The EMD SD40-2 is a 3,000-horsepower (2,200 kW) C-C diesel–electric locomotive built by EMD from 1972 to 1989. The SD40-2 was introduced in January 1972 as part of EMD's Dash 2 series, competing against the GE U30C.

Sold to LTEX.

May 17, 2024 · In November 1980, Union Pacific accepted delivery of four special SD40-2 locomotives from their builder, Electro Motive Division of General Motors. These four locomotives were part of test by UP and EMD for the builder to build an improved SD40-2 for UP.

Feb 20, 2009 · Of the 686 units (UP 3123-3808) delivered to the pre-merger Union Pacific from 1972 to 1980, four (UP 3804-3808) were a special SD40-2 model that EMD called SD40-2S, for SD40-2 Special, that included several enhancements to the regular SD40-2 specification, along with a slightly longer car body.

Jan 2, 2002 · UP's designation for these units is SD40-2. Assigned UP 2816-2825 in June 2001 to avoid conflict with new SD70Ms in the 4700 series. All 10 units retired on 6 June 2002 upon expiration of three-year operating lease; returned to owner Locomotive Leasing Partners (LLPX).

Feb 20, 2025 · The SD40-2 also featured EMD's latest AR10 alternator; its rectifier - with four banks of solid state silicon diodes - could quickly convert AC to DC for the traction motors. It also predominanely eliminated flashovers, a typical issue with DC generators.

Union Pacific Number 3105 is a model SD40-2C locomotive. The SD40-2 model and its variations were one of the best-selling locomotives manufactured by General Motors, Electro-Motive Division (EMD) at nearly 4,000 units. Because of their reliability, the SD40-2 has been the standard in the freight railroad industry for several decades.

UP had regular SD40 's numbered #3101 and #3103, part of the #3098-3122 series built in 1971. The Union Pacific 1998 Locomotive Directory lists SP #8632 and #8689 as originally UP #3101 and #3103 and goes on to list them as rebuilt from SD40 's.

UP 2734: Ex-SP, Rebuilt from SD40: SD40M-2 31577: 25: 50510: UP 2735: ex SP 8661, rebuilt frm ex WE, ex NW 1770 SD45, Sold to NRE: SD40M-2 35526 : 57380: UP 2735: ex SP 8661, ex WE 1770, ex NW 1770: SD40M-2 35526: 0: 2078138674: UP 2736: Ex-SP, Rebuilt from SD45: SD40M-2 33595: 18: 23166: UP 2737: Ex-SP, Rebuilt from SD45: SD40M-2

Here is some history on the UP SD40-2 fleet. Then there was the Fast Forty's UP 8000 - 8099. this group of units were geared to run with the UP 6900 class DD40X's. UP3240 through 3274, were renumbered 8000-8034, regeared 69:18 80MPH. The rest came new as UP8035 to UP8099. 8035-8099 were later regeard, and renumberd in to the low end of 3300's.