3tph on North Downs Line

[Wilts Wanderer]

The backwash from the Thameslink upgrade is a significant loss of resilience in the North Downs timetable. Given the amount of airport traffic from Reading, and the growth potential if the service frequency were to be increased, there is a need for a rethink. The current issue of trains being turned back at Redhill together with a poor onward Redhill/Gatwick connection, adding 45 minutes to the end to end journey, undermines the rationale for the service.

It would be a brave (and probably career-suicidal) transport minister who entertained a reduction in the Thameslink timetable to benefit performance of a side-route only, even one which links the most important multi-route interchange south of Birmingham (Reading) with London’s second airport.

 

[JamesRowden]

It would be a brave (and probably career-suicidal) transport minister who entertained a reduction in the Thameslink timetable to benefit performance of a side-route only, even one which links the most important multi-route interchange south of Birmingham (Reading) with London’s second airport.

One solution might be to scrap the 2tph of Victoria-Gatwick Gatwick Express services, and replace them with a 2tph Victoria-Redhill-Gatwick service with the Thameslink services synchronised with it to provide an every 10 minute service between Redhill and Gatwick. There would then be little need for North Downs Line trains to run through to Gatwick, and they could all terminate at Redhill or be extended through to Tonbridge.

 

[Minstral25]

The backwash from the Thameslink upgrade is a significant loss of resilience in the North Downs timetable. Given the amount of airport traffic from Reading, and the growth potential if the service frequency were to be increased, there is a need for a rethink. The current issue of trains being turned back at Redhill together with a poor onward Redhill/Gatwick connection, adding 45 minutes to the end to end journey, undermines the rationale for the service.

I think the problem we have is that the Thameslink (and Southern services to Reigate) are designed to work around GWR's proposed 3 train per hour service that was fed to GTR when planning Thameslink. In reality this was canned before Thameslink was running, so the resulting squeeze to fit back to a 2 tph North Downs service is in a lot of ways a complete mess.

 

[JonathanH]

One solution might be to scrap the 2tph of Victoria-Gatwick Gatwick Express services, and replace them with a 2tph Victoria-Redhill-Gatwick service with the Thameslink services synchronised with it to provide an every 10 minute service between Redhill and Gatwick. There would then be little need for North Downs Line trains to run through to Gatwick, and they could all terminate at Redhill or be extended through to Tonbridge.

No, really, no - that would be nonsense - the only reason anyone uses the service from further afield (ie other than local passengers) is because they can make one change at Reading for Gatwick. That much is obvious from the loadings on the Gatwick services relative to those on the stoppers which terminate at Redhill.

There might be other valid reasons for removing Gatwick Express services as they are currently set up but to provide connections at Redhill for people travelling from Reading and further west is not one of them.

 

[JamesRowden]

No, really, no - that would be nonsense - the only reason anyone uses the service from further afield (ie other than local passengers) is because they can make one change at Reading for Gatwick. That much is obvious from the loadings on the Gatwick services relative to those on the stoppers which terminate at Redhill.

There might be other valid reasons for removing Gatwick Express services as they are currently set up but to provide connections at Redhill for people travelling from Reading and further west is not one of them.

I contradict your entire post. I have used the service for Reading-Redhill-Tonbridge-Hastings and Reading-Gatwick-Pulborough/Shoreham/Hastings and Winchester-Woking-Guildford-Redhill-Tonbridge-Hastings journeys. I friend of mine has used it for Reading-Redhill-Tonbridge-Ashford-Sandwich journeys. I would use it for Devon to Hastings journeys if the journey times / fares were competitive. A sub 10 minute connection at Redhill for Gatwick rather than a reversal wouldn't put me off at all.

 

[JonathanH]

I think the problem we have is that the Thameslink (and Southern services to Reigate) are designed to work around GWR's proposed 3 train per hour service that was fed to GTR when planning Thameslink. In reality this was canned before Thameslink was running, so the resulting squeeze to fit back to a 2 tph North Downs service is in a lot of ways a complete mess.

