Union Pacific Heavy Challenger

Union Pacific Heavy Challengers

Technical specifications

Serial number(s)

69760–69779, 70158–70162, 70169–70182, 70678–70683, 72792–72811

Manufacturer(s)

American Locomotive Company (ALCO)

Build date

1942-1944

Total produced

71

Classification

4664-3, 4664-4, 4664-5

Wheel arrangement

4-6-6-4

Bore stroke

21 in × 32 in (533 mm × 813 mm)

Firegrate area

132 sq ft (12 m2)

Fuel type

Coal, oil

Heating area

2,162 sq ft (200.9 m2)

Performance figures

Maximum speed

70 mph (110 km/h)

Tractive effort

97,352 lbf (433.04 kN)

Factor of adhesion

4.15

Disposition details

Preserved

Nos. 3977 and 3985 were preserved

Disposition

No. 3985 under restoration, No. 3977 on display, remainder scrapped

Union Pacific Heavy Challengers was a series of 4-6-6-4 "Challenger" type steam locomotivesthat were built by the American Locomotive Company (ALCO) for the Union Pacific Railroad, as of today, two are still in preservation, those two being Nos. 3977 and 3985.

History[]

TBA

Construction[]

All members were built by the American Locomotive Company

Preservation[]

Two examples have survived into preservation, those two being Nos. 3977 and 3985.

No. 3977[]

No. 3977 was built in 1943 as part of the 4664-4 Batch of Heavy Challengers and when it was spared from scrap, it was first relocated to Cody Park in October 1968.

As of today No. 3977 is still on static display in Cody Park.

No. 3985[]

No. 3985 was built in July 1943 as part of the 4664-4 Batch of Heavy Challengers and was spared from the scrap heap, and was stored with Big Boy No. 4023 where 3985 was restored by a group of employed volunteers in March 1981 and where it ran on excursion service until October 14, 2010. It masqueraded as Clinchfield Heavy Challenger No. 676 (the next member of the Clinchfield Railroad Heavy Challengers), it's fallen sister locomotive No. 3967, and as a What-If Scenario for when it would have been converted to burn oil in the steam era, it was retired on January 2020 and rested until April 2022, it was donated to Silvis Illinois along with TTT-6 No. 5511 and is currently undergoing restoration.

Stock list[]

4664-3[]

Status: All Members Scrapped

Loco No.	Build date	Notes
3950	1942
3951	1942
3952	1942
3953	1942
3954	1942
3955	1942
3956	1942
3957	1942
3958	1942
3959	1942
3960	1942
3961	1942
3962	1942
3963	1942
3964	1942
3965	1942
3966	1942
3967	1942	Hauled an excursion train before being scrapped.
3968	1942
3969	1942

4664-4[]

Loco No.	Build date	Status	Notes
3975	1943	Scrapped
3976	1943	Scrapped
3977	1943	Preserved. On static display in Cody Park
3978	1943	Scrapped
3979	1943	Scrapped
3980	1943	Scrapped
3981	1943	Scrapped
3982	1943	Scrapped
3983	1943	Scrapped
3984	1943	Scrapped
3985	July 1943	Undergoing restoration to operating condition.
3986	1943	Scrapped
3987	1943	Scrapped
3989	1943	Scrapped
3990	1943	Scrapped	Tender was reused in the creation of Union Pacific's GTEL Coal Burner
3991	1943	Scrapped
3992	1943	Scrapped
3993	1943	Scrapped
3994	1943	Scrapped
3995	1943	Scrapped
3996	1943	Scrapped
3997	1943	Scrapped
3998	1943	Scrapped
3999	1943	Scrapped

4664-5[]