Why don't SWT Fasts Stop at Clapham Junction

[DynamicSpirit]

There seems to be quite a lot of demand for more SWT trains on the fast lines to stop at Clapham Junction, and as I understand it the standard explanation why so many trains don't stop there is that there aren't enough paths to allow it.

This puzzles me. My reasoning would have been that the moment some trains on the fast lines stop there, and some don't. That presumably wastes paths because it means some trains are slower than others. If instead, just about all trains stopped there, then all trains would end up travelling around the same speed, which would presumably allow more efficient use of the tracks and so free up, rather than consume, paths. While having all trains stop there would in many cases add a few minutes to journey times to Waterloo, I get the impression demand for interchanging at Clapham Junction is sufficient to justify that.

So what's wrong with my reasoning?

 

[yorkie]

This question crops up from time to time, here are some reasons why fast trains do not stop at peak times:-

The volume of traffic is so large that trains are unable to stop on the fast Southwestern lines at Clapham Jn in the peak. This has been the position for many years.

One of the reasons is that all available paths through Clapham Junction are used in the morning peak so any additional train stopping at Clapham Junction costs a couple of slots therefore less services can operate with the obvious consequences.

To maximise capacity you have to have a linear schedule, the loop for platform 7 at Clapham has a tight speed restriction and adds 2-3 minutes to a journey, either all trains stop at Clapham or none at all otherwise there would have to be a significant reduction in capacity. Southern have the advantage of not having to deal with such a spped restriction, plus practically all Southern trains stop at Clapham during the off peak wheras SWT operates differently.

Things have been this way since before NSE days.

As for why some trains call there off-peak, and some don't, that's because there is more spare capacity at off-peak times, so some trains can call.

However all Southern operated services should call at Clapham Junction, including their Express trains to Gatwick Airport (branded Gatwick Express) - there is no excuse for those trains not calling there!

But a station call there would take a couple of minutes at least due to the slow speeds and dwell time, this additional journey time is also unacceptable on long-distance services.

 

[swt_passenger]

The explanation (which still stands AFAIK) is provided in an appendix to the 2006 SW RUS: http://www.networkrail.co.uk/browse...th west main line/appendices/appendix 5.1.pdf

It confirms the 3.5 minute time to call at Clapham Jn, (whereas the peak headway actually used is 2.5 minutes). So if all trains stopped the theoretical capacity is about 17 tph, against the current service, where about 22 tph of the possible 24 tph are actually used (to give a 'firebreak' margin for delays).

Part of the explanation for the long dwell times not mentioned so far is that the up fast platforms are not long enough for any of the stock used on the peak services, whether they are 10.444, 12.450, or various 158/9 combinations up to ten car. SDO even if possible by individual carriage adds to the theoretical dwell time.

Another question that then arises is how do the peak trains manage to stop elsewhere 'en route', and the answer to that is that on route sections where calls occur they are not yet (or no longer) running at max capacity, because certain services will cross from or to the slow lines at Surbiton.

 

[JonathanH]

This question crops up from time to time, here are some reasons why fast trains do not stop at peak times:-




As for why some trains call there off-peak, and some don't, that's because there is more spare capacity at off-peak times, so some trains can call.

However all Southern operated services should call at Clapham Junction, including their Express trains to Gatwick Airport (branded Gatwick Express) - there is no excuse for those trains not calling there!

On the contrary, by having the Gatwick Express run fast through Clapham Junction, the following xx02/xx17/xx32/xx47 trains have a clearer path to stop at Clapham Junction. This is apparent from the next path being xx06/xx21/xx36/xx51, xx21/xx51 being non-stop at Clapham Junction and the East Grinsteads going at xx23/xx53.

Delaying the xx02/xx32 from Victoria would have pathing implications at Stoats Nest Junction and Gatwick Airport and would affect connections to the North Downs Line at Redhill.

 

[phil281]

The speed restriction annoys me, why can't they use platform 8? Before you say its too short it can be extended it over the points into platform 7 which is a pointless platform? Would speed up things so much

 

[richw]

There was a question on tonights The Chase, which is the busiest railway station in the UK, with the answer of Clapham Junction.
as above if more trains stopped it would reduce the available paths.

