How Much of the Tube is Actually Underground?

It's the sort of thing that turns up in quizzes and that I get asked a lot ... how much of the London Underground is actually underground? Turns out, there's not a straightforward answer as it depends on how you define a station as being 'Underground' ... let's discuss!
Geoff's Actual Underground Map: www.geofftech.c...
TfL's Tube Map Showing Tunnels: content.tfl.gov...
The Section 12 Fire Regulations Map: www.whatdothey...

[@frankmimnagh420]

Hi Geoff, I worked at TfL in their tunnels engineering department from 2008 to 2020. We worked out that there was roughly 41% of the tube in tunnel (excluding cut an cover sections and measuring from tunnel portal to tunnel portal). So we are converging to a number around 40%.

[@rjjcms1]

Deepthought still thinks the answer is 42.

[@kevinshannon9917]

Thank you for this comment. I was hoping someone could answer this question. For this question, I don’t care as much about stations underground as I do track underground. Thanks for your expertise!

[@ObjectReplacement]

Bearing in mind the new extensions and whatnot of the tube I feel like that would be I little bit more

[@riorobins1311]

Tunnel Engineers are quite scarce aren’t they? I work in tunnelling and do a lot of work for Thames Water, they had a tunnel engineer who was sick and they were searching months for s replacement

[@VongChung-f1q]

Ufvlvulfvufp7tgp

[@florian_aust]

6:45 "You may not disagree, but that is fine" - Geoff Marshall

[@DenkyManner]

Tfl can't err on the side of 'you can see daylight' when it's about emergency vehicle access.

[@sadiqmohamed681]

I think the criteria for the Fire Brigade would have to be how to get fire hoses in. If you can get to track-side, even if it is in a cutting, instead of having to come down stairs then that station would be overground. So I think any station where you can see daylight from the platform would fit that. I would love to see the LFB version of the map, which would have all their access points to stations.

[@roach5219]

Fortunately the London Fire Brigade have issued an urgent statement to clarify that they don't intend to use Geoff Marshall's video for emergency planning purposes ;)

[@QemeH]

From the Fire Precautions Regulations, regarding the definition of sub-surface stations: "A railway platform is an underground platform if the level of the roof or ceiling immediately above the platform and the permanent way to which it is adjacent is below the level of the surface of the ground adjacent to any exit from the railway station providing a means of escape from the station in case of fire." So it's not about vehicular access, but about passenger egress. If you can get out without walking UP, you're not underground...

[@michaelleiper]

@@QemeH Which would be why the Fire Brigade map will include any station with any underground platforms (like the Piccadilly line at Earls Court), where Geoff is excluding the station because of the District Line platforms.

[@pb4rton]

I used to work at Birmingham New Street station. For fire safety regulations this was classed as an underground station as most of the platforms are underneath a building. There are platform ends in the open, so it was classified as a sub-surface station. So I would guess that it would apply to the underground as well.

[@joermnyc]

So the dark gray on the map is all 15 stories below the street and the light gray is partially 15 stories down?

[@SkeledroMan]

The classification would be made clearer if you used platforms instead of stations

[@DAFPvnk]

yeah, because by his definition of "if the weather can touch it" means none of them are underground, they all have entrances above ground level - otherwise they would be pretty useless stations :P

[@kaitlyn__L]

Yes, I would be inclined to count the stations with just a handful of overground platforms to be, say, 25% overground or 50% or whatever the fraction of platforms, perhaps even incorporating a further fraction of those platforms that the weather still can't get to (the other side of the opening, basically, if the outside is immediately through one end of the tunnel). That way an entirely underground station is still 1 and an entirely overground station (like Leytonstone) is still 0. Of course, this method would give an answer that lies within the range Geoff said at the end.

[@adababalola3304]

GEOFF MARSHALL VIDEOS HOW MUCH OF THE TUBE IS ACTUALLY UNDRRGROUND

[@rjjcms1]

But there could also be one for total miles or kilometres of tunnel. Anyway,I like the idea of those maps by both TfL and Geoff that indicate where the tunnel parts are by the grey shading.

[@Leblribrbrrq]

Stations? Platform? The Underground is more than just the stations. I've expected an answer with the unit miles/kilometres. And then you can still argue about built-over and service tracks that are not used with passengers and all that …

[@welshgit]

I remember my first trip to London - a 2 week family holiday - I was 7. I was really excited by the underground, but felt completely cheated when the trains appeared out in the open.. Suddenly those great mystical tunnels felt more like a railway with a roof.

