Union Pacific Steam Locomotives, 1915-1962
Part 14, UP 3600 to UP 3718
This page was last updated on December 2, 2015.
(Return to UP Steam Locomotive Roster Index Page)
(Return to UP Steam Locomotive Index Page)
Roster Listing
UP 2-8-8-2 -- 3 locomotives (compound)
| 1915 UP Number |
First Number |
Builder | Builder Number |
Date Built |
Date Vacated |
Later Number |
Notes |
| UP 3600 (1st) | UP 2000 | Baldwin | 33981 | Nov 1909 | 1917 | OSL 3700 (1st) | 1 |
| UP 3601 (1st) | UP 2001 | Baldwin | 33982 | Nov 1909 | 1917 | OSL 3701 (1st) | 2 |
| UP 3602 (1st) | UP 2002 | Baldwin | 33983 | Nov 1909 | 1917 | OSL 3702 (1st) | 3 |
Description:
- Common Standard Class: MC-1
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches
- Cylinders: 26-40x30 inches
- Valve Gear:
- 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): 596,400 pounds
- Fuel: Coal
General Notes:
- Mallet Consolidation (MC)
- UP 3600-3602 were built as UP 2000-2002 in 1909; renumbered to UP 3600-3602 in 1915.
- UP 3600-3602 were sold to OSL in 1917; assigned as helper locomotives on Kings Hill eastbound out of Glenns Ferry, Idaho.
- For additional information see "Ocean Toads" by James Ehernberger, in The Streamliner, Volume 5, Number 2, page13
Notes:
- UP 3600 (1st) was built as UP 2000 in 1909; to UP 3600 (1st) in 1915; to OSL 3700 (1st) in 1917; vacated in 1928
- UP 3601 (1st) was built as UP 2001 in 1909; to UP 3601 (1st) in 1915; to OSL 3701 (1st) in 1917; vacated in 1928
- UP 3602 (1st) was built as UP 2002 in 1909; to UP 3602 (1st) in 1915; to OSL 3702 (1st) in 1917; vacated in 1928
UP 2-8-8-0 -- 15 locomotives (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
UP Number As Simple |
| UP 3600 (2nd) | Schenectady | 58262 | May 1918 | Coal | Oct 1943 | UP 3500 (2nd) |
| UP 3601 (2nd) | Schenectady | 58263 | May 1918 | Oil | Jul 1944 | UP 3501 (2nd) |
| UP 3602 (2nd) | Schenectady | 58264 | May 1918 | Coal | Sep 1942 | UP 3502 (2nd) |
| UP 3603 | Schenectady | 58265 | May 1918 | Coal | Oct 1943 | UP 3503 (2nd) |
| UP 3604 | Schenectady | 58266 | May 1918 | Oil | Sep 1944 | UP 3504 (2nd) |
| UP 3605 | Schenectady | 58267 | May 1918 | Coal | May 1943 | UP 3505 (2nd) |
| UP 3606 | Schenectady | 58268 | May 1918 | Oil | Nov 1944 | UP 3506 (2nd) |
| UP 3607 | Schenectady | 58269 | May 1918 | Coal | Sep 1943 | UP 3507 (2nd) |
| UP 3608 | Schenectady | 58270 | May 1918 | Oil | Dec 1944 | UP 3508 (2nd) |
| UP 3609 | Schenectady | 58271 | May 1918 | Coal | Jul 1942 | UP 3509 (2nd) |
| UP 3610 | Schenectady | 58272 | May 1918 | Coal | Jul 1942 | UP 3510 (2nd) |
| UP 3611 | Schenectady | 58273 | May 1918 | Coal | Nov 1943 | UP 3511 (2nd) |
| UP 3612 | Schenectady | 58274 | May 1918 | Coal | Sep 1942 | UP 3512 (2nd) |
| UP 3613 | Schenectady | 58275 | May 1918 | Oil | Aug 1944 | UP 3513 (2nd) |
| UP 3614 | Schenectady | 58276 | May 1918 | Coal | Jan 1943 | UP 3514 (2nd) |
Description:
- Common Standard Class: MC-2
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1942-1944)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1942-1944)
- Maximum Tractive Effort: 103,000 pounds
- Weight on Drivers: 457,500 pounds
- Weight in Working Order (Engine Only): 487,500 pounds
- Weight in Working Order (Engine and Tender): 704,700 pounds
- Fuel: Coal
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1918; rebuilt to simple locomotives in 1942-1944 (including changing drivers from 57 inches to 59 inches) and renumbered to UP 3500 series
