 Hey folks, welcome back to RM Transit, and welcome to this very special edition of Transit Explained, where I get to cover what may be my favorite metro network in the world, in the original Railway City, the London Underground. The Underground is special for so many reasons, its unique technical elements, its intriguing history, the cultural impact, and the beautifully varied locales where the system operates, not to mention the fantastic design. Oh, and it has an incredible 11 lines with 272 stations, and has been in operation for over 150 years. Much like the video I did on Tokyo earlier this year, which is absolutely worth a watch if you haven't seen it yet, this video required well over 100 hours of work, and has been in the work for months, and unlike Tokyo, I went the extra mile to pare things down to make the video shorter and more information dense, so if you enjoy it, let me know with a like and consider sharing it, or of course subscribing and hitting the bell icon so you stay in the loop with future videos. I hope that after watching this video you feel a lot more informed on the Underground, and we don't have much time, so let's dive in. Before we get started, this video is about the Tube. I already have an Explained video on the DLR, and I'll cover far more in future videos, such as the suburban railways, many of which operate like metros in their own right, so make sure to subscribe so you don't miss them, though also do check out my More Than The Tube video. The story of the London Underground really begins with the Metropolitan Railway, which was a commuter railway that originally opened in 1863, and had a tunnel which connected the Northern Railway terminals in London, such as Houston and Paddington, to the city centre, and would become the precursor to modern subway systems. Beyond the origin, you really need to know that on the London Underground, like many metro systems, there are more than one type of train. Now I'm going to talk more about the different types of trains, and what makes them different later, but for now I'll mainly just talk about the two distinct networks. The first of these networks is the Subsurface Network, which has its origins directly in the tracks and tunnels of the original Metropolitan Railway. There's an interesting dynamic here, whereas in other cities with two distinct networks based on legacy lines, the Subsurface lines have a different topology from the deep level lines. The Subsurface lines all share tracks and interlines through London's centre, with a loop of tracks being shared by several lines. This is of course highly reminiscent of the Chicago L, albeit with a bigger loop that's mostly underground or in trenches. The first line we should talk about is the Metropolitan Line, which has 34 stations over 67 kilometres of track. This line travels from Aldgate in the centre to far west and northwest of London, where several branches exist in what was and is known as Metroland, lands planned for development by the original Metropolitan Railway on essentially the same model as the Hong Kong MTR. The Metropolitan Line is the line which extends the furthest from London's centre. The next line is the District Line, which has 60 stations on 64 kilometres of track, the most stations of any line on the network, and an impressive number of stations for any single metro line. The District Line travels from far east of London in Upminster, west through the centre south of the Metropolitan Line, where it then splits into numerous branches which travel north, south, and west. Much like the DLR, a variety of services operate on the District Line, and that's likely the topic of a future video. After that comes the wonderful Circle Line, which as you may expect operates the looping route around central London that I referenced earlier, with the northern and eastern sections of the loop being shared with the Metropolitan Line and the southern and western sections being shared with the District Line. The Circle Line basically entirely overlaps other lines on its 36-stop, 27-kilometre route. Unfortunately, for fans of geometry, the Circle Line is no longer an actual Circle, and now extends west to Hammersmith, operating more like a rolled-up regular metro line. Finally, we have the Hammersmith and City Line, which has the distinctive honour of being the least used on the subsurface network. This line has 29 stations over 25 kilometres of track, and shares track with other subsurface lines for its entire length. Running from Hammersmith in the west, with the Circle Line, which it continues with along with the Metropolitan Line from Baker Street to Liverpool Street, where it splits from the Met and the Circle Line to group up with the District Line and then run out east. Now, the subsurface lines with the various branches, services, and interlining all tend to operate individual services on fairly low frequencies, which is a bit… Wait, sounds like someone has something to add here. There's a few places where the Underground actually shares its tracks. On the District Line, from Gunnersbury to Richmond, you can also catch the North London Line of the Overground. The line was originally built by a main line company, the London and South Western Railway, back before the concept of the London Underground existed, and so could connect to both the District Railway and the North London Railway. There was a similar situation between East Putney and Wimbledon, where South Western Railway runs occasional trains over the Underground track and again, that's because this was originally built as part of the London and South Western Railway's network. And in North West London, the Bakerloo Line shares the Euston to Watford branch of the Overground from Queens Park to Harrow and Wildstone. Anyway, I did a little video about the situation at Kew Gardens where I talk about it in more detail. Now I'm off back to my own channel. Jay, go away! The second major network consists of the deep level lines, so named because unlike the subsurface