Would it be possible to stop an additional fast train at Clapham Junction?

[infobleep]

This is more of an is it possible question than here's my idea.

Earlier this year one of the fast trains from Portsmouth to Waterloo stopped additionally at Clapham Junction.

From Guildford, it was the x49. Now it was timetabled to arrive at Clapham Junction at x22 but often arrived early.

It was a handy train for a connection down south towards Brighton.

At that stage, there wasn't an Alton to Waterloo service following it.

Currently, the x49 doesn't stop at Clapham Junction and is pathed to go through it at x14½, so 7 minutes earlier, discounting the ½. An Alton service is due to arrive x19 and depart x20. So 5 minutes later.

Are 5 minutes too short a headway to be able to stop the train from Portsmouth at Clapham Junction, given the train needs to slow down?

If it is, could the train from Alton be retimed slightly to depart Clapham Junction later or would that cause issues for trains departing Waterloo?

The reason I ask is that currently for most hours of the day, there is only 1 fast train an hour from Guildford to Clapham Junction and the same is in reverse. There is a better service on Sundays of 2 an hour.

The only hours where that isn't the case Monday to Friday is
6-7 (3 trains)
9-10 (2 trains)
17-18 (2 trains)
18-19 (2 trains)
20-21 (whilst its only 1 train, the 20:18 connects with a service at Woking, making the journey only a few minutes slower than travelling direct. This isn't the case at other times of the day)

Another alternative would be to put back the currently removed Haslemere service but I assume passenger numbers and maybe even staff numbers working, due to covid-19, doesn't allow for it.

I would find an x04 Guildford to Clapham Junction service useful as it is offset from the x40 Guildford to Gatwick Airport service. Using the x35 to Clapham Junction and heading down, one is overtaken by the x40. Whilst there is an x13 to Redhill, that only gets you into Gatwick Airport 10 minutes before the next x40 from Guildford. Hence the usefulness of the x04 or failing that the x49, as they never get overtaken.

 

[MarkyT]

Signalling/track layout issues and the sheer number of trains on the fasts, especially in the peak. All up fast trains scheduled to stop are switched into the up platform loop, platform #7. With the platform on the inside of the track curve, stepping height and distance is manageable in #7, but the turnout speed approaching from the west to access it is severely limited (15mph) compared to the through speed on the fast (40mph), with the signal aspect for the diverging route approach released from red (unless that's been changed in recent years). The up fast through Platform #8 is aggressively canted away from the platform face, which is on the outside of the curve. Trains are thus not scheduled to call at #8 due to the large horizontal and vertical stepping distances involved, although they can and have in an emergency. So the high through speed requires the cant which makes #8 unusable, which in turn slows stopping trains down significantly further back than otherwise necessary, to turnout to #7. If all trains stopped in the up direction perhaps speed lowered through the fast platform #8 could allow it to be used with reduced cant, but while it might just work off-peak, the peak main fast timetable requires continuous streams of trains to pass through at minimum headway, which doesn't allow the delay in the turning out of any of them into the platform loop (#7). It would probably be slightly more plausible to stop greater numbers of trains in the down direction because they use a platform (#9) that is actually on the down fast line, which with its cant leaning into the platform on the inside of the track curve results in good acceptable stepping distances and no turnout delays. The service ideally should be balanced in both directions though.

 

[jfollows]

I also posted relevant information in https://www.railforums.co.uk/thread...m-junction-lack-of-stops.219175/#post-5198148 about (not) stopping on the up fast at Clapham Junction

 

[infobleep]

I also posted relevant information in https://www.railforums.co.uk/thread...m-junction-lack-of-stops.219175/#post-5198148 about (not) stopping on the up fast at Clapham Junction

Thanks, I missed that thread.

As for things being equal in both directions. There are plenty of examples where equality doesn't occur. For example, no direct services to Hove on the Brighton mainline in the morning peak but there are such services from Hove onto the Brighton mainline in the evening peak. They can do this in the evening as they don't cross the down path but that still shows a difference.

Obviously, the number of trains running means they can't stop at Clapham Junction on platform 9 in the evening peak and I can appreciate why that is. So I guess my question was more related to off-peak when fewer trains run.

So how long is the required gap between a stopping service at Clapham Junction and the next non-stop service?

 

[zwk500]

Thanks, I missed that thread.

