Union Pacific Steam Locomotives, 1915-1962
Part 15, OWRR&N 3800 to UP 3999
This page was last updated on August 15, 2022.
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ORR&N 2-8-8-2 -- 3 locomotives (compound)
| 1915 OWRR&N Number |
First Number |
Second Number |
Builder | Builder Number |
Date Built |
Date Vacated |
Notes |
| OWRR&N 3800 | ORR&N 450 | OWRR&N 700 | Baldwin | 34016 | Nov 1909 | Sep 1928 | 1 |
| OWRR&N 3801 | ORR&N 451 | OWRR&N 701 | Baldwin | 34017 | Nov 1909 | Oct 1928 | 2 |
| OWRR&N 3802 | ORR&N 452 | OWRR&N 702 | Baldwin | 34018 | Nov 1909 | Nov 1928 | 3 |
OWRR&N added auxiliary 6000-gallon water tenders (6-R) to increase capacity for Huntington to Umatilla helper service 1925-1928. (Gordon McCulloch, A History of Union Pacific Steam)
Description:
- Common Standard Class: MC-1
- Drive Wheel Diameter: 57 inches
- Cylinders: 26&40x30
- Maximum Tractive Effort: 94,880 pounds
- Weight on Drivers: 394,150 pounds
- Weight in Working Order (Engine Only): 425,900 pounds
- Weight in Working Order (Engine and Tender): 599,181 pounds
- Fuel: Oil
General Notes:
- Mallet Compound (MC)
- Built as ORR&N 450-452 in 1909; renumbered to OWRR&N 700-702 in 1911; renumbered to OWRR&N 3800-3802 in 1915-1916.
- OWRR&N 3800 was equipped with a stoker in December 1917.
- OWRR&N 3802 was equipped with a stoker in March 1918.
- OWRR&N 3800-3802 were assigned to LaGrande, Oregon for service in the Blue Mountains.
- See "Ocean Toads, 1909 Monster Mallets", by James L Ehernberger, The Streamliner, Volume 5, Number 2, pages 13-24
Notes:
- OWRR&N 3800 was built as ORR&N 450 in 1909; to OWRR&N 700 in 1911; to OWRR&N 3800 in 1915; vacated in 1928
- OWRR&N 3801 was built as ORR&N 451 in 1909; to OWRR&N 701 in 1911; to OWRR&N 3801 in 1915; vacated in 1928
- OWRR&N 3802 was built as ORR&N 452 in 1909; to OWRR&N 702 in 1911; to OWRR&N 3802 in 1915; vacated in 1928
OWRR&N 2-8-8-0 -- 3 locomotives (compound)
| OWRR&N Number |
Builder | Builder Number |
Date Built |
Date Converted To Simple |
OWRR&N Number As Simple |
| OWRR&N 3803 (1st) | Brooks | 63776 | Mar 1923 | Apr 1944 | OWRR&N 3567 |
| OWRR&N 3804 (1st) | Brooks | 63777 | Mar 1923 | Apr 1944 | OWRR&N 3568 |
| OWRR&N 3805 (1st) | Brooks | 63778 | Mar 1923 | Apr 1944 | OWRR&N 3569 |
Description:
- Common Standard Class: MC-4
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1944)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1944)
- Maximum Tractive Effort: 103,000 pounds
- Weight on Drivers: 464,000 pounds
- Weight in Working Order (Engine Only): 494,500 pounds
- Weight in Working Order (Engine and Tender): 712,600 pounds
- Fuel: Oil (converted from coal)
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1923; rebuilt to simple locomotives in 1944 (including changing drivers from 57 inches to 59 inches) and renumbered to OWRR&N 3500 series
- Built as coal burners; converted to oil burners before 1938
UP 4-6-6-4 -- 15 locomotives "Light Challengers"
| 1944 UP Number |
First Number |
