Page 22: Speed-Zone 1: Sacramento to Red Bluff
Contents
Speed-Zone 2:
Red Bluff to Milepost 233
After leaving Red Bluff, there is first opportunity to gain an advantage by the tilting system. The line passes through a barrier of hillocks and hills in the middle of the valley. The tightest curve is located within the city of Red Bluff, and of no concern, if the train stops there. Other restrictions depend on the policy of Union Pacific. There are two options:
- 1) Mixed mode operation with freight on the existing singletrack.
-
Passenger train speed should be set to 90 mph. At 3 inches of superelevation and 7 inches
of unbalanced superelevation, as assumed for operation mixed with freight, there
are only 2 curves with major speed restrictions (No. 30: 69 mph, No. 34A: 74 mph). So the result is "90 mph with minor
slowdowns".
In comparison to the existing Talgos, that operate the Cascades service from Seattle to Portland, the current Talgo VII cars have been improved considerably, regarding air drag. This low drag, and the power-to-weight ratio of the example trains, will allow quick speed changes on a section like this.
4 miles out of 10 give an example of the curvature within these hills and hillocks, compatible with rather fast tilting train
operation.
- 2) Dedicated passenger rail track within the existing ROW.
- For cost reasons, this is a questionable option. Nonetheless, it might be the result of Union Pacific's policies towards passenger rail, and it shouldn't be forgotten, that a signal system upgrade to 90 mph needs matching installations in all the freight locos as well. Should separate track be unavoidable, slight modification of 4 curves would allow 110 mph for the whole distance, calculated with the 6 inches of superelevation and 9 inches of unbalanced superelevation, that are assumed for dedicated track. This option would save about 2 minutes, in comparison to the mixed-mode operation outlined above.