The Anonymous Widower

TfL Confirms Northern Line Extension Work Is ‘On Track’

The title of this post, is the same as that of this article on the Wandsworth Guardian.

It is good to hear, that there has been no further delays.

Part of the article talks about the use of the Kennington Loop, which is shown in this visualisation from at least a century ago.

But what I found useful was speculation about the services after the extension opens.

However, it is thought that when the new stations open, 16 trains per hour will carry on to Nine Elms and Battersea, leaving just eight trains per hour terminating at Kennington and travelling around the loop.

On the other hand, I wouldn’t be surprised to see all trains going to Battersea Power Station station, as it might be operationally easier and the higher frequency may attract more passengers.

February 19, 2021 Posted by | Transport | , , , | Leave a comment

Thoughts On The Closure Of The Northern Line At Bank To Complete The Upgrade To Bank Station

The Bank Station Upgrade is a major project that will increase the capacity of Bank station by forty percent.

This document on the Transport for London web site gives details of the project.

It was originally planned that sometime in late 2021, the Northern Line will be closed through Bank station.

The document says this.

We will need to close part of the Northern line Bank branch in 2021, between Kennington and Moorgate, to connect new and existing sections of tunnel safely. Trains will run less frequently on those sections of the Bank branch that are still open. Check back here for details.

This would mean that Bank, London Bridge, Borough and Elephant & Castle stations will be closed on the Northern Line.

To help passengers, TfL say, they will do the following.

  • Run 33% more trains on the Northern line Charing Cross branch
  • Review bus use and consider enhancing services where necessary
  • Investigate scope for passengers to use alternative National Rail services, such as Waterloo to London Bridge, and London Bridge to Cannon Street
  • Review available walking space on the Moorgate to London Bridge pedestrian corridor.

These are my thoughts.

The New Cannon Street Entrance To Bank Station

This visualisation shows the new Cannon Street entrance to Bank station.


  1. South is to the right and we’re looking from roughly the North-West.
  2. The existing twin bores of the Northern Line on the far side of the visualisation.
  3. The escalator connection to the District and Circle Lines at Monument station Starts at the Southern end of these two narrow platforms.
  4. The new single bore of the new Southbound tunnel on the near side of the visualisation.
  5. The triple escalators descending from the new Cannon Street entrance to one of the four cross-walks between the Northern Line platforms.
  6. The current Eastern ends of these cross-walks are shown in The Southbound Northern Line Platform At Bank Station.

But where is the Docklands Light Railway (DLR)?

This map from shows the lines at Bank station.


  1. The two existing Northern Line Platforms 3 and 4 are shown in black.
  2. The Central Line is shown in red.
  3. The DLR is shown in turquoise and sneaks under the Northern Line into Platforms 9 and 10.
  4. Platforms 7 and 8 are the platforms of the Waterloo and City Line.
  5. It would appear that the escalator connection between Bank and Monument stations goes between the existing tracks of the Northern Line.

So where is the Docklands Light Railway?

  • As Platforms 3 and 9 appear to be close together with Platform 9, the deeper of the two, I suspect we can’t see  the Docklands Light Railway in the visualisation, as it is hidden behind and underneath everything else.
  • I also suspect that the triple escalators between the new Northern Line cross-walks descend in the space at the Southern ends of Platforms 9 and 10.

This is the Northern end of the visualisation I showed earlier


  1. North is to the left.
  2. The two tracks and the narrow island platform of the current Northern Line on the far side of the visualisation.
  3. The two staircases leading up from Northern Line to a lobby, where passengers can walk North to the Central Line.
  4. The double escalator barrel going down to the DLR.
  5. The travelator that will connect the Northern and Central Lines
  6. The three cross passages linking the DLR escalators to the lobby between the Central and Northern Lines.
  7. The most Southerly of these cross passages has a lift to the DLR.

The new Southbound platform of the Northern Line, would appear to be to the West of the Docklands Light Railway.

It appears to be a very tight fit.

These pictures show the current status of the new entrance.

There would appear to be still a lot to be done.

This TfL image shows how it will look in 2022.

Ducking And Diving

No-one ducks and dives like Londoners. So rest assured, that if someone needs to get from A to B and the obvious route is blocked, Londoners will always get through. And if all else fails, a black cab will find a way, usually driven by a Londoner or someone infected with the ducking and diving virus.


