Speed Zone 4:
Shasta Lake, and the realignment for it

Redding to Milepost 296

The original 1870's railroad track is either located under water, in Shasta Lake, or it is a biking and hiking trail to the Shasta Dam. The new alignment, in use since 1942, has cut away 7 miles of the former distance. But even though the realignment uses lots of tunnels and bridges, the description "highspeed line" does not fit. The state of California, which did the survey in 1925, was clearly interested in keeping costs down. The Shasta Lake realignment needed 15 million $, a comparable value to 200 million $ today. In terrain as difficult as this one, with several miles of track on bridge or in tunnel, there is reason to call this acceptable value.

Bridge pillars in construction
The realignment work had to deal with very difficult terrain.

South of Redding, the time saved, in comparison to the "Coast Starlight", is caused by

BUT: Only 5 minutes are cut away by the tilting system.

North of Redding, this changes completely. Speed is always restricted by track geometry. On the other hand, this means: Even the 7 inches of cant deficiency, that are expected for mixed operation of Talgos with heavy freight, will cut major amounts of travel time.

Map of alignment north and south of Pit River Bridge.
Same bridge as on the picture, plus lots of tunnels north and south.

In the "good" parts, curve radius is 2864 feet, allowing 85 mph with tilting. In the "bad" parts, curve radius is 1432 feet, restricting to 60 mph with the assumed 3 inches of superelevation. Reasons for assuming certain values have been outlined on page 7 ff..

Speeds >79 mph require a different signal system, also to be installed in all freight engines. Considering the small gains within this speed zone, the author has calculated with 79 mph top speed, plus 60 and 70 mph in the parts with tighter curves.

Achievable timing
Location Distance ...added up  Time elapsed Coast Starlight Average speed ...added up
MP 296 30 mi (48 km) 189 mi (304 km) 00:36 02:30 - 51 mph (82 km/h) 76 mph (122 km/h)
Redding 0 159 mi (256 km) 00:02 01:54 03:15 - 84 mph (135 km/h)
Redding 25 mi (40 km) 159 mi (256 km) 00:17 01:52 ??:?? 89 mph (143 km/h) 85 mph (137 km/h)
MP 233 10 mi (16 km) 134 mi (216 km) 00:09 01:35 - 68 mph (109 km/h) 84 mph (135 km/h)
Red Bluff 0 124 mi (200 km) 00:01 01:27 - - 86 mph (138 km/h)
Red Bluff 39 mi (63 km) 124 mi (200 km) 00:26 01:26 - 91 mph (146 km/h) 87 mph (140 km/h)
Chico 0 85 mi (136 km) 00:01 01:00 01:56 - 85 mph (137 km/h)
Chico 44 mi (71 km) 85 mi (136 km) 00:29 00:59 ??:?? 91 mph (146 km/h) 87 mph (140 km/h)
Marysville WP 0 41 mi (66 km) 00:02 00:30 - - 86 mph (138 km/h)
Marysville WP 41 mi (66 km) 41 mi (66 km) 00:28 00:28 - 90 mph (145 km/h) 90 mph (145 km/h)
Sacramento 0 mi (0 km) 0 mi (0 km) 00:00 00:00 00:00 0 mph (0 km/h) 0 mph (0 km/h)

The shortest possible running time has been engraved in stone for this section – more than 60 years ago. Of all speed zones along the Shasta Route, this one would be the most expensive to speed up beyond the numbers given above, that are gained by the tilting system and more power to weight. Most bridges and tunnels are singletrack, outruling a parallel passenger track without building a completely new line, with underwater construction deep in Shasta Lake. High superelevation of the existing track, and higher track quality, allowing 9 inches of cant deficiency, could gain 3 minutes within this zone, but this is an unrealistic scenario as well, in mixed operation with heavy freight and double stacked containers.

When considering upgrades for shorter running time as outlined in this article, the author suggests to forget this speed zone. There are more promising parts further north, with more effect for the dollar spent on realignment.



Unit conversion for text on this page.
7 miles 11 kilometers  
7 inches of cant deficiency 178 mm of cant deficiency 1.17 m/s2 unbalanced lateral acceleration
2864 feet radius 873 m radius 2 degrees of curvature
85 mph 137 km/h  
1432 feet radius 437 m radius 4 degrees of curvature
60 mph 97 km/h  
79 mph 127 km/h  
70 mph 113 km/h  
9 inches of cant deficiency 229 mm of cant deficiency 1.51 m/s2 unbalanced lateral acceleration

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Last modified: 2005-06-03