[@Ealsante]

Well it literally was how they were built in the early days! Deep a deep ditch, put the railway in, put the roof over it.

[@msmediaab]

@@Ealsante so was the first parts of the Metro in Stockholm built as well. That was however in the 1950s on the Green line, while the other stations is mainly outdoors. The underground stations on the Red line is located about 15 - 20 m below the surface, and the first deep level (20 - 30 m) stations is mainly located on the Blue line. There are as well 2 special cases; Liljeholmen opened in 1964 as a surface station, but in the early 2000s, a brand new shopping centre was built on top of the station, meaning that if you want to go from platform to street level, you need to go up 1 floor. However, there is windows on one of the walls, so you can look out. This means that you are suddenly on street level. The other special case is Skärholmen, which is sort of built inside a building, so the station is located in the basement.

[@justanotheryoutubechannel]

I had an experience like this in reverse, I’d always been used to the tube being completely underground, but then I took a train that went outside and my mind was blown. It was such a fascinating experience to see something like that, I really had no idea they ever left the tunnels, and it made the tube so much more interesting to me. I also had a funny experience where our conventional train pulled up into a station, and a tube train came out of a tunnel into another platform further down the station, and it was such a bizarre thing to see.

[@christophernoble6810]

The whole thing is a real mixture for historical reasons. In Hamburg and Berlin some sections of the Ubahn. are elevated and you get the oddity of the Ubahn being above ground and the Sbahn being underground at one station! Fascinating stuff Geoff.

[@norbitonflyer5625]

We have that in London too, at Whitechapel the Underground platforms are on the surface and the Overground platforms are in a tunnel underneath.

[@OlePalnatokeAndersen]

Your exposure to weather metric is fine, but fails on a hypothetical overground station that has been encased in a shopping centre. You could also argue that cut-and-cover stations that are not covered, are really at least below ground level though not exactly underground.

[@lzh4950]

Reminds me in HK where quite a no. of stations' are located within shopping malls on 1 of their upper floors, so they feel more enclosed & like underground stations although they're elevated

[@pfscpublic]

My auntie told me how the tube stopped at the end of tunnel during the WW2 Blitz and how she and her boyfriend would have to walk the last bit home to East Acton in the open, sheltering when enemy planes flew over. She said the AA fire shell cases would rain down in front of them sheltering in a porch

[@AverytheCubanAmerican]

Waterloo & City is underground, that's for sure! The Little line that could

[@highpath4776]

But the depot for it is open to air and you can see daylight from Waterloo Platforms

[@lucasbarton1773]

I love the Waterloo and city line! I use it every day, or used to *sad face*

[@BenCol]

Lucas Barton _Every_ day? But it doesn’t run on Sundays.

[@EwanMarshall]

Sort of, the whole depot is unique in being below street level though. There is a shaft in the depot for ventilation and lowering/raising trains (used to have an elevator on a siding but there was a major accident with that). The line is considered a deep level line as it is more than 20m underground and was not constructed using cut and cover.

[@lucasbarton1773]

BenCol oh yeah, sorry I meant weekday

[@timjohnson689]

I love your dedication to exhaustively research all of this! There’s a good lesson on statistics in this - so much depends on how you define things.

[@wintrwunderland]

Maybe they could’ve called it the Overground if that name wasn’t already taken.

[@ianwood2031]

Maybe the Wombling Network. Underground Overground. 🙂

[@highpath4776]

@@ianwood2031 That is , interestingly, Whitechapel. Where the Overground is Underground and the Underground is Overground. Wimbledon incidentally is Open to the Air, as is Wimbledon Park , Southfields Too, but the track then goes in a Tunnel to East Putney which is also within walking distance of Wimbledon Common.

[@creativejamieplays7185]

wood wombeling free.

[@martinnyberg9295]

Hey Geoff, here’s an idea for your next video in this series: for the lines on the tube map that run alongside each other (yellow, pink, green et.al.) what percentage of the length do they actually share tracks? That question is easier to answer for the underground that I ride most often, the one in Stockholm. The three colours on the Stockholm TuB-map (TuB för TunnelBana) are three independent systems, with their own depots, connected only at two places (on the bridge between Gamla Stan and Slussen, and between stations Fridhemsplan and Rådhuset). What’s it like in London?

