Ponders End loop

[Alfie1014]

Ian Visits has some more details on the proposed passing loop planned at Ponders End;

https://www.ianvisits.co.uk/article...in-frequency-at-meridian-water-station-53005/

which includes this track layout. As others have said I can’t quite see what it will achieve timetable wise as any stopping service from north of Ponders End will have journey times increased whilst it’s overtaken?

 

[dk1]

This is mentioned by the train planning team at GA for future changes today.

 

[306024]

No doubt consultants have devised a cunning plan that will collapse as soon as it is handed to the GA timetable planners to implement

 

[Watershed]

Ian Visits has some more details on the proposed passing loop planned at Ponders End;

https://www.ianvisits.co.uk/article...in-frequency-at-meridian-water-station-53005/

which includes this track layout. As others have said I can’t quite see what it will achieve timetable wise as any stopping service from north of Ponders End will have journey times increased whilst it’s overtaken? View attachment 112390

Looks like it will enable trains to turnback there without conflict. Which could be pretty useful.

 

[alf]

Looks like the Ponders End loop, if it happens, will be as useful as the one put in on the slow lines at Tring.

Tring’s loop is used for turnaround every half hour, but never for looping;
& the unused 40 mph points at the Tring country end have had to be maintained for 15 years plus.

 

[zwk500]

Looks like the Ponders End loop, if it happens, will be as useful as the one put in on the slow lines at Tring.

Tring’s loop is used for turnaround every half hour, but never for looping;
& the unused 40 mph points at the Tring country end have had to be maintained for 15 years plus.

Not quite. Tring loop can be used as a loop in the Up direction, but isn't during normal service due to the terminating service. It also isn't regularly booked for looping during 2-track operation as that option would not be available if the 2-track is using the fasts. It has been booked to loop traffic for short-term amendments when the 2-track is on the slows on rare occasions. It can't be used as a loop in the down direction because the trailing points onto the down slow at the country end were run through some years ago and have never been fully repaired.

 

[Dave W]

I’m sure someone knows better but I can’t work out how an extra track fits in there - the station is bound by Brimsdown Ditch and Meridian Way to the east and housing to the left.

Am I missing something?

 

[zwk500]

I’m sure someone knows better but I can’t work out how an extra track fits in there - the station is bound by Brimsdown Ditch and Meridian Way to the east and housing to the left.

Am I missing something?

From a quick look at google, if you put a retaining wall in at the bottom of the gardens north of the A110 bridge you can get enough room to start the pointwork, then you either culvert over or put another retaining wall alongside Brimsdown ditch and you'll get enough space. It's tight but doable. No idea what the costs of flood mitigation will be though....

 

[mr_jrt]

Give CR2 is intended to 4 track this section, you would hope there was a plan for getting the space for 4 tracks, let alone 3! I wonder if they ultimately intend to slice off some land from the other side of Meridian Way and realign it to give the space through the rail corridor. Looks like a handful of industrial buildings and mostly car parking spaces. As suggested above, culverting might get you room for 3, though. I don't know the vertical levels at play, so hard to be sure...unless the eventual plan would be for the 4th track to go on the western side? Not sure how feasible that would be.

 

[zwk500]

Give CR2 is intended to 4 track this section, you would hope there was a plan for getting the space for 4 tracks, let alone 3! I wonder if they ultimately intend to slice off some land from the other side of Meridian Way and realign it to give the space through the rail corridor. Looks like a handful of industrial buildings and mostly car parking spaces. As suggested above, culverting might get you room for 3, though. I don't know the vertical levels at play, so hard to be sure...unless the eventual plan would be for the 4th track to go on the western side? Not sure how feasible that would be.

Will they have 4 platforms? It would be awkward but probably workable to have 2 side platforms outside the slow lines and the fast lines have no platforms in the middle. Might need the existing Up platform to be rebuilt a bit further back, but if you demolish the island platform there may well be space for 4 tracks and 2 platforms without moving Meridian Way.

 

[Class 170101]

Thats up to eight trains per hour using the middle road to be over taken, four up and four down services. Doesn't seem a recipe for reliability.

 

[BS56]

There is already a disused up loop between Enfield Lock and Brimsdown could any use be made of that ?

 

[zwk500]

There is already a disused up loop between Enfield Lock and Brimsdown could any use be made of that ?

It'll cost a similar amount to put it back as the Ponder's End loop would, and it's not good passenger service to dump the stopping train in the loop for 4-6 minutes not in a platform. It's also much more capacity intensive to have Stop in Platform-Stop in Loop-Stop in Platform than Stop in Platform loop (wait), go.

 

[Bald Rick]

as any stopping service from north of Ponders End will have journey times increased whilst it’s overtaken?

correct.

It Is fair to say there are ‘mixed views’ about this proposal. Some are quite keen. Some think it’s bonkers. I’m firmly in the latter camp. personal view, of course.

