Editing Lethbridge Viaduct (section)

== History ==
{{Location map|Canada Lethbridge|lat=49.69760|long=-112.86872|caption=Location of Lethbridge Viaduct in [[Lethbridge]]|float=left|width=200}}
Prior to the Lethbridge Viaduct, the main railway crossing over the Oldman River was a wooden trestle measuring {{cvt|894|m|ft}} long and {{cvt|20|m|ft}} high. The trestles on the original line out of Lethbridge totalled {{cvt|2.8|mi|order=flip}}. Many railways in the area went through the [[Crowsnest Pass]] between Lethbridge and [[Fort Macleod]], over steep grades that hampered operations. In addition, extensive cuts and many other bridges were needed to cross various creeks and [[coulee]]s. Past the [[St. Mary River (Montana-Alberta)|St. Mary River]] crossing, several large cuts and large bridges were also required, including a {{cvt|900|ft|order=flip}} trestle with a {{cvt|200|ft|order=flip}} span west of the St. Mary River, a {{cvt|600|ft|order=flip}} trestle at Eight-Mile Coulee, and another of {{cvt|900|ft|order=flip}} in length near Eight-Mile Coulee. At Sixteen-Mile Coulee there was a {{cvt|800|ft|order=flip}} trestle, {{cvt|133|ft|order=flip}} high with a {{cvt|200|ft|order=flip}} truss span over the creek.

Although the original route accomplished its purpose in allowing the CPR to rapidly complete the railway, it turned out to be expensive to operate. The original bridges were designed to last only about 10 years. In 1905, the CPR decided, to construct a completely new route on a better gradient to bypass the original line. The new line was built to the north of the Oldman River. It required two bridges, one in Lethbridge—the ''High Level Bridge''—over the Oldman River, and another large bridge over the Oldman River again west of [[Monarch, Alberta|Monarch]]. This route eliminated many curves and reduced the grade from 1.2 percent to only 0.4 percent. It also saved {{cvt|5.26|mi|order=flip}} of track.

[[File:Lethbridge Viaduct.gif|thumb|right|200px|The Lethbridge Viaduct in 1910]]

The Lethbridge Viaduct was designed by the CPR's [[bridge]] department in [[Montreal]], [[Quebec]]. Construction began in the summer of 1907, directed by CPR's Assistant Chief Engineer [[John Edward Schwitzer]]. Clearing and grading the site, construction of piers, and placement of the footings progressed while the steelwork was being prefabricated. The steelwork was manufactured by the Canadian Bridge Company of [[Walkerville, Ontario]]. Raising the steelwork began in mid-August 1908 and was performed by around 100 workers. Transport of the steel to the site required 645 railway cars while another 40 were needed to bring in equipment. Once the steelwork reached track level at the Lethbridge end, it was possible to begin assembly using a huge travelling crane called an "erection traveller", which was built on site at a cost of $100,000 and was used to lower the steel beams and girders into place. The last girder was placed in June 1909 and riveting was completed in August 1909. The total cost of the Lethbridge Viaduct's construction was $1,334,525.