[@rach_laze]

here are all the areas of the tube that share tracks, I don't have it in me to work out the percentage but basically all of the circle line is shared with either Hammersmith and City or Metropolitan lines Hammersmith (Met) - Near Aldgate [Circle Line / Hammersmith & City Line]. Just east of Baker Street - Near Aldgate [[Hammersmith & City / Metropolitan Line] Just east of Baker Street - Aldgate [[Circle Line / Metropolitan Line] Southern side Circle Line [Circle Line / District Line (main section)]. Western side Circle Line [Circle Line / District Line (Edgware Road - Wimbledon service)]. Harrow-On-The-Hill - Moor Park - Amersham [Chiltern Railways / Metropolitan Line]. Acton Town - Ealing Common [District Line / Piccadilly Line]. Rayners Lane - Uxbridge [Metropolitan Line / Piccadilly Line]. Queens Park - Harrow & Wealdstone [Bakerloo Line / Euston-Watford London Overground]. Aldgate East - Barking [District Line / Hammersmith & City Line]. Richmond - Gunnersbury [District Line / North London Line London Overground].

[@mcollier4566]

So this video is actually "How many of the Tube stations are actually underground". "How much of the Tube is actually underground" is next week's video?! How hard would it be to calculate just how much of the running lines is in tunnels and how much of it is open to the weather?

[@alejandrayalanbowman367]

Or how about "How much of the Underground is actually Tube?"

[@darylcheshire1618]

might there be sections of line between stations that are above ground or in a cutting? Not stations I know.

[@jackiespeel6343]

@@darylcheshire1618 Would Finchley Road-Baker Street Metropolitan line be an example of what you are looking for?

[@EElgar1857]

For a train nerd like me, this is excellent! I always enjoy your videos.

[@MagicaLucem]

Geoff is clearly a god. He is just unbelievably wise about the tube... So I was thinking ... shouldn't there be a statue of our Geoff on the tube system. . No brainer is it. ..yeah !!! The question must be... Where would you think on the tube network should the statue of Geoff be located? Sudbury Town ? Cockfosters? Then where...on a platform or in a forecourt or .. Terah.... above an entranceway ? So many questions... Can anyone help?

[@benjeffery1415]

Halfway down the fifteen storey steps at hampstead😂😂😂

[@stolenps4729]

Maybe ontop of Chiswick park?

[@darrenduffy1227]

Brixton

[@rohitdoestech]

Another great Geoff video. relaxing at home watching this on my tv..Hope your fine Geoff!

[@dvdvnr]

As I child in the 1960s I remember standing on Hounslow West station many times when it was a terminus and before the Heathrow extension was built. Back then it was completely "overground" and exposed to the weather. So, Geoff, would it be worth making a video on all the stations that have changed from one type to another?

[@jcrailwayvideos6588]

We now go to the weather with Geoff Marshall: (5:19) Look up, daylight, weather, in your face! 😎 Thank you Geoff. In other news...

[@michaelocyoung]

4:09 Yes I see a lot of grey areas there

[@JamesTheBell1]

06:47: "You may not disagree" Sir, yes, sir!

[@SK_3PT1]

were not in the military u kno but oki

[@Rodhern]

"But that is fine."

[@DanceswithDustBunnies]

Bravo! Someone who actually knows the difference between may and might. Although I think Geoff really meant to say "agree" rather than "disagree".

[@fredrickfraser1659]

Really the best way to answer this question would be to go to Google Earth, map out which sections of the tube are underground and which are exposed, and then to figure out from that what percent of the Tube is underground.

[@JBS319]

In this case, I'd almost suggest going with a New York approach where each set of platforms is considered a station. For example, 161st St Yankee Stadium would for you count as one station, and it shows as one dot on the subway map. The 4 is above ground and the B and D are below ground, and the MTA considers these to be separate stations. Times Square is a 4 station complex, Grand Central is 3 (as is Atlantic Avenue and Broadway Junction, the latter of which is also a case of split above and below ground). The oddest case here is Wilson Avenue on the L, where the southbound platform is aboveground and the northbound platform is below ground. So Baker St would count as four separate stations, two of which are below ground and one of which is above ground.

[@highpath4776]

Baker Street has Eight? Platforms . Two Hammersmith&City/Circle, Two Jubillee and Four Metropolitan (two through to the H&C and two terminating.

[@JBS319]

@@highpath4776 but the two terminating platforms are in the same part of the station as the two thru platforms, so that could count as one station. the two H&C would count as one station, etc...

[@norbitonflyer5625]

@@highpath4776 Ten: you forgot the Bakerloo

[@TheRip72]

6:46 "You may not disagree & that's fine". That amused me. Regarding Aldgate. As well as part of the platforms being out in the open, it also has a station roof ... but the platforms are below ground level.