lines, they run deep under Central London. These lines first opened several decades after the subsurface lines and are more numerous and generally more heavily used. Their later construction led to different design and planning sensibilities winning out. As such, the deep level lines do not share track with one another and intersect at various points in Central London, something which influenced metros in the Soviet Union in particular. Now as it turns out, the deep level lines do share the same track standards as the subsurface lines, which is important because they do share tracks and connect with the other lines in a number of places. The first line on the network was technically the Waterloo and City line, which utilized its depth to cross under the Thames and now acts as a shuttle between Waterloo and Bank, over just 2.5 kilometers. Next we have the Central Line, which is the longest line in the entire system at a whopping 74 kilometers, across which there are 49 stations. The Central Line operates from the west of the city into the center, intersecting the Circle Line midway north south before continuing northeast, where it travels up to Epping with a branch traveling east and then looping back to the Epping leg through small towns and farmland. The Northern Line is the most used line on the whole of the Underground, and is basically two separate lines which come together at two points, Camden Town and Kennington. The lines have a total of 52 stations over 58 kilometers of track. The Northern Line has three northern branches and two large southern ones, one which passes through the main commercial area of the city, and another passing through the traditional financial district. The line generally travels in a north-south direction, though somewhat hilariously it's not actually the line which travels to the northernmost point. It is, however, the line which travels to the southernmost point. Of course, just this year, the Northern Line was extended, with services on the western branch going beyond Kennington to Battersea Power Station and Nine Elms. Now regarding why the line isn't just split in two, the issue lies in Camden Town. At Kennington, the two sections of the Northern Line are isolated, but at Camden Town, a perennially overcrowded station, the services intertwine, and separating them would likely overcrowd the station, which is already dangerously overcrowded, with high transfer volumes. TFL does have plans to sort this out eventually, but until then, I'll be referring to it as the Northern Lines. The Bakerloo Line is probably my least favorite tube line, because I just find it somewhat boring. That said, it has 25 stations across its 23 kilometers of track. The line travels from the northwest of London before cutting straight through the center, parallel to the western Northern Line branch, and then continues south of the Thames to terminate at Elephant and Castle. The line I need to talk about next is my favorite tube line, and frankly, one of my favorite transit lines in the world, the Piccadilly Line. The Piccadilly Line has 53 stations over 70 kilometers of track, and has two branches in the west, one serving Uxbridge, which manages to cross the central line twice without a good connection, and one serving Heathrow, which converge and pass through the center of the circle line before turning north and traveling up to C**koster's. Now, the Heathrow branch is particularly interesting because upon opening, it was fairly influential in the metro world. The branch has also been very successful ridership-wise, taking perfect advantage of major reverse peak capacity. Now interestingly, the Piccadilly Line actually shares tracks with both the metropolitan and district lines, from the subsurface network on its Uxbridge branch. The Piccadilly Line also shares a corridor with separate tracks from the district line from Acton Town to Earl's Court, where the Piccadilly Line runs Express, a feature that London does have in a few locations, if not as extensively as New York. The Victoria Line is the second newest line on the London Underground Network, opening over 50 years after the last tube line before it in 1968. The line is relatively short by tube standards, with 21km of track and 16 stations across it, and is a marvel of design, which was intended to connect various major interchange points on other rail lines, traveling from the northeast to the center and then south of the Thames. Many of these connection points had incredibly engineered cross-platform transfers that I cover in more detail in my dedicated cross-platform transfer video. It's also the only significant tube line, assuming a two-station shuttle doesn't count significant, which is entirely underground. The final line in the network and the newest line, first opening in 1979, is the Jubilee Line, which has 27 stations on 26km of track. Both the Jubilee Line and the Victoria lines are incredibly well used, and a good testament to the power of removing congestion points and connecting hubs. In terms of alignment, the Jubilee Line starts northwest of London at Stanmore, before traveling south to parallel the Metropolitan Line, which operates as an express service with the Jubilee making all stops, before splitting again around Baker Street, and then traveling southeast through the city center and crossing the Thames a number of times on the iconic Jubilee Line extension, or JL8, which provides source to Canary Wharth, the Greenwich Peninsula, as well as West Ham, and Stratford, where the line terminates. The extension opened in 1999 and is noted for its elaborate architecture and its job connecting the docklands and other previously poorly served areas of London. As a fun bonus fact, traveling between Stratford and Canning Town, the Jubilee Line runs express while the DLR plays the role of the local. Now with that, we have the entire London Underground network, with the subsurface lines and the deep level lines. You can really see in these images just how different the