Speed Zone 5:
Sacramento River Canyon to Dunsmuir

As soon as the Shasta Lake realignment ends, the train is greated with a special welcome message: Curves of 546 feet radius. With the parameters, that are assumed for mixed operation with heavy freight in this article, this means a speed restriction to 37 mph.

The bad news: Such curves, or at least curves of 574 feet radius, are standard within this speed zone.

"Old alignment of the 1880s" is the usual explanation for this, but not the full story. Lots of contemporary track has been built differently, cutting through a river knee with a short tunnel here, bridging to the better side of the river there. Result hasn't been highspeed tracks, but at least, today's tilting trains can sqeeze quite some speed out of those alignments. South of Dunsmuir, the Sacramento River Canyon would have been well suited to this approach.

Doubletracked s-curve along the river, road above.
The curvature at Lamoine cannot be explained by "1880s" alone. Better solutions for this situation were available even back then.

The extremely tight curvature has had additional reasons:

  1. Not enough population to pay back high investment.

    Tight curvature was already explained as a logical result of US railroad history in this article. The Shasta Route connects California and Oregon. When the construction of the railroad started, the whole state of Oregon had about 150.000 inhabitants. In 1880, it was 175000. Completing the railroad helped to reach 320000 in 1890. In 1900, there were 415000 inhabitants of Oregon.

  2. Business of that time looked like temporary business.

    Along the line, main business activities were small-scale mining and the timber industry. The economy of those days was based on timber as construction material, and sawmills sprang up all along the line, as soon as it was completed. A 19th century timber industry shouldn't be imagined like a modern one, though. Instead of protecting future income, this was a business on the move, harvesting logs along its way. (Follow this link to a contemporary critical view of the 1880s logging in the Shasta region.) A business on the move does not fit to high investment into a fixed plant.

  3. Lack of funds.

    The "Oregon and California Rail Road" ran out of cash, before the Shasta Route was finished. A general economic crisis situation, and fund mishandling contributed to this, but without doubt, such circumstances favour cheap solutions.

  4. The curvy layout achieved a ruling grade of 1.27%.

    The operating concept of the 1880s was based on a long stretch of moderate grade, a pusher loco attachment point, and a final climb. The attachment point created a railroad settlement, which was called "Pusher" and later renamed to "Dunsmuir". Route layout and operating concept are best assumed to have been one plan, targeted at cost reduction under contemporary circumstances.

Map of curvature in a steep valley.
Another view on the Lamoine curves, this time on a topo map.

There are some stretches of track, that allow faster operation, but these are just a few miles long. Therefore, a realistic approach is, to assume a steady 37 mph run for this speed zone, and sum up the speedup possibilities for the punctuality buffer time.

If you are an UP engineer, and operate trains on this route, you will shake your head, when reading "speedup possibilities". Consider this:

  1. Length of this train is less than 1/10 of a freight.
  2. Acceleration is as good as for a freight engine with one half-loaded freight car behind.

This speed zone is one of those parts, where an out-of-the-box Talgo is unusable. In order to avoid excessive sway in station throats with several crossovers in rapid succession, the tilting mechanism is normally blocked below 43.5 mph. In the Sacramento River Canyon, this feature is a bug, and needs an override function for the engineer, or an automatic override.

Achievable timing
Station or MP Distance ...added up  Time elapsed Coast Starlight Average speed ...added up
Dunsmuir 0 216 miles (348 km) 00:01 03:14 05:05 - 67 mph (108 km/h)
Dunsmuir 26 miles (42 km) 216 miles (348 km) 00:44 03:13 ??:?? 36 mph (58 km/h) 67 mph (108 km/h)
MP 296 30 miles (48 km) 189 miles (304 km) 00:36 02:30 - 51 mph (82 km/h) 76 mph (122 km/h)
Redding 0 159 miles (256 km) 00:02 01:54 03:15 - 84 mph (135 km/h)
Redding 25 miles (40 km) 159 miles (256 km) 00:17 01:52 ??:?? 89 mph (143 km/h) 85 mph (137 km/h)
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 1880s track was laid down on the depositional side of the Sacramento at several sharp, erosional corners. This was bad engineering. Every major flood of the Sacramento claims back the track. Therefore, Union Pacific has an economic interest, to cut some of these oxbows, not for speed, but for cost. For the example trains, this would create some longer sections with 45 - 55 mph speed restriction, cutting about 5 of the 44 minutes in this short section. This is the same difference as for 125 mph versus 110 mph on the long stretch from Sacramento to Tehama Bridge.

Common interests of passenger carrier and host railroad improve the chances for implementation of a passenger rail project.

Unit conversion for text on this page.
546 feet radius 167 m radius 10 degrees 30 minutes of curvature
37 mph 59.5 km/h  
574 feet radius 175 m radius 10 degrees of curvature
43.5 mph 70 km/h  
45 mph 72 km/h  
55 mph 88.5 km/h  
125 mph 201 km/h  
110 mph 177 km/h  

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