They just used the GWR path that has been in place for over 20 years and replicated it on both sides of the hour.

I think where it falls down is that, before the timetable change, during the peaks the GWR trains had timings off this standard path - eg they left Gatwick a little before the hour rather than after it in the morning peak and that left time in the schedule to make the additional stops needed in the Blackwater Valley towards Reading. GWR are now more constrained and it puts pressure on the tight turnarounds at Reading in the morning peak - the service never recovers.

The timetable that partly made it into open data sites (I wish I had kept a copy) before 3tph was canned had some fairly off-pattern morning workings to try to build in more resilliance but when squeezed, it doesn't fit.

It would be a brave (and probably career-suicidal) transport minister who entertained a reduction in the Thameslink timetable to benefit performance of a side-route only, even one which links the most important multi-route interchange south of Birmingham (Reading) with London’s second airport.

There doesn't need to be a reduction in the Thameslink timetable to benefit performance of a side-route. The schedules and turnarounds at the Reading end just need to be less ambitious, with a bit more interworking between stoppers and fasts and the infrastructure on the North Downs line needs to fail a bit less often than it is at present. There is nothing obviously wrong with the path from Reigate to Gatwick and back if the trains present at Reigate on time.

Is 3tph still on the table or kicked into the long grass now?

 

[JonathanH]

I contradict your entire post. I have used the service for Reading-Redhill-Tonbridge-Hastings and Reading-Gatwick-Pulborough/Shoreham/Hastings and Winchester-Woking-Guildford-Redhill-Tonbridge-Hastings journeys. I friend of mine has used it for Reading-Redhill-Tonbridge-Ashford-Sandwich journeys. I would use it for Devon to Hastings journeys if the journey times / fares were competitive. A sub 10 minute connection at Redhill for Gatwick rather than a reversal wouldn't put me off at all.

Yes, clearly there are people making journeys that don't involve Gatwick but passengers with luggage would be put off with the need to change at Redhill for Gatwick and the lifts / stairs arrangement at Redhill simply isn't set up for a large number of passengers changing trains in the way you are suggesting.

 

[JamesRowden]

Yes, clearly there are people making journeys that don't involve Gatwick but passengers with luggage would be put off with the need to change at Redhill for Gatwick and the lifts / stairs arrangement at Redhill simply isn't set up for a large number of passengers changing trains in the way you are suggesting.

Unless they're originating at a North Downs station they will need to change trains anyway.

 

[JonathanH]

Unless they're originating at a North Downs station they will need to change trains anyway.

Yes, once at Reading which is set up for people to make connections (or to a lesser extent Guildford which is also easier to change at than Redhill)

 

[JamesRowden]

Yes, once at Reading which is set up for people to make connections (or to a lesser extent Guildford which is also easier to change at than Redhill)

I've never had any problems changing at Redhill. According to the (outdated) station map of Redhill station on National Rail Enquiries there were lifts on every platform. Disability regulations would make me think that there is a lift to the new platform 0.

 

[JonathanH]

I've never had any problems changing at Redhill. According to the (outdated) station map of Redhill station on National Rail Enquiries there were lifts on every platform. Disability regulations would make me think that there is a lift to the new platform 0.

I've never had any problems changing at Redhill * either but I haven't done so with suitcases, a family, pushchairs, elderly relatives etc.

There are lifts on every platform at Redhill. However, it would take some time to get the volume of people to use those lifts in the interchange time. I think you are suggesting that it wouldn't matter because there would be a train every ten minutes to Gatwick but people don't like to be the ones who have to wait an extra ten minutes because they weren't first to the lift (or in this case two lifts). Terminating trains also often go to the northern ends of platforms 0 and 1 and so it is a long walk back to the lifts at the south end of the platform.