[@OnkelJajusBahn]

The metro of Vienna has some very special caveat: Donauinsel station at the line U1 looks almost completely like an underground station. The only thing are two windows on the side. So there is no weather influence there whatsoever. But the station is actually lokated on the lower floor of a bridge crossing the river Danube. Here is Wikipedia article in German about it: de.wikipedia.org/wiki/U-Bahn-Station_Donauinsel Very interresting video. I also like those kind of calculations.

[@scythal]

My Viennese special other says this is true!

[@BulletNoseBetty]

In Toronto, the east-west Bloor Danforth line is both underground and overground. What's really fun is when it goes over the Don River. You're underground and all of a sudden you're high up in the air and then back underground!

[@flyingbananatree5661]

So where is the partial station (0.1%)? Extra-dimensional maybe.... I love the detail you`ve gone into here!

[@justsumting]

I was thinking the same and calculated the figures. The percentages are actually 61.5% and 38.5%.

[@helentodd1829]

Hi Geoff, remember watching your attempt of all stations on ‘The Tube’ years ago! Glad I found your KZbin channel!

[@ReaperUnreal]

I decided to do the same thing for the Toronto subway. There's equally some interesting grey areas. Consider Old Mill station that is well above ground on the east side, but in a tunnel on the west side, but is entirely covered. Or Keele station which is entirely covered but well above ground. However there's a section between Royal York and Islington that's above ground track, but both stations are underground. This was fun, thanks for the idea!

[@OntarioTrafficMan]

Yeah Old Mill is the classic example. From street level you go downstairs, and then the platform is on a bridge over the Humber River! Keele is odd too, I doubt most people would know that it's actually elevated, since the station is so dark.

[@michaelleiper]

You've got Stepney Green station (which I believe you once called a "pain in the bum") as underground. But on the Eastbound platform, near the exit, there's a bit where you can look out and see the sky

[@davegreenlaw5654]

We have a couple of stations that are like that, in a grey area. One, Old Mill on the Bloor-Danforth Line (Line 2), the western end is underground, and continues west in tunnels. However, the eastern end, about half of the station, is open, has large windows, and is actually elevated as you head east over the Humber River. Another one much like that is Eglinton West Station on the Yonge-University-Spadina Line (Line 1). Running north, it is underground at the southern end of the station, but the northern end, as the subway starts its run up the middle of the Allen Expressway, is full of daylight from the many windows.

[@DaReS297]

It's actually quite fascinating how we define 'station'. I see you (and myself to a degree) consider a station to be a hub, and each line has their own platforms at a certain level of that station, which makes sense in the context of the Tube. For comparison, in New York, a station in many cases refers to just one or two lines, and we consider stations to be connected underground into a multi-station hub or station complex. This mostly stems from the fact that stations are named after streets, and intersecting lines are therefore named after different streets (and have different 'stations'), even though they are actually in the same spot.

[@norbitonflyer5625]

We also get this (see Edgware Road, Hammersmith), and had it more in the past when different companies had stations next door to each other, which have since been connected - see Notting Hill Gate, Highbury & Islington. Kings Cross - St Pancras is two main line stations served by the same Tube station. Paddington is the other way round.

[@lewfinnis7795]

Regarding your comments about shopping centres built over stations, that hell-hole Birmingham New Street was classified as 'underground' when the regulations regarding smoking were changed following the Kings Cross fire, as so much of it is beneath the shopping centre above, though the platform ends are in the open.

[@caw25sha]

I always thought the underground/overground percentages referred to track miles rather than stations.

[@MattL3457]

In all honestly I would probably believe more of what geoff says than TFL.

[@highpath4776]

GM has the problem of one named station serving lines that are underground and open to air. I would proportion them- like Baker Street half and half rather than saying it is open or underground - I have not counted them though as a result.

[@MattL3457]

High Path as a northerner from West Yorkshire I have absolutely no clue. But Geoffs word is final. I tried messaging him and vkki on ALl the stations to being them sandwiches at Saltaire but that didn’t happen.

[@busesinbathbristol5899]

I agree but from the point of view from TFL their map is more based on emergency vehicle access and not just whether you can see daylight or not

[@kaitlyn__L]

@@highpath4776 indeed, every station that is home to more than one line is also correspondingly more likely to become a "overground station" in Geoff's system, even if only one platform out of 6 or 8 or 12 were open to the air. Of course classification is always slippery and that's part of what makes it fun to debate.