As ever Crossrail is the herd of elephants in the London railway system.

The Northern Line is possibly the most important North-South route across Central London with two branches through the centre; Bank and Charing Cross.

But Crossrail connects to these  North-South routes.

  • Lea Valley Lines at Stratford
  • East London Line at Whitechapel
  • Lea Valley and West Anglia Lines at Stratford
  • Northern Line Bank Branch at Moorgate/Liverpool Street
  • Northern and City Line at Moorgate/Liverpool Street
  • Thameslink at Farringdon
  • Northern Line Charing Cross Branch at Tottenham Court Road
  • Jubilee Line at Bond Street
  • Bakerloo Line at Paddington

Crossrail will give a lot of opportunities for ducking and diving.

Under original plans Crossrail was supposed to open in 2019, with the Bank station closure for the upgrade in 2021.

This phasing certainly seemed a good idea at the time.

  • Crossrail will be able to offer alternative routes during the closure.
  • If the Crossrail stations are substantially complete, they can release workers to finish Bank station.

I wonder, if it would be sensible to not upgrade the tracks through Bank station until Crossrail opens through Moorgate/Liverpool Street.

As I wrote in Your First Crossrail Service May Arrive In Time For Christmas, Crossrail could open this year.

So are we being prepared for the mother of all cunning plans?

  • Crossrail between Paddington and Abbey Wood opens before Christmas.
  • The closure of the Bank branch to allow the Bank station upgrade happens at a convenient time after the opening of Crossrail through Moorgate/Liverpool Street.
  • Moorgate continues to have a limited Northern Line service to the North.
  • Crossrail continues work on the other branches.


  1. There is a crossover to the North of Moorgate station, which might allow Moorgate to work as a two-platform terminal station handling up to 4 or 6 trains per hour (tph).
  2. If Crossrail is running at Moorgate, the station should be step-free to and from the deep-level platforms.
  3. Transport for London are looking at walking routes on the Moorgate and London Bridge route.
  4. During the closure of the Northern Line through Bank, passengers for the City will go to Moorgate and walk or perhaps take a bus.

It is my view, that Crossrail must be open, before the Northern Line through Bank station is closed to allow work to be completed.

A Demonstration of the Northern Line Capacity At Moorgate When Working As A Terminal Station

Yesterday, which was a Sunday, the Northern Line was closed between Moorgate and London Bridge stations.

  • After a walk, I returned home from Moorgate station via Angel station, where I got a 38 bus.
  • I was surprised to find that trains on the Northern Line were leaving Moorgate station for the North every four to five minutes.

This would seem to indicate that frequencies of between 12 and 15 tph are possible.

Current frequencies through Bank station are 24 tph in the Peak and 20 tph in the Off Peak, so it will be a substantial reduction. But it is better, than my original estimate earlier in this section.

33% More Trains on the Northern Line Charing Cross Branch

Currently, the Charing Cross branch has a capacity of twenty-four tph and handles the following services in the Peak.

  • 10 tph between Edgware and Kennington
  • 2 tph between Edgware and Morden
  • 10 tph between High Barnet and Kennington
  • 2 tph between High Barnet and Morden

And these services in the Off Peak.

  • 10 tph between Edgware and Kennington
  • 10 tph between High Barnet and Kennington


  1. Extra trains go between the two Northern branches and Morden via the Bank branch.
  2. Kennington and Morden can handle 28 tph and regularly does.
  3. The loop at Kennington turns twenty trains per hour in both the Peak and the Off Peak

If there is an increase of 33 % in the number of trains, this must mean that 32 tph will run through Charing Cross in the Peak and 28 tph in the Off Peak.

  • The signalling system on the Northern Line is the same as that on the Jubilee Line, where it handles 30 tph.
  • It also can handle up to 30 tph between Kennington and Morden on the Northern Line.
  • Perhaps it can be stretched to 32 tph through Charing Cross in the Peak.

If the Charing Cross branch can only be uprated to 30 tph, that is still an increase of 25 % in the number of trains.

The Kennington Loop

I mentioned the Kennington Loop and this beautiful old drawing shows its layout.


  1. South is at the top of the drawing.
  2. At present, as I said, the loop turns twenty tph all day.
  3. The extension to Battersea connects to the loop.

