Bakerloo Line extension to Lewisham on the surface?

[sbf kent]

Lead Project Engineer on the proposed Bakerloo line extension, Mo Gajia, was interviewed as part of the latest episode of U&Yesterday's Secrets of the London Underground. Mr Gajia added: "I mean, I like building tunnels, don't get me wrong - I'm a tunnel engineer. But, generally speaking, we would like to have it on the surface, and actually, that has other benefits as well, though, because you want people to get in and out of the station as quickly as possible, and you don't want people to have to use lifts and escalators." Would it be possible for the Bakerloo line to be part underground part overground and where would it go on the surface - down the middle of the Old Kent Road?

 

[cle]

Nuts. Is it April Fool's? How is it getting up from Elephant and that skyline... around the Tower Bridge interchange? or through the very protected Burgess Park?! insane.

Also pointless, as it's a straight shot in a tunnel. I also don't know how above ground would work through NXG - where the roads get narrow again, or indeed Lewisham station, plus the developments there. Maybe this guy is talking hypothetically without having looked at the route. This approach has worked in brownfield sites like for DLR, or indeed in countries with less nimbies and planning/aesthetic concerns, e.g Bangkok, but it's not really been how we've done things through inner London. I doubt it'd be bricked viaduct either, lol.

And Ladywell etc is at least trenched too, so it doesn't need to be 'high' as it were, to connect into NR.

 

[edwin_m]

Nuts. Is it April Fool's? How is it getting up from Elephant and that skyline... around the Tower Bridge interchange? or through the very protected Burgess Park?! insane.

Also pointless, as it's a straight shot in a tunnel. I also don't know how above ground would work through NXG - where the roads get narrow again, or indeed Lewisham station, plus the developments there. Maybe this guy is talking hypothetically without having looked at the route. This approach has worked in brownfield sites like for DLR, or indeed in countries with less nimbies and planning/aesthetic concerns, e.g Bangkok, but it's not really been how we've done things through inner London. I doubt it'd be bricked viaduct either, lol.

And Ladywell etc is at least trenched too, so it doesn't need to be 'high' as it were, to connect into NR.

As he was said to be the lead project engineer then I'd like to think he's had at least a cursory glance at the route, so I suggest he was talking hypothetically and there is no possibility of surface running between Lambeth North and Lewisham. However, any continuation to Hayes would be on the surface, taking over the Network Rail route.

Surface running is almost certainly cheaper and does have some accessibility benefits, but the latter may be something of a double-edged sword. Unless it's a tramway, passengers using the further platform have to use two lifts, escalators, stairs or long ramps anyway, which works out the same on average as having to use one of those on every use of an underground station. There's also a "community severance" effect where a surface alignment is difficult to cross and tends to isolate the people on either side from each other. This still applies to some extent for an elevated route, which can be crossed at ground level but it's often not particularly pleasant doing so.

 

[Mr. SW]

It's been tried before. 1988

 

[cle]

Surface running is almost certainly cheaper and does have some accessibility benefits, but the latter may be something of a double-edged sword. Unless it's a tramway, passengers using the further platform have to use two lifts, escalators, stairs or long ramps anyway, which works out the same on average as having to use one of those on every use of an underground station. There's also a "community severance" effect where a surface alignment is difficult to cross and tends to isolate the people on either side from each other. This still applies to some extent for an elevated route, which can be crossed at ground level but it's often not particularly pleasant doing so.

Hypothetically speaking yes. Best practice in the US, Australia, Asia - these days, is the median of a highway. Or if you're building through nothing, like Barking Riverside.

But for the Bakerloo, this is irrelevant. Other than the surface sections from Ladywell to Hayes which are established and more trenched - with some at-grade/level pedestrian access, which I agree, is great. But it's grandfathered in.

And you rightly call out the ghettoisation - seen across the US in the highway building - which severs neighborhoods and often had racial inequality impact. Would not happen here, especially in inner London.

 

[stuu]

Hypothetically speaking yes. Best practice in the US, Australia, Asia - these days, is the median of a highway. Or if you're building through nothing, like Barking Riverside.