[@donsharpe5786]

When we drove up to London from Wiltshire, we would park at Hounslow West, which was at ground level, and travelled into central London.

[@paulanderson79]

Most outer stations are on the surface.

[@mcwulf25]

Love the way you used the font at the end. Nice touch.

[@Psevdonim123]

The fact that Bakerloo shares tracks with Overground and northwest part of the Met uses National Rail infrastructure makes it even more ironic, and opens up a huge space for terminology jokes

[@1258-Eckhart]

Far more important to know if it's underground for evacuation purposes than if a drop of rain falls on 2% of the platform area. I'm with TfL here and would err if in any direction then even more towards the "covered is effectively enclosed" argument (--> 50%).

[@marchionybros1920]

Civic Center MARTA Station in Atlanta might be one of the strangest edge-cases. While its under the road, it's actually an elevated station above a highway. Both the roadway and station are built as a bridge over the highway.

[@ailaG]

Interesting. Maybe do one on how many kilometers of track are underground or overground too? The under-over ratio is bound to be small, I wonder jow small. They're building an underground train system over at my area / metropoline (different country) and people keep claiming that it's not an underground train system that they're building because most of it is above ground. Now I have some numbers to show them.

[@gregbruce1253]

Geoff I think you can put it into 3 basic categories, 1= all of the platforms are underground, 2= all platforms are above ground, 3= a mixture of underground and above ground. Just to add I also think if a station is built by the cut and cover method its underground.

[@howdyhamster]

I'm from the Dallas area and it's easy to work out how many DART stations are underground: One. Cityplace/Uptown. SMU/Mockingbird is below ground level, but counts as open-air following your weather rule. An interesting bit of trivia: there's a ghost station between the two named Knox-Henderson. It was excavated, but never completed, which is why passengers' ears pop while riding through that part of the tunnel.

[@metropod]

There was something just the other day, actually. Pelham Parkway station on the #5 train here in New York does not have the WiFi system the other stations that are below ground have here. It’s in an isolated “enclosed” section, no stations in tunnels nearby. (This section, the Dyre Avenue Line, was once a mainline rail route the city bought and converted for subway use) Someone asked New York City Transit about that Station the other on Twitter and they came back with an answer of “its not underground, it’s in an open cut that got roofed over, we don’t think it’s underground and didn’t count it as such”. Make of that what you will.

[@kamikazegargoyle]

Here's a couple of anecdotes from Tokyo's metro systems: the Toei and Tokyo Metro lines are almost completely underground, but there are a few exceptions. Unlike London they tend to come out of tunnels near the end of the line and then join onto other railway lines (often with through-service but you'll be charged separately for tickets as there's no zone system). So there's a few stations that are overground near the end of the line but the rest of the line is mostly/completely underground. For example Shibuya's Ginza line platform is actually the highest in the whole station complex. The Ginza and Marunouchi lines are the equivalent of London's cut-n-cover lines, not so far underground, so the Marunouchi line comes out of the tunnels a few times - there's a famous picture of Ochanomizu bridge with the Marunouchi line coming out and straight back into a tunnel to go over a river. Yotsuya station on the Marunouchi line is also mostly overground, and the Korakuen Marunouchi line station near Tokyo Dome is also completely overground. On the other hand, the newer Toei Oedo line is completely underground from start to finish. By some accounts that might make it one of the longest tunnels in the world at something like 40 km. (There are quite a few longer completely underground metro lines in China and other places but it's pretty cool all the same. I'm not 100% sure it really counts as one tunnel though if you have stations on the line)

[@tonywilson1845]

Geoff, I've just recently started watching your fantastically informative videos, especially the underground, purple trains and other 'oddities' like the £1.50 fare. I have mostly lived in Warrington and recently moved to Bristol so these areas are outside my railway experiences. I noticed in the what % of tube lines are overground, in the background it appears, that just like me, you have a large selection of OS maps (I think). Keep making these 'niche' videos.

[@Crepnick]

Fellow Warringtonian!

[@ste2442]

I’ve recently just finished working for network rail in Warrington at the slutchers lane depot

[@mcwulf25]

Aldgate was the first example I thought of. And some of those cut and covers in the Kensington area.

[@Tomsonic41]

Baker Street is interesting because although the Circle line platforms are fully underground now, that wasn't always the case. You've probably seen those lit-up ceiling recesses - these were originally wide open when the station was built, allowing daylight in and smoke out.