This map from shows a map of the loop.


  1. The Charing Cross branch goes to the North-West from Kennington.
  2. The Bank branch goes to the North-East from Kennington.
  3. ,The lines to Battersea are shown dotted.
  4. Trains using the extension to Battersea can only use the Charing Cross branch.

I don’t know, but I wouldn’t be surprised, if the line speed to and from Battersea, is faster than it is round the loop.

It’s just that the lines to Battersea are not such a sharp curve and they have been recently designed and built.

As the Modern branch can handle 30 tph, I wouldn’t be surprised to find that the Battersea extension has been designed to handle this frequency.

The Northern Line Extension To Battersea

This document on the Transport for London web site gives details of the Northern Line Extension To Battersea.

This paragraph introduces the project.

The Northern line extension (NLE) between Kennington and Battersea will help regenerate the Vauxhall, Nine Elms and Battersea areas by supporting new jobs and homes. The extension is scheduled to be completed in autumn 2021.

The opening of the extension could offer benefits to the existing Northern Line.

As I said in the previous section, twenty tph are turned at Kennington using the loop.

Will all these trains now use the new Battersea extension, when it opens?

  • The Battersea extension is fully double-track.
  • Battersea Power Station station has two platforms and a cross-over, so if Brixton and Walthamstow Central stations can handle in excess of 30 tph, I suspect London’s newest terminal station can too!

If the Battersea extension has a design capacity of 30 tph, it would certainly be able to handle 20 tph.

So I wouldn’t be surprised to see all trains that currently turn at Kennington will take the Battersea extension, when it opens.

There must surely be the interesting possibility of before the Battersea extension opens to passengers, using it to turn the trains that would otherwise use the loop at Kennington. It would certainly be a very thorough test, of track and signalling.

I am fairly certain, there would be advantages in having the Battersea extension open before the Bank branch is upgraded.

  • Running trains to Battersea could be more efficient than using the Kennington Loop.
  • Opening the Battersea extension would need the signalling at Kennington to be upgraded and fully tested, so any changes needed for increased frequencies on the Charing Cross branch could be performed at the same time.
  • All the residents of the new housing in Battersea. would have an Underground connection.

Opening the Battersea extension will change passenger patterns on the Northern Line and as the changes will be difficult to predict, it would surely be better to upgrade Bank station, after the opening of the Battersea extension.


Thameslink is not mentioned in any of the Transport for London documents, but surely it has a big part to play.

  • Thameslink serves a lot of stations in South and South East London and beyond, including Brighton, East Croydon, Orpington, Sevenoaks and Woolwich Arsenal.
  • Thameslink has an interchange with the Circle and District Lines at Blackfriars.
  • Thameslink has an interchange with the Metropolitan and Circle Lines at Farringdon.
  • Thameslink will have an interchange with Crossrail at Farringdon.
  • Blackfriars and City Thameslink stations have good walking routes along the River and to the City.

Thameslink should be appearing on the Tube Map any time soon.

Waterloo And City Line

I am missing the Drain, as it is the easiest way for people in the area, where I live to get to Waterloo station.

I just take a bus to Bank and then walk underground to London’s shortest Underground line.

According to this article on London SE1, it is closed because of the covids, but should reopen in April 2021.

Surely, Transport for London could reopen the line, if they vaccinated all the drivers.

As the Waterloo and City Line has an independent new entrance on Wallbrook, there should be no reason, why it couldn’t reopen before the Northern Line through bank is upgraded.

The Central Line At Bank Station

Nothing has been said, about whether the Central Line will be closed through Bank station, during the upgrade.

I don’t think it will be continuously closed, although access to some parts may be restricted.

There could be partial closures at weekends or in the evenings.

So for commuters and other must-travellers, I suspect the Central Line will get through.

The Circle And District Lines At Monument Station

My thoughts about the Circle and District Line would be similar to the Central Line.

But these lines with their connections at Westminster, Blackfriars, Cannon Street, Tower Hill and Whitechapel could prove important during the works.

The Docklands Light Railway At Bank Station

Again my thoughts about the Docklands Light Railway would be similar to the Central Line.

But there is a lot of work going on to improve access to the Docklands Light Railway, and this could result in a closure to allow completion.