*Edit - that's a bit of a lie - I have frequently missed connections I would like to have made but that isn't the point.

 

[JN114]

While more resilience at the Reading end would help - while it's not diagrammed we can build resilience at the Reading end when required by stepping up with other resources. The problem is at the Gatwick end. We cannot go through late without adversely affecting services on the Brighton mainline - I'm normally happy to go through late and sort it out at Reading for the next round trip.

 

[JamesRowden]

I've never had any problems changing at Redhill * either but I haven't done so with suitcases, a family, pushchairs, elderly relatives etc.

There are lifts on every platform at Redhill. However, it would take some time to get the volume of people to use those lifts in the interchange time. I think you are suggesting that it wouldn't matter because there would be a train every ten minutes to Gatwick but people don't like to be the ones who have to wait an extra ten minutes because they weren't first to the lift (or in this case two lifts). Terminating trains also often go to the northern ends of platforms 0 and 1 and so it is a long walk back to the lifts at the south end of the platform.

*Edit - that's a bit of a lie - I have frequently missed connections I would like to have made but that isn't the point.

I don't think there are as many air / long distance passengers using the service as you seem to think. If there were then the interior/capacity of the turbos (and possibly the proposed future 769s) would be a bigger issue than changing at Redhill (considering how full the trains are departing Reading in the afternoon/evening).

 

[JonathanH]

While more resilience at the Reading end would help - while it's not diagrammed we can build resilience at the Reading end when required by stepping up with other resources. The problem is at the Gatwick end. We cannot go through late without adversely affecting services on the Brighton mainline - I'm normally happy to go through late and sort it out at Reading for the next round trip.

Yes, but what is the reason that the train is presenting at Reigate / Redhill late? That has nothing to do with Thameslink unless it is a carry over from the previous journey.

Today looks like everything has gone to the Airport - 0832 left Reading six minutes late but made up time - 1732 lost time in the Blackwater Valley because the timings are too tight for the extra stops - 1932 has a tight turnaround at Reading due to Waterloo timings and ran between 7 and 10 minutes late throughout until making up some time at Reigate. I guess it depends a lot on rail conditions.

 

[JN114]

Yes, but what is the reason that the train is presenting at Reigate / Redhill late? That has nothing to do with Thameslink unless it is a carry over from the previous journey.

Various reasons - that’s the point. A better-crafted timetable would enable running through to Gatwick - the recent lack of which being the gripe that raised this sub-thread - regardless of delay. As it is if we’re late Sussex are instructing us that we’re not going beyond Redhill. Before the new Thameslink timetable it wasn’t perfect but at least it was my decision as a GWR controller to terminate at Redhill or not.

 

[TEW]

I don't think there are as many air / long distance passengers using the service as you seem to think. If there were then the interior/capacity of the turbos (and possibly the proposed future 769s) would be a bigger issue than changing at Redhill (considering how full the trains are departing Reading in the afternoon/evening).

The interior of the 165s is an issue on the services in my opinion. The 166s, although not ideal, did have a decent provision for luggage, the 165s have next to none and it shows, there is always luggage everywhere when I use the line now. The flip side is that the higher seating of the 165s does allow more people to sit down on the busier services.

 

[The Ham]

In reality the line either needs to go to 3tph or there needs to be an upgrade to allow longer trains to run. Ideally also electrified with the signalling sorted so that there's scope for more services at a later date as well as passive provision for longer platforms (i.e. signals located so that longer trains stopping at them don't block level crossings*) and more scope for timetable recovery of things go wrong.

* Provision for 10/12 coach trains would probably be excessive, but as long as it didn't cause problems it would be ideal - so that it was fixed once and for all.

 

[Minstral25]

They just used the GWR path that has been in place for over 20 years and replicated it on both sides of the hour.