[@roach5219]

4:08 "There are some grey areas" Most of the map is a grey area Geoff :D

[@raychambers3646]

Overground ,underground ,your wombling free as we say in Wimbledon!

[@montyirish206]

There is a section at Victoria station on the district/circle line platform where there is daylight and weather. It’s nearly at the end of the platform. If you look up, you can see a big skyscraper.

[@highpath4776]

I think its the Car Park next to Victoria Coach Station ? (cant be thats a bit too far away), ! Platforms 16-20 Victoria main line are under an office development ?

[@markstramtrainbuscapades1729]

I've always felt that the Metropoloitan Line platforms at Baker Street have the feel of a main line terminus, which, of course, is as the Meropolitan Railway sort of intended it!

[@richardturnnidge]

By the title of the video, I thought you were going to measure linear length of lines which are underground/overground, therefore needing a proper map rather than the standard tube diagram. As well as the partially exposed stations and parts of track in zones 1/2, with longer overground sections outside zone 1, that might make the percentage 'underground' even less?

[@ClarinoI]

As I said in the previous video, you should forget about the stations, and concentrate on the lines. That'll give you a much better idea, and you won't have the issue of trying to figure out if something is underground or not because some platforms at a given station are exposed to the weather but others are deep level.

[@neilbain8736]

I've always wanted to know this. Including cut and cover as clearly the weather shouldn't get in makes it underground since it is covered. If the weather gets in, then it's below ground, simply because it's below ground level but not actually under any ground on account of all the fresh air freely polluting your lungs with heavier than air vehicle particulates, and sweetie wrappers, coke cans, bird crap etc. being dropped from above. If stations want to stick out into daylight and fog the issue, then fine, we have to adapt to various proclivities. We all know undergrounds can be a bit ac/dc anyway and just because the Underground has 2 supply rails, it’s clearly got current issues but that's just the way it is.

[@GoranNewsum]

I have a love hate relationship with "it depends how you define it" answers! On the one hand, it's good, because it's open to discussion, but sometimes you do just want a definitive answer!

[@huwthomas931]

Surely you should be measuring by track miles, not stations to say "how much of the underground" is underground?

[@Ganliard]

So the real question answered here is "how many of the undergraund is underground"?

[@johnstilljohn3181]

Here's my test - if you can see rails on Google Earth, the stations not underground...!

[@transportflick923]

John Still John what about Bermondsey where you can see daylight from the underground platforms?

[@johnstilljohn3181]

@@transportflick923 Ah yes - but look on Google Earth...!

[@RealConstructor]

If you dig a hole in the ground, is the hole underground or on ground or overground ? Or is it only underground if you bury it with ground? I would say underground is if you dig a hole, if it’s buried with ground or not. So below surface level is underground in my opinion, if you can see daylight or not.

[@SaturnCanuck]

Very cool. In Toronto much is underground, but, like London, in the suburbs the trains run overground. Yet, some stations -- such as Victoria Park and Warden -- while the track is above ground the stations are covered -- full buildings but open at either end.

[@kk-transport]

2:24 even the best You-tuber's are not perfect but well done on correcting yourself when editing.

[@LondonTransportMaster]

I'd go with track distance, so you don't look at stations, but the actual length of the network. That makes it fair for stations like Notting Hill Gate, which are both.

[@driverone7857]

2:27 When I went to London to see the Science Museum, I took the Circle line from Blackfriars to South Kensington. The direction I was sitting meant I thought Sloane Square was a fully underground station/cut and cover tunnel station

[@peteregan3862]

A civil engineer has a different perspective. Tunnels built cut-and-cover or bored are treated largely same for operational safety requirements. Similarly with track in cuttings, at ground level and aboveground (embankments/viaducts/bridges). Stations provide for vertical and horizontal movement of people. The 'station box' design is used to hold back earth. Even 50 metres below ground it would be possible to look up and see daylight, rain, snow fall on you if no structure was built in/over the box. 'Underground' should define the track between stations. Station platforms open to the weather are a development opportunity. Living at/close to railway stations and being able to rely on trains, walking and cycling for most travel needs allows a far better serviced neighbourhood (retail, etc). Roads are low people density environments. The less people need to use big vehicles, the less road we need.

[@PhilSergeant88]

Hi Geoff, you’ve missed a bit on your map. If going westbound on the district line, there’s a tiny underground section between Upney and Barking where it crosses underneath the c2c track, so there’s then a cross-platform interchange for passengers at Barking between westbound c2c and westbound District and also Hammersmith starters. The tube then crosses c2c over a bridge shortly after leaving Barking. which then of course means no cross-platform interchange at West Ham. Heading eastbound towards Upminster it remains overground all the way.

