SWR Engineering plans: why are they diverting via Chertsey and not Epsom?

Just having a browse on open train times maps and it struck me as odd that Portsmouth services are going via Chertsey and not Epsom. With the amount of Guildford crew sat spare this weekend I can’t see crew knowledge being an issue, and I’d imagine journey times would be quicker.

pompeyfan said:

Just having a browse on open train times maps and it struck me as odd that Portsmouth services are going via Chertsey and not Epsom. With the amount of Guildford crew sat spare this weekend I can’t see crew knowledge being an issue, and I’d imagine journey times would be quicker.

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Won't Epsom be busy enough with SWR and SN outer suburban services taking up space?

robert7111a said:

Won't Epsom be busy enough with SWR and SN outer suburban services taking up space?

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surely you could fit 1 extra service in each direction though?

Just 'enjoyed' a there and back on the Pompey route on a train packed with people going to the American Football game at Wembley. The trundle via Chertsey added more than an hour on the time to Petersfield going out and about 50m coming back to London. Some trains were being indicated as not stopping between Woking and Fratton. Were they being sent via Fareham? I wonder if Staines has ever had such a good Sunday service lol

leytongabriel said:

Were they being sent via Fareham? I

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Quite possibly, as there were third rail problems between Haslemere and Havant, so with no Southern at Havant for 9 days, must have been tough.

pompeyfan said:

Just having a browse on open train times maps and it struck me as odd that Portsmouth services are going via Chertsey and not Epsom. With the amount of Guildford crew sat spare this weekend I can’t see crew knowledge being an issue, and I’d imagine journey times would be quicker.

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You'd leave barely any service for passengers at Woking if they went via Epsom.

Chertsey makes much more sense and has been the service plan for years when Surbiton is closed for engineering work.

It is quite unusual to have engineering work where Surbiton, but not Wimbledon is closed. There would have been enough train crew to divert Portsmouth services via Epsom for sure, pathing probably not so easy. Probably not a lot in it when it comes to journey times. 2 Portsmouth via Chertsey and 1 Haslemere via Epsom an hour might have been a good compromise though.

leytongabriel said:

Just 'enjoyed' a there and back on the Pompey route on a train packed with people going to the American Football game at Wembley. The trundle via Chertsey added more than an hour on the time to Petersfield going out and about 50m coming back to London. Some trains were being indicated as not stopping between Woking and Fratton. Were they being sent via Fareham? I wonder if Staines has ever had such a good Sunday service lol

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At the last time they had engineering works and diverted via Staines they would have had a good Sunday service. On Saturday though they didn't seem to be stopping at Staines.

During the week, between 18:00 and 20:00, they only run 3 trains am hour from Woking to Guildford, rather than 4. So I agree with TEW, running 2 via Chertsey and 1 via Epsom would be good. I can't say if it's possible though.

greaterwest said:

You'd leave barely any service for passengers at Woking if they went via Epsom.

Chertsey makes much more sense and has been the service plan for years when Surbiton is closed for engineering work.

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on Saturday there was 1 fast and 1 all stations stopper per hour. I concede the bit about Woking - Guildford being a busy flow, but the rest of your answer seems a ‘bit the railway has always done it that way’

@TEW makes a good point that it’s unusual for Raynes park area to still be open when Surbiton is closed.

pompeyfan said:

on Saturday there was 1 fast and 1 all stations stopper per hour. I concede the bit about Woking - Guildford being a busy flow, but the rest of your answer seems a ‘bit the railway has always done it that way’

@TEW makes a good point that it’s unusual for Raynes park area to still be open when Surbiton is closed.

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Perhaps so, but you would also need the crew knowledge to divert via Epsom, and believe it or not but Epsom is not a very common diversion for Portsmouth services, it usually only happens with specific authorisation from Control in times of major disruption.

The main problem IMX with the Chertsey diversions (Southampton services) is not so much the alternative route, but the appalling paths they get given. They speed through about as far as Barnes and then crawl along behind stoppers pretty much all the way to Byfleet.

Would it not be a better compromise (more people get inconvenienced, but less severely) to reduce the frequency of the 'regular' Staines lines services when engineering happens to give more clear runs for the diverted fasts? This could include for example turning the Readings and Windsors into 'dividers' at Staines to clear up 2 paths an hour over the part of the route just up from Staines (or if dividing is too problem-prone, reduce the frequency of each to hourly and run at maximum length), and reducing the frequency of the Weybridge stopper to one per hour (freeing up another path).

To compensate they could even stop some diverted main line services at e.g. Richmond and Staines; a steady journey at decent pace with a couple of extra stops is much better than continuously crawling along behind signals! Something like this sort of flighting:

xx00 diverted express service (fast Clapham to Woking)
xx03 diverted main line service (Clapham Staines)
xx06 diverted main line service (Clapham Richmond Staines)
xx09 Reading and/or Windsor
(stoppers on the Barnes-Twickenham section slot in here)
xx30 diverted express service (fast Clapham to Woking)
xx33 diverted main line service (Clapham Staines)
xx36 diverted main line service (Clapham Richmond Staines)
xx39 Reading and/or Windsor
(stoppers on the Barnes-Twickenham section slot in here)

Could this work?

greaterwest said:

Perhaps so, but you would also need the crew knowledge to divert via Epsom, and believe it or not but Epsom is not a very common diversion for Portsmouth services, it usually only happens with specific authorisation from Control in times of major disruption.