Date To 3800 Series |
Builder | Builder Number |
Date Built |
1949-1950 UP Number |
Date Vacated |
| UP 3800 (2nd) | UP 3900 | Apr 1944 | Schenectady | 68745 | Sep 1936 | Aug 1957 | |
| UP 3801 (2nd) | UP 3901 | Apr 1944 | Schenectady | 68746 | Sep 1936 | UP 3701 | Sep 1957 |
| UP 3802 (2nd) | UP 3902 | Apr 1944 | Schenectady | 68747 | Sep 1936 | UP 3702 | Dec 1958 |
| UP 3803 (2nd) | UP 3903 | Apr 1944 | Schenectady | 68748 | Sep 1936 | May 1959 | |
| UP 3804 (2nd) | UP 3904 | Apr 1944 | Schenectady | 68749 | Sep 1936 | UP 3704 | Jul 1959 |
| UP 3805 (2nd) | UP 3905 | Apr 1944 | Schenectady | 68750 | Sep 1936 | Feb 1956 | |
| UP 3806 | UP 3906 | Apr 1944 | Schenectady | 68751 | Sep 1936 | Jul 1962 | |
| UP 3807 | UP 3907 | Apr 1944 | Schenectady | 68752 | Sep 1936 | UP 3707 | Aug 1957 |
| UP 3808 | UP 3908 | Apr 1944 | Schenectady | 68753 | Sep 1936 | Apr 1957 | |
| UP 3809 | UP 3909 | Apr 1944 | Schenectady | 68754 | Sep 1936 | UP 3709 | Aug 1957 |
| UP 3810 | UP 3910 | Apr 1944 | Schenectady | 68755 | Sep 1936 | UP 3710 | Sep 1956 |
| UP 3811 | UP 3911 | Apr 1944 | Schenectady | 68756 | Sep 1936 | UP 3711 | Sep 1956 |
| UP 3812 | UP 3912 | Apr 1944 | Schenectady | 68757 | Sep 1936 | Dec 1958 | |
| UP 3813 | UP 3913 | Apr 1944 | Schenectady | 68758 | Sep 1936 | Sep 1956 | |
| UP 3814 | UP 3914 | Apr 1944 | Schenectady | 68759 | Sep 1936 | UP 3714 | Jun 1957 |
Description:
- Common Standard Class: CSA-1
- Cabside Class: CSA-69
- Drive Wheel Diameter: 69 inches
- Cylinders: 22&22x32 inches
- Maximum Tractive Effort: 97,400 pounds
- Weight on Drivers: 386,000 pounds (as built) (in later years their weight-on-drivers varied between 399,660 pounds and 407,610 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only): 566,000 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender): 876,000 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine))
- Fuel: Oil (eight locomotives converted to coal, then back to oil)
General Notes:
- Challenger Simple Articulated (CSA)
- UP 3800-3814 were built as UP 3900-3914 in 1936; to UP 3800-3814 in 1944 to clear the 3900 series for use by new 4664-5 class Challengers
- Eight locomotives (UP 3801, 3802, 3804, 3807, 3809, 3810, 3811, 3814) were converted to coal burners in 1949 and renumbered to UP 3701-3714; all eight locomotives were converted back to oil burners in 1950 and renumbered back to their 3800 series numbers
- (Read more about UP's 4-6-6-4 Light Challenger locomotives)
UP 4-6-6-4 -- 25 locomotives "Light Challengers"
| 1944 UP Number |
First Number |
Date To 3800 Series |
Builder | Builder Number |
Date Built |
1949-1950 UP Number |
Date Vacated |
| UP 3815 | UP 3915 | Apr 1944 | Schenectady | 68924 | Aug 1937 | Dec 1958 | |
| UP 3816 | UP 3916 | Apr 1944 | Schenectady | 68925 | Aug 1937 | Apr 1957 | |
| UP 3817 | UP 3917 | Apr 1944 | Schenectady | 68926 | Aug 1937 | UP 3717 | Jun 1957 |
| UP 3818 | UP 3918 | Apr 1944 | Schenectady | 68927 | Aug 1937 | UP 3718 | Mar 1961 |
