4–8–4 Union Pacific FEF Series

Last steam locomotives built for the Union Pacific. No. 844 never retired.

Wrote about 4–8–4's general configuration, Selecting Timken 1111 4–8–4 for type’s characteristics but Union Pacific’s FEF Series beyond shadow of doubt apex locomotives of any “Northern” (Four-Eight-Four) locos.

FEF Series totaled 45 built by ALCO between 1937 and 1944 and operated until 1959, 4–8–4’s last steam locomotives built for Union Pacific Railroad.

Four locos survive, Three preserved and magnificent UP №484 remains in steam, №844 only steam loco never retired by US Class I railroad, In 1900 132 Class I railroads August 2021 just 7 remain.

Origins of UP’s 4–8–4's.

Late 1930s rising trainloads started to exceed limits of 4–8–2’s steaming capabilities, Came to head when UP President Jeffer’s business car part of train that stalled through lack of steam, While waiting for rescue “do something” telegram sent to ALCO resulting in superb FEF 4–8–4's.

FEF 4–8–4’s numbered 45 locos in three batches, Could reach over 100 mph, Produced 4,000 to 5,000 HP, Ran 14,000 miles a month.

Monthly figure impressive, Required well organised support infrastructure and skilled workforce, Expert design and superbly built locomotives that were fit for purpose, Shows evidence of close working relationship enjoyed between UP and ALCO.

FEF-1. First batch 20 locomotives.

20 delivered by ALCO in 1937, Simple elegant design based on deep expertise and experience, Two outside cylinders, Proven valve gear, Tapered connecting rods that reduced mass of reciprocating steel, Crank pins had sleeve bearings to reduce friction.

Fitted with ALCO’s lateral motion devices to leading coupled wheels helped negotiating curves.

Uncluttered appearance oozing power, Frequently moving at speeds exceeding 100 mph, Forces and stresses anticipated and managed, Excellent results as shown in high monthly milage.

FEF-2. Second batch 15 locomotives.

15 more delivered 1939, Improvements including larger cylinders, change in superheater increased superheat area and boiler pressure smoke deflectors driving wheel diameter increased Provision of 14 wheeled centipede tender increased water supply.

FEF-3 Third batch 10 locomotives.

With WW II traffic levels UP ordered 10 more, Diesel units not available, ALCO followed FEF-2 but boiler similar to FEF-1.

After WWII.

Coal supplies affected by strikes, 1946 UP converted 4–8–4’s to oil burning 6,000 US gallons tank was fitted in the bunker spaces.

UP dieselized 1950s, №844 never retired, Freight work last revenue service, Reserved for excursion work 1960, №844 still steaming, Two sisters static display, №838 in storage as source of spare parts.

General: Total weight FEF-3 411.8 ton Total length 114 ft 2+5⁄8 in Boiler pressure 300 PSI Tractive Effort FEF-2/3 63800 lbf, Preserved: FEF-1: №814 preserved remainder scrapped FEF-2: №833 preserved, remainder scrapped FEF-3: Nos. 844 and 838 preserved remainder scrapped.

Join Medium with my referral link — Dr John Frederick Rose. Read every one of my stories and thousands of other writers on Medium. Your membership fee helps support me and other writers you read. You’ll also get full access to every story on Medium.