- UP 3600-3614 built as coal burners; five locomotives (UP 3601-3604, 3606, 3608, 3613) converted to oil burners after 1932 and before 1938
- Oil burners converted back to coal burners in November 1947 through January 1948; assigned to coal branches in the Rock Springs, Wyoming area
UP 2-8-8-0 -- 19 locomotives (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
UP Number As Simple |
| UP 3615 | Brooks | 61905 | Jul 1920 | Coal | Aug 1943 | UP 3515 |
| UP 3616 | Brooks | 61906 | Jul 1920 | Coal | Aug 1942 | UP 3516 |
| UP 3617 | Brooks | 61907 | Jul 1920 | Coal | Jun 1937 | UP 3517 |
| UP 3618 | Brooks | 61908 | Jul 1920 | Coal | Sep 1937 | UP 3518 |
| UP 3619 | Brooks | 61909 | Jul 1920 | Coal | May 1942 | UP 3519 |
| UP 3620 | Brooks | 61910 | Aug 1920 | Oil | Jul 1937 | UP 3520 |
| UP 3621 | Brooks | 61911 | Aug 1920 | Oil | Feb 1939 | UP 3521 |
| UP 3622 | Brooks | 61912 | Aug 1920 | Oil | Nov 1937 | UP 3522 |
| UP 3623 | Brooks | 61913 | Aug 1920 | Oil | Sep 1937 | UP 3523 |
| UP 3624 | Brooks | 61914 | Aug 1920 | Oil | Aug 1937 | UP 3524 |
| UP 3625 | Brooks | 61915 | Aug 1920 | Oil | Apr 1937 | UP 3525 |
| UP 3626 | Brooks | 61916 | Aug 1920 | Oil | Mar 1938 | UP 3526 |
| UP 3627 | Brooks | 61917 | Aug 1920 | Oil | Jun 1937 | UP 3527 |
| UP 3628 | Brooks | 61918 | Aug 1920 | Oil | Nov 1937 | UP 3528 |
| UP 3629 | Brooks | 61919 | Aug 1920 | Oil | May 1937 | UP 3529 |
| UP 3630 | Brooks | 61920 | Aug 1920 | Oil | Aug 1937 | UP 3530 |
| UP 3631 | Brooks | 61921 | Aug 1920 | Oil | Jun 1937 | UP 3531 |
| UP 3632 | Brooks | 61922 | Aug 1920 | Oil | Jun 1937 | UP 3532 |
| UP 3633 | Brooks | 61923 | Sep 1920 | Coal | Sep 1937 | UP 3533 |
Description:
- Common Standard Class: MC-3
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1937-1943)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1937-1943)
- Maximum Tractive Effort: 106,900 pounds
- Weight on Drivers: 472,000 pounds
- Weight in Working Order (Engine Only): 502,500 pounds
- Weight in Working Order (Engine and Tender): 720,600 pounds
- Fuel: (see above)
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1920; rebuilt to simple locomotives in 1937-1943 (including changing drivers from 57 inches to 59 inches) and renumbered to UP 3500 series
- UP 3620-3632 (13 locomotives) were converted from coal burners to oil burners before 1938
- UP 3620-3629 were leased to OWRR&N in 1920.
- UP 3630-3633 were leased to OSL in 1920.
UP 2-8-8-0 -- 5 locomotives (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
UP Number As Simple |
| UP 3634 | Brooks | 63771 | Mar 1923 | Coal | Aug 1943 | UP 3534 |
| UP 3635 | Brooks | 63772 | Mar 1923 | Coal | Jan 1942 | UP 3535 |
| UP 3636 | Brooks | 63773 | Mar 1923 | Oil | Jun 1937 | UP 3536 |
| UP 3637 | Brooks | 63774 | Mar 1923 | Oil | Nov 1937 | UP 3537 |
| UP 3638 | Brooks | 63775 | Mar 1923 | Oil | May 1937 | UP 3538 |
Description:
- Common Standard Class: MC-4
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1937-1943)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1937-1943)
- Maximum Tractive Effort: 106,900 pounds
- Weight on Drivers: 472,000 pounds
- Weight in Working Order (Engine Only): 502,500 pounds
- Weight in Working Order (Engine and Tender): 720,600 pounds
- Fuel: (see above)
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1923; rebuilt to simple locomotives in 1937-1943 (including changing drivers from 57 inches to 59 inches) and renumbered to UP 3500 series
- UP 3636-3638 were converted from coal burners to oil burners before 1938, the date of the updated folio diagram book.
