Union Pacific 4023 is a preserved member of the 4-8-8-4 Big Boy class built by the American Locomotive Company in Schenectady, New York in November 1944. It is one of eight surviving UP Big Boys[1] being preserved across the United States. 4023 also has the distinction of being the only surviving Big Boy that was part of the second group built in 1944, as all the other surviving Big Boys are from the first group built in 1941.

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Union Pacific 4023
No. 4023 in its current display site in 2007
Type and origin Power type Steam Builder American Locomotive Company Serial number 72780 Build date November 1944 Rebuild date 1957
Specifications Configuration: ​  • Whyte 4-8-8-4  • UIC (2′D)D2′ h4 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 36 in (914 mm) Driver dia. 68 in (1,727 mm) Trailing dia. 42 in (1,067 mm) Wheelbase Locomotive: 72 ft 5+1⁄2 in (22.09 m) Overall: 117 ft 7 in (35.84 m) Length Locomotive: 85 ft 3.4 in (25.99 m) Overall: 132 ft 9+1⁄4 in (40.47 m) Width 11 ft (3.4 m) Height 16 ft 2+1⁄2 in (4.94 m) Adhesive weight 545,200 lb (247,000 kg) Loco weight 772,250 lb (350,300 kg) Tender weight 436,500 lb (197,990 kg) Total weight 1,208,750 lb (548,300 kg) Fuel type Coal Fuel capacity 28 short tons (25.4 t; 25.0 long tons) Water cap. 25,000 US gal (95,000 l; 21,000 imp gal) Firebox:  • Firegrate area 150 sq ft (14 m2) Boiler 95 in (2,400 mm) Boiler pressure 300 lbf/in2 (2.1 MPa) Heating surface 5,735 sq ft (533 m2)  • Tubes and flues 5,035 sq ft (468 m2)  • Firebox 720 sq ft (67 m2) Superheater: ​  • Type Type A  • Heating area 2,043 sq ft (190 m2) Cylinders 4 Cylinder size 23.75 in × 32 in (603 mm × 813 mm)
Performance figures Maximum speed 80 mph (130 km/h) Power output 7,000 hp (5,200 kW) @ Cylinder Tractive effort 135,375 lbf (602.18 kN) Factor of adh. 4.02
Career Operators Union Pacific Railroad Class 4884-2 Last run 1959 Retired 1962 Preserved 1963 Restored 1974 (cosmetically) Current owner City of South Omaha, Nebraska Disposition On static display at Kenefick Park in Omaha, Nebraska

History

In the early 1940s, the Union Pacific Railroad designed the only simple articulated steam locomotive with a 4-8-8-4 wheel arrangement, which would be known as the "Big Boy" and would be the largest steam locomotive in the world. These locomotives began being constructed in 1941 by the American Locomotive Company in Schenectady, New York, and No. 4023 is one of the last five of these built in 1944. No. 4023 was assigned for fast and heavy freight trains through the Wasatch Mountains and over Sherman Hill.

After its last run took place in 1959, No. 4023 was stored in the UP's scrapline with the other Big Boy locomotives. What might’ve likely been the reason for 4023's mint condition to be saved for preservation is that it was given a class 3 overhaul in 1957. In 1963, No. 4023 was cosmetically repainted to be put on display for that year's National Railway Historical Society (NRHS) Convention in Cheyenne, Wyoming alongside 4-6-6-4 "Challenger" No. 3985 and 4-8-4 "Northern" No. 844. Once the convention was over, No. 4023 was moved along with No. 3985 inside the Cheyenne roundhouse for storage.[2] In 1974, No. 4023 was cosmetically restored and towed to Omaha, Nebraska for static display in front of the Union Pacific's locomotive shops. After the locomotive shops were closed in 1988, No. 4023 was moved to the original Kenefick Park on Abbott Drive, near the former UP shop site. After redevelopment in the area forced the closure of Kenefick Park, No. 4023 was temporarily housed outside of the Durham Museum in Downtown Omaha.[3]

In Spring of 2005, No. 4023 was moved by truck on a highway[4] to a more permanent home at the new location of Kenefick Park[5] alongside an EMD DDA40X No. 6900.[6] During one of its cosmetic restorations, several functional appliances were replaced with new, fake appliances, including the safety valves, whistle, lubricators, and a new boiler jacket. As of 2022, No. 4023 is still on display at Kenefick.

References