Review Bus Use

When I come into London Bridge station, I usually go to the bus station and get a bus, which stops within fifty metres of my front door. Going to London Bridge isn’t as convenient and I take a variety of routes.

But the corridor between London Bridge and Old Street via Bank and Moorgate has three bus routes; 21, 43 and 141, the last two of which terminate in the bus station at London Bridge. I suspect that the frequency of the last two buses could be increased, if they had a few more buses and drivers, and turned them faster at London Bridge.

I also feel there is scope to run a shuttle between Finsbury Square and London Bridge station.

  • It would loop round Finsbury Square at the Northern end.
  • It would loop through London Bridge station, as the 43 and 141 buses currently do.
  • They would serve Moorgate and Bank.
  • As it will be running through a busy part of the City with lots of pedestrians, these buses should be either battery or hydrogen.
  • But as they should be high-capacity double-deckers, battery probably wouldn’t have enough power.

What better way would there be, to showcase London’s new hydrogen buses?

And I’m sure Jo Bamford, would make sure that London had enough new Wrightbus hydrogen buses  to provide the service.

National Rail Between Charing Cross/Waterloo And London Bridge

I am probably not alone in using this route in preference to the Jubilee Line to travel between Westminster and London Bridge, as where there is an alternative to the deep-level Underground, I will often use it.

In my case coming home from Waterloo, I’ll often hop to London Bridge on National Rail and then get a 141 bus home.

This is classic ducking and diving on my part.

I’m sure others will do the same during the Bank branch closure.

I would also hope, that season tickets would allow passengers to swap terminals without too much trouble and any expense.

National Rail Between Cannon Street And London Bridge

Using Cannon Street instead of London Bridge could be an relatively easy alternative for many passengers.

  • It connects to the Circle and District Lines.
  • There are East-West buses outside the station.

This Google Map shows the location of the station.

There are a number of useful walking routes from the station, which is towards the bottom of the image slightly towards the right.

  • Bank station is about 300 metres and six minutes away.
  • The North-South buses between Moorgate and London Bridge on King William Street are 200 metres and three minutes away.
  • St. Paul’s is a bit further but it does have the Central Line and lots of buses including the 76 to Moorgate and Old Street stations.

At seventy-three, I can still walk between Cannon Street and Moorgate stations in 15 minutes.

Walking Between London Bridge and Moorgate

Transport for London have said they will review this,

It is not a difficult walk and it has improved since traffic was reduced at Bank.


As originally planned, the timings of the various projects were such that these projects would be more of less completed before the upgrade of the tracks at Bank station was to be performed.

  • Crossrail
  • The Northern Line Extension to Battersea.
  • The new Wallbrook entrance to Bank station.

But no-one had foreseen Covid-19.

So I would plan the date of the Northern Line closure with the utmost care.

February 8, 2021 Posted by | Health, Transport | , , , , , , , , , , , , , , , , , | 6 Comments

Northern Line Extension ‘On Track’ For 2021 Opening

The title of this post, is the same as that of this article on Transport Network.

I’m looking forward to using the line in the Autumn.

This map from, shows the track layout of the extension.



  1. The extension starts from the existing Kennington Loop at Kenning station.
  2. There is an intermediate station at Nine Elms.
  3. As with many two-platform stations, there is a cross-over in the approach. It is shown in a picture in the article.

Hopefully, the extension will eventually be extended to Clapham Junction.

Step-Free Interchange At Kennington Station

I have been worried about this and from the comment of others like Melvyn, I am not alone.

This map from, shows the track layout at Kennington station.


  1. Elephant and Castle station is at the North-East corner of the map and is on the Bank branch of the Northern Line.
  2. The pair of tracks going North-West are the Charing Cross branch of the Northern Line.
  3. The pair of tracks going South-West are the Morden branch of the Northern Line.
  4. Trains going South  to Morden can use either Platform 2 or 4, depending, whether they have come Charing Cross or Bank.
  5. Trains going North  from Morden can use either Platform 1 or 3, depending, whether they are going to Charing Cross or Bank.
  6. The Kennington Loop allows trains from Charing Cross that arrive in Platform 2 to go direct to Platform 1 to return to the North.
  7. There appears to be a revering siding, which can also reverse trains from either Platform 2 or 4 and send them North from Platform 1 or 3.
  8. Chords South of the platforms allow trains to and from Charing Cross to access the tracks to Morder and the reversing siding.
  9. The Battersea Power Station branch, is shown in dotted lines and connects to the Kennington Loop.

