Shockwaves would only happen if the train was going supersonic, which would be insane. The noise would be the least difficult engineering problem if that was the case.
The real limiting factor for trains speed is the rail. Things have to bank the right amount, it has to be smooth enough, turns can't be too sharp, etc. High speed trains have to slow down in more populated areas because there is more stuff in the way that stops the rail from being built optimally, including areas were people will not tolerate the noise of a train. Beyond that aerodynamics and energy requirements become an issue. Eventually friction in general becomes too large. But that is at much higher speeds than the speed limits the rails create.
Think like highways in the US. One 65 mph highway can be safe to travel at 140 on, while another can only be safe at 55. But nobody has bothered to go and survey the road to set the speed limit to a sane number. If this was done many highways could have their safe speed dramatically increased with very minor modifications, it's just nobody bothers because the speed limit is so low anyways. Rails are the same way.
Shockwaves would only happen if the train was going supersonic, which would be insane. The noise would be the least difficult engineering problem if that was the case.
The real limiting factor for trains speed is the rail. Things have to bank the right amount, it has to be smooth enough, turns can't be too sharp, etc. High speed trains have to slow down in more populated areas because there is more stuff in the way that stops the rail from being built optimally, including areas were people will not tolerate the noise of a train. Beyond that aerodynamics and energy requirements become an issue. Eventually friction in general becomes too large. But that is at much higher speeds than the speed limits the rails create.
Think like highways in the US. One 65 mph highway can be safe to travel at 140 on, while another can only be safe at 55. But nobody has bothered to go and survey the road to set the speed limit to a sane number. If this was done many highways could have their safe speed dramatically increased with very minor modifications, it's just nobody bothers because the speed limit is so low anyways. Rails are the same way.