Rail Series: Surmounting the Tehachapi Barrier
Dec. 17, 2012
By Stan Brin
Now comes the hard part. As Ned Ryerson, that great observer of infrastructure complications, would say, it’s a doozy.
Most Californians pay little notice to the Tehachapi Mountains, the great barrier isolating Southern California from the rest of the state.
They’re just a place to pass through when driving up and down the Grapevine on I-5. They aren’t as high or as scenic as the Sierras, and are full of wind farms. Sometimes our ears pop. No big deal.
Back in the 1870s, however, those mountains were a big deal.
The Central Pacific completed its part of the Transcontinental Railroad in 1869, but the railroad needed another seven years to link central and southern California. That was in 1876, the nation’s centennial year. In 1876, Custer faced the Sioux at Little Big Horn, Thomas Edison hadn’t yet invented the light bulb, and the population of the entire state was only about 750,000.
That seven year trip South wasn’t easy. The route became a maze of spaghetti-like loops, turns and switchbacks. That it could be built at all in the age of wooden sailing ships was considered an engineering miracle. There are plaques and monuments to the men who designed it.
For the first time, people could reach Los Angeles from the East without traveling by covered wagon, stage coach or steam ship. Millions flocked West to enjoy snow-free winters. La-La land was born.
One small stretch of this route, known today as the Tehachapi Loop, is still famous among railfans all over the world.
On YouTube, you can watch a dozen or so videos of Union Pacific trains — the Union Pacific eventually bought out the California-based Central Pacific — taking a mile-long, snake-like tour all the way around a hill between two mountains. The trains then pass over their own tails having gained a precious 77 feet in elevation — without actually going anywhere. One such video of the Tehachapi Loop has received, at last count, more than 191,000 hits.
The reason for this tortuous route is the underappreciated fact that steel wheels running on steel rails aren’t very efficient at grades over 1 percent, a rise in elevation of one foot per hundred feet traveled.
A route as long, and as convoluted, as the current Tehachapi line clearly can’t be expected to meet the needs of 21st century rail passengers.
In fact, the Tehachapi route is so steep, and so slow, and so congested, that the Union Pacific permits passenger traffic to use it only one day per year. On every other day, Amtrak passengers are required to take buses over the Grapevine, and re-board trains at lower elevations.
Hardly an alternative to High-Speed Rail.
And, of course, as the videos clearly demonstrate, the Tehachapi Loop still allows only a single pair of tracks to pass through it. Trains can chug up and down the mountains in only one direction at a time which, as I have said before, is acceptable for freight, but lousy for passengers.
Contemporary engineers would simply abandon the current route and follow I-5, and to allow traffic to move quickly, they would electrify at least that portion of the route.
What? Electrification of railroads? That probably hit a nerve. Most Americans think that electric trains belong on ping-pong tables in garages.
In fact, all diesel locomotives are actually electrically powered. Their on-board diesel engines don’t provide torque directly to their wheels; they simply generate electricity that is sent to a set of electric motors that drive the wheels. A purely electric train receives its power from overhead cables, and doesn’t need a diesel engine. The motors can be heavier and more powerful.
One American line that has already been electrified is the Keystone Corridor in Pennsylvania, where ordinary trains routinely travel from Harrisburg to Philadelphia at 110 miles per hour without fancy, streamlined locomotives and the “high-speed rail” cachet. They just get from one city to another really quickly.
Once the conceptual problem of electric trains is out of the way, we can consider the cost.
A new line between Chatsworth, north of Los Angeles, and Bakersfield would be approximately 100 miles long. It would be mostly rural, but would have to be double-tracked entirely, so we’ll assume that it would cost $2 billion. Electrification, consisting of an overhead power line, would be a secondary cost. I have no figures for this.
Once the trains reached their Bakersfield stop, the locomotives would be switched. Or maybe the entire line could be electrified, allowing trains to zip non-stop.
But even if the cost of electrification were hundreds of millions, and even if the process had to be completed along the entire length of the line, the total cost of the new line from San Diego to Sacramento would still be, realistically, under $9 billion. Which happens to be the low-balled price the HSR advocates threw at Californians in the first place.
I know that this plan leaves out two metropolitan areas that the HSR plan is supposed to reach, Riverside County and the San Francisco Bay Area. Both regions are detours away from the Sacramento-to-San Diego corridor. To add them to a non-stop line running over 100 mph would boost the price well above $9 billion.
(I would like to look into this subject further in another story. A planned expansion of the Alameda Corridor will lead the way to Riverside County, but the Bay Area is already crowded with tracks and passenger trains, Caltrain and BART. Reaching San Francisco from the South might prove to be difficult. Route planners might have to add an elevated platform or an underground trench, similar to the Alameda Corridor, before residents of the area would be willing to allow a new high speed line through their communities.)
Still, the price of a very fast, but conventional rail line devoted to passenger traffic is likely to be a tiny fraction of a rarified, specialized and probably unfeasible 210 mph-High Speed Rail.
And when this medium-speed project is done, there is little doubt that it would actually work. It already works everywhere else.
June 19, 2013