one of the systems that unfortunately is stuck with the technology to this day in many cases there were three doors per side per car but in some cases there were just two again like in taipei now cars are designated into one of three classes first came val NUMBER_TOKEN then val NUMBER_TOKEN and then val NUMBER_TOKEN if the names sound fancy and interesting they're really not it's actually super simple the name just means literally the width so val NUMBER_TOKEN was NUMBER_TOKEN meters wide and val NUMBER_TOKEN is NUMBER_TOKEN meters wide now obviously one of the most important aspects of val is the a automatic and indeed val was one of the world's first automated transit systems and some of its elements are actually still quite unique for example despite using computerized signaling like the early dlr network in london val systems at least initially used fixed block ceiling which is something i'll discuss in a future video about signaling suffice to say it's a little strange to use computerized signaling with a more dated signaling technique at the same time early systems used physical means of train detection where in some cases trains would literally be detected by breaking a laser beam interestingly a lot of the research that flowed into creating val also flowed into creating other more advanced automated signaling technologies these technologies actually went on to be really important for example the technology that allows the rer system in paris to operate incredibly frequently or the systems that underlie the automated signaling in lyon and later in paris so val was just one step on this march towards automated metros now in some senses val remains really impressive to this day the really short trains and rubber tires meant that the system could operate on insanely tight headways of as little as NUMBER_TOKEN seconds between trains that's because the trains are so short and can accelerate so quickly because the rubber tires that they get out of the platform and into the platform very quickly if you think about it a train can't stop at the platform until the train before it is out of the platform and so hence why the frequencies can be so high on valve systems at the same time valves have the same retro transit energy as the vancouver skytrain and scarborough rt in canada in that despite using a lot of weird finicky technology it actually performs really well in the case of leo the system has had really high reliability and really high service frequencies and that's quite impressive especially considering this is really NUMBER_TOKEN technology for automated trains now one major feature of valve especially when the first system opened in leo was platform screen doors in fact leo was arguably the first system in the entire world to have a modern implementation of platform screen doors platform screen doors are really important on a super high frequency system because they tell passengers where to wait on the platform so that when the train comes in passengers can get off the train and the passengers boarding can quickly board now i've almost made it sound like val is actually possibly pretty good and that is not the case of course the first issue with the system is that fundamentally it's a rubber tire metro which has all of the same issues that every other rubber tire metro faces at the same time unlike the rubber-tired metros in mexico city or paris val systems don't have standard train tracks and steel wheels alongside the rubber tires which means they don't get to benefit from a lot of the regular train stuff taipei who used val probably quite regrettably on the brown line is a
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