- UP 3637 was equipped with a tender traction booster removed from an OWRR&N 9700 class 4-12-2
UP 2-8-8-0 -- 5 locomotives (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
UP Number As Simple |
| UP 3639 | Brooks | 64402 | Aug 1923 | Coal | Jan 1938 | UP 3539 |
| UP 3640 | Brooks | 64403 | Aug 1923 | Coal | Sep 1942 | UP 3540 |
| UP 3641 | Brooks | 64404 | Aug 1923 | Coal | Mar 1942 | UP 3541 |
| UP 3642 | Brooks | 64405 | Aug 1923 | Oil | Aug 1937 | UP 3542 |
| UP 3643 | Brooks | 64406 | Aug 1923 | Coal | Aug 1943 | UP 3543 |
Description:
- Common Standard Class: MC-5
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1937-1943)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1937-1943)
- Maximum Tractive Effort: 106,900 pounds
- Weight on Drivers: 472,000 pounds
- Weight in Working Order (Engine Only): 502,500 pounds
- Weight in Working Order (Engine and Tender): 720,600 pounds
- Fuel: (see above)
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1923; rebuilt to simple locomotives in 1937-1943 (including changing drivers from 57 inches to 59 inches) and renumbered to UP 3500 series
- UP 3642 was converted from a coal burner to a oil burner before 1938
- UP 3642 was equipped with a tender traction booster removed from an OWRR&N 9700 class 4-12-2
UP 2-8-8-0 -- 1 locomotive (compound)
| 1923 UP Number |
First Number |
Date To UP |
Builder | Builder Number |
Date Built |
Date Converted To Simple |
UP Number As Simple |
| UP 3644 | OSL 3703 (1st) | Oct 1923 | Schenectady | 58277 | May 1918 | Apr 1942 | UP 3544 |
Description:
- Common Standard Class: MC-2
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1942)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1942)
- Maximum Tractive Effort: 103,000 pounds
- Weight on Drivers: 457,500 pounds
- Weight in Working Order (Engine Only): 487,500 pounds
- Weight in Working Order (Engine and Tender): 704,700 pounds
- Fuel: Coal
General Notes:
- Mallet Compound (MC)
- UP 3644 was built as OSL 3703 as a compound locomotive; to UP 3644 in 1923; converted to simple in 1942 and renumbered to UP 3544
- Built as coal burner (as OSL 3703, as UP 3644, and as UP 3544); converted to oil burner in 1943-1945; converted to coal burner in November 1947 to January 1948 and assigned to Rock Springs coal runs.
UP 2-8-8-0 -- 20 locomotives (compound)
| 1915 Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
UP Number As Simple |
| UP 3645 | Brooks | 65665 | Jun 1924 | Coal | May 1937 | UP 3545 |
| UP 3646 | Brooks | 65666 | Jun 1924 | Coal | Dec 1943 | UP 3546 |
| UP 3647 | Brooks | 65667 | Jun 1924 | Coal | Jun 1937 | UP 3547 |
| UP 3648 | Brooks | 65668 | Jun 1924 | Oil | Aug 1937 | UP 3548 |
| UP 3649 | Brooks | 65669 | Jun 1924 | Oil | May 1937 | UP 3549 |
| UP 3650 | Brooks | 65670 | Jul 1924 | Coal | Apr 1937 | UP 3550 |
| UP 3651 | Brooks | 65671 | Jul 1924 | Oil | Jul 1937 | UP 3551 |
| UP 3652 | Brooks | 65672 | Jul 1924 | Oil | Oct 1937 | UP 3552 |
| UP 3653 | Brooks | 65673 | Jul 1924 | Oil | Oct 1937 | UP 3553 |
| UP 3654 | Brooks | 65674 | Jul 1924 | Oil | Aug 1937 | UP 3554 |
| UP 3655 | Brooks | 65675 | Jul 1924 | Coal | Jun 1937 | UP 3555 |
| UP 3656 | Brooks | 65676 | Jul 1924 | Coal | Feb 1942 | UP 3556 |
| UP 3657 | Brooks | 65677 | Jul 1924 | Coal | Jun 1937 | UP 3557 |