I took these pictures at Kennington station today.


The platforms are in two pairs, which are connected by walk-through passages, with Platforms 2 and 4  for Southbound trains and Platforms 1 and 3 for Northbound trains.

  1. Each platform has a proper clock.
  2. The only access to the pair of platforms is by steep long stairs.
  3. The stairs need to be rebuilt with proper handrails on both sides.
  4. The last picture shows the handrails at Moorgate station.

Currently, the system allows journeys between the North and Morden, either directly or with a walk-across change at Kennington station.

  • Going South to Morden, if you get a train, that reverses at Kennington, you would wait for a train to turn up on either Platform 2 or 4, that is going the whole way.
  • Going North from Morden, if you get a train going to the wrong Northern destination, you would get off at Kennington and wait for a train to turn up on either Platform 1 or 3, that is going to the destination you desire.

What is needed on all platforms, is more comprehensive information displays.

  • Displays on Platforms 2 and 4, would show details of all Southbound trains. whether they terminated at Kennington or went to Morden, or in future went to Battersea Power Station station.
  • Displays on Platforms 1 and 3, would show details of all Northbound trains.

Displays would indicate destination and time as now, but with the addition of platform, where you catch the train.

If there is one problem it is taking a train between Battersea Power Station and Morden stations.

This public domain drawing from the Internet shows the station, after the Kennington Loop had been built in the 1920s and 1930s.


  1. We are looking from the North.
  2. The Kennington Loop at the far end of the station.
  3. The four platforms of the station numbered 2, 4, 3 and 1 from left to right.
  4. The stairs between the two pairs of platforms, leading to overbridges.
  5. The lift tower and a spiral staircase leading to and from the surface.

I can now sum up the step-free status of the station.

  • Passengers entering or leaving the station, must walk up or down a staircase like that shown in the first picture.
  • Passengers needing to change to another train going in the same direction, just walk across to the other platform in the pair.
  • Passengers needing to change to another train going in the opposite direction, as they would going between Battersea Power Station and Morden stations, will need to climb one set of stairs and descend another.

It does appear that in an ideal world lifts will need to be added.

Thoughts On Future Step-Free Access At Kennington Station

In the future, it is planned that the Northern Line will be split into two lines.

  • Battersea Power Station and Edgware
  • Modern and High Barnet

Will this increase the number of passengers, who need to do the opposite direction change, as there will just be more trains running on all branches?

Alternative Step-Free Access

But, there may be another way to go between Battersea Power Station and Morden stations.

  • Take a train from Battersea Power Station to Waterloo.
  • Walk across the platform at Waterloo to the Southbound platform.
  • Take a train from Waterloo back to Kennington.
  • Walk across from Platform 2 at Kennington to Platform 4.
  • Take the first train from Platform 4 to Morden.

The reverse journey between Morden and Battersea Power Station stations would be.

  • Take a train from Morden to Kennington.
  • Walk across from Platform 3 at Kennington to Platform 1
  • Take a train from Platform 1 to Waterloo.
  • Walk across the platform at Waterloo to the Southbound platform.
  • Take the first train from Waterloo to Battersea Power Station.


  1. Both routes have two changes; one at Kennington and one at Waterloo,
  2. All changes are step-free.
  3. All changes are very simple

It should also be noted that Battersea Power Station, Nine Elms and Waterloo are all or will be fully step-free stations.

The two routes I have outlined have one big advantage. They already exist and the only costs would be training of staff and indicating the routes to passengers.

January 6, 2021 Posted by | Transport | , , , , , | 2 Comments

Northern Line Extension Around Kennington Station – 10th July 2020

I took a trip to Kennington this afternoon to look at the sites of the Northern Line Extension around Kennington station.

These pictures show Kennington station.

It appears work is still proceeding inside the station to complete the extra passageways.

This Google Map shows the station.

As the hoardings seen in Braganza Street were not there this afternoon, have the builders finished the major works at the station?

I then walked to the site in Kennington Park, where there is a construction site, where they are building a headhouse.

This page on the TfL web site gives more details.

I took these pictures of the site today.

There does seem to be work to do, but I’ve no idea how much.

This Google Map shows the site.