topology of both the subsurface and the deep level lines are. With regard to future lines and extensions, London's main project at the moment is Crossrail, a new cross city heavy rail line which will operate as rapid transit, not unlike the Paris RER, especially with the opening of the Northern Line extension. Well of course there are many often talked about extensions to the network, for brevity I'll leave those to a future video. Now I'd be lying if I said I wasn't extremely excited to talk about the rolling stock for this video because the underground is really unique. The first thing to discuss is the distinction between the subsurface and deep level lines of the underground, which primarily comes down to the loading gauge of the trains. If you think I should make a video on railway loading gauge, leave a comment down below. Suffice to say, the trains on the deep level lines are much smaller, just around 2 and a half meters wide and much more tube-like, because they were designed to fit into tunnels created with early tunneling shields, originated in London, which are the precursor to modern TVMs, giving the system its tube name. In order to get this circle-like shape, which fills the upper half of a tunnel, a number of unconventional design decisions had to be made. For one, the doors on the trains are actually curved, so watch your head. At the same time, the odd door arrangement, with single doors at the end of each car, is a side effect of the trains, not unlike low-floor trams, having bogies and wheel sets which extend under the longitudinal seats within the carriage. This type of design is really unique for a metro train, and means the floor of the train is actually quite low. By comparison, the subsurface trains are substantially larger, at roughly 3 meters wide and with a similar profile to mainline trains in the UK, which harkens back a bit to Tokyo, I must say. Since the two types of trains are different heights, both to their roof and floor, when sharing platforms, they are can be a pretty large vertical gap, which is an accessibility nightmare. This could be solved in some cases with two back-to-back platforms with different heights. Despite the different sizes, as mentioned before, the rails and power system, which consist of two power rails, one between the running rails and one on the side, like a typical third rail, are compatible, as evidenced by the interlining seen on the network in a few places. The voltage across these rails is typically 630 volts, although the voltage of the individual rails varies, and in some places it's up to 750 volts for better performance with the newer trains. With that out of the way, let's take a look at all of the rolling stock currently operating on the network, starting with the trains on the subsurface network. These lines use the somewhat boring but entirely charming S-stock, which comes in two variants known as the S7, which naturally has seven cars, and the S8, which has eight. The S-stock has roughly 17 meter long cars with three doors per side, and were manufactured by Bombardier with the first introduction in 2010. The S8 stock operates on the metropolitan line, while the S7 stock operates on the Hammersmith and City, Circle, and District lines. Both train types are fully interlinked with open gangways, and have higher than normal top speeds to take advantage of longer interstation gaps. The deep-level lines have a much more varied roster of trains, which are given names based on the development year, while the subsurface lines, well, they get a letter. The 1972 stock is used on the Bakerloo line and features seven car trains with roughly 16 meter cars that have two single doors and two double doors per car. These trains were manufactured by Metro Camel, who you may remember also made a lot of the rolling stock for the Hong Kong MTR. A few years later, the 1973 stock was introduced on the Piccadilly line. These trains feature six cars with roughly 17 meters per car, and look slightly nicer than the 1972 stock, and were also built by Metro Camel. The 1992 stock operates on the Waterloo and City line in a four-car configuration, and the central line in an eight-car configuration, of roughly 16 meter long cars. While the door arrangement was similar to earlier deep-level trains, these trains utilized external sliding doors. Manufacturing was done by a company which, by a shocking number of acquisitions and divestments, was part of Bombardier, before it was acquired by Alstom. 1995 and 1996 stock are in many non-technical ways similar, technical being things like drive units and suspension. The 1995 stock came in six-car sets and operate on the Northern line while the 1996 stock came in seven-car sets and operate on the Jubilee line. Worth mentioning, the Jubilee line sets were actually retroactively extended. Both models feature roughly 18 meter cars and were manufactured by a consortium of Alstom and Metro Camel. The 2009 stock operate on the Victoria line and were manufactured by Bombardier. Trains are eight cars long, with each car being 16.5 meters long. These trains probably have my least favorite design, which is saying something given I tend to dislike older train models. I just can't get over the raised portion of the front fascia, which reminds me of the M8 rolling stock on Metro North in the New York area. Now, while a lot of London's rolling stock is pretty new or middle-aged, the trains on the Bakerloo and Piccadilly line are nearly 50 years old, and hence they are being replaced with the casually named New Tube for London trains. These trains will be very different from existing deep level trains, and will be made by Siemens. They probably deserve a video of their own, so leave a comment for that. Plans call for them to arrive in the mid-2020s. Now, while the rolling stock of the tube is fascinating, entire careers have been made talking about interesting facts about the tube. I'll try to summarize here, but it will really just be a speedrun. You should really go check out Jeff Marshall