| UP 3658 | Brooks | 65678 | Jul 1924 | Coal | Jun 1937 | UP 3558 |
| UP 3659 | Brooks | 65679 | Jul 1924 | Coal | Dec 1943 | UP 3559 |
| UP 3660 | Brooks | 65680 | Jul 1924 | Coal | Oct 1937 | UP 3560 |
| UP 3661 | Brooks | 65681 | Jul 1924 | Oil | Jun 1938 | UP 3561 |
| UP 3662 | Brooks | 65682 | Jul 1924 | Coal | May 1937 | UP 3562 |
| UP 3663 | Brooks | 65683 | Jul 1924 | Coal | Jul 1943 | UP 3563 |
| UP 3664 | Brooks | 65684 | Jul 1924 | Oil | Aug 1937 | UP 3564 |
Description:
- Common Standard Class: MC-6
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1937-1943)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1937-1943)
- Maximum Tractive Effort: 106,900 pounds
- Weight on Drivers: 472,000 pounds
- Weight in Working Order (Engine Only): 502,500 pounds
- Weight in Working Order (Engine and Tender): 720,600 pounds
- Fuel: (see above)
General Notes:
- Mallet Compound (MC)
- Built as compound locomotives in 1924; rebuilt to simple locomotives in 1937-1943 (including changing drivers from 57 inches to 59 inches) and renumbered to UP 3500 series
- Eight locomotives (UP 3648, 3649, 3651-3654, 3661, 3664) were converted to oil burners before 1938
- Seven locomotives (UP 3648, 3649, 3651-3654, 3664) were equipped with a tender traction booster removed from an OWRR&N 9700 class 4-12-2s
UP 2-8-8-2 -- 5 locomotives (ex N&W Y-3) (USRA pattern)
| 1945 UP Number |
Previous Number |
Date To UP |
Builder | Builder Number |
Date Built |
Date Vacated |
| UP 3670 | N&W 2030 | Jun 1945 | Schenectady | 61098 | May 1919 | Nov 1947 |
| UP 3671 | N&W 2020 | Jun 1945 | Schenectady | 61088 | Apr 1919 | Nov 1947 |
| UP 3672 | N&W 2025 | Jun 1945 | Schenectady | 61093 | May 1919 | Jul 1947 |
| UP 3673 | N&W 2041 | Jun 1945 | Schenectady | 61109 | May 1919 | Dec 1947 |
| UP 3674 | N&W 2013 | Jun 1945 | Schenectady | 61081 | Apr 1919 | Nov 1947 |
Description:
- Cabside Class: 2-8-8-2
- Drive Wheel Diameter: 57 inches
- Cylinders: 25&39x32 inches
- Maximum Tractive Effort: 114,154 pounds
- Weight on Drivers: 485,200 pounds
- Weight in Working Order (Engine Only): 539,000 pounds
- Weight in Working Order (Engine and Tender): 825,533 pounds
- Fuel: Coal
General Notes:
- Mallet Compound (MC)
- These five locomotives were built as N&W Y-3; to UP in 1945 to help move wartime traffic across Wyoming; vacated and scrapped 1947 as soon as traffic slowed down.
OSL 2-8-8-2 -- 3 locomotives (compound)
| 1917 OSL Number |
First Number |
Second Number |
Date To OSL |
Builder | Builder Number |
Date Built |
Date Vacated |
| OSL 3700 | UP 2000 | UP 3600 (1st) | 1917 | Baldwin | 33981 | Nov 1909 | Nov 1928 |
| OSL 3701 | UP 2001 | UP 3601 (1st) | 1917 | Baldwin | 33982 | Nov 1909 | Nov 1928 |
| OSL 3702 | UP 2002 | UP 3602 (1st) | 1917 | Baldwin | 33983 | Nov 1909 | Nov 1928 |
Description:
- Common Standard Class: MC-1
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches
- Cylinders: 26&40x30 inches
- Weight on Drivers: 394,150 pounds
- Weight in Working Order (Engine Only): 425,900 pounds
- Weight in Working Order (Engine and Tender): 596,400 pounds
- Maximum Tractive Effort: 94,880 pounds
- Fuel: Coal
General Notes:
- Mallet Compound (MC)
- Built as UP 2000-2002 in 1909; renumbered to UP 3600-3602 in 1915-1916; sold to OSL in 1917 and renumbered OSL 3700-3702.
