HS2: What services and facilities might be passively provided for at Calvert for a possible station?

[kevin_roche]

Moderator note: split from https://www.railforums.co.uk/thread...ive-high-speed-rail-line-the-go-ahead.200154/

In the Oakervee Review (on Page 53, see post #32 above for a link) there is mention that passive provision for a station at the junction with East - West Rail should be made.

Does that mean leaving space for 6 platforms like there will be at OOC or would four handle the number of trains that would have to stop?

I assume they would all have to stop so that they did not get closer together.

 

[edwin_m]

In the Oakervee Review (on Page 53, see post #32 above for a link) there is mention that passive provision for a station at the junction with East - West Rail should be made. Does that mean leaving space for 6 platforms like there will be at OOC or would four handle the number of trains that would have to stop. I assume they would all have to stop so that they did not get closer together.

If they all stopped then logically it would have to be three platforms in each direction. I don't think that's remotely likely.

The problem with stopping fewer than that is that each stopping train needs a path to arrive and another empty path a few minutes later to drop into on departure. The only way that can be done without loss of capacity or unnecessary waiting time is if about 6TPH stop, so that each restarting train drops into the path vacated by the next train slowing down to stop about 10min later. Reduction from 18TPH to 14TPH may make this slightly less severe, but if an otherwise unused path is used for a Calvert stopper it removes the resilience provided by having that path available to accommodate a late train elsewhere on the route.

I think this is what the Japanese do on their high speed lines, but they have high population density along most of the routes so there are many intermediate stations that require reasonably frequent service. To justify a station at Calvert would require a pretty large settlement there. EWR creates few connection opportunities in either direction from Calvert it serves MK and Oxford, both of which will be quicker to London or Birmingham by existing routes.

 

[kevin_roche]

If they all stopped then logically it would have to be three platforms in each direction. I don't think that's remotely likely.

The problem with stopping fewer than that is that each stopping train needs a path to arrive and another empty path a few minutes later to drop into on departure. The only way that can be done without loss of capacity or unnecessary waiting time is if about 6TPH stop, so that each restarting train drops into the path vacated by the next train slowing down to stop about 10min later. Reduction from 18TPH to 14TPH may make this slightly less severe, but if an otherwise unused path is used for a Calvert stopper it removes the resilience provided by having that path available to accommodate a late train elsewhere on the route.

I think this is what the Japanese do on their high speed lines, but they have high population density along most of the routes so there are many intermediate stations that require reasonably frequent service. To justify a station at Calvert would require a pretty large settlement there. EWR creates few connection opportunities in either direction from Calvert it serves MK and Oxford, both of which will be quicker to London or Birmingham by existing routes.

Thank you. I'm not any kind of expert but you confirmed my thoughts.

 

[miami]

Not all trains are due to stop at Interchange are they?

 

[The Ham]

Not all trains are due to stop at Interchange are they?

Indeed they are not, for instance the Liverpool services aren't expected to call there if memory serves correctly.

 

[MarkyT]

In the Oakervee Review (on Page 53, see post #32 above for a link) there is mention that passive provision for a station at the junction with East - West Rail should be made. Does that mean leaving space for 6 platforms like there will be at OOC or would four handle the number of trains that would have to stop. I assume they would all have to stop so that they did not get closer together.

It would be undesirable to stop everything there, but the only way to incorporate a small number of stops per hour at a Chiltern Parkway without losing capacity is to have another train (2) ready to go at the intermediate station to slot into the shadow fast path of the train (1) turning off onto the deceleration lane. Obviously the spare train (2) has to leave before the other train (1) arrives, so it can't be the same train, and on a 30-minute interval service, through trains stopping would dawdle for a good 20 odd minutes at the intermediate stop, unattractive for a through journey across the stop as well as representing poor stock utilisation. Would probably mean 4 through platforms on a conventional side island design.

Instead, I'd go for a 30-minute interval high-speed service terminating at Buckingham Junction from London, and another service filling the path gaps north thereof. That could be a Cross Country High-Speed tendril from Birmingham or further north going to Heathrow T5 via Oxford, Reading, and the airport's western connection. Would require a North - Oxford chord at the Chiltern Junction.

Infrastructure:

Fast junction and grade-separated 'slip lanes' at the north end leading to...
Flat junction with EWR and shared 'classic' station.

Terminating shuttles from London accommodated at a double face island terminal placed between widely spaced HS2 fast lines with fast junction and centre slip lane(s) on approach from London.

