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.

Map of hills, north of Red Bluff.
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.

Achievable timing
Station or MP Distance ...added up  Time elapsed Coast Starlight Average speed ...added up
MP 233 10 miles (16 km) 134 miles (216 km) 00:09 01:35 - 68 mph (109 km/h) 84 mph (135 km/h)
Red Bluff 0 124 miles (200 km) 00:01 01:27 - - 86 mph (138 km/h)
Red Bluff 39 miles (63 km) 124 miles (200 km) 00:26 01:26 - 91 mph (146 km/h) 87 mph (140 km/h)
Chico 0 85 miles (136 km) 00:01 01:00 01:56 - 85 mph (137 km/h)
Chico 44 miles (71 km) 85 miles (136 km) 00:29 00:59 ??:?? 91 mph (146 km/h) 87 mph (140 km/h)
Marysville WP 0 41 miles (66 km) 00:02 00:30 - - 86 mph (138 km/h)
Marysville WP 41 miles (66 km) 41 miles (66 km) 00:28 00:28 - 90 mph (145 km/h) 90 mph (145 km/h)
Sacramento 0 0 00:00 00:00 00:00 0 mph 0 mph

The numbers in the table are based on the first option: Mixed operation with freight, 90 mph, some slowdowns. For 110 mph operation on dedicated passenger rail track, with curves straightened to avoid slowdowns, substract 2 minutes.



Unit conversion for text on this page.
  90 mph 145 km/h
  3 inches 76 mm
7 inches unbalanced superelevation 178 mm unbalanced superelevation 1.17 m/s2 unbalanced lateral acceleration
  69 mph 111 km/h
  74 mph 119 km/h
  110 mph 177 km/h
  6 inches 152 mm
9 inches unbalanced superelevation 229 mm unbalanced superelevation 1.51 m/s2 unbalanced lateral acceleration

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