuit layout, and looking at the booked working there's never anything arriving less than ½ min before a departure or 1½ min after a departure. Less trains means that the platforms at termini can be occupied for longer - ie new headway less 30 seconds, notwithstanding if you've got an odd service interval that doesn't fit cleanly the stand time might need to be tinkered with further.

If you're saying that the single platforms at Barking and Plaistow are a bottleneck, restricting the service: what about OB45/train waiting at OB37 or EE210/train waiting at EE225?

I apologise if I've got completely the wrong end of the stick, but I just can't see a straightforward (well, any; if I'm being honest) relationship between the stand time at Richmond/Wimbledon/Ealing and Hammersmith being a function of the bays at Plaistow and Barking. There are other factors en route that would need to be considered; not the least of which being WB services from Tower Hill, Manky House and the middle pair at Aldgate.

EDIT: You're not thinking of maintaining the same (WTT 137) headway with less trains are you? In that case I can understand completely the shortening of layover time - however I'm still flummoxed by the single platforms at Barking and Plaistow.

[citysig]

Nov 18, 2009 12:18:35 GMT @jv3531 said:

One thing was missed - penalties ;D It seems to me that due to ever tightning on penalty margin, it is better to run a service late than to cancel it all together.... At least they then meet more targets and have fewer fines to pay!

Not exactly. These days measuring of a train service on LU is mostly done using lots of wild calculations, but the main part is the service headway - the frequency of services at a particular location.

In order to satisfy a headway, this may indeed mean that a train will run "late." But of course it is only late as far as us the operator is concerned. Our customers do not generally have access to our timetables and so to them it's only a train.

In theory, although the H&C currently uses 16 trains for it's off-peak service, with a bit of juggling, you could have as many as 4 of them "cancelled" yet still manage to maintain a service that meets the headways we would be measured on.

Cancellations do get recorded of course, but they only factor into things if delays and missed headways come as a consequence.

[Colin]

And snapshots, don't forget yer snapshots MetControl!! ;D ;D ;D

A quick explanation of the other way in which service control is measured against a target:

Starting at 6am (9am on Sundays), and then every 3 hours until midnight, service control has a snapshot target - the number of trains in service against the number specified at that hour in the WTT. It doesn't matter where they are, or whether or not they are on time, etc; as long as a train is not cancelled it is in service. If all scheduled trains are in service at the time specified, service control has met it's snapshot target. If a train is cancelled at 1 minute past the hour specified but re-enters service at xx59 in the hour before the next snapshot, both snapshots will not show the cancellation. Needless to say many things that happen are based around snapshot times ;D ;D

As for the cancellation verses service recovery benefits, lets try a couple of examples and see what people think:

Bakerloo line, weekday morning peak. There's a signal failure at Paddington on the northbound, and because there are points involved, there is an initial delay whilst they are scotched & clipped. We'll be kind and say it's taken 15 minutes to get the first train through, but of course as each subsequent train passes through the area, it too will be delayed as the driver applies the appropriate procedure. So, how long will it take for trains to start blocking back behind the failure? How long will it take to start affecting the Southbound? Don't forget that having trains sat in the tunnel between stations is a massive no no.

Well this was one of the many scenarios I did as part of my controller training (something I will be repeating next year, but that's another thread on it's own!).

With a headway of 2 or 3 minutes, and only 2 platforms at Elephant & Castle (where stepping back is employed), it doesn't take a genius to realise that you must cancel trains if you are to have any hope of recovering the situation.

In another scenario, (which I can't remember right now), I had no option but to suspend the service Paddington to Piccadilly Circus both roads. I had trains reversing South to North at Paddington and North to South at Piccadilly Circus. Whilst the service North of Paddington wasn't such an issue, the time it takes to reverse there was and if I hadn't cancelled a few trains, they would have soon blocked back though Queens Park. The Elephant & Castle to Piccadilly Circus 'shuttle' was much more critical however - it only needed 5, maybe 6 trains maximum (again it takes time to reverse at Piccadilly Circus) yet I had something like 10 or 11 trains in that section. Cancelling trains was a must do. Sod the "penalties"!!

Remember I said you mustn't have trains in tunnels between stations? Well take the Victoria line - they have more trains in service than platforms - cancellations are one of the first actions a Victoria line controller will take.

On lines like the District, well all of SSR really, cancellations are not always an immediate concern/consideration - but it is a tool that is used quite often and can usually be more than justified when the bean counters start getting involved (usually long after the event and with plenty of time to analyse the ins & outs of whether or not a cancellation was justified ).