 

[The Ham]

It would be undesirable to stop everything there, but the only way to incorporate a small number of stops per hour at a Chiltern Parkway without losing capacity is to have another train (2) ready to go at the intermediate station to slot into the shadow fast path of the train (1) turning off onto the deceleration lane. Obviously the spare train (2) has to leave before the other train (1) arrives, so it can't be the same train, and on a 30-minute interval service, through trains stopping would dawdle for a good 20 odd minutes at the intermediate stop, unattractive for a through journey across the stop as well as representing poor stock utilisation. Would probably mean 4 through platforms on a conventional side island design.

Instead, I'd go for a 30-minute interval high-speed service terminating at Buckingham Junction from London, and another service filling the path gaps north thereof. That could be a Cross Country High-Speed tendril from Birmingham or further north going to Heathrow T5 via Oxford, Reading, and the airport's western connection. Would require a North - Oxford chord at the Chiltern Junction.

Infrastructure:

Fast junction and grade-separated 'slip lanes' at the north end leading to...
Flat junction with EWR and shared 'classic' station.

Terminating shuttles from London accommodated at a double face island terminal placed between widely spaced HS2 fast lines with fast junction and centre slip lane(s) on approach from London.

That's quite a lot just to provide a station which, unless there was a significant amount of development locally to it, wouldn't see a whole lot of use.

A station local to me with 800,000 passengers a year, for a settlement with ~8,000 people (about 3,500 homes) only justifies 2tph (circa 530 seats per service) as part of running with quite a few other stations.

The above would effectively be 4tph (2 to/from London and 2 to/from Birmingham/Heathrow), each with at least 550 seats. I'm not sure that building something like 7,000 homes to justify that sort of service would be welcomed by those living nearby.

I wouldn't be surprised if the review suggested passive provision so that it appears to show that something could be done, even though the reality is that the paths would be of much better use serving other locations.

 

[edwin_m]

Not all trains are due to stop at Interchange are they?

Indeed they are not, for instance the Liverpool services aren't expected to call there if memory serves correctly.

The Interchange station is near the start of the four-track section which then splits in two for Birmingham or the North. So the timetable can be arranged so that trains calling at the Interchange use a different track and go the other way at the junction, if they would otherwise conflict with non-stopping trains. That's not possible at a Calvert station unless you four-track most of the way to Birmingham.

 

[MarkyT]

That's quite a lot just to provide a station which, unless there was a significant amount of development locally to it, wouldn't see a whole lot of use.

A station local to me with 800,000 passengers a year, for a settlement with ~8,000 people (about 3,500 homes) only justifies 2tph (circa 530 seats per service) as part of running with quite a few other stations.

The above would effectively be 4tph (2 to/from London and 2 to/from Birmingham/Heathrow), each with at least 550 seats. I'm not sure that building something like 7,000 homes to justify that sort of service would be welcomed by those living nearby.

I wouldn't be surprised if the review suggested passive provision so that it appears to show that something could be done, even though the reality is that the paths would be of much better use serving other locations.

I'm not arguing FOR the station, just mulling what plausible facilities MIGHT be passively provided for. From that, I coined the idea of trains from the north diverging at Calvert for Oxford and Heathrow to balance the paths of the London stoppers. Such trains wouldn't need to stop at Calvert clearly, only a junction is needed for them to gain EWR to Oxford. Without the London shuttles though, the Heathrow trains would clearly create unused shadow paths of their own at the London end, so what could they be used for instead. That's the problem with station proposals for Calvert and areas north thereof. HS2 is deliberately routed through a whole load of relative nothingness as far as population and commerce are concerned (which is clearly a positive overall, taking noisy expresses out of town centres, releasing capacity for more stoppers and freight, etc).

 

[Bald Rick]

In the Oakervee Review (on Page 53, see post #32 above for a link) there is mention that passive provision for a station at the junction with East - West Rail should be made. Does that mean leaving space for 6 platforms like there will be at OOC or would four handle the number of trains that would have to stop. I assume they would all have to stop so that they did not get closer together.

In this case, passive provision will almost certainly mean leaving what space they can for the station within the land secured by the Act. Personally, I doubt it will happen.

 

[camflyer]

A link between HS2 and EWR would be great to improve links between the east of England and the North West. However the lines intersect in the middle of nowhere which makes a new station hard to justify.