London's Transport Infrastructure

[Christopher125]

Originally Posted by Rational Plan

Others over at Rail forum have dumped all over the idea, but I don't know I feel there is plenty of scope for a North South line through the Isle of Dogs.

I dont agree - there simply isnt enough off-peak demand from the Docklands area to justify prioritising the huge expense required when the Tube has such major capacity issues.

Chris

[mr_jrt]

I'm still of the opinion that a Stratford <-> Canary Wharf link between Crossrail's branches would give most of the benefits of the northern section.

[mackenziesoley]

Originally Posted by mr_jrt

I'm still of the opinion that a Stratford <-> Canary Wharf link between Crossrail's branches would give most of the benefits of the northern section.

Agreed plus it'd be much cheaper.

[sotonsi]

Originally Posted by streetquark

Where is the central London aspect any different for existing routes? If you get an EB H&C train you can simply change trains.

Though surely you'd try and minimise such cross-platform changes at Stamford Brook - by making Ealing Broadway, rather than Richmond, an H&C branch. And, of course, Ravenscourt Park is where the District line becomes PIXC, so having passengers changing from the H&C at Stamford Brook doesn't solve that problem.

What arrogance. More like break proposals instead of testing.

house of cards' collapse. Then again, I've certainly understated the case for your proposal, and for that I apologize.

Extra branching off existing routes does not justify a fractional reduction in tunnel (c. 0.1-2 of a mile assuming you didn't realised Stamford Brook-Acton Park was not tunnel).

OK, here's your plan roughly drawn on google maps. You are quite right - it's only 1/8th of a mile (200m) less tunneling on the central line route - you can just about squeeze two tracks on the former track bed (wasn't it single track), so run on the surface there.

I was also wrong on the "reusing that disused trackbed is longer" - it's the same distance via Acton Park and via Turnham Green, though you have some tightish curves getting back onto the current alignment.

Also, you are adding additional complexity to the SSLs (basically branching the H&C route at Turnham Green), so your point about extra branching off existing routes isn't that valid - especially when it is simply moving a branching further east.

Swapping onto a busier route.

Almost anything would be busier than the Ealing Broadway Central Line branch post-Crossrail. This same Crossrail will greatly relieve congestion on the Central line approaching the City from the West - all the way from Ealing Broadway in. Add in the White City terminators, and you easily have capacity to take a busier route and relieve the District and Piccadilly lines far better than the H&C would.

Nope.

(about interchange movements from Ealing Common direction to Northfields direction and vice versa at Acton Town).

Bollocks - there's an interchange footbridge which would only be used for such movements. On Monday, doing my regular Amersham - Northfields (note, I wouldn't be inconvenienced by your proposal) journey, I (at the front of the pack) turned around at the end of the bridge. 20 people from my (ex-Uxbridge) train were on it at that point. OK, it was 1700 hours, so peak time, but there were still lots of people leaving the train, walking along the platform, going up the stairs. Lets call it an average of a dozen people per train, and ignore reverse movements - this is a conservative estimate of that interchange. That's 144 people an hour - we're talking thousands of movements a day. OK, some, like me, will get off at Northfields, but I see mostly different faces getting off at Northfields to those who boarded at Acton Town with me.

I reckon that if you counted, the only reason any of the cross-/same-platform interchanges would be more than over-the-bridge interchanges is when a train changes its destination at Acton Town (so really the train is making the cross-/same-platform interchange, not the passengers!)

nope.

(to my point that you are only increasing Heathrow branch frequencies).
Here's a diagram that I think shows your proposal (from what you have explained of it - if I've not understood, or I'm second guessing your thoughts because you've done a poor job of explaining it, please tell me). The first shows the current situation, the latter in what I understand to be your proposal. Each 3-pixel wide line represents 6 or 7tph. I do not have the 3tph Northfields terminators, nor some of the Wimbledon trains (I don't think) - it's a little over simplified.

As you can see, you need to sort out Earls Court or Praed Street - recent changes in service patterns have shown that you cannot reliably fit more trains in there.

The salient point is the frequencies can be increased.