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@pompeyfan mentioned that a lot of Guildford crew were spare this weekend, and would have been able to operate diverted Portsmouth services via Epsom, that is correct. Train crew would not have been a problem operating diverts via Epsom this weekend.

nickw1 said:

Would it not be a better compromise (more people get inconvenienced, but less severely) to reduce the frequency of the 'regular' Staines lines services when engineering happens to give more clear runs for the diverted fasts? This could include for example turning the Readings and Windsors into 'dividers' at Staines to clear up 2 paths an hour over the part of the route just up from Staines (or if dividing is too problem-prone, reduce the frequency of each to hourly and run at maximum length), and reducing the frequency of the Weybridge stopper to one per hour (freeing up another path).

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They already thin out the service on the Windsor lines but there is nowhere to overtake between Barnes and Virginia Water and loads of stops to provide a service to. The main principle is that one of the local services stops at Barnes and allows fast trains to go past but they will still catch up with whatever is in front before they get to Staines. It is one of the reasons why there aren't any faster services to Reading.

Possibly what is needed is a different track layout at Twickenham to allow overtaking and then some other provision somewhere near Staines but it would have to be justified on the basis of the normal services rather than just for engineering work.

Dividing at Staines would not work - curved platform - lack of capacity if it goes wrong etc. The trains already run at maximum length.

greaterwest said:

Perhaps so, but you would also need the crew knowledge to divert via Epsom, and believe it or not but Epsom is not a very common diversion for Portsmouth services, it usually only happens with specific authorisation from Control in times of major disruption.

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it’s not usually a diverted route because of crew knowledge not being right place right time but Bournemouth services divert via the new line during blocks when crew are assembled correctly. I believe there is a 20mph restriction through Epsom on 23m stock and as such 444s aren’t allowed to be booked via Epsom

pompeyfan said:

it’s not usually a diverted route because of crew knowledge not being right place right time but Bournemouth services divert via the new line during blocks when crew are assembled correctly. I believe there is a 20mph restriction through Epsom on 23m stock and as such 444s aren’t allowed to be booked via Epsom

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I remember in the mid-00s, that if Wimbledon was open, the fast Pompey services would divert via Epsom calling additionally at Wimbledon. Shuttle service from Woking to Haslemere connecting with fast from Waterloo. If Wimbledon wasn't open, services would terminate at Woking/Surbiton as appropriate. Pompey services never diverted via Staines and 444s were certainly run via Epsom with a guard (& driver?) change at Guildford.

Of late, for whatever reason, the preference has been to route via Staines.

molecrochip said:

I remember in the mid-00s, that if Wimbledon was open, the fast Pompey services would divert via Epsom calling additionally at Wimbledon. Shuttle service from Woking to Haslemere connecting with fast from Waterloo. If Wimbledon wasn't open, services would terminate at Woking/Surbiton as appropriate. Pompey services never diverted via Staines and 444s were certainly run via Epsom with a guard (& driver?) change at Guildford.

Of late, for whatever reason, the preference has been to route via Staines.

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I can verify that; I have seen - although not for some years now - 444s on diverts passing my garden between Ewell West and Epsom.

molecrochip said:

I remember in the mid-00s, that if Wimbledon was open, the fast Pompey services would divert via Epsom calling additionally at Wimbledon. Shuttle service from Woking to Haslemere connecting with fast from Waterloo. If Wimbledon wasn't open, services would terminate at Woking/Surbiton as appropriate. Pompey services never diverted via Staines and 444s were certainly run via Epsom with a guard (& driver?) change at Guildford.

Of late, for whatever reason, the preference has been to route via Staines.

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While it is true that pompey services did divert via Epsom, they have diverted via Chertsey for longer than that.

If all SWR lines are closed at Wimbledon for engineering work, then only alternative for mainline services is to divert via Chertsey or there'd be no through services at all to Waterloo from Pompey or Weymouth and while the number of direct tph maybe reduced with some terminating short, there has always been a direct train via Chertsey in my memory, since the late 90s

theironroad said:

While it is true that pompey services did divert via Epsom, they have diverted via Chertsey for longer than that.

If all SWR lines are closed at Wimbledon for engineering work, then only alternative for mainline services is to divert via Chertsey or there'd be no through services at all to Waterloo from Pompey or Weymouth and while the number of direct tph maybe reduced with some terminating short, there has always been a direct train via Chertsey in my memory, since the late 90s

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Presumably there’s a good case for developing and keeping to the same long term diversions, to save reinventing the wheel every time there’s a minor change to the possession area. Keeps all the staff, both SWR traincrew and NR signallers, familiar with a known plan.

theironroad said:

While it is true that pompey services did divert via Epsom, they have diverted via Chertsey for longer than that.

If all SWR lines are closed at Wimbledon for engineering work, then only alternative for mainline services is to divert via Chertsey or there'd be no through services at all to Waterloo from Pompey or Weymouth and while the number of direct tph maybe reduced with some terminating short, there has always been a direct train via Chertsey in my memory, since the late 90s

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I recall travelling January 2005 or 2006 to London from Fratton and every weekend being diverted via Epsom. One weekend the possession extended to include the lines at Raynes Park. That weekend Portsmouth services stopped at Woking. You had to join Weymouth services and the conditions were uncomfortable if my memory serves correctly.