Re: High Speed Rail: Pros and Cons
Posted: Sun 09 Jun 2019, 19:56:24
Iptec,
ONE of the major problems with trying to significantly raise the NEC speed is the track spacing. The tracks are too close together, they need to be spread apart. That is an extremely difficult effort, more likely impossible. Even you had the ROW (width-and mostly you don’t) ALL of the catenary poles will be in the way, and every single bridge would need to be replaced.
Much of this ROW is 4 track, the putter 2 tracks supporting the local commuter service. So you need to start from the outside in, redo the commuter tracks, which means replacing every single station.
But also the tracks substructure, the sub grade and ballast, are insufficient to support higher speeds. Back in the 70’s AMTRAK ran under, massive strings of equipment that picked up the rail, scooped out the ballast, cleaned it discarding the fines, and put the rail back often in new concrete ties. That was a massive and expensive project that allowed them to do higher speed, but not good enough to do much beyond where they are now. In short to meet Biden’s goals you would need to start 6’ under the existing rail top and excavate all the sub-ballast and build a new rail bed, complete with new and improved drainage.
The existing NEC ROW is relatively twisty, the Acela vehicles can only make the speed they do because they tilt. This has already caused problems because when first introduced some bright light figured out that it could cause the vehicles to side swipe one another. That was big news back then. So anyway that trick has already been used to get them where they are.
And remember that all of these renovations would have to be accomplished while maintaining existing service.
The existing g ROW is pretty well maxed out speed wise. Trying to straighten curves is massively expensive. When they built the Garden State Parkway hey put a big S-curve in the ROW at Metro Park to keep the parkway reasonably straight. I think that little obstacle is on the order of 12 lanes that would need moving to straighten that particularly troublesome S curve.
All joking aside, it would be cheaper and more practical to tunnel the route.
ONE of the major problems with trying to significantly raise the NEC speed is the track spacing. The tracks are too close together, they need to be spread apart. That is an extremely difficult effort, more likely impossible. Even you had the ROW (width-and mostly you don’t) ALL of the catenary poles will be in the way, and every single bridge would need to be replaced.
Much of this ROW is 4 track, the putter 2 tracks supporting the local commuter service. So you need to start from the outside in, redo the commuter tracks, which means replacing every single station.
But also the tracks substructure, the sub grade and ballast, are insufficient to support higher speeds. Back in the 70’s AMTRAK ran under, massive strings of equipment that picked up the rail, scooped out the ballast, cleaned it discarding the fines, and put the rail back often in new concrete ties. That was a massive and expensive project that allowed them to do higher speed, but not good enough to do much beyond where they are now. In short to meet Biden’s goals you would need to start 6’ under the existing rail top and excavate all the sub-ballast and build a new rail bed, complete with new and improved drainage.
The existing NEC ROW is relatively twisty, the Acela vehicles can only make the speed they do because they tilt. This has already caused problems because when first introduced some bright light figured out that it could cause the vehicles to side swipe one another. That was big news back then. So anyway that trick has already been used to get them where they are.
And remember that all of these renovations would have to be accomplished while maintaining existing service.
The existing g ROW is pretty well maxed out speed wise. Trying to straighten curves is massively expensive. When they built the Garden State Parkway hey put a big S-curve in the ROW at Metro Park to keep the parkway reasonably straight. I think that little obstacle is on the order of 12 lanes that would need moving to straighten that particularly troublesome S curve.
All joking aside, it would be cheaper and more practical to tunnel the route.