[@marsgal42]

My first thought on borderline stations was Earl's Court. The Piccadilly Line platforms are definitely underground but the District Line platforms are at cut and cover level under a large roof.

[@ryanrowe6097]

How much of the docklands light railway is actually over or near the docklands

[@ruairievans]

It uses a disused viaduct from Tower Gateway and the whole Docklands area was leveled during the blitz so there was lots of room to make it above ground

[@norbitonflyer5625]

Nearly all of it, except Bank, the two branches from Poplar and Canning Town to Stratford, and the sections south of the Thames. (All the London Docks were on the north bank except the Surrey Docks - the name is a clue! - which are served by Rotherhithe, Canada Water and Surrey Quays on the Overground.

[@holger_p]

Most lines or street names describe the destination, not the location. Imagine every railway in England would be called the English Line to fulfill your requirement.

[@ianmoseley9910]

Some people I know argue that Tube is bored tunnel only and does not include cut and cover

[@altypeRR]

I think a fairer way with those stations that are partial (lines on different levels) is to take how many are underground vs open to the sky and give it a percentage of the whole station. So say 3 underground vs 1 over gives you 75% underground. Those that have been built on top of are not underground they are just covered.

[@car_tar3882]

What is the furthest out underground underground station? Here in the dc area more specifically the northern suburbs in Maryland the last three stations of the red line are underground because people didn’t want the demolition of 25 buildings which seems quite unusual. They also happen to be the closest to a London station with one tube per direction instead of the station being one huge area like the other stations.

[@RS-pb2se]

Wasn’t expecting Geoff is to be a little inaccurate with his counting. If it’s too tricky to measure through metres of track, I would’ve counted the platforms. For example, there 10 platforms at Bakers Street. 6 platforms would be underground with the 4 metropolitan platforms being overground.

[@AndrewWilsonStooshie]

If you're working out a percentage then you could count stations that are partially open as 0.5.

[@LewisCroden]

System length 402 km (250 mi)[1] There are 20 miles (32 km) of cut-and-cover tunnel and 93 miles (150 km) of tube tunnel

[@Mission-Study-Official]

Hi Geoff! Just some suggestions... Are you going to add the Elizabeth line to the map? Also, the London Overground would be an interesting one - how much of it is actually underground?

[@rayizard5687]

You would have fun classifying Cleveland Ohio's Tower City Station. If you enter from Public Square you'd say yeah it's underground since you went down escalators to get to the platform but the tower itself was built against a cliff so track level is ground level, but so is the entrance

[@liftboy92]

I'm sorry Geoff, but on your map I spotted the Bakerloo Line's Maida Vale and Warwick Avenue to be overground. I recall them being underground.

[@smoktephoto]

I was going to say that this would be useful so we know which stations will have no phone signal, but then I remembered that Geoff previously released a video about 4G internet being in the Tube tunnels.

[@RatelHBadger]

This video is incredibly spotty and nerdy and I love it!!!!

[@raptokvortex]

Wouldn't you measure it by length of track underground?

[@matthewteller6095]

What about Blackfriars? At the eastern end of the sub surface lines platform there is a short section of open air definitely big enough for the weather to come in. Co-ordinates: 51.511763, -0.103183

[@rhodrage]

On account of most of the Underground being overground, I propose the Wombles should be in charge, as the song goes.

[@huzayfah]

Morden station is actually considered to be a tunnel station by tfl despite being "not underground"

[@neuralwarp]

I would think, from a fire and rescue perspective, what the Fire Services need to know is whether any passengers or patrons are admitted to any part of a tube premises where they would need to climb one or more steps in order to evacuate during an emergency.

[@brian9731]

And then you get places like Farringdon and Baker Street which has some "above" ground track next to them but the track is predominantly sub-surface "under" ground. Or the little bit of the Met line which does not have a station but did have many years ago just across the road from Lord's.

[@davidspear9790]

If they had to dig down before laying the track and building the stations, then it would be underground, regardless if it was built over afterwards. If they only way to access the station or line is by descending, then it's underground, I would say

[@allensanders5535]

anything below ground level is considered underground by definition. doesn't have to be completely covered by ground, just below ground level

[@MichalBergseth-AmitopiaTV]

Oslo Metro in Norwegian is actually T-bane.. which means underground :D but out of all of the stations, only 16 stations out of 103 stations are underground. Interesting facts!

