The Union Pacific FEF series consists of forty-five "Northern" steam locomotives built in three classes for the Union Pacific Railroad by the American Locomotive Company (ALCO) between 1937 and 1944. The FEF acronym comes from the first letters of the wheel arrangement, Four Eight Four. They were in operation until overtaken by dieselization, with all but one retired by 1959.

The final steam locomotives built for the Union Pacific, the FEFs represented the apex of dual-service steam locomotive development in the United States, as funds and research were thereafter concentrated into the development of diesel-electric locomotives. Designed to burn coal, they were converted to run on fuel oil in 1946. FEFs pulled a variety of passenger trains, such as the Overland Limited, Los Angeles Limited, Portland Rose and Challenger,See Edmonson, Harold A. and Goodheart, David. "Union Pacific's 8444," at 1 (1989, Goodheart Publications). until diesel-electric locomotives took over passenger service. Many FEF series locomotives were reassigned to freight service during the last years of their careers.

Four FEF series locomotives survive, including No. 844, which remains in operational condition and runs in excursion service. It is one of the Union Pacific's oldest serving locomotives, and the only steam locomotive never permanently retired by a North American Class I railroad.

Origins In the late 1930s, rising trainloads started to exceed the traction limits of the 4-8-2s that were the mainstay of UP passenger operations. One day in 1937, with UP President William Jeffer's business car in the rear, a 7000-class 4-8-2 demonstrated the lack of steaming power inherent in the type. Even as the train was waiting for rescue, a telegram was sent to ALCO in Schenectady, New York, asking for an improved design. The result was the FEF series, a class of locomotives that could produce between 4,000 and 5,000 drawbar horsepower and reliably operate at 100 mph. They would run about 14,000 miles a month.

Models The FEF series consisted of three classes of steam locomotives: FEF-1 (20 units), FEF-2 (15 units), and FEF-3 (10 units). Like other Union Pacific steam classes, the acronym comes from the first letter of the spelling of its wheel arrangement, Four Eight Four. + Table of orders and numbers Class Quantity ManufacturerAlco Order

No. Serial Nos. Year built UP No. Notes FEF-1 20 American Locomotive CompanyS-1769 68808-68827 1937 800–819 Converted to oil fuel in 1945–1946. FEF-2 15 American Locomotive CompanyS-1811 69161-69175 1939 820–834 Converted to oil fuel in 1945–1946. FEF-3 10 American Locomotive CompanyS-1937 72782-72791 1944 835–844 Converted to oil fuel in 1945–1946. No. 844 in excursion service since 1960; renumbered to 8444 from 1962 to 1989.

FEF-1

The first 20 locomotives, numbered 800–819, were delivered by ALCO in 1937. As a whole they followed the simplest possible arrangement of two outside cylinders, without the complicated accessories on many other locomotives, in order to achieve an uncluttered appearance.. Fitting ALCO's lateral motion devices to the leading coupled wheels eased the negotiation of curves. Despite frequently running faster than , the strain on the coupling and connecting rods were kept within acceptable limits. There were many reports of the class reaching the design limit of .

FEF-2

The second batch of 15 locomotives, numbered 820–834, was delivered in 1939. Their improvements included larger cylinders, better tractive effort, smoke deflectors on the sides of the smokebox, and driving wheels that were three inches wider in diameter. The biggest change was the replacement of the 12-wheeled tender with a 14-wheeled "pedestal" or "centipede" tender. UP 833 has been tied to claims to have hit the classes' max speed of 120 mph, but was not officially recorded due to the speed violating Union Pacific's corporate rules.

FEF-3

Except for the use of some substitute materials, the final batch of 10 locomotives, numbered 835–844, were nearly identical to the FEF-2. After World War II, coal supplies were limited by a series of strikes. To continue operations unfettered, UP converted the 800s to burn oil, and fitted a tank in the bunker space. Otherwise, few modifications were needed to ensure years of mainline service. These were the last steam locomotives delivered for the UP. Like many late era steam locomotives, their service lives were short due to rapid dieselization. A former manager of the Union Pacific Steam Program said, "Although it is stated that the UP FEF Series were designed to safely operate at , no one really knows how fast the final 4-8-4 could go. The last FEF-3 was actually never retired."

Surviving examples Four FEF series locomotives survive. No. 814 (FEF-1) and No. 833 (FEF-2) are on static display. No. 844 (FEF-3) has remained operational and is used in excursion service. No. 838 (FEF-3) is used solely as a source of spare parts for No. 844.

+ Surviving FEF locomotivesTypeNumberImageDate builtSerial numberLocationCoordinatesNotes FEF-1 814 September 1937 68822 RailsWest Railroad Museum, Council Bluffs, Iowa FEF-2 833 October 1939 69174 Utah State Railroad Museum, Ogden, Utah Originally on display at Pioneer Park in Salt Lake City, Utah. FEF-3 838 December 1944 72785 Union Pacific Railroad, Cheyenne, Wyoming Source of spare parts for 844. FEF-3 844 December 1944 72791 Union Pacific Railroad, Cheyenne, Wyoming The only steam locomotive never retired by a North American Class I railroad.UP historical locomotives

See also Union Pacific Challenger Union Pacific Big Boy

References

Union Pacific Northerns at steamlocomotive.com maintained by Wes Barris

Further reading