As for things being equal in both directions. There are plenty of examples where equality doesn't occur. For example, no direct services to Hove on the Brighton mainline in the morning peak but there are such services from Hove onto the Brighton mainline in the evening peak. They can do this in the evening as they don't cross the down path but that still shows a difference.

At Hove, there's local circumstances with the contra-peak flow being miniscule, and as you say conflicting moves across both Preston Park junction and Hove Junction. The proximity of Brighton station for the change means the lack of services is manageable. Clapham junction would see a much more even flow in each direction, especially off-peak.

So how long is the required gap between a stopping service at Clapham Junction and the next non-stop service?

2.5 minutes following a stopping train, 2 minutes following a non-stop. But you've also got to include Dwell + 2mins platform re-occupation for successive stopping trains.

 

[Sebastian O]

Jumping in on a thread - why are they termed up Ludgate and down Ludgate?

 

[zwk500]

Jumping in on a thread - why are they termed up Ludgate and down Ludgate?

Not 100% sure, but the suggestion (from Wikipedia, I admit) is that the connecting lines were built by the LCDR, intending to operate commuter services to Ludgate Hill station.

 

[infobleep]

At Hove, there's local circumstances with the contra-peak flow being miniscule, and as you say conflicting moves across both Preston Park junction and Hove Junction. The proximity of Brighton station for the change means the lack of services is manageable. Clapham junction would see a much more even flow in each direction, especially off-peak.

2.5 minutes following a stopping train, 2 minutes following a non-stop. But you've also got to include Dwell + 2mins platform re-occupation for successive stopping trains.

I'm sure Hove might be more even if trains could go direct in the morning. It certainly added time having to change at Brighton, compared to travelling direct, when I use to do it occasionally but maybe trains connect better now in the morning or I expected too much. I wasn't travelling to Hove but further afield.

Back to Clapham. The non-stopping train from Portsmouth passes through Clapham Junction 4.5 minutes before the stopping train from Alton. Does that not meet the criteria of 4.5 minutes?

Clearly, there must be something else involved or they would do it.

So could they retime the Alton train back 1 minute because it seems as if it's very close to being possible but currently isn't? This only arises because the x04 services are not running.

It must be said that when the x49 did stop at Clapham Junction, there wasn't a return fast service stopping at Clapham Junction. So 2 up and 1 down. So that was uneven but better than nothing.

 

[HamworthyGoods]

I'm sure Hove might be more even if trains could go direct in the morning. It certainly added time having to change at Brighton, compared to travelling direct, when I use to do it occasionally but maybe trains connect better now in the morning or I expected too much. I wasn't travelling to Hove but further afield.

Back to Clapham. The non-stopping train from Portsmouth passes through Clapham Junction 4.5 minutes before the stopping train from Alton. Does that not meet the criteria of 4.5 minutes?

Clearly, there must be something else involved or they would do it.

So could they retime the Alton train back 1 minute because it seems as if it's very close to being possible but currently isn't? This only arises because the x04 services are not running.

It must be said that when the x49 did stop at Clapham Junction, there wasn't a return fast service stopping at Clapham Junction. So 2 up and 1 down. So that was uneven but better than nothing.

The Alton train you mention is fixed by its Waterloo arrival time of xx29 where it crosses into a low numbered platform ahead of the xx30 Portsmouth departure.

This idea, whilst I can see your rationale potentially soon though lands you with a replatforming Waterloo exercise…

 

[zwk500]

Back to Clapham. The non-stopping train from Portsmouth passes through Clapham Junction 4.5 minutes before the stopping train from Alton. Does that not meet the criteria of 4.5 minutes?

Clearly, there must be something else involved or they would do it.

The SRT for a stopping train is 1.5 minutes longer than for a passing train, and the dwell for Up Main Fast services is 1.5 minutes, so the Portsmouth would depart only 1.5 minutes ahead of the Alton and it needs to be 2.

So could they retime the Alton train back 1 minute because it seems as if it's very close to being possible but currently isn't? This only arises because the x04 services are not running.

This point is covered above.

 

[HamworthyGoods]

2.5 minutes following a stopping train, 2 minutes following a non-stop. But you've also got to include Dwell + 2mins platform re-occupation for successive stopping trains.