[@eduardocamaradiez2979]

But this only looks at the stations and the question is 'how much of the underground' so what if you checked to see how many km of track are covered and how many aren't. This would also then eliminate any grey area stations which are partly open/underground or have some lines covered and some open. New video? ;)

[@MichelleBradley]

i think a better way to determine this is to determine how much revenue track (exclusive of sidings, points and depots) is underground vs. overground/open air measured in miles/km.

[@MaidaValeTom]

Well arguably the metropolitan line platforms at Baker Street are a black spot for most networks, so the phone signal point doesn’t really work here 😂. Sometimes I’ve found more signal down in the escalator hall of the Bakerloo and Jubilee better than I have on the Met platforms... Referencing 6:40

[@sintsmeding2371]

Hi Geoff, have you listened to the latest podcast of Well There's Your Problem about the 1987 Kings Cross Fire? What are your thoughts on this event and about their view on this tragic event?

[@rickyzuc]

Probably extremely difficult if no impossible to work out? But the stations themselves are only a small percentage of the whole network, if you factor in the actual rails, I reckon a hell of a lot more of the network is outside.

[@Sim0nTrains]

That Fire precaution regulations map, is that not the Secret Tube map that only for employees or is that a different map all together? but it was very interesting indeed.

[@zanelindsay1267]

Interesting, but I was expecting to hear a percentage number based on track mileage rather than a station count. On the map at 3:14 I was puzzled to see a spur from the Jubilee line going to Charing Cross but apparently that's not normally used now.

[@SteveBrandon]

Now you've got me thinking about Ottawa's LRT system. Officially, the "underground" section is only downtown, from Lyon Station in the west to Rideau Station in the east, a measly three "underground" stations. But St. Laurent Station is in a tunnel that is below ground level and, while you can see daylight from the east end of the platform, the end of the tunnel is still around 50 metres away. You can't really see daylight looking west because of the southwest twist under the Queensway towards Tremblay Station (which connects to Ottawa's main intercity train station, well away from downtown). I'm not sure whether that means I should count Ottawa's LRT system as having three "underground" stations or whether I should add St. Laurent as the fourth. I miss living in Montreal. The Metro was 100% "underground". Unless you disqualify stations like Angrignon that have skylights through which sunlight illuminates the platform during the middle of the day.

[@kaitlyn__L]

I didn't even know Ottawa had a LRT! I only used the buses. (After the debacles of even two-segment bendy-buses in the UK, I was surprised to ride on a three-segment one! And I observed quite a bit of fare dodging by people who get on and off on the back-most segment.)

[@SteveBrandon]

@@kaitlyn__L The LRT just opened last September (though there is a separate north-south diesel "O-Train" line west of downtown that has been in operation since 2001). The first few months of operation of the Ottawa LRT were plagued with problems and breakdowns although now that most downtown workplaces have shut down for the time being, there hasn't been much news on that front. I moved to Ottawa from Pincourt (near Montreal) at the end of 2004 so I don't remember any three-segment buses. The longest ones in operation in Ottawa now are two segments and made-in-UK Alexander Dennis double deckers that used to serve those Transitway routes that became redundant when the LRT opened have reduced the number of bendy buses on the road. Some of the people who got on the bendy buses in the back may have been fare-hoppers but rear door boarding was permitted for pass holders. These days, there are no more paper passes so the rear doors on bendy buses and double-deckers have the same "Presto" card tap readers that you find at the front of all buses. For over a month now, it's been rear door-boarding only for all buses except for people with special needs to minimize exposure for drivers.

[@broadway254]

Thank you. I've waited ages for this one to be done ❤️

[@davidtyas2249]

How about we define it in terms of volume - that is, we work out how much volume the above ground stations, above ground parts of stations and above ground tracks and alignments take up, and how much volume below ground stations, below ground parts of stations and tunnels take up. (Note: to define the volume of above ground tracks and alignments, pretend the tracks and alignments are as tall as the trains that go on top of them)

[@railrunners]

Pretty sure you can see daylight at Victoria on the sub surface platform if you stand in the right place... because I was there when it rained once Victoria or cannon street, not sure which

[@y2an]

Since the point of the underground is to get between stations without interfering with surface structures, wouldn’t miles of track in true tunnels be a better measure?

[@trevorhart545]

Would it not be simpler to give 1. Percentage of "Tube Train" track underground 2. Percentage of "Underground Train" track underground 3. Percentage of "Overground Train" track underground BUT should that be just track that is within London not outliers Amersham etc?