The GE AC4400CW, sometimes referred to as "AC44CW," is a diesel-electric locomotive with a power output of 4,400 horsepower (3,300 kW) that was manufactured by GE Transportation Systems from 1993 to 2004. It shares similarities with the Dash 9-44CW but stands out by featuring AC traction motors rather than DC ones, with each motor having a separate inverter. In terms of appearance, the AC4400CW bears a resemblance to GE's more powerful locomotive, the AC6000CW.
Over a span of 11 years, a total of 2,834 AC4400CW units were produced for North American railroads. By 2005, all major Class I freight railroads had at least one AC4400CW in their fleet, with the exceptions of Norfolk Southern and Canadian National. However, Norfolk Southern later acquired 36 former CEFX AC4400CWs in August 2023. Due to stricter emissions regulations that came into effect in January of that year, GE ceased the production of the AC4400CW and introduced the ES44AC as its replacement.
Design Variations:[]
The AC4400CW was the first GE locomotive to offer an optional self-steering truck design, designed to enhance traction and reduce railhead wear. This feature was requested by various railroads, including Canadian Pacific, Cartier Railway, CSX, Ferromex, Ferrosur, and KCS.
CSX ordered many of its AC4400CW locomotives with an additional 20,000 lb (9,100 kg) of weight to increase tractive effort. These units were later modified in 2006-2007 with "high tractive effort" software upgrades and were rebranded as CW44AH.
Rebuilds:[]
In 2017, the Canadian Pacific Railway enlisted General Electric to modernize 30 of its 9500 and 9600-series AC4400CW units. These units underwent significant upgrades, including the removal of the original front cab, and were equipped with modern GE standards, including PTC and FTO systems. These improvements resulted in up to 10 percent fuel efficiency gains, a 40 percent increase in reliability, and a 50 percent improvement in haulage capacity. These rebuilt units were designated as AC4400CWM (CWM for Modernized). A second order, the 8130-8144 series, retained their original steerable trucks, while the third batch, the 8000-8064 series, featured an Evolution Series-sized fuel tank and radial trucks. A fourth batch of rebuilds in 2019 included units from the 8145-8160 and 8064-8080 series.
The Union Pacific Railroad (UP) initially ordered some of its AC4400CWs with Controlled Tractive Effort (CTE) software, leading to their designation as AC4400CW-CTE. This software later became standard on a portion of their ES44AC locomotives. The CTE software restricts tractive effort to match the TE levels of Dash series locomotives.
In 2018, UP placed an order for 20 rebuilds from GE for its AC4460AC fleet and later announced plans to upgrade 1,000 of its AC4460ACs and AC44s into the new C44ACM class over 15 years. Unlike Canadian Pacific, the initial 20 rebuilds did not receive a new crew cab.
CSX and Wabtec entered a partnership to rebuild CSX's extensive AC4400CW fleet. The initial batch of 10 units was rebuilt at Wabtec's Erie, Pennsylvania facility, with 40 more rebuilds expected to follow. These rebuilds were designated as CM44ACs by CSX.
Operators:[]
The AC4400CW locomotives have been owned and operated by various railroads. While there have been changes over time, the following is a summary of the owners and operators:
- Union Pacific: 1,338 units, numbered 5554-6887 and 7080-7297, delivered between 1994 and 2004, with most units later rebuilt to C44ACMs.
- CSX Transportation: 615 units, numbered 1-173, 201-599, and 5101-5122, delivered between 1994 and 2002. These units are slated for rebuilding to CM44AC/CM44AHs and renumbering to the 7000-7299 and 7500 series.
- Canadian Pacific: 438 units, spanning various number ranges, delivered between 1995 and 2004. Many of these units were rebuilt to AC44CWMs and renumbered as 8100-8280.
- Southern Pacific: 279 units, numbered 100-378, delivered in 1995. These units were eventually acquired by Union Pacific.
- Kansas City Southern: 175 units, numbered 4500-4574, 4575-4596, 4597-4608, and 4609-4624 (formerly 2000-2039), delivered in 1999. The KCSM 4500-4574 units are ex-TFM 2600-2674.
- BNSF: 121 units, numbered 5600-5717 and 5838-5840, delivered between 1999 and 2004. Some of these units were leased to Metrolink in 2016.
- Ferromex: 75 units, numbered 4500-4549 and 4550-4574, delivered between 1998 and 2000.
- CIT Capital Finance: 60 units, numbered 1001-1025 and 1026-1059, delivered between 2001 and 2004. A few units were sold to CMQ in 2017, later returned in the 2020s, and 36 units were sold to NS in 2023.
- Ferrosur: 38 units, numbered 4400-4414, 4415-4429, and 4430-4437
Identification[]
The AC4400CW shouldn't be confused with its DC predecessor (C44-9W or the "Dash 9").
One notable difference is the style of trucks or bogies, which are usually placed on either, or both sides of the locomotive; while another difference is that a large radiator cabinet cover is placed on one side of the locomotive.
Another notable difference, is the fact that some U.S Class 1 railroads (aside from Mexican and Canadian) often paint lightning bolts on the sides of the cab or radiator.