- Assigned to Glenns Ferry, Idaho, for eastbound helper service on Kings Hill.
- Retired in 1928 with completion of second main track on Kings Hill grade.
- See "Ocean Toads, 1909 Monster Mallets", by James L Ehernberger, The Streamliner, Volume 5, Number 2, pages 13-24
OSL 2-8-8-0 -- 1 locomotive (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Date Vacated |
1923 UP Number |
| OSL 3703 (1st) | Schenectady | 58277 | May 1918 | Oct 1923 | UP 3644 |
Description:
- Common Standard Class: MC-2
- Cabside Class: MC-57
- Drive Wheel Diameter: 57 inches (rebuilt to 59 inches in 1942)
- Cylinders: 26&41x32 inches (rebuilt to 23&23x30 inches in 1942)
- Maximum Tractive Effort: 103,000 pounds
- Weight on Drivers: 457,500 pounds
- Weight in Working Order (Engine Only): 487,500 pounds
- Weight in Working Order (Engine and Tender): 704,700 pounds
- Fuel: Coal
General Notes:
- Mallet Compound (MC)
- Built as OSL 3703 in 1918; to UP 3644 in 1923; converted from compound to simple in 1942 and renumbered to UP 3544
- Built as coal burner (as OSL 3703, as UP 3644, and as UP 3544); converted to oil burner in 1943-1945; converted to coal burner in November 1947 to January 1948 and assigned to Rock Springs coal runs.
- OSL 3703 was equipped with a Street stoker.
OSL 2-8-8-0 -- 2 locomotives (compound)
| Road Number |
Builder | Builder Number |
Date Built |
Fuel | Date Converted To Simple |
OSL Number As Simple |
| OSL 3704 (1st) | Brooks | 63779 | Mar 1923 | Coal | Apr 1944 | OSL 3565 |
| OSL 3705 (1st) | Brooks | 63780 | Mar 1923 | Oil | Apr 1944 | OSL 3566 |
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: 106,900 pounds
- Weight on Drivers: 472,000 pounds
- Weight in Working Order (Engine Only): 502,500 pounds
- Weight in Working Order (Engine and Tender): 720,600 pounds
- Fuel: (see above)
General Notes:
- Mallet Compound (MC)
- OSL 3705 was converted from a coal burner to an oil burner between 1930 and 1938.
UP 4-6-6-4 -- 8 locomotives "Light Challengers"
| 1949 UP Number |
First Number |
Second Number |
Date To 3700 Series |
Builder | Builder Number |
Date Built |
Date Vacated |
1950 UP Number |
| UP 3701 (2nd) | UP 3901 | UP 3801 (2nd) | 1949 | Schenectady | 68746 | Sep 1936 | 1950 | UP 3801 (2nd) |
| UP 3702 (2nd) | UP 3902 | UP 3802 (2nd) | 1949 | Schenectady | 68747 | Sep 1936 | 1950 | UP 3802 (2nd) |
| (UP 3703) | ||||||||
| UP 3704 (2nd) | UP 3904 | UP 3804 (2nd) | 1949 | Schenectady | 68749 | Sep 1936 | 1950 | UP 3804 (2nd) |
| (UP 3705) | ||||||||
| (UP 3706) | ||||||||
| UP 3707 (1st) | UP 3907 | UP 3807 | 1949 | Schenectady | 68752 | Sep 1936 | 1950 | UP 3807 |
| (UP 3708) | ||||||||
| UP 3709 (1st) | UP 3909 | UP 3809 | 1949 | Schenectady | 68754 | Sep 1936 | 1950 | UP 3809 |
| UP 3710 (1st) | UP 3910 | UP 3810 | 1949 | Schenectady | 68755 | Sep 1936 | 1950 | UP 3810 |
| UP 3711 (1st) | UP 3911 | UP 3811 | 1949 | Schenectady | 68756 | Sep 1936 | 1950 | UP 3811 |
| (UP 3712) | ||||||||
| (UP 3713) | ||||||||
| UP 3714 (1st) | UP 3914 | UP 3814 | 1949 | Schenectady | 68759 | Sep 1936 | 1950 | 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 from oil in 1949; converted back to oil in 1950)
General Notes:
- Challenger Simple Articulated (CSA)
- UP 3701-3714 were built as UP 3901-3914 in 1936; to UP 3801-3814 in 1944; to UP 3701-3714 (coal burners) in 1949; back to UP 3801-3814 (oil burners) in 1950