| UP 3819 | UP 3919 | Apr 1944 | Schenectady | 68928 | Aug 1937 | Jul 1957 | |
| UP 3820 | UP 3920 | Apr 1944 | Schenectady | 68929 | Aug 1937 | Aug 1957 | |
| UP 3821 | UP 3921 | Apr 1944 | Schenectady | 68930 | Aug 1937 | Apr 1957 | |
| UP 3822 | UP 3922 | Apr 1944 | Schenectady | 68931 | Aug 1937 | Sep 1957 | |
| UP 3823 | UP 3923 | Apr 1944 | Schenectady | 68932 | Aug 1937 | Jul 1959 | |
| UP 3824 | UP 3924 | Apr 1944 | Schenectady | 68933 | Aug 1937 | Jul 1957 | |
| UP 3825 | UP 3925 | Apr 1944 | Schenectady | 68934 | Aug 1937 | Apr 1957 | |
| UP 3826 | UP 3926 | Apr 1944 | Schenectady | 68935 | Aug 1937 | Nov 1956 | |
| UP 3827 | UP 3927 | Apr 1944 | Schenectady | 68936 | Aug 1937 | Dec 1958 | |
| UP 3828 | UP 3928 | Apr 1944 | Schenectady | 68937 | Aug 1937 | Jul 1959 | |
| UP 3829 | UP 3929 | Apr 1944 | Schenectady | 68938 | Aug 1937 | Jul 1957 | |
| UP 3830 | UP 3930 (1st) | Apr 1944 | Schenectady | 68939 | Aug 1937 | May 1959 | |
| UP 3831 | UP 3931 (1st) | Apr 1944 | Schenectady | 68940 | Aug 1937 | Jun 1957 | |
| UP 3832 | UP 3932 (1st) | Apr 1944 | Schenectady | 68941 | Aug 1937 | May 1959 | |
| UP 3833 | UP 3933 (1st) | Apr 1944 | Schenectady | 68942 | Aug 1937 | Nov 1956 | |
| UP 3834 | UP 3934 (1st) | Apr 1944 | Schenectady | 68943 | Aug 1937 | Nov 1954 | |
| UP 3835 | UP 3935 (1st) | Apr 1944 | Schenectady | 68944 | Aug 1937 | Nov 1956 | |
| UP 3836 | UP 3936 (1st) | Apr 1944 | Schenectady | 68945 | Aug 1937 | Nov 1956 | |
| UP 3837 | UP 3937 (1st) | Apr 1944 | Schenectady | 68946 | Aug 1937 | Jul 1957 | |
| UP 3838 | UP 3938 (1st) | Apr 1944 | Schenectady | 68947 | Aug 1937 | May 1959 | |
| UP 3839 | UP 3939 (1st) | Apr 1944 | Schenectady | 68948 | Aug 1937 | Aug 1957 |
Description:
- Common Standard Class: CSA-2
- Cabside Class: CSA-69
- Drive Wheel Diameter: 69 inches
- Cylinders: 22&22x32 inches
- Maximum Tractive Effort: 97,400 pounds
- Weight on Drivers: 403,000 pounds (as built) (in later years their weight-on-drivers varied between 399,660 pounds and 407,610 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only, UP 3915-3933): 582,000 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only, UP 3934-3939): 584,100 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender, UP 3815-3833): 894,000 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender, UP 3834-3839): 896,100 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine)
- Fuel: Oil (two locomotives converted to coal then back to oil)
General Notes:
- Challenger Simple Articulated (CSA)
- UP 3815-3839 were built as UP 3915-3939 in 1937; to UP 3815-3839 in 1944 to clear the 3900 series for use by new 4664-5 class Challengers
- UP 3817 and 3818 were built as oil burners; converted to coal-burners in 1949 and renumbered to UP 3717 and 3718; converted back to oil burners in 1950 and renumbered back to UP 3817 and 3818.
- UP 3834-3839 (six locomotives) were built as coal burners; converted to oil burners upon delivery and assigned to passenger service on the LA&SL.
