Union Pacific 5511 is a "Santa Fe" type steam locomotive built by the Baldwin Locomotive Works (BLW) in September 1923 as part of the Union Pacific Railroad's TTT-6 class. While other railroads referred to this wheel arrangement as the “Santa Fe” type, Union Pacific simply categorized it by its wheel configuration—2-10-2—and class. It is the last surviving 2-10-2 of 144 units operated by the UP from 1917 to the end of steam in 1959, and the only complete UP steam locomotive equipped with Young valve gear.

The locomotive ran in revenue service until being withdrawn in 1956. Afterwards, it remained in storage in the UP's roundhouse in Cheyenne, Wyoming. In April 2022, Union Pacific announced that No. 5511 was among several pieces of equipment to be donated to Railroad Heritage of Midwest America (RRHMA) in Silvis, Illinois, with plans to rebuild No. 5511 for operational purposes once Challenger No. 3985 is rebuilt. As of 2026, both Nos. 3985 and 5511 are still undergoing operational restoration.

History Revenue service Between 1917 and 1924, the Union Pacific Railroad was facing new operational challenges. As freight traffic increased and the railroad expanded across the rugged terrain of the American West, especially through the Wasatch Mountain and Sherman Hill, UP needed more powerful locomotives to handle long, heavy trains over steep grades. By the 1910s, the Mallet compound articulateds were powerful but complex, and the traditional 2-8-0 “Consolidation” types were becoming outdated. UP engineers, working with the Baldwin Locomotive Works, began looking for a solution that could provide strong tractive effort, reliable performance, and a simpler mechanical layout. Union Pacific purchased 144 2-10-2 "Santa Fe" types, divided into classes TTT-1 through -7. American Locomotive Company (ALCO) built 18; Baldwin Locomotive Works, 88; and Lima Locomotive Works, 37. All UP 2-10-2s had the same cylinder dimensions, driving wheel diameter, and boiler pressure.

As rail traffic increased, these locomotives became workhorses for UP’s freight division. No. 5511 was the twelfth of 25 TTT-6s built in 1923. It was initially assigned to pull heavy freight trains over the steep grades of the Wasatch Mountain Range between Ogden, Utah, and Green River, Wyoming. With the introduction of the 4-6-6-4 "Challengers", which could climb steep grades better than the 2-10-2s, No. 5511 was reassigned to pull long freight trains across the Great Plains in Wyoming, Nebraska and Iowa. Sometimes, the locomotive would help push freight trains up Sherman Hill.

By the end of 1956, No. 5511 was removed from the UP's active list before it was used as a stationary boiler in Ogden and then Green River. In December 1958, No. 5511 was filmed to appear in Last of the Giants, a UP film that mostly featured the railroad's 4-8-8-4 "Big Boys". During filming, because the locomotive was no longer operational, it was coupled to a string of freight cars with an EMD diesel locomotive coupled to the other side to push, while tires were burned in No. 5511's smokebox to give the illusion of it being fully operative. After filming, the locomotive was sent to Cheyenne, where its piston rods were cut and it was to be scrapped with the rest of its class members. An unknown employee ordered the locomotive to be held for preservation due to its movie appearance. As a result, the locomotive was moved from Green River to Cheyenne and stored inside the UP's roundhouse.

Preservation By the end of the 1960s, No. 5511 became the only 2-10-2 locomotive from the UP to be preserved. The locomotive was repainted for a cleaner appearance and stored inside the UP's Cheyenne Roundhouse for the next six decades. During that time, the locomotive was repainted and moved onto a turntable to be displayed for a National Railway Historical Society (NRHS) convention. The locomotive was then stored without boiler jacketing.

Restoration In April 2022, the UP announced that it would donate to the Railroading Heritage of Midwest America (RRHMA) No. 5511, three other locomotives, and several other pieces of rolling stock from the heritage fleet, including 4-6-6-4 No. 3985, EMD DDA40X "Centennial" No. 6936, and an EMD E9 B unit. On May 13, 2022, RRHMA launched a fundraiser to raise money to restore 5511 and 3985 to operation. On September 14, 2022, No. 5511 was moved from the Cheyenne roundhouse for the first time since 1970 and around the yard for testing behind Big Boy No. 4014. That November, UP moved No. 5511 and the rest of the donated equipment to the RRHMA's shop in Silvis, Illinois. The restoration of 5511 and 3985 began in January 2023.

On September 8, 2026, No. 5511's boiler was pressurized for the first time since 1958, and it passed an FRA-witnessed hydrostatic test. RRHMA expects a test firing of the locomotive to take place before the end of the year.

See also Southern Pacific 975 Southern Pacific 5021

References

External links UP No. 5511 TTT-6 Locomotive #5511 – Santa Fe UP Steam