Joel N. Weber II
Engineer
Wikipedia's Wind farm article says:
Consider a railroad car 400 feet long, on a track with a curve with a 20,000 foot radius. (I believe that in practice, 186 MPH track has a somewhat larger curve radius than that). Consider a right triangle whose points are the center of the circle, the center of the width of the railroad car at one end of the railroad car, and the center of the railroad car. The square root of (20,000 * 20,000 - 400 * 400) is about one foot less than the 20,000 feet, which suggests that, assuming our 400 foot railroad car has the same width throughout its length, it will be about one foot closer to the center of the circle at its center than at its ends.
This suggests that curves intended for 186 MPH and faster operation probably will not by themselves prevent the use of the track to transport 400' long wind turbine parts.
However, that still leaves open the question of whether the other dimensions of a wind turbine blade will fit within the clearance of a railroad.
Also, there's the question of whether any 45 MPH interchanges connecting one 186 MPH+ track to another 186 MPH+ track will present an obstacle. (Perhaps a crane can be used to move a wind turbine part from a railroad car on one track to a railroad car on another track. Or perhaps the interchanges could be built so that the insides of the curves have space for oversize freight.)
There's the question of whether catenary supports might get in the way. I think there are several possible options here: temporarily removing parts of the catenary system where wind turbine parts are being unloaded, or building some catenary supports with a very strong vertical support on one side of the track so that the vertical support on the other side of the track is unneeded. I believe the catenary in Massachusetts (which is probably about the newest catenary in the US and thus a reasonable thing to look at to get a sense of modern practice) tends to have poles every 200'; on that spacing, it might be possible to put the center of a 364' wind turbine blade directly between a pair of vertical catenary poles, and rotate the blade and then slide it off the railroad car.
When designing high speed track, it might be desirable for each high speed rail system to have both a connection to an airport that could be used for oversize freight, and a connection to a port that could be used to transfer oversized freight from ships.
I'm imagining that oversized freight shipments might happen during track maintenance windows, if track maintenance were generally scheduled for midnight to 6 AM, and if the track maintenance crews end up not needing to use every single maintenance window for track work. And I would not expect the oversized shipments to occur at high speeds.
Being able to build onshore wind farms with larger blades may turn out to be a more cost effective option than the alternatives, though it seems likely that not enough high speed track will be built near enough to good wind farm locations for a substantial fraction of the US's energy consumption to be powered by onshore wind turbines where the blades were delivered via high speed tracks.
I do wonder if the California High Speed Rail folks have looked at whether there might be any US Department of Energy grant money available to study these possibilities and to construct any infrastructure which might be useful for shipping large wind turbine parts but not directly useful to passenger rail.
To get an idea of the size of a large blade used in an offshore wind farm, I looked at Wikipedia's Cape Wind article, which claims the blade diameter for that project will be 364 feet.
Consider a railroad car 400 feet long, on a track with a curve with a 20,000 foot radius. (I believe that in practice, 186 MPH track has a somewhat larger curve radius than that). Consider a right triangle whose points are the center of the circle, the center of the width of the railroad car at one end of the railroad car, and the center of the railroad car. The square root of (20,000 * 20,000 - 400 * 400) is about one foot less than the 20,000 feet, which suggests that, assuming our 400 foot railroad car has the same width throughout its length, it will be about one foot closer to the center of the circle at its center than at its ends.
This suggests that curves intended for 186 MPH and faster operation probably will not by themselves prevent the use of the track to transport 400' long wind turbine parts.
However, that still leaves open the question of whether the other dimensions of a wind turbine blade will fit within the clearance of a railroad.
Also, there's the question of whether any 45 MPH interchanges connecting one 186 MPH+ track to another 186 MPH+ track will present an obstacle. (Perhaps a crane can be used to move a wind turbine part from a railroad car on one track to a railroad car on another track. Or perhaps the interchanges could be built so that the insides of the curves have space for oversize freight.)
There's the question of whether catenary supports might get in the way. I think there are several possible options here: temporarily removing parts of the catenary system where wind turbine parts are being unloaded, or building some catenary supports with a very strong vertical support on one side of the track so that the vertical support on the other side of the track is unneeded. I believe the catenary in Massachusetts (which is probably about the newest catenary in the US and thus a reasonable thing to look at to get a sense of modern practice) tends to have poles every 200'; on that spacing, it might be possible to put the center of a 364' wind turbine blade directly between a pair of vertical catenary poles, and rotate the blade and then slide it off the railroad car.
When designing high speed track, it might be desirable for each high speed rail system to have both a connection to an airport that could be used for oversize freight, and a connection to a port that could be used to transfer oversized freight from ships.
I'm imagining that oversized freight shipments might happen during track maintenance windows, if track maintenance were generally scheduled for midnight to 6 AM, and if the track maintenance crews end up not needing to use every single maintenance window for track work. And I would not expect the oversized shipments to occur at high speeds.
Being able to build onshore wind farms with larger blades may turn out to be a more cost effective option than the alternatives, though it seems likely that not enough high speed track will be built near enough to good wind farm locations for a substantial fraction of the US's energy consumption to be powered by onshore wind turbines where the blades were delivered via high speed tracks.
I do wonder if the California High Speed Rail folks have looked at whether there might be any US Department of Energy grant money available to study these possibilities and to construct any infrastructure which might be useful for shipping large wind turbine parts but not directly useful to passenger rail.
