GE AC4400CW
The GE AC4400CW is a diesel-electric locomotive that was built by GE Transportation Systems between 1993 and 2004. It is like the Dash 9-44CW, but features AC traction motors instead of DC, with a separate inverter per motor. In appearance, the AC4400CW is similar to GE's more powerful locomotive, the AC6000CW.
Over the 11 years in which it was produced, GE constructed 2,834 examples for North American railroads. In 2005, all Class I freight railroads except Norfolk Southern and Canadian National owned at least one AC4400CW. As a result of more stringent emissions requirements that came into effect on January of that year, GE no longer offers the AC4400CW, replacing it with the ES44AC.
Four repainted Canadian Pacific Railway AC4400CW units were used in the filming of the 2010 hit movie Unstoppable.
Design variations
The AC4400CW was the first GE locomotive to offer an optional self-steering truck design, intended to increase adhesion and reduce wear on the railhead. This option was specified by Canadian Pacific, Cartier Railway, CSX for their units 200-599, Ferromex, Ferrosur, and KCS.CSX ordered many of its AC4400CW locomotives with extra weight to increase tractive effort. These same units were also modified in 2006-2007 with a "high tractive effort" software upgrade and redesignated CW44AH.
Rebuilds
In 2017 Canadian Pacific Railway requested that General Electric modernize 30 of its 9500 and 9600-series AC4400CW units. The original units had the original front cab completely removed and upgraded to current GE standards with upgraded electrical systems including PTC and FTO systems. Other improvements GE has made include up to 10 percent fuel efficiency gains, 40 percent increase in reliability and 50 percent increase in haulage ability. The units were subsequently placed into service with the designation AC4400CWM. The first batch of rebuilds also had their original Steerable trucks replaced with GEs High Adhesion trucks instead of steerable, where later batches each individual engine kept the trucks they already had.The following year Canadian Pacific asked GE to similarly rebuild several more batches for a total of 110 locomotives. The second order retains their steerable trucks. The third batch will feature an Evolution Series sized fuel tank and radial trucks. In 2019 a fourth batch of rebuilds happened, 8145-8160 & 8064-8080 from the 95/9600-series. In 2020 the 8500 series is slated to be rebuilt at 8201-8280.
Union Pacific ordered many of their AC4400CWs with Computerized Tractive Effort software, giving them the designation of AC4400CW-CTE. This software package is now standard on their ES44ACs as well.
In 2018 Union Pacific placed a small order for 20 rebuilds from GE of their AC4460AC fleet and later announced over the next fifteen years they will be upgrading 1000 of their AC4460ACs and AC44s into what they call a C44ACM. Unlike CP, the original 20 rebuilds did not receive a new crew cab.
CSX and Wabtec have announced a partnership in rebuilding CSX's large AC4400CW fleet. An initial batch of 10 CW44ACs were rebuilt at Wabtec's Erie, Pennsylvania facility, with 40 more to follow into 2020. The rebuilds will be numbered in both the 7000 and 7200-series and CSX is referring to them as CM44AHs.
Operators
AC4400CW owners and operators past and present include:| Owners | Qty | Numbers | Notes | Year delivered |
| Union Pacific | 1338 | 5554-6887 and 7080-7297 | 6147-6425 are ex-Southern Pacific and 6703-6737 are ex-Chicago and North Western, most have been repainted. 5668, 5836, 5842, 6536, 6707, and 7139 have wrecked and were retired. | 1994-2004 |
| CSX Transportation | 615 | 1-173, 201-599, 5101-5122 CW44AC. | Units 201-599 equipped with self-steering trucks. Units 23, 130, 151, 168, 220, 320, 365, 384, 399, 496, 517, 546, 571, and 597 are wrecked and retired. 326, 445, 469 and 518 have been sold to Canadian Pacific. Many will be rebuilt and modernized by Wabtec and be in the 7000 and 7200-number series and classed as CM44AH. | 1994-2002 |
| Canadian Pacific | 438 | 8500-8580, 8600-8655, 9500-9683, 9700-9740, 9750-9784 and 9800-9840. | The 9751, 9758, 9777, and 9782 were used in the 2010 film Unstoppable. Several units will be or have been rebuilt and are classified as AC4400CWM. Rebuilt units are renumbered 8000-8080, 8100-8160, 8200-8280. The 8644, 9538, 9630, and 9703 have all been wrecked and retired. | 1995-2004 |
| Southern Pacific | 279 | 100-378 | 145 and 224 were wrecked in 1996, the other 277 units went in to the Union Pacific fleet in the 1996 acquisition. | 1995 |
| Kansas City Southern | 175 | 4575-4596, 4597-4608 and 4609-4624 | 4580 and 4581 retired | 1999 |
| BNSF | 121 | 5600-5717, 5838-5840 | 40 units leased to Metrolink and converted to PTC throughout 2016. | 1999-2004 |
| Ferromex | 75 | 4550-4549 and 4550-4574 | 1998-2000 | |
| CIT Capital Finance | 60 | 1001-1025, 1026-1059 | 1026-1059 have been on long term lease to Canadian Pacific since 2004 | 2001-2004 |
| Ferrosur | 38 | 4400-4414, 4415-4429, 4430-4437 | 4428 Retired | 2000-2004 |
| Chicago & North Western | 35 | 8801-8835 | All units went to the Union Pacific in the 1995 acquisition. | 1994 |
| Cartier Railway | 17 | 11-12, 13-17 and 18-29 | 2001-2007 | |
| Quebec, North Shore and Labrador | 12 | 415-421 and 422-426 | 2005-2006 | |
| Cerrejón | 5 | 10010-10014 | ||
| General Electric Corporation Leasing | 11 | 2000, later renumbered 4400, 4000-4009 | 2000 was the GECX test unit | 1993-1997 |
| Central Maine and Quebec Railway | 2 | 1002 and 1006 | Former CEFX 1002 and 1006 | 2001 |
| Ferrominera del Orinoco | 2 | 1058-1059 | 2004 |