- (Read more about UP's 4-6-6-4 Light Challenger locomotives)
UP 4-6-6-4 -- 15 locomotives "Light Challengers"
| Road Number |
Builder | Builder Number |
Date Built |
Date Renumbered |
1944 UP Number |
| UP 3900 | Schenectady | 68745 | Sep 1936 | Apr 1944 | UP 3800 |
| UP 3901 | Schenectady | 68746 | Sep 1936 | Apr 1944 | UP 3801 |
| UP 3902 | Schenectady | 68747 | Sep 1936 | Apr 1944 | UP 3802 |
| UP 3903 | Schenectady | 68748 | Sep 1936 | Apr 1944 | UP 3803 |
| UP 3904 | Schenectady | 68749 | Sep 1936 | Apr 1944 | UP 3804 |
| UP 3905 | Schenectady | 68750 | Sep 1936 | Apr 1944 | UP 3805 |
| UP 3906 | Schenectady | 68751 | Sep 1936 | Apr 1944 | UP 3806 |
| UP 3907 | Schenectady | 68752 | Sep 1936 | Apr 1944 | UP 3807 |
| UP 3908 | Schenectady | 68753 | Sep 1936 | Apr 1944 | UP 3808 |
| UP 3909 | Schenectady | 68754 | Sep 1936 | Apr 1944 | UP 3809 |
| UP 3910 | Schenectady | 68755 | Sep 1936 | Apr 1944 | UP 3810 |
| UP 3911 | Schenectady | 68756 | Sep 1936 | Apr 1944 | UP 3811 |
| UP 3912 | Schenectady | 68757 | Sep 1936 | Apr 1944 | UP 3812 |
| UP 3913 | Schenectady | 68758 | Sep 1936 | Apr 1944 | UP 3813 |
| UP 3914 | Schenectady | 68759 | Sep 1936 | Apr 1944 | UP 3814 |
Description:
- Common Standard Class: CSA-1
- Cabside Class: CSA-69
- Drive Wheel Diameter: 69 inches
- Cylinders: 22&22x32 inches
- Maximum Tractive Effort: 97,400 pounds
- Weight on Drivers: 386,000 pounds (as built) (in later years their weight-on-drivers varied between 399,660 pounds and 407,610 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only): 566,000 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender): 876,000 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine))
- Fuel: Coal (converted to oil in 1941-1943)
General Notes:
- Challenger Simple Articulated (CSA)
- UP 3900-3914 were built in 1936 was coal burners; converted to oil burners starting in September 1941; completed in March 1943
- Built as UP 3900-3914 in 1936; to UP 3800-3814 in 1944 to clear the 3900 series for use by new 4664-5 class Challengers
- (Read more about UP's 4-6-6-4 Light Challenger locomotives)
UP 4-6-6-4 -- 25 locomotives "Light Challengers"
| Road Number |
Builder | Builder Number |
Date Built |
Date Renumbered |
1944 UP Number |
| UP 3915 | Schenectady | 68924 | Aug 1937 | Apr 1944 | UP 3815 |
| UP 3916 | Schenectady | 68925 | Aug 1937 | Apr 1944 | UP 3816 |
| UP 3917 | Schenectady | 68926 | Aug 1937 | Apr 1944 | UP 3817 |
| UP 3918 | Schenectady | 68927 | Aug 1937 | Apr 1944 | UP 3818 |
| UP 3919 | Schenectady | 68928 | Aug 1937 | Apr 1944 | UP 3819 |
| UP 3920 | Schenectady | 68929 | Aug 1937 | Apr 1944 | UP 3820 |
| UP 3921 | Schenectady | 68930 | Aug 1937 | Apr 1944 | UP 3821 |
| UP 3922 | Schenectady | 68931 | Aug 1937 | Apr 1944 | UP 3822 |
| UP 3923 | Schenectady | 68932 | Aug 1937 | Apr 1944 | UP 3823 |
| UP 3924 | Schenectady | 68933 | Aug 1937 | Apr 1944 | UP 3824 |
| UP 3925 | Schenectady | 68934 | Aug 1937 | Apr 1944 | UP 3825 |
| UP 3926 | Schenectady | 68935 | Aug 1937 | Apr 1944 | UP 3826 |
| UP 3927 | Schenectady | 68936 | Aug 1937 | Apr 1944 | UP 3827 |
| UP 3928 | Schenectady | 68937 | Aug 1937 | Apr 1944 | UP 3828 |
| UP 3929 | Schenectady | 68938 | Aug 1937 | Apr 1944 | UP 3839 |