Yes that's what they reverted to but that was not the 3tph plan that GTR were working with in October 2017 that had been presented by GWR. For example, the off-peak Reigate to Victoria services were originally supposed to leave Reigate at xx:06 & xx:36, but because the GWR services haven't got out of the way as originally expected, they leave at xx:00 and xx:30 and sit at Redhill for 7 minutes unnecessarily.

In terms of passengers, North Downs trains from my occasional use from Reigate to Guildford are more about local passengers and have lesser usage for Gatwick passengers (I think there are a couple very popular with Gatwick passengers but most are pretty devoid). Whenever I get on at Guildford my visual check is that the train virtually empties and a whole new set of passengers gets on. I would thus say the usage by through passengers should not be the demand that drives the service but it is a very useful service to keep

 

[FenMan]

The timetable that partly made it into open data sites (I wish I had kept a copy) before 3tph was canned had some fairly off-pattern morning workings to try to build in more resilliance but when squeezed, it doesn't fit.

The upgraded Sunday timetable provides some clues to how 3tph would work, with Gatwick departures from Reading at xx:18 and xx:48 and the return journeys timed to depart Gatwick at xx:47 and xx:17, giving 12 minute layovers at both ends.

The hourly stopper would be threaded in between, departing Reading at (rough example timings) 12:04 with a 12 minute layover at Guildford to allow a Gatwick to overtake and then continuing to Redhill, arriving at 13:34. The return would depart Redhill at 13:43, arriving Guildford at 14:21. After the 13:47 ex-Gatwick has overtaken, the stopper would depart Guildford at 14:36, arriving in Reading at 15:19. Alternatively, the stopper would be timed for half an hour later giving a shorter turnaround at Reading.

There's a rough example of this in the current weekday timetable where the 09:03 Gatwick - Reading overtakes the 08:51 Redhill stopper at Guildford. However I have to say that neither service is particularly robust when comes to keeping to time.

The current timings of Thameslink services at Redhill clash with what GWR have (or had) in mind, not to mention SWR's - currently thwarted - plans for 4tph between Reading and Waterloo, the retiming of the Pompey trains at Guildford to achieve 4tph and the switching of Guildford - Ascot services to Guildford - Farnham.

Who'd be a planner?

 

[JonathanH]

I'm not sure about that - I think Option 1 in this document is closer to what was in mind, at least off-peak, although the departures from Gatwick would have needed to stay at xx00 / xx30 - the Sunday timetable that the North Downs line service needs to fit around is quite different on all the associated routes from the weekday one.

https://www.surreycc.gov.uk/__data/...Assessment-Report-FINAL-120615.compressed.pdf

 

[Bikeman78]

Yes, that ridiculous routing of the up Brighton to Bedford trains along the slow lines from Balcombe Tunnel Junction (to allow the Southern Brighton to Victoria to overtake at Three Bridges), then to the westernmost line south of Gatwick to stop in platform 3 (xx03-xx06) northbound.

Of course, a delayed Reading to Gatwick train may also delay the xx03 stopper from Gatwick via Redhill to Bedford and potentially, by first delaying the Bedford to Gatwick (xx52-xx55 at Redhill) the southbound train to Horsham (immediately behind at Gatwick) which would result in a short turnaround. The Bedford to Gatwick may also delay the up Brighton to Victoria Gatwick Express which stops on platform 1 at Gatwick (xx11-xx12). Operation of Gatwick seems far too complicated in the GTR timetable.

20 years ago there were far more crossing moves between platforms 1 & 2 and the fast lines with a Gatwick Express every 15 minutes. Despite this, thanks to the longer turnround time, turning Reading trains around at Redhill was rare. I should know, I used them often enough in the '80s and '90s to visit my gran in Reigate.

All of platforms 1 to 3 are reversible and it's possible to get to 1 or 2 from the down slow without conflicting with a train going from 3 to the up fast. The most ridiculous part of the timetable (already mentioned above) is that the fastest train on the route runs slow line from Balcombe Tunnel to Gatwick then crosses from platform 1 to the up fast. What are they thinking? It's completely uneccessary. It could follow the Bognor along the up fast from Three Bridges and not conflict with anything.