Nope see above. Then again, Chelney would allow a reduction in Wimbledon services, enabling a few more trains to head west on the District line.

FYI there are 4 tracks through Boston Manor.

Two of which are simply depot access to the west. Looking at the layout, the southern-most tracks of each directional pair at Northfields go into the depot, via a grade-separated junction, and these two come out of it. You could use them as-is, but then you are paired by speed, not direction, which is not good for interchange.

Picc to Rayners, augmented by District sounds good, but lets make it Ealing Broadway, or better yet (OK, it's slightly more tunneling because you'd want to emerge south of Acton Town and pick up that station's cross-platform Interchange) Northfields/Boston Manor via the slow tracks, that way we have segregation of the Piccadilly line - you can still have fast trains skip South Ealing and Northfields on the fast tracks if you desire. With the H&C/Circle, you can have District to Uxbridge/Richmond, Circle to Ealing Broadway and H&C to Rayners Lane, giving all the SSL stations in West London (other than Chiswick and Ravenscourt Parks) two options.

Your scheme has merit, but
1)There's little need to build a new Piccadilly line, given that the H&C/Circle service can fit on the current slow tracks. Unless you have trains reversing at Paddington, or magically able to get through the capacity constraints at the edge of zone 1, or rerouted from Wimbledon.
2)You don't deal with crush-loading on the District line approaching zone 1, because next-to-no-one is going to get to zone 1 from Stamford Brook via Paddington.

It's like the most recent two suggestions here - both done by serious people, serious motives, but with serious flaws: the BML2 and the 'Stepney Green chord'. All three are somewhat join-the-dots obvious and cheap solutions to the problems (not enough trains going west of Hammersmith especially to Hounslow, capacity shortfalls on the BML, two Crossrail branches in East London that will not cope with demand), but don't really solve the problems they set out to (discussed at length above, fails to serve the major traffic generators that aren't on the south coast, fails to deal with the PIXC going into zone 1 and gums up the works for frequency increases that might help sort that).

All three would be good schemes to build, but they really ought to be examined more - both in terms of negative effects and value for money.

[Angle42]

Originally Posted by mr_jrt

I'm still of the opinion that a Stratford <-> Canary Wharf link between Crossrail's branches would give most of the benefits of the northern section.

There are already two connections between these points. why do you need a third?

[mr_jrt]

Originally Posted by Angle42

There are already two connections between these points. why do you need a third?

The DLR is slow. It's a glorified tram. Good for short hops, not suitable for long end-to-end journeys.

The Jubilee line is overloaded between Stratford and Canary Wharf because of the above. You may as well accept that there is a large flow between Stratford and Canary Wharf and skip the intermediate stops, which conveniently links two Crossrail branches whose service levels are limited by having limited capacity in the core.

I suspect the amount of relief this would afford to the Jubilee line would then enable it to be returned to it's primary purpose, aka a metro line rather than a glorified Canary Wharf-Stratford shuttle. You can then either resurrect the Thamesmead branch idea, or push on northwards from Stratford up the Lea Valley.

[LondonerMiles]

Unfortuantley, Crossrail and even the new Cable Car has killed any hope of the Thamesmead exstention. However, It would seem better to have the Abbey Wood arm which has already became an appendix to the jubilee line. Even so, the old Fleet exstention could be resurected to become a loop either side of the Thames.

[streetquark]

Originally Posted by sotonsi

As you can see, you need to sort out Earls Court or Praed Street - recent changes in service patterns have shown that you cannot reliably fit more trains in there.

Good diagram.

Yes you would need to sort out EC and Paddington and as I previously pointed out something east of Praed Street if not adaptable at Paddington itself to increase H&C frequencies would be desirable if not crucial for any scheme westwards (the other possibility involving alteration of Wimbledon branch services in conjunction with Crossrail doesn't look a great idea - EDIT I see you have mentioned it).

Hopefully not too much at EC/Paddington would allow you an extra 8 or so paths westward. Add to this the 12tph currently on offer from the H&C and overall you would have c. 20 paths.