Will they have 4 platforms? It would be awkward but probably workable to have 2 side platforms outside the slow lines and the fast lines have no platforms in the middle.

the Crossrail 2 proposal had slows lines on the west side, fast lines on the east side. Saves a load of grade separation.

 

[zwk500]

the Crossrail 2 proposal had slows lines on the west side, fast lines on the east side. Saves a load of grade separation.

Ah, thanks for that. Not so familiar with Crossrail 2 proposals.

 

[306024]

Looks like it will enable trains to turnback there without conflict. Which could be pretty useful.

Depends on how passenger loadings are predicted to grow south of Ponders End. Using a path through Brimsdown which doesn’t serve Enfield Lock or Waltham Cross may not be optimal.

It Is fair to say there are ‘mixed views’ about this proposal. Some are quite keen. Some think it’s bonkers. I’m firmly in the latter camp. personal view, of course.

So I'm not losing my marbles (yet). I did wonder whether there was something in this I was overlooking.

 

[Starmill]

No doubt consultants have devised a cunning plan that will collapse as soon as it is handed to the GA timetable planners to implement

A consultant will do whatever they've been contracted to do. If the client has asked for a loop at Ponders End to be designed (for example) the consultant isn't going to suggest that they've put the loop in the wrong place. There's room for clarification questions which may well prompt a rethink, but not an awful lot else.

Looks like it will enable trains to turnback there without conflict. Which could be pretty useful.

Sure, that's absolutely right. But it's tricky to see an awful lot of benefit here given the improbability of trains turning back there very frequently, and the compromises necessary for a fast train to overtake.

 

[Bikeman78]

correct.

It Is fair to say there are ‘mixed views’ about this proposal. Some are quite keen. Some think it’s bonkers. I’m firmly in the latter camp. personal view, of course.

What is the proposed service after the loop is completed? As I understand it, the aim is for more trains to stop at Meridian Water but an extra stop and being looped isn't likely to be popular.

 

[Bald Rick]

What is the proposed service after the loop is completed? As I understand it, the aim is for more trains to stop at Meridian Water but an extra stop and being looped isn't likely to be popular.

IIRC the original proposal (from some years ago) was for the Stratford - Stortfords to be looped, and picking up an extra stop, whilst the Hertfords would drop the stop that the Stortford gained but pick up Meridian Water.

not good news for some stations, eg Roydon.

don’t know how it has evolved since, if at all.

 

[cle]

Ahh - I assumed it was 2 net new shuttles from Stratford, except 2tph would turn back at Meridian Water and 2tph at Ponders End (so 4tph for Meridian Water) ? So basically a loop but used as another turnback/bay - with passing trains threaded around ?

 

[Bald Rick]

Ahh - I assumed it was 2 net new shuttles from Stratford, except 2tph would turn back at Meridian Water and 2tph at Ponders End (so 4tph for Meridian Water) ? So basically a loop but used as another turnback/bay - with passing trains threaded around ?

definitely not - that would need more trains.

 

[Class 170101]

Ahh - I assumed it was 2 net new shuttles from Stratford, except 2tph would turn back at Meridian Water and 2tph at Ponders End (so 4tph for Meridian Water) ? So basically a loop but used as another turnback/bay - with passing trains threaded around ?

definitely not - that would need more trains.

Unless services were sacrificed elsewhere, note that services as I write this aren't as frequent as pre-pandemic, so I imagine there might well be stock available.

 

[Bald Rick]

Unless services were sacrificed elsewhere, note that services as I write this aren't as frequent as pre-pandemic, so I imagine there might well be stock available.

oh there’s stock available. But it still would have to be paid for.

 

[Class 170101]

oh there’s stock available. But it still would have to be paid for.

Aren't developers paying for the whole cost of the loop including services then?

 

[Bikeman78]

IIRC the original proposal (from some years ago) was for the Stratford - Stortfords to be looped, and picking up an extra stop, whilst the Hertfords would drop the stop that the Stortford gained but pick up Meridian Water.

not good news for some stations, eg Roydon.

don’t know how it has evolved since, if at all.

Thanks. Presumably the timetable will be significantly altered. At the moment the Stratford-Stortfords aren't at Ponders End at the right time to be overtaken in the down direction. In the up direction they have the Cambridge and the Stansted catching up but looping for both to overtake would be quite a time penalty.

Also it depends what happens with Stansted Express in the medium term. If it stays half hourly then the loop at Ponders End isn't needed. You could squeeze an extra stop on the Stratford-Stortford and possibly avoid the need to loop at Broxbourne or Harlow.

 

[Bald Rick]

. At the moment the Stratford-Stortfords aren't at Ponders End at the right time to be overtaken in the down direction.

yes, they’d be waiting quite a while!