- 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 -- 8 locomotives
| 1952 UP Number |
First Number |
Date To 3700 Series |
Builder | Builder Number |
Date Built |
Date Vacated |
| UP 3700 (2nd) | UP 3930 (2nd) | 1952 | Schenectady | 72792 | Aug 1944 | Jan 1961 |
| UP 3701 (3rd) | UP 3931 (2nd) | 1952 | Schenectady | 72793 | Aug 1944 | Jan 1961 |
| UP 3702 (3rd) | UP 3932 (2nd) | 1952 | Schenectady | 72794 | Aug 1944 | Mar 1961 |
| UP 3703 (2nd) | UP 3934 (2nd) | 1952 | Schenectady | 72796 | Aug 1944 | Mar 1961 |
| UP 3704 (3rd) | UP 3937 (2nd) | 1952 | Schenectady | 72799 | Aug 1944 | Dec 1958 |
| UP 3705 (2nd) | UP 3938 (2nd) | 1952 | Schenectady | 72800 | Aug 1944 | Oct 1959 |
| UP 3706 | UP 3943 | 1952 | Schenectady | 72805 | Aug 1944 | Mar 1961 |
| UP 3707 (2nd) | UP 3944 | 1952 | Schenectady | 72806 | Aug 1944 | Jun 1961 |
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: Oil (converted from coal in 1952)
General Notes:
- These eight UP 3900 series locomotives were converted from coal to oil in 1952 and renumbered to UP 3700-3707
UP 4-6-6-4 -- 10 locomotives
| 1952 UP Number |
First Number |
Builder | Builder Number |
Date Built |
Date Vacated |
Notes |
| UP 3708 | UP 3975 | Schenectady | 70158 | Jun 1943 | Mar 1961 | |
| UP 3709 (2nd) | UP 3976 | Schenectady | 70159 | Jun 1943 | Oct 1959 | |
| UP 3710 (2nd) | UP 3977 | Schenectady | 70160 | Jun 1943 | Nov 1961 | 1 |
| UP 3711 (2nd) | UP 3978 | Schenectady | 70161 | Jun 1943 | Dec 1958 | |
| UP 3712 | UP 3979 | Schenectady | 70162 | Jun 1943 | Mar 1961 | |
| UP 3713 | UP 3980 | Schenectady | 70169 | Jun 1943 | Jun 1961 | |
| UP 3714 (2nd) | UP 3981 | Schenectady | 70170 | Jun 1943 | Dec 1958 | |
| UP 3715 | UP 3982 | Schenectady | 70171 | Jun 1943 | Jul 1962 | |
| UP 3716 | UP 3983 | Schenectady | 70172 | Jun 1943 | Oct 1959 | |
| UP 3717 (2nd) | UP 3984 | Schenectady | 70173 | Jun 1943 | 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: Oil (converted from coal-burners in 1945)
General Notes:
- UP 3708-3717 were built as UP 3975-3984 in 1943; converted from coal burners to oil burners in 1945 and assigned to service on the Northwestern District (OWRR&N); renumbered to UP 3700 series in 1952
Notes:
- UP 3710 (2nd) was used in snow melting service at North Platte, Nebraska; renumbered to UP 900079 "Roadway Locomotive" in November 1961; retired in May 1968 and donated to City of North Platte, Nebraska; displayed as UP 3977 in Cody Park.
UP 4-6-6-4 -- 2 locomotives "Light Challengers"
| 1949-1950 UP Number |
First Number |
Second Number |
Date To 3700 Series |
Builder | Builder Number |
Date Built |
Date Vacated |
Later Number |
| UP 3717 (1st) | UP 3917 | UP 3817 | 1949 | Schenectady | 68926 | Aug 1937 | 1950 | UP 3817 |
| UP 3718 | UP 3918 | UP 3818 | 1949 | Schenectady | 68927 | Aug 1937 | 1950 | UP 3818 |
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): 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 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)
- Fuel: Coal (converted from oil in 1949; converted back to oil in 1950)
General Notes:
- UP 3717 and 3718 were built as UP 3917 and 3918 in 1937; to UP 3817 and 3818 in 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.
- (Read more about UP's 4-6-6-4 Light Challenger locomotives)
###