If the shaft under the headhouse, is covered by the green cover, it’s not going to be enormous.

Finally, I walked to Kennington Green, where they are building another headhouse.

This page on the TfL web site gives more details.

I took these pictures of the site today.

It looks like the new concrete building on the far side of site will be clad in bricks to fit in with the houses.

This Google Map shows the site.

It does appear to be a very different design to the other site.

But there is still some time to go.


July 10, 2020 Posted by | Transport | , | 1 Comment

After One Tunnel Finishes In London, Another One Starts

Crossrail’s massive tunnel under London is now in the fitting out stage and some of the capitals human moles, are probably now working on the Thames Tideway Scheme to create a super sewer under London.

But according to this article in Global Rail News, others have moved on to Kennington and have started to dig their way to Battersea for the Northern Line Extension.

This though is one of London’s traditional smaller-bore tube tunnels and the tunnellers are stating in a traditional way. This is said.


The article also has this map of the line.

Although TBMs will be used to construct much of the extension, tracked excavators supplied by Schaeff are being used initially to excavate the tunnels around the Kennington loop, where the new line meets the existing railway.

This map from, shows the layout of the lines at Kennington station.

Track Layout At Kennington

Track Layout At Kennington


  • The map can’t show it, but the platforms at Kennington are on two levels.
  • There is also a reversing siding between the two tracks going South.
  • Charing Cross Branch trains use the loop and Bank Branch trains use the siding to reverse.
  • The extension to Battersea is shown in dotted lines.

It was very good of the engineers, who extended the Northern Line in 1926, to future-proof it with a loop, that looks like it makes the extension to Battersea, easier to build!

October 22, 2016 Posted by | Transport | , , , | 3 Comments

Before Northern Line Extension – Kennington

I took these pictures of Kennington station as I passed through on my way to Battersea.

I hope that the station gets a makeover with the extension. It is rather tired and shabby, although it had a refurbishment in 2005.

Perhaps Transport for London are hoping that most passengers will pass straight through on their way to and from the delights of Battersea and Tooting.

August 2, 2015 Posted by | Transport | , , | Leave a comment

A Heritage Station With Four Clocks

After writing my piece about the Northern Line Extension, I went to have a look at Kennington station.

It is a Grade II Listed building, but to me one of its best features is the four clocks.

The layout is unusual in that the two Southbound platforms are underneath the two Northbound ones. But both pairs of platforms have level access between the platforms. So if you came up from Morden and wanted to go to say Tottenham Court Road, you’d just walk across to the Charing Cross branch, if you were on a train going via Bank.

When the Northern Line Extension opens, this will probably mean that there is cross-platform access from the extension to the Bank branch.

It would certainly seem that when the station was substantially rebuilt in 1926, that whoever redesigned the station had the foresight (luck?) to design a station that could be easily linked to a branch to Battersea and Clapham Junction.

November 16, 2014 Posted by | Transport | , , , , | Leave a comment

Will The Northern Line Extension Go All The Way?

There has been masses of reports about the Northern Line Extension in the special rail media and on the BBC and in other publications, like Time Out and the Standard.

Despite the long term aim of taking the extension to Clapham Junction, mentioned in the Wikipedia entry for the project.

Provision will be made for a possible future extension to Clapham Junction railway station by notifying the London Borough of Wandsworth of a reserved course underBattersea Park and subsequent streets

There has been no discussion about the extra station.

There has also been no statements from the consortium building the line about how they will actually construct the line.

As it is not the longest of tunnels, I suspect to save money, at the expense of possibly some extra time, they will use just one tunnel boring machine (TBM). It won’t be one of the ten-million-pounds-a-time  beasts used for Crossrail, as Underground tunnels are generally much smaller in diameter. Although, I wouldn’t be surprised to see the tunnels made slightly larger than normal for reasons of safety and perhaps to re-use a refurbished TBM from another project.

One thing that London Underground doesn’t like is lines that end deep in the ends of tunnels. For reasons of cost in the 1960s, the Victoria line is like this at both ends and according to Wikipedia, there have been proposals for creating a large reversing loop at Brixton to both reach Herne Hill and increase capacity.

Reversing loops also eliminate any possibility of a Moorgate disaster, which has still not been satisfacorily explained. But operationally they remove the need for trains to crawl into the end station for safety reasons, and reduce the time it takes to turn trains, thus increasing the frequency on the line.