and Jego Hazard's channels to learn more about the history and peculiarities of this amazing system, as well as abandoned lines and other awesome stuff. Now, let's get going, because we've got a London Underground-sized amount of ground to cover. The Underground uses a blend of different types of signaling, with significant ATC or CBTC deployment across the network. This enables platform screen doors, but they only exist at a few stations on the Jubilee Line extension, which don't actually align all that well because of the type of signaling used. That said, they're protected for on the Northern Line extension, crazy that the extensions are so infrequent these days that that's a specific reference. There's also the 4LM project, which is progressively converting the entire subsurface network to CBTC, albeit with many delays in the process. This is likely the largest re-signaling project currently happening in the world, and is extremely important and complicated because of the intricacy and interlining of the subsurface network. Partially owing to investments into signaling and infrastructure reliability, the London Underground actually operates weekend 24-hour service, which is still fairly uncommon for a metro, but a very nice change from the earlier closing times around midnight. See my 24-hour service video for more on that. The Waterloo and City line doesn't have a track connection to any other line, and so when trains need to be delivered or changed out, they are removed from a shaft by a crane. Another surprising fact, most of the London Underground is actually above ground, be it in cuttings or on embankments or in rail corridors. Fairly well known, parts of certain stations were previously used as air-raised shelters, a feature which is surprisingly common in metro systems around the world. The London Underground has an incredibly high cost recovery, where fare revenue covers a large portion of operations. This can be attributed to high fares, especially when travelling through the central zones, as well as efficient operations. The entire network has had trains operated by one employee for over a decade. Given the subsurface network's history with the Metropolitan Railway, parts of it actually originally operated with steam trains, which is part of the reason for certain design decisions and frequent open sections on the subsurface network. These sections allowed trains to release smoke and steam stored on board, where it wouldn't clog up the tunnels quite as badly, but it was an imperfect system to That said, while steam trains fortunately no longer operate on the network, air quality on the tube is still notoriously bad, especially on the poorly ventilated deep level tube lines. This is exacerbated by the heat in the tunnels, which has kept the deep level tube lines from having AC thus far. Modern transit wayfinding also wouldn't exist without London, whose tube map originating from designer Henry Beck has influenced almost every rail map and map made since. I've mentioned before how some systems like the Montreal Metro and older sections of the New York subway use hills at stations to act as a form of regenerative braking, trading speed for elevation. This is actually a feature seen on a number of sections of the tube. There are many stations on the London Underground, such as on the outer parts of the Metropolitan Line that receive very infrequent service for a metro, because of the low ridership and numerous branches on the system. This shows some of the connections between the current underground and older mainline railways. Also somewhat unusual for a metro system, some stations on the London Underground require selective door opening, which is where part of the train sits off the platform and doors on only some cars open. Now beyond all the crazy unique features, there are also a lot of elements of the Underground that I simply love. These include the London Underground originating many technologies that inspired other systems, from tunneling to modern wayfinding and everything in between. Without London, we wouldn't have metros as we know them today. Things weren't always this way either, and like another early 1900s railway system across the Atlantic, in the late 20th century the Underground was in rough shape, but since massive amounts of work and funds have gone into significantly improved older parts of the system. Now this second part isn't entirely because of the Underground, but it is still amazing how good the coverage of London, north of the Thames that is, is by the tube. In many areas, you're never more than a few minutes walk from a station, and thanks to the Piccadilly, you can even start a British or European vacation with a ride on the tube. Perhaps more than most metros, London has giant interconnected stations. This has to do with the way the network came together, sometimes with extensive planning, and sometimes with little at all. That said, few systems have stations quite as gargantuan and maze-like as London. Of course, as I mentioned before, most of the system is above ground, and this is a wonderful antidote to claims that rapid transit belongs underground, or that you can't have a high-quality rapid transit system without tunnels, because London certainly does. London's underground infrastructure is legendary. With the train running tunnels for existing and abandoned tube and mainline railways, pedestrian and station walkways, and elevator and escalator shafts, the ground in central London would look a lot like Swiss cheese if you could take a slice. Most importantly of all though, I'd argue London originated the concept of rail mass transit, and in the process changed the world. The speed and comfort of modern cities would not be possible without it, and for this, we all owe London a debt of gratitude. So that's it. The London Underground explained in one video, my last explained video of 2021. Making this video has been a goal of mine since I started making videos, and I'm so happy to share it with you.