 

[louis97]

The speed restriction annoys me, why can't they use platform 8? Before you say its too short it can be extended it over the points into platform 7 which is a pointless platform? Would speed up things so much

As far as I was aware, P8 isnt used because of a huge gap, which is deliberate to allow for trains to be able to pass through at the maximum possible speed, rather than at a slower speed which reducing the gap would cause. Open to correction on that though.

 

[DynamicSpirit]

The explanation (which still stands AFAIK) is provided in an appendix to the 2006 SW RUS: http://www.networkrail.co.uk/browse...th west main line/appendices/appendix 5.1.pdf

It confirms the 3.5 minute time to call at Clapham Jn, (whereas the peak headway actually used is 2.5 minutes). So if all trains stopped the theoretical capacity is about 17 tph, against the current service, where about 22 tph of the possible 24 tph are actually used (to give a 'firebreak' margin for delays).

Part of the explanation for the long dwell times not mentioned so far is that the up fast platforms are not long enough for any of the stock used on the peak services, whether they are 10.444, 12.450, or various 158/9 combinations up to ten car. SDO even if possible by individual carriage adds to the theoretical dwell time.

Another question that then arises is how do the peak trains manage to stop elsewhere 'en route', and the answer to that is that on route sections where calls occur they are not yet (or no longer) running at max capacity, because certain services will cross from or to the slow lines at Surbiton.

Ah, thanks swt_passenger, that would be the explanation I was looking for.

Edit: Reading the RUS you linked to reveals this:

It appears that the additional 3½ minutes journey time necessary to stop trains at Clapham Junction disbenefits passengers for Waterloo more than the interchanging passengers benefit. Moreover, this disbenefit would drive some passengers off the trains, adding to road congestion.

So they are saying stopping more trains at Clapham Junction is more of a disadvantage than an advantage. I'm not sure how plausible that is - but if/when CR2 is built presumably the benefits of stopping at CLJ will become much greater. The suggestion that an extra 3.5 minutes journey time will induce passengers travelling into London to swap to the car seems a little absurd to me, considering how bad traffic in central London is.

On the other hand I see the 3.5 minutes quoted isn't dwell time, it also covers slowing down. I don't think the slowing down component would reduce available paths, it would only be if the dwell time at the station gets too close in magnitude to the interval between trains. That seems to me to throw some doubt on whether having all trains stopping would reduce paths.

 

[MCR247]

On the other hand I see the 3.5 minutes quoted isn't dwell time, it also covers slowing down. I don't think the slowing down component would reduce available paths, it would only be if the dwell time at the station gets too close in magnitude to the interval between trains. That seems to me to throw some doubt on whether having all trains stopping would reduce paths.

Well don't you think that Network Rail is going to know what it is talking about...? :roll:

 

[MidnightFlyer]

As far as I was aware, P8 isnt used because of a huge gap, which is deliberate to allow for trains to be able to pass through at the maximum possible speed, rather than at a slower speed which reducing the gap would cause. Open to correction on that though.

I believe that to be the case too. Anything stopping will use p7.

 

[DynamicSpirit]

Well don't you think that Network Rail is going to know what it is talking about...? :roll:

lol, I'm sure that in most cases Network Rail do know more than you or I do. But that's not going to stop me questioning it if something they've written appears illogical or silly If their reasoning is in fact sound then, given the number of rail insiders and experts here, I'm sure someone will explain and put me right....

 

[Lrd]

On the other hand I see the 3.5 minutes quoted isn't dwell time, it also covers slowing down. I don't think the slowing down component would reduce available paths, it would only be if the dwell time at the station gets too close in magnitude to the interval between trains. That seems to me to throw some doubt on whether having all trains stopping would reduce paths.

It takes less time for a train to sail through platform 8 than it does for it to stop at platform 7, you still have the same headways (the minimum time between trains) to keep to, therefore if there was more trains stopping then you wouldn't have enough time in the hour to keep all trains running. If they want to keep the same amount of trains then there is no way to fit them through, they only way to increase the amount of trains calling is to remove trains passing through.

I know I didn't explain that too well so hopefully someone else will explain what I am trying to get at.

 

[30907]

The only way to have up fast trains stopping in the peak would be to use two platforms alternately, as at London Bridge. Which brings us back to the short length of P7... and the turnout restriction would still delay the following train.

BTW I'd always thought the reason for using P7 was that it was on the inside of the curve so you didn't need additional staff to dispatch the train.