Of these you could still send c. 6tph piccs down the Uxbridge branch to add to the new District service (EDIT I see you have mentioned the branch idea) which would still increase Heathrow frequency west of Acton Town from existing levels (bear in mind the additional ex-Boston Manor service too) and still have 8 or so paths to go where its needed or where there is capacity, i.e. Boston Manor.

Nope see above.

Ditto.

Picc to Rayners, augmented by District sounds good, but lets make it Ealing Broadway, or better yet (OK, it's slightly more tunneling because you'd want to emerge south of Acton Town and pick up that station's cross-platform Interchange) Northfields/Boston Manor via the slow tracks, that way we have segregation of the Piccadilly line - you can still have fast trains skip South Ealing and Northfields on the fast tracks if you desire. With the H&C/Circle, you can have District to Uxbridge/Richmond, Circle to Ealing Broadway and H&C to Rayners Lane, giving all the SSL stations in West London (other than Chiswick and Ravenscourt Parks) two options.

Any splitting of the Picc seems to point to surfacing at Acton Town for good or bad whether its Boston Manor slows, Ealing Bdy or keeping some for Rayners Lane. I would hope the extra paths available would justify one or other combination of services such as those mentioned in this post unless a combination that keeps the Picc one service/branch only could be found that is preferable but i'm not sure it's cheaper to keep the picc in tunnel past Acton town anyway so it might be a moot point.

It's like the most recent two suggestions here - both done by serious people, serious motives, but with serious flaws: the BML2 and the 'Stepney Green chord'. All three are somewhat join-the-dots obvious and cheap solutions to the problems (not enough trains going west of Hammersmith especially to Hounslow, capacity shortfalls on the BML, two Crossrail branches in East London that will not cope with demand), but don't really solve the problems they set out to (discussed at length above, fails to serve the major traffic generators that aren't on the south coast, fails to deal with the PIXC going into zone 1 and gums up the works for frequency increases that might help sort that).

BML2 is pie in the sky even if we should start considering Isle of Dogs as the 3rd city centre but if someone wants to stump up the cash (and that would be the second less-than-perfect new line to Canary Wharf)...

Personally I would look at trying to straighten out and 4-track Lewisham-Marsh Wall DLR. As for the rest, the DLR Stratford HL branch is not exactly heavily used and there are surely better central area options for BML2.

'Twas I who first considered the Stepney Eastern curve way back. It wasn't thought of as a join the dots but to address a particular issue at the time. Initially it was a modest idea but it seems it isn't a compromise on the Stratford-Canary Wharf route as the alignment and times would seem to favour it (as would the lack of intermediate stations). I can't see any constraint capacity-wise. The branch frequencies combined are restricted by the core capacity, if the eastern curve is put in there is enough capacity overall for existing services and the new service, leading onto extra branching too, i.e. Lea Valley (BML2's recent suggestion noted). If the core doesn't increase in capacity that's it, if it does then that just mean more options for the new service. Even if one central-bound branch demanded increases at the expense of the other I cannot see how the new service wouldn't be justified unless one of the branches were to have such low frequencies as to make it non-viable in its own right. Of course overall capacity increase, e.g.g to 30 tph would make such a scenario even less likely.

If we're talking service disruption while the 2 new tunnels are joined to each branch then that seems minor. I would be more concerned with access from tunnelling machines. If they could design now and build it alongside the existing project it would certainly be easier.

[streetquark]

Originally Posted by Angle42

There are already two connections between these points. why do you need a third?

I will add to mr_jrt's accurate description of the existing DLR services.

They only go to Stratford, they are not outer suburban commuter routes.

Stratford HL DLR is like a Hogwarts station.

Plans to extend the jub from North Greenwich flounder (apart from there being no money for anything of course) due to North Greenwich-Stratford being so busy.

Options present themselves for future DLR developments, i.e. Bow-Hackney. The Bow-Stratford stretch of the DLR could then be abandoned and capacity expanded on the line into Liverpool Street and at Stratford HL station.