The problem with the TL timetable is that it has to mesh in with the Brightom main line, MML and ECML which has resulted in a sub optimal timetable on all three.

 

[JonathanH]

It is possible that the Brighton to Victoria train goes up the slow line as a sop to Redhill demands for a through service to Brighton - by sending it up the slow line it gives same platform interchange at Gatwick and therefore a quick connection between Brighton and Redhill.

Of course, that doesn't happen in the down direction.

It was all a bit easier when Gatwick Express sat in platforms 1 and 2 and the Reading train went to the sidings. In the up direction, the trains from Platforms 1 and 2 were 'perfectly' spaced - xx08 / xx23 / xx38 / xx53 to slot in behind the previous Gatwick Express departure xx05 / xx20 / xx35 / xx50 and the arrival xx15 / xx30 / xx35 / xx50.

The timetable on the slow lines isn't driven by capacity at Gatwick any more or the Gatwick Express and is much more of a hotchpotch than it was before 2015.

 

[JonathanH]

The more obvious reason for the up Brighton to Victoria Gatwick Express to go up the up slow is to allow the down Victoria to Arun Valley train a clear path to cross fast to slow north of Three Bridges.

Either way it doesn't obviously hinder the Reading to Gatwick service.

 

[Deepgreen]

I've never had any problems changing at Redhill. According to the (outdated) station map of Redhill station on National Rail Enquiries there were lifts on every platform. Disability regulations would make me think that there is a lift to the new platform 0.

Then you, sir, are extremely lucky! Redhill is a notoriously badly-managed node and suffers from frequent and serious delays and last-minute platform changes. I have just got home from a journey involving the place and my NDL train lost about 15 minutes on its approach to Redhill because of the inability of the railway to manage itself there. A NR leaf-buster stood in platform 2 for at least 12 minutes when it should have reversed and cleared the station immediately. Meanwhile trains were queueing outside and my train was switched from 2 to 1 at the last moment. It left nearly 25 late. This is cross-platform, but when (as is frequently the case) the switch is to 0, the interchange is not easy when the subway is clogged with incoming passengers. With 12 car platforms, a secondary interchange route at the north end of the platforms is sorely needed, especially given the frequent last-minute platform changes which give passengers at the north ends almost no chance of making the interchange in time (given, also, the sporadic and unreliable/inaudible live P.A. use there!).

Earlier today I had to abandon the NDL at Dorking Deepdene (towards Redhill) when a train stood in the platform there and we were told a person had been taken ill. Three police cars, two ambulances and a GWR pick-up were parked outside the station (for one ill person - so much for stretched emergency services!). This evening our guard announced that a person had been taken ill earlier at Gomshall(?). Why, we wondered, was there such a massive emergency services presence at Dorking if the stricken train was at Gomshall (immediately next to the A25 road), and why was the train at Deepdene being held there for so long if it wasn't the train carrying the ill person (it would have been ahead of, not behind, the affected train)? The usual shambolic, inconsistent (or totally absent) information regime prevailed. Incidentally, the platform DMIs at Deepdene appear to work on the basis that all trains are assumed to have left on time, as they disappear from the screens after/at the scheduled departure time, to be replaced by the next train, whether they have actually left or not!! For example, at 1206, the DMI showed the train in the platform as being the 1211 when it was obviously the preceding one. I have seen at least two people on previous occasions get up to the platform, see the next train described as being half an hour away and leave again (presumably for a taxi or bus instead), not realising that their train is actually only a couple of minutes late and still to arrive! My train this evening at Deepdene was also being described as the following one even as we alighted onto the platform (about 23 late).

All this with 2TPH - the crazy idea of 3TPH would presumably lead to complete chaos!

