Editing Tehachapi Loop (section)

{{Short description|Rail line spiral between the Central Valley and Mojave Desert}}
{{Use mdy dates|date=September 2024}}
[[File:Tehachapi Loop Aerial.jpg|thumb|Aerial overview of the Tehachapi Loop in 2022]]
[[File:Intermodal train on Tehachapi Loop.jpg|thumb|BNSF train on Tehachapi Loop in 2011, with mixed [[trailer-on-flatcar]] and [[Double-stack rail transport|double-stack]] container manifest]]
[[File:Tehachapi Loop.jpg|thumb|A panoramic view of the Tehachapi Loop looking north-west]]
[[File:TehachapiLoop usps.jpg|thumb|[[Pictorial cancellation]] from the [[Keene, California|Keene]] Post Office celebrating the Loop's 129th anniversary]]

The '''Tehachapi Loop''' is a {{convert|3779|ft|mi km|2|adj=mid|-long}} [[Spiral (railway)|spiral]],<ref name=ASCE>{{cite web |title=Tehachapi Pass Railroad Line |url=https://www.asce.org/project/tehachapi-pass-railroad-line/ |website=asce.org |publisher=[[American Society of Civil Engineers]] |access-date=22 October 2020 |archive-date=21 September 2020 |archive-url=https://web.archive.org/web/20200921124049/https://www.asce.org/Project/Tehachapi-Pass-Railroad-Line/ |url-status=dead }}</ref> or [[helix]], on the [[Union Pacific Railroad]] [[Mojave Subdivision]] through [[Tehachapi Pass]], of the [[Tehachapi Mountains]] in [[Kern County, California|Kern County]], south-central [[California]]. The line connects [[Bakersfield]] and the [[San Joaquin Valley]] to [[Mojave, California|Mojave]] in the [[Mojave Desert]].

Rising at a steady two-percent grade, the track gains {{convert|77|ft}} in elevation and makes a {{convert|1210|ft|m|adj=mid|-diameter}} circle.<ref name=ASCE /><ref>{{cite journal |last1= Ande|first1=Howard |year=2010 |title=Tehachapi in the 21st Century |journal=NRHS Bulletin |publisher= National Railway Historical Society|volume= 75|issue=Spring 2010 |pages= 4–21}}</ref> Any train that is more than {{convert|3,800|ft|m|}} long—about 56 [[Boxcar|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.<ref name=ASCE /> Passenger trains such as [[Amtrak]]'s ''[[San Joaquins]]'' are banned from the loop, although the ''[[Coast Starlight]]'' can use it as a detour.<ref name="interestingengineering"/> Its frequent trains and scenic setting make the Tehachapi Loop popular with [[railfan]]s.<ref name="interestingengineering"/><ref>{{cite journal |last1=Lustig |first1=David |title=Hotspot: California's Tehachapi Mountains |journal=[[Trains (magazine)|Trains]] |date=July 2022 |volume=82 |issue=7 |pages=46–47 }}</ref> In 1998, it was named a [[National Historic Civil Engineering Landmark]]. It is also designated as [[California Historical Landmark]] #508.<ref name=CHL>{{cite ohp|508|Tehachapi Loop|October 7, 2012}}</ref>