Union Pacific 844 is a class "FEF-3" 4-8-4 "Northern" type steam locomotive owned and operated by the Union Pacific Railroad for its heritage fleet. Built in December 1944 by the American Locomotive Company (ALCO) of Schenectady, New York, No. 844 is one of four surviving FEF series locomotives and the only one in operation.

fef-3-8444号机车，拍摄于1988年 照片中的蒸汽火车头，是1台4-8-4“Northern”（“北方”）轮式干线客运蒸汽机车。 它通体为灰色，但司机室底部和煤水车中部绘有以深灰色为主的条纹。

The Union Pacific FEF series consists of 45 4-8-4 "Northern" steam locomotives built by the American Locomotive Company (ALCO) between 1937 and 1944 and operated by the Union Pacific Railroad until 1959. Like the other Union Pacific steam classes, the acronym comes from the first letter of the spelling of its wheel arrangement: Four Eight Four.

Steam Locomotive No. 844 is the last steam locomotive built for Union Pacific Railroad. It was delivered in 1944. A high-speed passenger engine, it pulled such widely known trains as the Overland Limited, Los Angeles Limited, Portland Rose and Challenger.

Union Pacific 844 is a 4-8-4 steam locomotive which the Union Pacific dubbed, originally enough, "Four-Eight-Fours" and classed them as such (Class FEF-1 through FEF-3).

UP, however, did not want to call their 4-8-4s by its competitor’s name and instead referred to them as “FEF” types, standing for “Four-Eight-Four.” ABOVE: Thanks to either some bad firing or a little showmanship, UP 8444 puts on a spectacular display of smoke at Point of Rocks, Wyo., on August 31, 1968.

Union Pacific FEF-3 4-8-4 844, has the exclusive distinction of being the only steam locomotive in the United States to have never been taken off of its original owner's active roster. ...more....

Union Pacific FEF-3 #8444. One of the most famous of the many great Northerns, Union Pacific's FEF-3 is as popular today as ever. Built for passenger service in 1944, the Union Pacific's ten FEF-3s also found their way into freight service.

Built for passenger service in 1944, the Union Pacifics ten FEF-3s also found their way into freight service. While her nine sisters were retired along with the rest of Union Pacifics steam, the last one delivered, No. 844 has never lost her spot on the roster. (Though she did adopt the number 8444 from 1962 to 1989 to avoid confusion with a GP30.)

Many people know the engine as No. 8444, since an extra “4” was added to its number in 1962 to distinguish it from a diesel numbered in the 800 series. The steam engine regained its rightful number in June 1989, after the diesel was retired. Hailed …