Due to the approach control into platform 7 at Clapham Junction 2.5 platform re-occupation is used for this platform. If you look at the schedules for about 07.00 on an SX where there are successive calls all the trains are pathed out accordingly. 2 minutes re-occ was found to be a bit over optimistic.

 

[infobleep]

The SRT for a stopping train is 1.5 minutes longer than for a passing train, and the dwell for Up Main Fast services is 1.5 minutes, so the Portsmouth would depart only 1.5 minutes ahead of the Alton and it needs to be 2.

This point is covered above.

Of course, they can't retime the Portsmouth train earlier as there is a Weymouth train stopping there.

The only solution is to eventually restore the x04 services from Guildford.

 

[infobleep]

Tonight I was kn the 17:19 Guildford to Waterloo. It passes through Clapham Junction 1m early and got into Waterloo 7m early. It did the same yesterday.

So if it is getting into Waterloo so early, why can't it stop at Clapham Junction.

Surely the train behind will be able to recover from the delay and also get into Waterloo early as the issue was ½ minute extra needed.

Perhaps someone could explain why this wouldn't work.

 

[zwk500]

Tonight I was kn the 17:19 Guildford to Waterloo. It passes through Clapham Junction 1m early and got into Waterloo 7m early. It did the same yesterday.

So if it is getting into Waterloo so early, why can't it stop at Clapham Junction.

Surely the train behind will be able to recover from the delay and also get into Waterloo early as the issue was ½ minute extra needed.

Perhaps someone could explain why this wouldn't work.

Because what happens on the day can't always be timetabled for.

 

[30907]

Because what happens on the day can't always be timetabled for.

In this case the train has 8min pathing allowance (most xx19 have 4min) because not hitting Waterloo before its platform is free is extremely important in the evening peak. Stopping at CLJ would still delay the following Alton train, as mentioned above.

 

[infobleep]

In this case the train has 8min pathing allowance (most xx19 have 4min) because not hitting Waterloo before its platform is free is extremely important in the evening peak. Stopping at CLJ would still delay the following Alton train, as mentioned above.

So does the Alton train also have an 8 minute pathing allowance because if not, it will be booked to arrive before the train in front of it.

Actually I see there is a 5½ minute pathing allowance at Clapham Junction, according to Real Time Trains. The Alton train is due to arrive into Waterloo at the same time. I appreciate they are different platforms.

I am surprised the Working Timetable doesn't have an earlier arrival time for the train from Portsmouth.

 

[30907]

I am surprised the Working Timetable doesn't have an earlier arrival time for the train from Portsmouth.

Presumably the full timetable doesn't have a free platform, but the reduced one does, hence the early arrival.

 

[infobleep]

Presumably the full timetable doesn't have a free platform, but the reduced one does, hence the early arrival.

But if they are reducing the timetable, as per the consiltstion, then they could modify this.

 

[zwk500]

But if they are reducing the timetable, as per the consiltstion, then they could modify this.

They could, but not right this minute. The availability of rolling stock and drivers will also be a consideration, as the train can't arrive Waterloo until the platform is free.

 

[infobleep]

They could, but not right this minute. The availability of rolling stock and drivers will also be a consideration, as the train can't arrive Waterloo until the platform is free.

Indeed they can't but in terms of the 17:19 and other x19 trains, they arrive in around 7 minutes early so there is clearly a platform free. Obviously not in the case of disruption but that is also the case for trains that regularly can't arrive in 7 minutes early.

Next week I've noticed the working timetable has the 17:19 as arriving at 17:56 rather than 17:59, as it did the previous 2 weeks at least. It should still arrive in 3-4 minutes earlier than that and the Public Timetable is still 17:59.

They might not want to change it at this precise moment but maybe they might at the next round of timetable changes.

 

[zwk500]

They might not want to change it at this precise moment but maybe they might at the next round of timetable changes.

They need to be told people want it! If you think it would be helpful, find SWR's timetable consultation on their website, and ask your MP to raise the issue on your behalf.

If nothing else, SWR will be able to state the reason they have for not doing it.

 

[infobleep]

They need to be told people want it! If you think it would be helpful, find SWR's timetable consultation on their website, and ask your MP to raise the issue on your behalf.

If nothing else, SWR will be able to state the reason they have for not doing it.

I already have that in hand and have spoken to my local councilor about it.