 

[Helvellyn]

Now if Stagecoach had been allowed to keep the 20 year franchise for SWT it had been awarded at theturn of the century, we'd probably by now be bemoaning the "old" Clapham Junction, but enjoying the benefits of the "new" Clapham Junction, built on the straight tracks between Clapham and Queenstown Road, able to take 12 car trains on straight platforms. That might possibly have allowed more trains to stop at Clapham Junction, but the headways issue would still exist.

 

[Muzer]

Now if Stagecoach had been allowed to keep the 20 year franchise for SWT it had been awarded at theturn of the century, we'd probably by now be bemoaning the "old" Clapham Junction, but enjoying the benefits of the "new" Clapham Junction, built on the straight tracks between Clapham and Queenstown Road, able to take 12 car trains on straight platforms. That might possibly have allowed more trains to stop at Clapham Junction, but the headways issue would still exist.

Sorry, I'm not quite up to speed with this - can someone tell me what happened to the loss of the 20 year franchise? I didn't even know they had been awarded one...

 

[Zoe]

Sorry, I'm not quite up to speed with this - can someone tell me what happened to the loss of the 20 year franchise? I didn't even know they had been awarded one...

Around 2000 there was a plan to award a series of 20 year franchises. In 2001 Stagecoach were announced as preferred bidder for the South West franchise and heads of terms were signed. In 2002 there was a change in policy by the SRA to shorter franchises (the only 20 year deal that actually went ahead was Chiltern) and Stagecoach only ended up with thee year deal to 2007 when the current franchise including Island Line was tendered.

 

[Muzer]

Ah, I see, thanks. Yeah, definite shame it didn't go ahead.

Somewhat related to this - I might be going crazy, but were there plans at one point for a Greater Western franchise to merge the current SWT + FGW, or am I thinking of something else? If there were plans, do they still exist or have they been dropped?

 

[Zoe]

Somewhat related to this - I might be going crazy, but were there plans at one point for a Greater Western franchise to merge the current SWT + FGW, or am I thinking of something else? If there were plans, do they still exist or have they been dropped?

I believe you are thinking of the plan to transfer the Waterloo to Exeter route to the Wessex franchise.

 

[Muzer]

Ah, quite possibly, yeah, I had read about that recently, thanks.

 

[infobleep]

Could they ever change the platform layout or track layout to allow trains to stop there?

Alternatively would they run fast trains which switch to slow lines after Wimbledon. After all I believe the slow line platforms are being extended.

I regularly travel through central London only because no fast trains stop at Clapham Junction and if I went to Clapham Junction during peak rush hour it would extend my already long journey by another 20-30minutes. I wonder how many other people are in the same situation.

What about trains stopping in the evening? Can't they lengthen platform 9 or does that have the same curve problems? I see that during the morning at one point there is only a 3 minute gap between trains leaving platform 9. If they can't stop trains in the morning, at least why not stop trains in the evening.

I mean currently if one is travelling from Clapham Junction to Poole during peak rush hour, it takes an extra hour to get there from Clapham Junction. So 3+ hours instead of 2. You arriving something like 15 minutes before you would do if you travelled outside of peak rush hour.

Alternatively I do not see why an easement can't be put in place to allow passengers to travel up to London Waterloo. After all that is the route that National Rail Enquiries want to send people during peak rush hour.

They are doing work at the moment to entend the canopy on platform 9 at Clapham Junction but it's not the canopy that passengers such as myself would like extended but the platforms, so trains can stop there.

Yesterday morning the 7.10 from Haslemere was cancelled due to the speed restriction through Wimbledon. The next service, which forms the 7.45 from Guildford, was stopped at Witley and Milford to pick up passengers. This caused the train to run late and it end up behind another train from Woking. Whilst it would have been delayed regardless, I believe from looking at the times, that the 2 extra stops caused it to be further delayed into London than it otherwise would have been.

Contrast this to the evening. In the evening the 18.39 to Poole from Waterloo was cancelled and started at Basingstoke. The next train, which was the Portsmouth one which I was on, didn't stop at Clapham Junction to pick up passengers. Yet a reasonable number of passengers get 18.39 train from Clapham Junction. It is the only train which you can get to pick up the Portsmouth train because that train stops at West Byfleet instead of Clapham Junction. It is a 12 car train of course. It would have made our train late but then they happily stopped a morning train and further delayed that.

Interestingly if they introduce longer trains on the SWT network in the next couple of years, will even fewer trains stop at Clapham Junction? Are they required to stop fast trains there or could they cancel them all if they liked?