We seem to have wandered way off topic, but never mind, hopefully there's some food for thought within this post and I'm quite happy to continue the thread drift as it's already gone too far to recover anyway ;D ;D ;D ;D

[mrfs42]

Nov 19, 2009 4:34:24 GMT Colin said:

And snapshots, don't forget yer snapshots MetControl!! ;D ;D ;D

Just goes to show; you can learn something every day!

I've occasionally pondered the trumpeting of snapshots in the WTT; realising that they couldn't possibly be purposeless............

Wonder what changed between '95 - '98ish to put the 'snapshots' in?

[Deleted]

Nov 19, 2009 0:14:29 GMT mrfs42 said:

You're not thinking of maintaining the same (WTT 137) headway with less trains are you? In that case I can understand completely the shortening of layover time - however I'm still flummoxed by the single platforms at Barking and Plaistow.

Your the timetable expert MRFS, however my point was two fold. Because as soon as a H&C train leaves Barking bay or Plaistow bay, the next train is waiting to enter the bay. If you extend the platform dwell times at terminals (which is indeed excellent for service recovery) you hold the train outside and waiting to come in unless that train is not as frequent (ie. with a greater headway between). For the new timetable that is exactly the case. The longer dwell time at Plaistow and Barking is possible only because the H&C service headway is increased from a train every 8mins to a train every 10mins.

My contra reference in respect of the District Line (because this thread is WTT138) where we have multiple platform availability is that we are indeed maintaining the same headway as WTT 137 (x5 mins to Upminster and Wimbledon and x10 mins to Richmond and Ealing) and thus in order to give additional dwell time at Richmond (up from 12 mins to 18) and maintain the same headway an additional train is required when compared to WTT137, and that is set number T25. (I haven't yet had time to examine how reduced layover at Wimbledon is achieved with the same headway and same running time on what looked like the same number of trains).

Hence my conclusion that increased layover time can only be achieved at the expense of either, headway or running times or needing additional rolling stock. (thus expanding upon your thoughts that reduced rolling stock means additional layover time at termini)

[Deleted]

Nov 17, 2009 21:36:14 GMT @innocentabroad said:

Err... how can they promise a "more reliable" service on the T-Cup and the Wimblewares with two fewer trains?

Thanks for the answers, guys. I take it that those of you who believe that fewer trains = better service would therefore expect the "main line" operated by D stock to have a worse service under the new WTT as there are to be more trains!

[Colin]

Not in WTT138's case, no.

The extra trains are being provided to give additional layover time at terminus's - headways remain the same as before.

[Deleted]

Nov 19, 2009 14:44:50 GMT Colin said:

Not in WTT138's case, no.

The extra trains are being provided to give additional layover time at terminus's - headways remain the same as before.

So why not at Wimbledon too? Sorry I don't accept your earlier answer - surely you can't just send a C stock down the main line whenever you feel like it and you certainly can't send a D stock north of HSK

(Sorry if you think I'm being obstreperous...)

[Deleted]

The additional running time on a peak rounder from Upminster to Wimbledon is in excess of 10 minutes when compared to WTT137, so this must certainly play a factor in the requirement of additional trains, allied to the terminus layovers increasing

[citysig]

Nov 19, 2009 4:34:24 GMT Colin said:

And snapshots, don't forget yer snapshots MetControl!! ;D ;D ;D

If all scheduled trains are in service at the time specified, service control has met it's snapshot target.

Just to polish this bit a little if I may.

Trains can be cancelled by Service Control, but not generally because of Service Control.

For this reason, although it is Service Control who issue the Snap-shot, cancellations will be shown with their respective reasons - this could be earlier signalling failure, defective train, no train operator, passenger action etc.etc.

So, technically, much as it's issued by us, it's more the snap-shot for those external to Service Control who are responsible for the assets that make up the whole service. So there is never a time where we would "fail" to meet "our" snap-shot. Keep in mind that although we play with pieces to provide the service, someone else is responsible for making sure they are there to play with ;D

[mrfs42]

Nov 19, 2009 21:30:09 GMT @shedcompnodosh said:

in excess of 10 minutes

That low humming noise you can hear?

It's not the Taos Hum it's JP Thomas spinning in his grave.

I spent an enjoyable hour this afternoon reading the District timetables 1908 - 1911 - such major alterations then in the schedule would have been picked up in the 'Black Book' long before they're necessary and introduced wholesale. Were the problems that chronic to require such an acute reaction - very, very interesting.

I suppose someone will say it - so I'll get a pre-emptive strike in: Could this extra 10 minutes be the price to pay for the Extended Circle? [1]
(I'll keep my thoughts under wraps, protempore - not 'cos I'm scared to say it).

aspect - TVM I'll revisit it when I'm not quite so pooped!