| UP 3930 (1st) | Schenectady | 68939 | Aug 1937 | Apr 1944 | UP 3830 |
| UP 3931 (1st) | Schenectady | 68940 | Aug 1937 | Apr 1944 | UP 3831 |
| UP 3932 (1st) | Schenectady | 68941 | Aug 1937 | Apr 1944 | UP 3832 |
| UP 3933 (1st) | Schenectady | 68942 | Aug 1937 | Apr 1944 | UP 3833 |
| UP 3934 (1st) | Schenectady | 68943 | Aug 1937 | Apr 1944 | UP 3834 |
| UP 3935 (1st) | Schenectady | 68944 | Aug 1937 | Apr 1944 | UP 3835 |
| UP 3936 (1st) | Schenectady | 68945 | Aug 1937 | Apr 1944 | UP 3836 |
| UP 3937 (1st) | Schenectady | 68946 | Aug 1937 | Apr 1944 | UP 3837 |
| UP 3938 (1st) | Schenectady | 68947 | Aug 1937 | Apr 1944 | UP 3838 |
| UP 3939 (1st) | Schenectady | 68948 | Aug 1937 | Apr 1944 | UP 3839 |
Description:
- Common Standard Class: CSA-2
- Cabside Class: CSA-69
- Drive Wheel Diameter: 69 inches
- Cylinders: 22&22x32 inches
- Maximum Tractive Effort: 97,400 pounds
- Weight on Drivers: 403,000 pounds (as built) (in later years their weight-on-drivers varied between 399,660 pounds and 407,610 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only, UP 3915-3933): 582,000 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine Only, UP 3934-3939): 584,100 pounds (as built) (in later years their weight varied between 569,820 pounds and 590,550 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender, UP 3815-3833): 894,000 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine)
- Weight in Working Order (Engine and Tender, UP 3834-3839): 896,100 pounds (as built) (varied between 892,420 pounds and 915,000 pounds depending on type of feedwater heater and weight of front engine)
- Fuel: Coal (converted to oil)
General Notes:
- Challenger Simple Articulated (CSA)
- UP 3915-3933 were built in 1937 as coal burners; converted to oil burners starting in 1941-1943
- UP 3834-3839 (six locomotives) were built as coal burners; converted to oil burners upon delivery and assigned to passenger service on the LA&SL.
- Built as UP 3915-3939 in 1937; renumbered to UP 3815-3839 in 1944 to clear the 3900 series for use by new 4664-5 class Challengers
- (Read more about UP's 4-6-6-4 Light Challenger locomotives)
UP 4-6-6-4 -- 20 locomotives "Late Challengers"
| Road Number |
Builder | Builder Number |
Date Built |
Date Vacated |
1952 UP Number |
| UP 3930 (2nd) | Schenectady | 72792 | Aug 1944 | 1952 | UP 3700 (2nd) |
| UP 3931 (2nd) | Schenectady | 72793 | Aug 1944 | 1952 | UP 3701 (3rd) |
| UP 3932 (2nd) | Schenectady | 72794 | Aug 1944 | 1952 | UP 3702 (3rd) |
| UP 3933 (2nd) | Schenectady | 72795 | Aug 1944 | Jun 1959 | |
| UP 3934 (2nd) | Schenectady | 72796 | Aug 1944 | 1952 | UP 3703 (2nd) |
| UP 3935 (2nd) | Schenectady | 72797 | Aug 1944 | Jun 1959 | |
| UP 3936 (2nd) | Schenectady | 72798 | Aug 1944 | Jun 1959 | |
| UP 3937 (2nd) | Schenectady | 72799 | Aug 1944 | 1952 | UP 3704 (3rd) |
| UP 3938 (2nd) | Schenectady | 72800 | Aug 1944 | 1952 | UP 3705 (2nd) |
| UP 3939 (2nd) | Schenectady | 72801 | Aug 1944 | Jun 1959 | |
| UP 3940 | Schenectady | 72802 | Aug 1944 | Jul 1959 | |
| UP 3941 | Schenectady | 72803 | Aug 1944 | Sep 1959 | |
| UP 3942 | Schenectady | 72804 | Aug 1944 | Dec 1959 | |
| UP 3943 | Schenectady | 72805 | Aug 1944 | 1952 | UP 3706 |
