Hi guys, I'm 19 and since the start of this year I have had a large interest in trains and the rail network, I know quite a lot but not as much as a lot of people I have a lot of questions of which Google can't answer no where near as good as members on this website.
I'm quite interested in hs2 I know quite a lot but I've heard about a thousand different things about it and I just don't know what's true, what will be the operating speed? If someone could give me a detailed answer that would be great also I'm more accustomed to mph than kph.
Also I've heard that at be start it will be a certain speed then it will increase as the years go on? Is this true and if so why not just operate at maximum speed from the start like I said detailed answers would be great guys thanks
You don't need to preface your posts with your little bio. Most people on here read most things and will recognise your username and remember your 'story'.
The design goal speed of the HS2 infrastructure is 400km/h (250mph). The engineering companies HS2 Ltd contracts to plan and design the routes try to achieve this for as long as possible in as many places as is reasonably possible, but in various places and for various reasons the maximum main line speed drops down to anywhere between 360km/h (225mph) and 190kmh (120mph). Much of the route through South Yorkshire is limited to 360km/h due to the hills, with the 190km/h limitation being at Sheffield Meadowhall due to the lobbying efforts of the Firth Rixson metal company as the route can then avoid their factory. In general, there are greater speed restrictions on the eastern arm of the Y network from Birmingham to Leeds than there are anywhere else as the route passes through hillier terrain and through more populated areas. The western arm is mostly 400km/h, including the high speed bypass tunnels underneath Crewe, other than a 300km/h (186mph) section necessary to weave between the Greater Manchester and Merseyside towns.
As the route approaches its termini the speed will obviously decrease as trains have to decelerate anyway. The highest possible speed for a train taking the diverging route at a set of points is 230km/h (140mph) so all spur routes (into Birmingham, Manchester and Leeds) are limited to this, as is the first few kilometres of the eastern arm of the Y. The speed drops the closer the route is to London as well, with the viaduct across the Colne Valley (north of Heathrow) limited to 320km/h (200mph) and the tunnels on either side limited to around the same. Above 230km/h, it is necessary to increase the diameter of the tunnel due to aerodynamic effects so the cost will increase and more spoil must be disposed of, so if the case for a higher speed tunnel is marginal from a journey time perspective it is unlikely to be built.
These speeds are the maximum the infrastructure is designed to be used at every day. It might be possible to run faster for the purposes of high speed testing, but they will never be exceeded by normal services. At this point in time, it is possible to purchase high speed train sets with a maximum everyday service speed of 360km/h and this is what HS2 Ltd predict will be done. However, the normal operating speed that the timetable is written for will be only 330km/h (205mph), with the 360km/h capability of the trains being used only to make up time if there are delays. On lower speed sections, the normal operating speed will be reduced similarly up to a point. One of the reasons that the infrastructure speed is specified to be higher than what is possible to run every day with current technology is that there is experience around the world to say that train technology can advance to the point where those speeds are useful and possible. For example, the original Tokaido Shinkansen between Tokyo and Osaka is only normally capable of 270km/h (170mph) as it was built back in the 1960s, with the initial fleet of trains only running at around 230km/h. As modern trains are more than capable of running at >300km/h now, new rolling stock that is capable of tilting very slightly into corners to allow 300km/h running on these lines is now in use to use the line as efficiently as possible while all new Shinkansen are built to run at 360km/h for standard rail lines and 500km/h (310mph) for the new maglev Chuo Shinkansen between Tokyo and Osaka.