 

[455driver]

train length is irrelevant to stopping fast trains at Clapham jn as the Desiros are all fitted with SDO, the problem is extra trains run during the peaks and there is simply not the line capacity to allow for the station stop, the first (fast train) stops are at Surbiton where the train is routed onto the slow lines.

All lines in and out of Waterloo run at maximum capacity.

 

[mister-sparky]

Well probably because they're supposed to be FAST trains. So why should they stop 10mins out of Waterloo?!

 

[Bedpan]

Ah, I see, thanks. Yeah, definite shame it didn't go ahead.

Somewhat related to this - I might be going crazy, but were there plans at one point for a Greater Western franchise to merge the current SWT + FGW, or am I thinking of something else? If there were plans, do they still exist or have they been dropped?

Wasn't the Greater Western franchise formed by the merger of Great Western and Thames Trains?

Ah, I see, thanks. Yeah, definite shame it didn't go ahead.

Somewhat related to this - I might be going crazy, but were there plans at one point for a Greater Western franchise to merge the current SWT + FGW, or am I thinking of something else? If there were plans, do they still exist or have they been dropped?

Wasn't the Greater Western franchise formed by the merger of Great Western and Thames Trains?

Back to the subject in hand.....what I don't get is why it takes 3.5 minutes to stop a train there. I thought that the standard time taken to make a station stop is around 2 minutes. This is in fact borne out on the Thameslink line. The fats train from Harpenden to London leaves 4 minutes after the slow train and usually passes the slow train when it is Mill Hill Broadway / Hendon area - ie the slow train has made 2 -3 extra stops in those 4 minutes. There is a speed limit of 40mph (it used to be 40, so assume it still is) through Clapham Junction and it must take less time to stop from 40mph than it does to stop from 80 odd mph.

 

[455driver]

During the peaks if a "fast" train was to stop at Clapham jn the train behind it will catch it up so instead of going through at 40 (up) or 50 (down) it will crawl through at 10 (after stopping at the signal before), imagine the delays it would cause!

 

[heart-of-wessex]

I've wondered why SWTs 159s use P7 at Clapham, the times I've been on one that stops there uses 7 instead of 8, and nothing passes us or uses 8 anyway in the process, plus you have to slow down for a signal check into P7. Couldn't they use P8 and be done with it?

I did also hear about in the early days of SWT with Slammers, pre CDL stock, commuters were protesting about not enough expresses calling there. Apparently some would pull the emergency chord at the right moment for the train to stop somewhere in the platform, and as there's no door locks, they'd just open the door and get off!

Couldn't exactly do that now anyway.

 

[Tomnick]

Back to the subject in hand.....what I don't get is why it takes 3.5 minutes to stop a train there. I thought that the standard time taken to make a station stop is around 2 minutes.

I'm sure this has already been done to death - but the restrictive approach control arrangements for trains being turned into P7, plus the slow speed through the connections either side of the station, means quite a substantial time penalty for stopping Up (Main) Fast trains.

 

[Harlesden]

Perhaps I am a little naive, but if I boarded a "fast" train at Waterloo, I would be rather disappointed if it began slowing down minutes after departing to stop at a station which already has plenty of services calling there.
Surely the solution is for a passenger waiting at Clapham Junction wanting a fast train to take the first available train to the first stop where the fast train calls. Clpaham Junction is a little too close to Central London to be a stop for fast trains.
I emphasize that this is my personal opinion with my own expectation of what a fast service should be - a limited stop service.

 

[swt_passenger]

I'm sure this has already been done to death - but the restrictive approach control arrangements for trains being turned into P7, plus the slow speed through the connections either side of the station, means quite a substantial time penalty for stopping Up (Main) Fast trains.

I also quoted the NR explanations on the previous page. If infobleep had read the thread he'd have the answers to this weeks version of the questions already...

 

[martinsh]

Well don't you think that Network Rail is going to know what it is talking about...? :roll:

They don' have a good track record in that regard ....

 

[455driver]

Couldn't they use P8 and be done with it.

No because platform 8 is on the outside of the curve and has a massive drop from the train to platform!

This is a recording have a nice day!
Can anyone (be bothered to) find one of the thread where these same questions have been answered (several times) before!
Or maybe the people asking the questions could visit the site and they would see for themselves why things cant be done!