| UP 3944 | Schenectady | 72806 | Aug 1944 | 1952 | UP 3707 (2nd) |
| UP 3945 | Schenectady | 72807 | Aug 1944 | Oct 1959 | |
| UP 3946 | Schenectady | 72808 | Aug 1944 | Jul 1960 | |
| UP 3947 | Schenectady | 72809 | Aug 1944 | Dec 1959 | |
| UP 3948 | Schenectady | 72810 | Aug 1944 | Dec 1959 | |
| UP 3949 | Schenectady | 72811 | Aug 1944 | Oct 1959 |
Description:
- Cabside Class: 4664-5
- Drive Wheel Diameter: 69 inches
- Cylinders: 21&21x32 inches
- Maximum Tractive Effort: 97,350 pounds
- Weight on Drivers: 406,200 pounds
- Weight in Working Order (Engine Only): 634,500 pounds
- Weight in Working Order (Engine and Tender): 1,071,000 pounds
- Fuel: Coal
General Notes:
- Eight UP 3900 series locomotives were converted from coal to oil in 1952 and renumbered to UP 3700-3707
- (Read more about UP's Late Challengers)
UP 4-6-6-4 -- 20 locomotives "Late Challengers"
| Road Number |
Builder | Builder Number |
Date Built |
Date Vacated |
| UP 3950 | Schenectady | 69760 | May 1942 | Mar 1961 |
| UP 3951 | Schenectady | 69761 | May 1942 | Dec 1959 |
| UP 3952 | Schenectady | 69762 | May 1942 | Jul 1960 |
| UP 3953 | Schenectady | 69763 | May 1942 | Feb 1960 |
| UP 3954 | Schenectady | 69764 | May 1942 | Feb 1960 |
| UP 3955 | Schenectady | 69765 | May 1942 | Dec 1958 |
| UP 3956 | Schenectady | 69766 | May 1942 | Feb 1960 |
| UP 3957 | Schenectady | 69767 | May 1942 | Feb 1960 |
| UP 3958 | Schenectady | 69768 | May 1942 | Mar 1960 |
| UP 3959 | Schenectady | 69769 | May 1942 | Jul 1960 |
| UP 3960 | Schenectady | 69770 | May 1942 | Dec 1958 |
| UP 3961 | Schenectady | 69771 | May 1942 | Dec 1958 |
| UP 3962 | Schenectady | 69772 | May 1942 | Mar 1960 |
| UP 3963 | Schenectady | 69773 | May 1942 | Oct 1959 |
| UP 3964 | Schenectady | 69774 | May 1942 | Oct 1959 |
| UP 3965 | Schenectady | 69775 | May 1942 | Jul 1960 |
| UP 3966 | Schenectady | 69776 | May 1942 | Mar 1960 |
| UP 3967 | Schenectady | 69777 | May 1942 | Mar 1960 |
| UP 3968 | Schenectady | 69778 | May 1942 | Apr 1960 |
| UP 3969 | Schenectady | 69779 | May 1942 | Apr 1960 |
(Read more about UP's Late Challengers)
Description:
- Cabside Class: 4664-3
- Drive Wheel Diameter: 69 inches
- Cylinders: 21721x32 inches
- Maximum Tractive Effort: 97,350 pounds
- Weight on Drivers: 403,700 pounds
- Weight in Working Order (Engine Only): 627,000 pounds
- Weight in Working Order (Engine and Tender): 1,063,500 pounds
- Fuel: Coal
UP 4-6-6-4 -- 25 locomotives "Late Challengers"
| Road Number |
Builder | Builder Number |
Date Built |
Date Vacated |
1952 UP Number |
Notes |
| UP 3975 | Schenectady | 70158 | Jun 1943 | 1952 | UP 3708 | |
| UP 3976 | Schenectady | 70159 | Jun 1943 | 1952 | UP 3709 (2nd) | |
| UP 3977 | Schenectady | 70160 | Jun 1943 | 1952 | UP 3710 (2nd) | 1 |
| UP 3978 | Schenectady | 70161 | Jun 1943 | 1952 | UP 3711 (2nd) | |
| UP 3979 | Schenectady | 70162 | Jun 1943 | 1952 | UP 3712 | |
| UP 3980 | Schenectady | 70169 | Jun 1943 | 1952 | UP 3713 | |
| UP 3981 | Schenectady | 70170 | Jun 1943 | 1952 | UP 3714 (2nd) | |
| UP 3982 | Schenectady | 70171 | Jun 1943 | 1952 | UP 3715 | |
| UP 3983 | Schenectady | 70172 | Jun 1943 | 1952 | UP 3716 | |
| UP 3984 | Schenectady | 70173 | Jun 1943 | 1952 | UP 3717 (2nd) | |