 

[Bikeman78]

It is possible that the Brighton to Victoria train goes up the slow line as a sop to Redhill demands for a through service to Brighton - by sending it up the slow line it gives same platform interchange at Gatwick and therefore a quick connection between Brighton and Redhill.

Of course, that doesn't happen in the down direction.

It was all a bit easier when Gatwick Express sat in platforms 1 and 2 and the Reading train went to the sidings. In the up direction, the trains from Platforms 1 and 2 were 'perfectly' spaced - xx08 / xx23 / xx38 / xx53 to slot in behind the previous Gatwick Express departure xx05 / xx20 / xx35 / xx50 and the arrival xx15 / xx30 / xx35 / xx50.

The timetable on the slow lines isn't driven by capacity at Gatwick any more or the Gatwick Express and is much more of a hotchpotch than it was before 2015.

Which brings us back to my suggestion that the turn round time needs to increase and the unit needs to shunt via the sidings. The service will never be reliable with only nine minutes at one end and 13 at the other. If the unit shunts at Gatwick then the arrival from Reading can use any vacant platform.

 

[Bikeman78]

The more obvious reason for the up Brighton to Victoria Gatwick Express to go up the up slow is to allow the down Victoria to Arun Valley train a clear path to cross fast to slow north of Three Bridges.

Either way it doesn't obviously hinder the Reading to Gatwick service.

There is no conflict between the up Brighton and down Arun Valley at Three Bridges. The conflict is between the up Arun valley (dep TBD platform 1 xx04/xx34) and the up Brighton (pass TBD platform 2 xx07/xx37). The sensible solution is for the Brighton to stay on the fast throughout and follow the Arun Valley after it crosses to the up fast or the Arun Valley use the up slow and cross to the fast at Gatwick. If you look at RTT, the signallers appear to be adopting the latter solution on the day. Granted there is still a conflict north of Gatwick with the Peterborough to Horsham but the conflict at Three Bridges is removed.

 

[tsr]

Earlier today I had to abandon the NDL at Dorking Deepdene (towards Redhill) when a train stood in the platform there and we were told a person had been taken ill. Three police cars, two ambulances and a GWR pick-up were parked outside the station (for one ill person - so much for stretched emergency services!). This evening our guard announced that a person had been taken ill earlier at Gomshall(?). Why, we wondered, was there such a massive emergency services presence at Dorking if the stricken train was at Gomshall (immediately next to the A25 road), and why was the train at Deepdene being held there for so long if it wasn't the train carrying the ill person (it would have been ahead of, not behind, the affected train)? The usual shambolic, inconsistent (or totally absent) information regime prevailed. Incidentally, the platform DMIs at Deepdene appear to work on the basis that all trains are assumed to have left on time, as they disappear from the screens after/at the scheduled departure time, to be replaced by the next train, whether they have actually left or not!! For example, at 1206, the DMI showed the train in the platform as being the 1211 when it was obviously the preceding one. I have seen at least two people on previous occasions get up to the platform, see the next train described as being half an hour away and leave again (presumably for a taxi or bus instead), not realising that their train is actually only a couple of minutes late and still to arrive! My train this evening at Deepdene was also being described as the following one even as we alighted onto the platform (about 23 late).

All this with 2TPH - the crazy idea of 3TPH would presumably lead to complete chaos!

I would advise you not to speculate about that of which you know little. There was a passenger taken ill at Deepdene, extremely seriously ill in fact, requiring over an hour of emergency medical intervention before they could carefully be moved. Hence the extensive incident response. One or two services then had to be turned at Gomshall after Network Rail elected to get staff to operate the groundframe there. There were also trains turning back at Shalford and Guildford. Naturally the guard could have got a little muddled between trains being terminated at different points, given it would have been a rather busy day, but it was all in reaction to the same root cause anyway. I am sure most people were just glad to hear an explanation.

