Susquehanna River Bridge Replacement study

[west point]

PRR. Small point . Believe the high voltage lines are now nominal 138 kV ? Wasn't that done when PRR went to 11.5 kV CAT and Amtrak to 12.0 kV increasing high voltage to 138 kV ?

 

[CraigDK]

While the engineering and design isn't complete, the current construction time estimate given in the document is 77 months including 12 months of building new OCS and transmission structures before any actual bridge construction begins.

They're obviously going to have to do something about the substation and transmission lines to Safe Harbor. This may be a good thing especially with the owner of the substation upstream raising the rates.

The Perryville substation is Amtrak-owned and will not be significantly impacted by the bridge work. That is the switching terminus of four 132kV circuits that originate at Safe Harbor. The four-circuit transmission line from Safe Harbor will require relocation of the tower on the north side of the tracks, but otherwise is unaffected.

The electric traction preliminary work involves new catenary and transmission overbuild structures for about a mile north and south of the bridge to accommodate the track relocations for the new bridges along with permitting the installation of constant-tension catenary. With those new structures in-place, traffic disruptions for cutovers when tracks are shifted will be minimized.

Thanks! I wanted to assume it would be similar to what you are describing, but the EA (at least from my reading of it, I might have missed it) didn't provide much on the construction details as far as changes in the transmission and catenary structures.

 

[PRR 60]

PRR. Small point . Believe the high voltage lines are now nominal 138 kV ? Wasn't that done when PRR went to 11.5 kV CAT and Amtrak to 12.0 kV increasing high voltage to 138 kV ?

You're right. I'm an old school guy, and the PRR drawings show the original voltages, so that is what got burned into my brain. The specified voltages (12kV, 138kV) are nominal operating values used for system calculations. The actual voltage varies from moment to moment, particularly at the catenary level.

 

[west point]

PRR. Small point . Believe the high voltage lines are now nominal 138 kV ? Wasn't that done when PRR went to 11.5 kV CAT and Amtrak to 12.0 kV increasing high voltage to 138 kV ?

You're right. I'm an old school guy, and the PRR drawings show the original voltages, so that is what got burned into my brain. The specified voltages (12kV, 138kV) are nominal operating values used for system calculations. The actual voltage varies from moment to moment, particularly at the catenary level.

PRR that sucker hole caught me as well. Nominal voltages are important. Our power companies try to keep our home voltages to about 2 -3 % of nominal. Last saw for Amtrak CAT it is about +/- 10 % so high of 13.2 kV and low 10.8 kV. So the ACS-64s can do regeneration to the 13.2 kV CAT voltage ? What complicates the problem is the multiple voltages that Amtrak operates. Have no idea how the 12.5 kV 60 Hz is handled as if it is also 10% ? Was told by some one that Amtrak wants to up the 25 HZ CAT to 12.5 kV and maybe that one reason why. Understand there are some problems to raise nominal voltages to 12.5 kV ? That would raise highest allowed voltage to ~ 13.8 kV ?

 

[CraigDK]

The public outreach meeting that was scheduled for tonight has been moved back to Thursday March 23.