Originally Posted by LondonerMiles

Unfortuantley, Crossrail and even the new Cable Car has killed any hope of the Thamesmead exstention.

Ironically a SE-NE Crossrail link is its saviour.

[Angle42]

Originally Posted by streetquark

I will add to mr_jrt's accurate description of the existing DLR services.

They only go to Stratford, they are not outer suburban commuter routes.

Stratford HL DLR is like a Hogwarts station.

I agree that the DLR is not the best system for moving people over long distances but Stratford to Canary Wharf is not that far and journey times not too long.

There will be a relatiivly easy transfer from Crossrail at Stratford and there is already a good distribution of stops throughout the Canary Wharf area. I think that this is a better option than having people get off at Isle of Dogs from a Crossrail spur - the connectivity with the DLR there will be relatively poor.

Originally Posted by streetquark

Plans to extend the jub from North Greenwich flounder (apart from there being no money for anything of course) due to North Greenwich-Stratford being so busy.

Gven the route of Crossrail to Woolwich and beyond, I've always thought that and extension of the Jubilee Line from North Greenwich should stay north of the Thames - i.e. City airport and then Daghenham/Rianham.

Surely an extra spur would allow more trains through North Greenwich than are posisble at the moment.

[mackenziesoley]

Originally Posted by Angle42

I agree that the DLR is not the best system for moving people over long distances but Stratford to Canary Wharf is not that far and journey times not too long.

There will be a relatiivly easy transfer from Crossrail at Stratford and there is already a good distribution of stops throughout the Canary Wharf area. I think that this is a better option than having people get off at Isle of Dogs from a Crossrail spur - the connectivity with the DLR there will be relatively poor.

Gven the route of Crossrail to Woolwich and beyond, I've always thought that and extension of the Jubilee Line from North Greenwich should stay north of the Thames - i.e. City airport and then Daghenham/Rianham.

Surely an extra spur would allow more trains through North Greenwich than are posisble at the moment.

Problem is if there is space to squeeze any extra trains though North Greenwich, Stratford needs them. Unless you run a shuttle to North Greenwich.

[NCT]

Thamesmead is only a couple of bus stops from Abbey Wood, which is getting Crossrail. I don't think this area is busy enough to warrant another metro service.

[Angle42]

Originally Posted by mackenziesoley

Problem is if there is space to squeeze any extra trains though North Greenwich, Stratford needs them. Unless you run a shuttle to North Greenwich.

Is Stratford able to turn as many trains around as could fit on the line.

Stratford has three bays but I've never been sure whether the line could handle more trains.

[cle]

Brixton does the most with 2 bays. Arguably, the more there are, the more complex the stepping back process.

[Rational Plan]

The problem with the idea of a link with two branches of the crossrail line, is the idea that there is loads of spare capacity. The slow lines out of stratford are full. There is no space to run trains direct to Canary Wharf. If they can get more lines to run on crossrail the majority of passengers would want them to run to Central London.

[sotonsi]

Rational Plan - that is precisely my complaint.

You might be able to up each branch to 16tph (from 12) and the Liverpool Street ML - Gidea Park trains to 8tph (from 6) to meet the huge capacity gap heading into Central London. This is 24tph on the Shenfield branch after a 33%/6tph increase into Central London needed to enable people to be able to board trains at Whitechapel in the AM peak. Two branches merging south of Stratford gives you a reliability problem, even with the planned 12tph Crossrail, 6tph Liverpool Street and 6tph (that's not going to do much to relieve the Jubilee) minimum 'Stepney curve' frequency, let alone the much-needed increase in Central London frequency.

The long term solution is surely to split the two branches into two-cores - this is mighty difficult with a curved link in place.

[mr_jrt]

Originally Posted by Rational Plan

The problem with the idea of a link with two branches of the crossrail line, is the idea that loads of spare capacity. The slow lines out of statford are full. There is no space to run trains direct to Canary Wharf. If they can get more lines to run on crossrail the majority of passengers would want them to run to Central London.

Handily, there's also the Stratford to Coppermill Junction line which can take services. I think a Stansted to Canary Wharf service would go down VERY well.