[1] I'm not saying it 'is', <Para Handy> 'chust ponderin' </Para Handy>

[Colin]

Nov 19, 2009 20:08:29 GMT @innocentabroad said:

So why not at Wimbledon too?

What? Have extended layover times?

I don't work in timetables so I can only suggest an answer.....

Trains travelling to Richmond or Ealing Broadway do suffer from reliability issues whereas the D stock Wimbledon trains tend to suffer less so (and in any case have the C stock service as back up) - I would assume that timetables are thinking the best way to improve reliability on the Ealing & Richmond roads is to increase the layover time at those locations, coupled with a few minutes additional running time.

Also, it is far easier to turn a late running Wimbledon train at Parsons Green that it is to turn a late running Richmond train at Gunnersbury. Whilst turning a late running Ealing train at Acton Town is possible, via 26 siding to the west of the station, it will have an impact on the Piccadilly line and it is therefore not a routine reversal move - in fact in the 5 years I've been driving on the District, I never known a D stock to go in there.

Reversing at Hammersmith, via Barons Court siding, is also technically possible but would definitely upset the Piccadilly line and is therefore not usually ever an option.

So in essence, it's case of either divert an Ealing/Richmond train to Parsons Green, or sort it out at the east end of the line. That's just moving a problem around rather than solving it, which is what WTT138 appears to be doing.

I would stress that what I have said is merely an educated guess.

Nov 19, 2009 20:08:29 GMT @innocentabroad said:

Sorry I don't accept your earlier answer - surely you can't just send a C stock down the main line whenever you feel like it and you certainly can't send a D stock north of HSK

(Sorry if you think I'm being obstreperous...)

obstreperous? I have no idea what that means, but I'm not concerned about that - what does concern me is where you get the idea that I said anything about sending a D stock north of High Street Kensington. I'm a professional District line driver and so I would never ever be daft enough to make such an absurd suggestion!!

C stocks on the District 'main'? What is wrong with that? (not that I recall saying that either - perhaps a quote of what I'm supposed to have said would be useful )

If there is a problem, or a cancellation gap that needs covering, the line controller is perfectly within their rights to divert a C stock Wimbledon service as they see fit. C stocks also operate on the District 'main' as Circles or Hammersmith & City's - so there's hardly a precedent being set

Nov 19, 2009 21:30:09 GMT @shedcompnodosh said:

The additional running time on a peak rounder from Upminster to Wimbledon is in excess of 10 minutes when compared to WTT137, so this must certainly play a factor in the requirement of additional trains, allied to the terminus layovers increasing

Wimbledon layovers are not increasing - they are actually decreasing.

And where do you get an additional 10 minutes running time on peak Wimbledon's from? A few random comparisons.......

WTT137	WTT138	Differential
(T33) UPM 0718½ - WIM 0846½	(T11) UPM 0718½ - WIM 0851	+4½
(T107) DAGE 0753½ - WIM 0912	(T42) DAGE 0750 - WIM 0911	+2½
(T61) WIM 1742½ - UPM 1909½	(T105) WIM 1740 - UPM 1915½	+6
(T21) WIM 1725½ - DAGE 1842½	(T61) WIM 1727½ - DAGE 1850½	+6
(T75) ERD 0827½ - WIM 0859	(T77) ERD 0824½ - WIM 0855	-1
(T162) WIM 0757½ - ERD 0829½	(T70) WIM 0755 - ERD 0827½	-½
(T162) WIM 1721 - ERD 1753	(T71) WIM 1724 - ERD 1757½	+1½
(T74) ERD 1643 - WIM 1714½	(T71) ERD 1644½ - WIM 1715	+1

So the biggest increase is 6 minutes, in line with the increases in running time for the Ealing & Richmond roads. Actually, having re-read this post prior to hitting the post button; I presume you have made your comments after consulting both WTT's - assuming that to be the case, are you misreading WTT137? I only ask as the vast majority of Wimbledon trains that do go past Barking in the peaks, in WTT137, do not go past Dagenham East, which is 10 minutes from Upminster funnily enough.....and there are far more Wimbledon trains to & from Upminster in the peaks in WTT138...

[Deleted]

Regarding the difficulties inherent in turning trains at Gunnersbury, I wonder if a reversal there would be easier if the existing trailing crossover on the London side of the station were supplemented with a central reversing siding on the Richmond side of the station. The former four-track alignment provides plenty of space that could be used to get a siding of sufficient length for S7s and 378s, and with the station now under the TLC of LO, staff should be available to assist with reversals.

Would that make it easier to write a timetable like WTT138?

