The Tehachapi Loop

[Heel n Toe]

photo/post: Jack Turner

The Tehachapi Loop is a 3,779-foot-long (0.72 mi; 1.15 km) spiral, or helix, on the Union Pacific Railroad Mojave Subdivision through Tehachapi Pass, of the Tehachapi Mountains in Kern County, south-central California. The line connects Bakersfield and the San Joaquin Valley to Mojave in the Mojave Desert.

Rising at a steady two-percent grade, the track gains 77 feet (23 m) in elevation and makes a 1,210-foot-diameter (370 m) circle. Any train that is more than 3,800 feet (1,200 m) long—about 56 boxcars—passes over itself going around the loop. At the bottom of the loop, the track passes through Tunnel 9, the ninth tunnel built as the railroad was extended from Bakersfield.

The line averages about 36 freight trains each day. Passenger trains such as Amtrak's San Joaquin are banned from the loop, although the Coast Starlight can use it as a detour. Its frequent trains and scenic setting make the Tehachapi Loop popular with railfans. In 1998, it was named a National Historic Civil Engineering Landmark. It is also designated as California Historical Landmark #508.

One of the engineering feats of its day, the Loop was built by Southern Pacific Railroad to ease the grade over Tehachapi Pass. Construction began in 1874, and the line opened in 1876. Contributors to the project's construction include Arthur De Wint Foote and the project's chief engineer, William Hood.

The project was constructed under the leadership of Southern Pacific's civil engineers, James R. Strobridge and William Hood, using a predominantly Chinese labor force. The Tehachapi line necessitated 18 tunnels, 10 bridges, and numerous water towers to replenish steam locomotives. Between 1875 and 1876, about 3,000 Chinese workers equipped with little more than hand tools, picks, shovels, horse-drawn carts, and blasting powder cut through solid and decomposed granite to create the helix-shaped 0.72-mile (1.16 km) loop with grades averaging about 2.2 percent and an elevation gain of 77 feet (23 m). In 1882, the line was extended through Southern California and the Mojave Desert with a workforce of 8,000 Chinese men.

The White Cross at the top of the Loop in the first photo is called "The Cross at the Loop" and is dedicated to the memory of two Southern Pacific Railroad employees killed on May 12, 1989, in a train derailment in San Bernardino, California.

[unclebilly]

We have something similar here…

Spiral Tunnel in Yoho Nationl Park…



The loops are carved into the mountain as a tunnel.

https://parks.canada.ca/pn-np/bc/yoho/culture/kickinghorse/visit/spirale-spiral

[wdfifteen]

This is very interesting. I had no idea, though it makes sense. Thanks for posting!

[wildthing]

TIL... something new.

I thought from the title it was something about the Hyundai testing facility near the area...

[masraum]

Originally Posted by unclebilly

We have something similar here…

Spiral Tunnel in Yoho Nationl Park…



The loops are carved into the mountain as a tunnel.

https://parks.canada.ca/pn-np/bc/yoho/culture/kickinghorse/visit/spirale-spiral

Very cool.

Originally Posted by wdfifteen

This is very interesting. I had no idea, though it makes sense. Thanks for posting!

Right, going straight up a hill is a lot for a train. Trains have a much harder time using the automotive method of switchbacks even though they do corner like they're on rails.

This is a wide photo, but with lots of good info/detail.

[Evans, Marv]

I lived in Tehachapi as a kid from 1950 to 1956. Some of my most heart felt memories as a kid come from there. The loop was a thing we were all aware of. With two friends, I rode my bicycle from the town down below the loop and back up. Looking back, that was quite a ride. I used to enjoy seeing the huge steam locomotives coming through town - especially the cab forward ones. Many times I hiked around the mountains on both sides of the valley to see petrographs and an old, mining ghost town that had a story of chinese miners trapped in a collapsed tunnel still making tapping sounds in hopes somebody would let them out. Those were days when kids would be out of the house roaming and exploring until dark. It's one of the few places I'd consider moving back to, though I know it wouldn't have the same atmosphere.

[jcwade]

I went around the loop in the 70's as an extraboard brakeman for the Southern Pacific, too many times for me.
I hated the trip to Bakersfield as you were always in run 8 going uphill or full dynamics going downhill. Terribly noisy all the way.
This was before the days of eye and hearing PPE.
As soon as I had a little seniority, I transferred to Local Freight on the PE side.
Much quieter, but my hearing was finally (mostly) saved when I got off the ground and became a Yardmaster.

[Seahawk]

Originally Posted by jcwade

I went around the loop in the 70's as an extraboard brakeman for the Southern Pacific. too many times for me.

What an interesting perspective.

During my first squadron tour in San Diego, one of the Department Heads was a train guy...he asked me if I want to fly and see the "Loop" in the SH-60B.

It is really neat to see from the air.

[MMARSH]

Yeah the loop is very cool.

One of my favorite rides is on Woodford-Tehachapi Rd and takes me right by there. There is a loop look out there as well.

[ckissick]

I was wondering how steep a railroad track for freight can be. Wiki said preferably 1.5% or less. So even with the loop, 2% is a bit too steep.

[KFC911]

This is a cool thread ...

"The Tehachapi Loop" will now be playing in my head all day....

Thanks to Lowell George ....

".... And I've been from Tuscon to Tucumcari... Tehachapi to Tonopah ...."

Didn't know about the history tho'....

Thanks!