Reversing loops with stations are not unknown in the UK. Terminal 4 at Heathrow is served by the Piccadilly Line in this way and the Merseyrail Loop Line, is a larger example, that reverses and provides several stations for the Wirral Line. It could also be argued that Bank station on the Docklands Light Railway is two platforms on a reversing loop.

So could a similar solution be used at Battersea to turn the trains? Look at this map of the area.

Around Battersea

Battersea Power Station and Battersea Park are obvious, but notice the Underground roundel marking Kennington station in the top-right corner and the British Rail symbol marking Clapham Junction station in the bottom-left.

The extension joins the current Northern line at Kennington and the Battersea station is proposed to be somewhere near the power station.

At present, Charing Cross branch trains reversing at Kennington, can go round the Kennington Loop. Wikipedia says this about the loop.

A loop tunnel south of the station enables southbound Charing Cross branch trains to be terminated at Kennington, leave the station in a southward direction and, traversing the loop, enter the northbound Charing Cross branch platform.

So instead of building two tunnels from Kennington to Battersea, with all the cost of two TBMs or the hassle of turning a single one round, I do wonder, if a cheaper and easier way of building the tunnels, would be to start in the Kennington Loop with a single TBM, tunnel via Nine Elms to Battersea and then create a wide reversing loop before returning to Battersea to dig the second tunnel back to the other side of the Kennington Loop.

One of the consequences of good project management is often that what the engineers build in the end is quite different, but better, more affordable and earlier to what the politicians said they wanted. For this reason alone, I wouldn’t be surprised if the Northern Line Extension is just a single tunnel, dug by a single refurbished TBM.

The cost savings are probably small change in a one-billion pound project, but the time spent inserting and removing a second machine, probably comes off the overall project time.

It then doesn’t take a great leap of the imagination to see that this construction/reversing loop could be extended so that it passes under Clapham Junction station.

There are other advantages too.

Operations, Safety and Reliability

I’ve mentioned the operational advantages of the reversing loop in quicker turn back of the trains and possible safety advantages, but as the extension is going to be a continuation of the Charing Cross branch of the Northern line and an extension of the Kennington Loop, there could be no complicated track work at Kennington. This will mean that the branch used through Central London, will determine the ultimate destination of the train. But this would allow London Underground to split the two lines and probably arrange dedicated platforms for the two northern branches at the operational nightmare that is Camden Town.

The reliability of two continuous lines would probably be a lot higher, than one that was constantly splitting and joining back again.

But whatever happens to the rest of the line, if the extension was a continuous reversing loop with no points or sidings, it could be built faster and would probably cost less, have a higher capacity and probably be more reliable.

The only problem would be if a train were to break down in the loop. But what happens on the Heathrow loop on the Piccadilly line?

Battersea and Nine Elms Stations

Digging the extension as a loop, also means that the two stations at Battersea and Nine Elms, become classic below ground stations of the Underground, like say Southgate and Manor House of the 1930s, and the modern Canary Wharf, where escalators and lifts descend to a wide lobby between the two lines.

Costs could even mean that they were identical below the surface, although architects would probably exercise some flare on the surface.

I also wonder if stations could be built with no escalators, but large efficient lifts, that were scheduled, so they went up and down in time with the trains.

Lift-only stations would be best as double-ended, with the lifts even coming up into car parks of the over-site development.

There is tremendous scope here for a good architect to build passenger-friendly and lower cost stations.

I’ve always believed that urban stations should have development on top, just like my local one at Dalston Junction. But how many stations anywhere make efficient use of expensive land?


A big problem with London Underground’s deep level lines, like the Northern, is keeping everything cool. All over London, you see structures like I photographed here. A continuous reversing loop must have advantages as all three stations would double as ventilation shafts, so there would be no need for any extra holes in the ground. If modern regulations mean that the tunnels have to be built with a walkway for evacuation, like those on the Docklands Light Railway, these larger diameter tunnels would probably help ventilation.

A secondary advantage of a well-ventilated reversing loop, is that it would be cool, so any trains on the loop could cool themselves down, just like many deep-level trains, do by basking on the surface in the suburbs.