Hardly best practice, it happens a lot because its an easy choice of route. But they are usually horrible stations to use and are often relatively far from the centre of the communities they are supposed to serve

 

[MarkyT]

Hardly best practice, it happens a lot because its an easy choice of route. But they are usually horrible stations to use and are often relatively far from the centre of the communities they are supposed to serve

Median tracks can be good for longer distance express routes with few intermediate stations, and tracks can turn off the highway at those few places to call in at a more convenient site nearby. Even when functioning primarily as car-based railhead facilities, median stations are often a poor passenger experience with long walks from parking lots to the platforms.

 

[eldomtom2]

Hypothetically speaking yes. Best practice in the US, Australia, Asia - these days, is the median of a highway.

I see a lot of criticism of highway-median construction nowadays for creating stations that are awkward to access and fairly inhospitable.

 

[edwin_m]

But they are usually horrible stations to use

https://thumbs.dreamstime.com/z/passengers-traveling-stop-as-bus-approaches-yenibosna-metrobus-station-istanbul-turkey-july-km-rapid-transit-251397510.jpg

This is actually a busway but illustrates quite well how terrible these stations can be.

 

[sprunt]

Where would the underground line emerge between Lewisham and Ladywell if the extension to Hayes were ever completed? Has that level of planning for the extension been published?

 

[cle]

To be clear, I hate the highway median things personally. Mandurah in Perth has been pretty incredible though.

By best practice, I meant - viability to get funded and built (and avoiding nimby/protective concerns, per the topic)

 

[Snow1964]

Seems AECOM and WW+P have been appointed to do feasibility studies on the 4 stations of Bakerloo extension to Lewisham.

I am guessing something has moved on from pipedream status if money is being committed for architects to check it can be built and/or design stations.

AECOM and WW+P have been appointed by Transport for London (TfL) to deliver the feasibility study on four new stations as part of the Bakerloo Line Extension project.

Work on the feasibility study will be carried out over the next eight months, with the four new stations – Burgess Park, Old Kent Road, New Cross Gate, Lewisham – expected to be operational by 2040 according to TfL, subject to planning and funding approval. WW+P, which is lead architect for the project, will focus the design aspects of the study. AECOM, the world’s trusted infrastructure consulting firm, will be responsible for all engineering matters, including civil, structural, mechanical and geotechnical engineering, as well as stakeholder engagement and consent.

“We are delighted to be working on this project, connecting southeast London with much-needed transport links to the heart of the city,” says Shadi Shekarrizi, Rail Director for London and the Southeast at AECOM. “The benefits of this project to these areas will be tremendous and will be felt by communities across Lewisham, Southwark and beyond, potentially providing a £1.5bn boost to the economy each year. These new stations will support regeneration across these areas, incentivising new housing development while reducing traffic congestion and overcrowding on local public transportation, and improving air quality.”

AECOM and WW+P Architects selected to provide design services on four new London Underground stations as part of Bakerloo Line Extension (BLE) - Premier Rail

AECOM and WW+P Architects selected to provide design services on four new London Underground stations as part of Bakerloo Line Extension (BLE) Premier Rail

premierconstructionnews.com

 

[MarkyT]

Going back to the original subject I think there's a consensus emerging that the nearer the surface a station is the better for costs, accessibility, safety and ambiance with possibility of some natural light filtering down into the facility. That would involve trenches for stations with bored sections between coming up as close to the surface as possible into the boxes. While that usually can't apply in the very densest parts of cities, where mining out from an initially bored tunnel is sometimes the only affordable, acceptable solution, as with the central London stations of the Elizabeth Line, along the Old Kent Road are many lower value industrial and commercial sites that might be acquired and used for such station trenches, then redeveloped along with the surrounding area. Some capped or partially open C&C in this vicinity beyond the immediate station boxes might also be possible. Elevated might also be practical for some sections and good design of slender modern viaducts in harmony with their surrounding landscape need not lead to an unpleasant environment beneath.

 

[SynthD]

The Jubilee line extension and Paddington’s Elizabeth line section. shows what is possible with bringing light down into a deep level station. If you severely limit the oversite development you can install windows over the escalators down, but onto the platforms is a stretch.

Anything better than that may require actual cut and cover, which is only viable before people move into an area, eg what Barking Riverside could have been. Same for road median viaducts, as OKR is the A2.