[Deleted]

Nov 20, 2009 4:14:01 GMT Colin said:

Nov 19, 2009 20:08:29 GMT @innocentabroad said:

So why not at Wimbledon too?

What? Have extended layover times?

I don't work in timetables so I can only suggest an answer.....

Trains travelling to Richmond or Ealing Broadway do suffer from reliability issues whereas the D stock Wimbledon trains tend to suffer less so (and in any case have the C stock service as back up) - I would assume that timetables are thinking the best way to improve reliability on the Ealing & Richmond roads is to increase the layover time at those locations, coupled with a few minutes additional running time.

Also, it is far easier to turn a late running Wimbledon train at Parsons Green that it is to turn a late running Richmond train at Gunnersbury. Whilst turning a late running Ealing train at Acton Town is possible, via 26 siding to the west of the station, it will have an impact on the Piccadilly line and it is therefore not a routine reversal move - in fact in the 5 years I've been driving on the District, I never known a D stock to go in there.

Reversing at Hammersmith, via Barons Court siding, is also technically possible but would definitely upset the Piccadilly line and is therefore not usually ever an option.

So in essence, it's case of either divert an Ealing/Richmond train to Parsons Green, or sort it out at the east end of the line. That's just moving a problem around rather than solving it, which is what WTT138 appears to be doing.

I would stress that what I have said is merely an educated guess.

obstreperous? I have no idea what that means, but I'm not concerned about that - what does concern me is where you get the idea that I said anything about sending a D stock north of High Street Kensington. I'm a professional District line driver and so I would never ever be daft enough to make such an absurd suggestion!!

C stocks on the District 'main'? What is wrong with that? (not that I recall saying that either - perhaps a quote of what I'm supposed to have said would be useful )

If there is a problem, or a cancellation gap that needs covering, the line controller is perfectly within their rights to divert a C stock Wimbledon service as they see fit. C stocks also operate on the District 'main' as Circles or Hammersmith & City's - so there's hardly a precedent being set

Nov 19, 2009 21:30:09 GMT @shedcompnodosh said:

The additional running time on a peak rounder from Upminster to Wimbledon is in excess of 10 minutes when compared to WTT137, so this must certainly play a factor in the requirement of additional trains, allied to the terminus layovers increasing

Wimbledon layovers are not increasing - they are actually decreasing.

And where do you get an additional 10 minutes running time on peak Wimbledon's from? A few random comparisons.......

WTT137	WTT138	Differential
(T33) UPM 0718½ - WIM 0846½	(T11) UPM 0718½ - WIM 0851	+4½
(T107) DAGE 0753½ - WIM 0912	(T42) DAGE 0750 - WIM 0911	+2½
(T61) WIM 1742½ - UPM 1909½	(T105) WIM 1740 - UPM 1915½	+6
(T21) WIM 1725½ - DAGE 1842½	(T61) WIM 1727½ - DAGE 1850½	+6
(T75) ERD 0827½ - WIM 0859	(T77) ERD 0824½ - WIM 0855	-1
(T162) WIM 0757½ - ERD 0829½	(T70) WIM 0755 - ERD 0827½	-½
(T162) WIM 1721 - ERD 1753	(T71) WIM 1724 - ERD 1757½	+1½
(T74) ERD 1643 - WIM 1714½	(T71) ERD 1644½ - WIM 1715	+1

So the biggest increase is 6 minutes, in line with the increases in running time for the Ealing & Richmond roads. Actually, having re-read this post prior to hitting the post button; I presume you have made your comments after consulting both WTT's - assuming that to be the case, are you misreading WTT137? I only ask as the vast majority of Wimbledon trains that do go past Barking in the peaks, in WTT137, do not go past Dagenham East, which is 10 minutes from Upminster funnily enough.....and there are far more Wimbledon trains to & from Upminster in the peaks in WTT138...

Where I get the additional 10+ minutes on an Upminster-Wimbledon rounder from is the "link time allowance data" that was actually used to compile the timetable itself, as opposed to comparing trips between WTT's.

A friend in the TTO showed me this yesterday.

It lists each section between stations and between which time bands (if any) trains have an RTV applied to them. (Run Time Variation, above and beyond the base run time)

I did quote the word 'rounder', you appear to be looking at one way trips in your comparisons!

As for Wimbledon layovers, they will always remain comparitvely low when compared to EBY/RMD, as TTO will always attempt (I'm sure there are some recent examples where they may not, early or late, before someone pulls me up on it!) to avoid inverted layovers at Wimbledon between C & D, therefore the D stocks to WDN need to pretty much match the layovers of the C's.