Clapham Junction Station

In the future when the station at Clapham Junction is added, little or no tunnelling will be needed, as construction will probably involve sinking a shaft to link it to the current Clapham Junction rail station and creating a new platform or platforms alongside the reversing loop.

I would go for the single platform. In some ways then, this station would be like the Piccadilly Line station at Heathrow Terminal 4, which has a single platform on a one-way loop from Hatton Cross to Heathrow Central.

No surface buildings would be required and space would only be needed to sink the shaft during the construction phase.

Opening Clapham Junction station could give a problem in that some passengers will transfer off the trains from Basingstoke, Portsmouth, Southampton and other places to complete their journeys. Will the Northern Line cope?

On the other hand the new Clapham Junction station will link to Crossrail at Tottenham Court Road, so Clapham Junction would get a hopefully step-free link to Crossrail and on to Heathrow.

Platform Edge Doors

Regulations will probably mean that all the stations would have to be constructed with platform edge doors. A loop extension would probably have the minimum number of platform faces, thus subtracting another saving from the cost.

If I was designing the stations, all platform faces would be identical to save costs.

But if you went for lift-only stations, this could mean that a better design evolved, where the safety functions of the platform edge doors were achieved in better ways.

Train Stabling

A loop extension, if built in its simplest form, would not have any sidings for storing trains overnight or perhaps holding them when there was a problem on the Northern line.

But as the loop would of necessity be rather long between Battersea and Clapham Junction, the trains could be stabled or held in the loop. If staff needed to leave or join the trains and if the tunnel had a walkway, they’d just walk along to the nearest station.

Ease Of Construction

There has been a report in Global Rail News that the Northern Line Extension might be completed before Crossrail.

A loop extension leading off the Kennington Loop has implications for building the extension in a quick and affordable manner, so this might explain the optimism.

Consider the following.

1. No terminal station, platforms, junctions or sidings would need to be built.

2. As the main construction at Kennington only takes place on the Kennington Loop, trains on the Bank branch running to Morden will be unaffected. Trains on the Charing Cross branch would probably be suspended, unless some other way of turning them back could be found.

3. One TBM digs the whole tunnel in a continuous operation.

4. The project length is determined by the time to dig the tunnel, fit it out with track and signalling, connect it to the existing network and then give it an extensive testing, as once the TBM has passed, the construction of the platforms can be started in parallel with the rest of the project.

5. It would probably be easier to adjust the route of a loop tunnel to avoid other infrastructure and the proposed route of Crossrail 2. Victorian engineers didn’t have machines of the accuracy of today’s modern TBMs.

6. Crossrail needed a lot of shafts to insert and extract the TBMs and other equipment and materials. I’m no expert, but surely material could be brought in by service trains on the Morden branch of the Northern line, to avoid digging too many shafts.


I strongly believe the first phase of the Northern Line Extension will be built as a loop off the Kennington Loop and include all the tunnelling for the extension to Clapham Junction.

Clapham Junction station would not look like a terminus, as it would only be a single platform on a reversing loop.

So the second phase would solely be the fitting out of the station and connecting it to the rail station.


November 15, 2014 Posted by | Transport | , , , , , , | 2 Comments

Battersea Gets Its Tube

The extension of the Northern Line to Battersea has been given the go ahead.

Construction will begin in spring 2015 and it is hoped the line, which will be extended from Kennington to Battersea, will open by 2020.

Two new stations will open – Nine Elms to the east and one at the heart of the Battersea Power Station development.

The full cost is expected to be up to £1bn, which will be funded by developments in the area.

I think one of the most significant parts of the report is the last line of that extract.

According to Wikipedia, the original proposal was put together in May 2010, and I certainly saw an exhibition about the extension in December 2012,

I know it’s only a short extension, but to go from proposal to construction start in two years is some sort of record for London.

Surely, all big infrastructure projects should be started like this. And of course financed if possible in a local manner or by developers.

The one question about what is proposed, is when is it going to be extended to Clapham Junction.

I suspect that if they did this, it would be so successful, it would swamp the Northern Line and throw Battersea back to the 1960s, with respect to transport links.

This is the schematic of the route.

The Route

The Route

And this is what the area looks like in Google.

The Google View

The Google View

I couldn’t quite align the two maps, but you can just see the Kia Oval at the right in the Google view.

November 13, 2014 Posted by | Transport | , , , , , | Leave a comment