Originally Posted by sotonsi

Rational Plan - that is precisely my complaint.

You might be able to up each branch to 16tph (from 12) and the Liverpool Street ML - Gidea Park trains to 8tph (from 6) to meet the huge capacity gap heading into Central London. This is 24tph on the Shenfield branch after a 33%/6tph increase into Central London needed to enable people to be able to board trains at Whitechapel in the AM peak. Two branches merging south of Stratford gives you a reliability problem, even with the planned 12tph Crossrail, 6tph Liverpool Street and 6tph (that's not going to do much to relieve the Jubilee) minimum 'Stepney curve' frequency, let alone the much-needed increase in Central London frequency.

The majority of passengers don't suddenly pop into existence at Stratford - they arrive on the NR services and change to the Jubilee. If the services can get them TO Stratford, they are quite sufficient for getting them to Canary Wharf. Given the platform arrangements - it'll be a much easier interchange as well.

Branches merging is no big problem.

[ill tonkso]

An Hourly service between Stanstead and the Wharf could do wonders for the Airports growth actually. It still has a reputation as a holidaymakers airport.

[sotonsi]

Originally Posted by mr_jrt

Handily, there's also the Stratford to Coppermill Junction line which can take services. I think a Stansted to Canary Wharf service would go down VERY well.

though you'd still have to use the slow lines through Stratford (or make the interchange poor).

Neither RP, or I, are saying "there's no demand for it", we're saying there's not enough capacity on the tracks shared with Crossrail for it. Yes a STN - CW service would go down well, but not this way. In fact, I'd argue that demand is enough for a fully new-build line taking Lea Valley terminators (and extra services) through to CW (shame, other than you'd overload Crossrail heading into The City even more, that they didn't plan the CW station as 4-track, with Crossrail interchanging well with terminating services from the Lea Valley - and when the Crossrail branches were eventually segregated, the Lea Valley could be a branch off the via CW line).

The majority of passengers don't suddenly pop into existence at Stratford - they arrive on the NR services and change to the Jubilee. If the services can get them TO Stratford, they are quite sufficient for getting them to Canary Wharf. Given the platform arrangements - it'll be a much easier interchange as well.

Well indeed, but changing (from Central line, or Shenfield line - given you are now talking about Lea Valley line trains because it was pointed out that there's no room on the Shenfield line) to a 10-minutely service on the same very very crowded island-platform (with strong flows of people trying to sweep you on a train to Whitechapel and beyond) isn't going to be pleasant. Changing at Whitechapel, using the JLE or DLR are going to be more pleasant and so people will only change to the Stepney curve services if the next train at platform 5 is going to CW or they are masochistic.

To give some serious congestion relief to the JLE, you'd need 12tph, and then we hit major quart-into-pint-pot problems.

Branches merging is no big problem.

Reliability-wise a more complex network cannot reliably have the high frequencies needed to cope with the demand of such big traffic flows. See the Northern line for details. Or the District line. Or various main lines coming into London (say the SWML slows north of Raynes Park, where you've had too many branches merge in).

IIRC, streetquark proposed it when I mentioned the capacity gap on the Crossrail branches - it makes that problem more difficult to solve (with both the medium term and long term solutions of frequency upping and splitting the line), rather than solving it.

[Rational Plan]

Forgetting the problem of interlining services on two separate branches together, there is the problem of unequal demand. Currently a lot of trains pull into Stratford and people get off to get to Canary Wharf. If there was spare capacity you could run extra services direct to the Wharf, which a lot commuters would like. The problem is there is not lots of spare capacity, users to the Wharf have to compete with people going to the City.

What percentage of people get off at Stratford, I doubt it's 50%. With separate rail heads you need have less trains to chose from. For example a local station may have 4 trains an hour to London, which sounds great, not so great when only tow of them go to Liverpool street.

It's the problem that exists in South east London. You may have 6 trains an hour but, for many it's only 2 an hour, for that is the train that gets them to Victoria or Charing Cross. I know plenty on here have argued that they should build proper interchanges and run some lines like metros.