As for the station CIS system, don’t forget that it does suffer from limitations of knowing where trains actually are, given this is a rural route with some sparse sections of train describer data. If one train is cancelled or removed from the screens, but still actually stood at the station, then the system may only be able to automatically generate information that the train next expected in the platform is the next service due. Other limitations also apply.

 

[Deepgreen]

I would advise you not to speculate about that of which you know little. There was a passenger taken ill at Deepdene, extremely seriously ill in fact, requiring over an hour of emergency medical intervention before they could carefully be moved. Hence the extensive incident response. One or two services then had to be turned at Gomshall after Network Rail elected to get staff to operate the groundframe there. There were also trains turning back at Shalford and Guildford. Naturally the guard could have got a little muddled between trains being terminated at different points, given it would have been a rather busy day, but it was all in reaction to the same root cause anyway. I am sure most people were just glad to hear an explanation.

As for the station CIS system, don’t forget that it does suffer from limitations of knowing where trains actually are, given this is a rural route with some sparse sections of train describer data. If one train is cancelled or removed from the screens, but still actually stood at the station, then the system may only be able to automatically generate information that the train next expected in the platform is the next service due. Other limitations also apply.

Well, most of the reason that I (and so many others involved) knew little was that we were told almost nothing (as usual). As I said, my later journey included an announcement by the train guard that the passenger had been taken ill earlier at Gomshall, so that gave me at least a lead (albeit wrong, it seems). Those who were forced to detrain earlier at Deepdene may well have been travelling back later and would have wondered why their morning train could not have continued (being ahead of the supposed illness at Gomshall), so it's not entirely irrelevant. This, by the way, still doesn't explain why three police cars were required, even if two ambulances were.

Every time I have used Deepdene in the last year or more, the CIS problem I mentioned has appeared, so it is not sporadic, but the norm. I make no apologies for complaining about an 'information' system which consistently provides significantly wrong information. Passengers (the pests!) should not have to expect a rural (but popular) railway to have an unreliable information regime, where the frequency of service actually demands a more reliable system than a high-frequency one, allowing passengers to avoid waiting for potentially a hour or more if given wrong information.

I also make no apologies for speculation, as that is one of the functions of a discussion forum. Had I claimed my speculation to be hard facts, that would be different.

 

[Deepgreen]

The upgraded Sunday timetable provides some clues to how 3tph would work, with Gatwick departures from Reading at xx:18 and xx:48 and the return journeys timed to depart Gatwick at xx:47 and xx:17, giving 12 minute layovers at both ends.

The hourly stopper would be threaded in between, departing Reading at (rough example timings) 12:04 with a 12 minute layover at Guildford to allow a Gatwick to overtake and then continuing to Redhill, arriving at 13:34. The return would depart Redhill at 13:43, arriving Guildford at 14:21. After the 13:47 ex-Gatwick has overtaken, the stopper would depart Guildford at 14:36, arriving in Reading at 15:19. Alternatively, the stopper would be timed for half an hour later giving a shorter turnaround at Reading.

There's a rough example of this in the current weekday timetable where the 09:03 Gatwick - Reading overtakes the 08:51 Redhill stopper at Guildford. However I have to say that neither service is particularly robust when comes to keeping to time.

The current timings of Thameslink services at Redhill clash with what GWR have (or had) in mind, not to mention SWR's - currently thwarted - plans for 4tph between Reading and Waterloo, the retiming of the Pompey trains at Guildford to achieve 4tph and the switching of Guildford - Ascot services to Guildford - Farnham.

Who'd be a planner?

How does a 2 tph Sunday timetable example help when considering a weekday 3tph timetable (with a much busier railway, with different timings anyway)?

 

[big all]

i suspect the number off bodies present was possibly for safety in transporting a possibly 20 stone person as near to level down the stairs and around the corner on a stretcher with possible oxygene or other equipment required to be attached
but fully a guess as only time and facts will give us the truth
its also possible that one off the cars was an advanced paramedics car