| UP 3985 | Schenectady | 70174 | Jun 1943 | 2 | ||
| UP 3986 | Schenectady | 70175 | Jun 1943 | Apr 1960 | ||
| UP 3987 | Schenectady | 70176 | Jun 1943 | Apr 1960 | ||
| UP 3988 | Schenectady | 70177 | Jun 1943 | Oct 1960 | ||
| UP 3989 | Schenectady | 70178 | Jun 1943 | Aug 1960 | ||
| UP 3990 | Schenectady | 70179 | Jun 1943 | Aug 1960 | ||
| UP 3991 | Schenectady | 70180 | Jun 1943 | Mar 1961 | ||
| UP 3992 | Schenectady | 70181 | Jun 1943 | Aug 1960 | ||
| UP 3993 | Schenectady | 70182 | Jun 1943 | Aug 1960 | ||
| UP 3994 | Schenectady | 70678 | Jul 1943 | Jul 1959 | ||
| UP 3995 | Schenectady | 70679 | Jul 1943 | Oct 1960 | ||
| UP 3996 | Schenectady | 70680 | Jul 1943 | Oct 1960 | ||
| UP 3997 | Schenectady | 70681 | Jul 1943 | Oct 1960 | ||
| UP 3998 | Schenectady | 70682 | Jul 1943 | Dec 1960 | ||
| UP 3999 | Schenectady | 70683 | Jul 1943 | Dec 1960 |
Description:
- Cabside Class: 4664-4
- Drive Wheel Diameter: 69 inches
- Cylinders: 21&21x32 inches
- Maximum Tractive Effort: 97,350 pounds
- Weight on Drivers: 407,500 pounds
- Weight in Working Order (Engine Only): 633,500 pounds
- Weight in Working Order (Engine and Tender): 1,070,000 pounds
- Fuel: Coal (UP 3975-3984 converted to oil)
General Notes:
- UP 3975-3984 (10 locomotives) were painted two-tone gray beginning in December 1946, while assigned to passenger service on the Northwestern District (OWRR&N); repainted back to standard black after being shopped and assigned to helper service east of Ogden, Utah.
- UP 3975-3980 (5 locomotives) were converted to oil in November 1944 and assigned to the Los Angeles passenger pool, generally operating between Caliente and Los Angeles. Records indicate UP 3975-3980 joined the Huntington-Portland-Seattle pool in August 1946. (Gordon McCulloh, email dated March 9, 2014)
- UP 3981-3984 (5 locomotives) were converted to oil in November 1946 and were sent to the Northwest Division. Smoke lifting Wind Wings were being added beginning late in 1945. UP 3977 was photographed with them on January 6, 1946. (Gordon McCulloh, email dated March 9, 2014)
- UP 3975-3984 (10 locomotives) were re-assigned to helper service on UP's wasatch grade east of Ogden, Utah in 1950, and were renumbered to the UP-3700 series in 1952. (Read more about UP 3975-3984)
- (Read more about UP's Late Challengers)
Notes:
- UP 3977 was renumbered to UP 3710 (2nd) in 1952; used in snow melting service in North Platte yard after October 1959, renumbered to UP 900079, "Roadway Locomotive" in November 1961; stored in the roundhouse at North Platte, Nebraska, and reported to have been fired up and prepared each December for snow melting service (photo in Trains magazine, May 1967, on December 6, 1966); donated to City of North Platte in June 1968; renumbered back to UP 3977; displayed at Cody Park, North Platte, Nebraska.
- UP 3985 was first retired in July 1962; stored at Cheyenne, Wyoming, until placed on display at the Cheyenne depot in October 1974; removed from display in September 1979 and returned to service April 1981 (reinstated to roster in March 1981). (Read more about UP 3985 in service after 1981 as part of UP's Heritage Fleet)
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