The primary long haul passenger from about 1910-1922 were light and heavy pacific's (P-77) and MacArthur's (Mac) In 1922 to help speed up passenger trains the UP bought there first 4-8-2 (MT-73) the "sports model" (The designer of the engine came down to see the locomotive and said, "yes boys that's a real sporty model" and the name stuck) These were some of the most powerful mountains ever built. When 7002 was tested with lightweight roller bearing side rods the engine snapped side rods. For all there power when the MT-73 were first built they had a terrible slipping problems in the Blue Mountains of eastern Oregon. To compensate for this the UP bought 2-10-2 for use on passenger in the Blue Mountains. Later when the mountains were rebuilt in the 30's with one piece cast frames the added weight allowed them to do a better job in the Blue Mountains. In the late 1930's some of the CSA early challengers were put on long haul passenger service on the LASL and OWR&N. In 1937 the FEF-1 took over most of the long haul passenger with the other classes in reserve or bumped to light or local passenger service.