Tunnel Number 41, or the Big Hole, is a single-track railway tunnel underneath Mount Judah in the Sierra Nevada, near Norden, California. It is owned by Union Pacific Railroad, in service as a part of the Roseville Subdivision of the Overland Route. Daily freight trains as well as Amtrak's California Zephyr utilize the line.
|Other name(s)||The Big Hole, Summit Tunnel|
|Coordinates||39°18′18″N 120°19′3″W / 39.30500°N 120.31750°WCoordinates: 39°18′18″N 120°19′3″W / 39.30500°N 120.31750°W|
|Owner||Union Pacific Railroad|
|Length||10,325 ft (3,147 m)|
|No. of tracks||1|
|Track gauge||4 ft 8+1⁄2 in (1,435 mm) standard gauge|
|Highest elevation||6,887 ft (2,099 m)|
|Tunnel clearance||double-stack container capable|
Built by Southern Pacific to bypass the curves over Donner Pass along the First transcontinental railroad, it opened to traffic in 1925 as the third-longest rail tunnel in the United States at 10,325 feet (2 mi; 3,147 m) in length. The new tunnel and cutoff shortened the route by 1.29 miles (2.08 km) and was 132 feet (40 m) lower in elevation than the previous bore through the summit, Tunnel No. 6. The new and old single track routes were used in tandem as a double-tracked route until the old route was abandoned in 1993. The line is capable of transporting double-stacked containers.
- List of tunnels documented by the Historic American Engineering Record in California
- Tunnel motors — locomotives designed to cope with long tunnels, especially those in the Sierra Nevada
- ^ Schwab, Jenell (March 21, 2012). "In search for missing skiers, officials find third man in Donner Summit train tunnel". Tahoe Daily Tribune. Retrieved November 10, 2020.
- ^ "UP's 2nd Largest Tunnel Gets Overhaul". Union Pacific. July 15, 2013. Retrieved November 10, 2022.
- ^ McDonald, Joseph; Nelson, Brian; Olson, Brian; Iden, Michael; Fritz, Steven; Honc, Randell (January 2008). "Locomotive Exhaust Temperatures During High Altitude Tunnel Operation in Donner Pass". ASME 2008 Internal Combustion Engine Division Spring Technical Conference. pp. 375–384. doi:10.1115/ICES2008-1625. ISBN 978-0-7918-4813-5. Retrieved November 10, 2020.
- ^ a b "Donner Pass: Southern Pacific's Sierra Crossing". Donner Summit Historical Society. Retrieved November 10, 2020.
- ^ Signor, John (1985). Donner Pass : Southern Pacific's Sierra crossing. San Marino, Calif: Golden West Books. ISBN 9780870950940.
- ^ Janet Fullwood (October 20, 2005). "In their tracks". Sacramento Bee. Retrieved November 10, 2020.
- ^ "UP improves Donner Pass tunnels to bolster double-stack operations". Progressive Railroading. November 24, 2009. Retrieved May 27, 2019.
- Historic American Engineering Record (HAER) No. CA-215, "Central Pacific Transcontinental Railroad, Tunnel No. 41, Milepost 193.3, Donner, Placer County, CA", 8 photos, 4 data pages, 2 photo caption pages