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.

The Union Pacific FEF-2 is the second batch of the FEF Series (FEF meaning, "four-eight-four") which consisted of fifteen 4-8-4 "Northern" steam locomotive types built by the American Locomotive Company (ALCO) in 1939 for the Union Pacific Railroad (UP).

These locomotives were designated as Class FEF-2. They were designed to have 80" drivers, 25 x 32 cylinders, a boiler pressure of 300 psi, and a weight of 483,000 lbs giving each a tractive effort of 63,750 pounds (63,800 nominal).

UP (Union Pacific) No. 833 is a type of FEF-2 Class (FEF meaning, "four-eight-four") 4-8-4 'Northern' steam locomotive that was built by ALCO (Schenectady Locomotive Works) in 1939. It is the only remaining member of Union Pacific's FEF-2 class.

Specs - serial #69170, class FEF-2, massive 77" drivers, impressive 300 psi boiler pressure, 24.5x32" cylinders, engine weight of 465,000 lb, tractive effort of 63,611 lb. UP 823, 825 and 832 were sold to Luria Brothers and Company of Pueblo, Colorado, in May 1963; moved for scrap to Columbia-Geneva Steel Corporation, Provo, Utah.

Sep 14, 2004 · But what's the difference between UP's FEF-2 and FEF-3 engines? In looking at photos, I can't find any. Pilots - the FEF-2 has a GSC drop-coupler pilot, while the FEF-3 has a GSC swing-coupler pilot (same as used on the 3985 and BigBoys). The light at the end of the tunnel may be the headlight of an on-coming train. Thanks!

FEF-3 class, UP Steam Program.

The FEF-2’s were designed for a top speed of 110 mph and developed maximum continuous horsepower at 90 mph. Jabelmann was a great believer in standardization, and the FEF-2’s contained many components also used in UP’s 4-8-8-4 Big Boys and 4-6-6-4 Challengers.

Jan 8, 2014 · I was looking up some info on UP 825, as I have an HO scale version I picked up. Just curious how it should look compared to the prototype. I found some really nice pictures and figured you may find them interesting.

The Union Pacific FEF Series (FEF meaning, "four-eight-four") consists of forty-five 4-8-4 "Northern" steam locomotive types built by the American Locomotive Company (ALCO) between 1937 and 1944 and operated by the Union Pacific Railroad until 1959.