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A CSX Transportation AC6000CW passing through the New River Gorge, West Virginia in February 2008
Type and origin
Power type Diesel-electric
Builder GE Transportation
Model AC6000CW
Build date 1995–2001
AAR wheel arr. C-C
UIC classification Co′Co′
Gauge 4 ft 8 12 in (1,435 mm)
Wheel diameter 42 in (1,067 mm)
Length 76 ft 0 in (23.16 m)
Width 10 ft 3 in (3.12 m)
Height 16 ft 0 in (4.88 m)
Axle load 72,000 lb (32.7 tonnes) max
Locomotive weight 423,000 lb (192,000 kilograms) - 432,000 lb (196,000 kilograms)
211.5 short tons (188.8 long tons; 191.9 t) - 216 short tons (193 long tons; 196 t)
Fuel type diesel fuel
Fuel capacity 5,500 US gal (21,000 l; 4,600 imp gal) or 6,200 US gal (23,000 l; 5,200 imp gal)
Prime mover GE 7FDL16, 7HDL16, GEVO-16 (rebuilds)
Engine RPM range 200 - 1050
Engine type 45° V16, four stroke cycle
Aspiration Twin turbocharger, model 7S1408D
Displacement 251.2 liters (15,330 cu in) (7HDL16, GEVO-16)[1]
175.2 liters (10,690 cu in) (7FDL16)[2]
Alternator GE GMG201
Traction motors GE GEB13 AC
Cylinders 16
Transmission diesel electric
AC Alternator to DC link to AC Traction inverters and Motors
Multiple working Yes
Performance figures
Maximum speed 75 mph (121 km/h) (worn wheels)
Power output 6,250 hp (4,660 kW)
Tractive effort Starting: 181,000–200,000 lbf (810–890 kN)
Continuous: 166,000 lbf (740 kN) @ 11.6 mph (18.7 km/h)
Factor of
2.16 to 2.35
Locomotive brake Dynamic and Electropneumatic brake
Train brakes WABCO EPIC 3102 Electropneumatic, others with WABCO 26L pneumatic
Operator(s) CSX Transportation, Union Pacific Railroad BHP Billiton
Locale North America, Australia

The AC6000CW is a 6,000 horsepower (4,500 kW) diesel electric locomotive that is built by GE Transportation. This locomotive, along with the EMD SD90MAC, is the most powerful single-engined diesel locomotive in the world, surpassed in power by only the dual-engine EMD DDA40X.


The AC6000CW was designed at the height of a horsepower race between the two major locomotive manufacturers, Electro-Motive Diesel of London, Ontario and GE Transportation of Erie, Pennsylvania in the early to mid 1990s. The goal was 6,000 horsepower (4,500 kW).

GE partnered with Deutz-MWM of Germany in 1994 to design and construct the 7HDL engine for the locomotives. The first locomotive constructed was the "Green Machine" GE 6000, the nickname due to the green paint scheme. The first production models were also built in 1995: CSX Transportation 600-602, and Union Pacific Railroad 7000-7009. After testing was completed by GE, they were released to their respective owners in late 1996.

Union Pacific Railroad 7391, an example of the 106 "Convertibles" built for Union Pacific Railroad with the 7FDL engine

The initial locomotives suffered from various mechanical problems with the most severe being the engine itself. There were major vibration problems which were addressed by increasing the engine mass to alter the resonant frequency. This in turn caused problems with the twin turbochargers. These problems caused GE to push back full production of the new model until 1998. Changes such as stiffer materials and increased engine wall thickness (to increase mass) were in place at full production.

GE built 106 AC6000CWs for Union Pacific with the older, proven 7FDL engine, rated for 4,400 hp (3,300 kW). These units were originally supposed to be converted to the 6,000 hp (4,500 kW) 7HDL engine after the problems were worked out with the engine, but this never occurred. GE considers these units as AC6000CW "Convertibles," while UP classifies them as CW44/60ACs or AC4460CWs.

The AC6000CW ended production in 2001, although Union Pacific's 75xx series remains in daily use as of 2010, mostly on rock and gravel trains in Texas. Union Pacific designates these units as C60AC, CSX as CW60AC.

On June 21, 2001, all eight of the Australian railroad BHP Billiton's GE AC6000s combined to set the world record for the heaviest and longest train. It hauled 99,734 tons and 682 wagons for 275 kilometres (170.9 miles) between Yandi mine and Port Hedland. The train was 7.3 kilometres (4.536 miles) long and carried 82,000 tons of iron ore.[3] The record still stands.


BHP Billiton's AC6000CW 6071 at Finucane Island on the Goldsworthy railway, Western Australia in April 2012, an EMD SD70ACe can be seen at right
Hood end view of CSX Transportation's 627 at Pinner's Point in Portsmouth, Virginia, note the enlarged radiator section overhanging the rear of the unit

In 2013 these were replaced by EMD SD70ACes.[6] As of 2014 the remaining 7 are being scrapped after unsuccessful attempts to sell them due to the high costs of exporting them.

  • CSX Transportation:
    • 3 units, numbered 600-602, were among the first production AC6000CW's built.
      • 601 is lettered "The Spirit of Waycross".
      • 602 is lettered "The Spirit of Maryland" & is the only AC6000 on CSX to retain its original Hi-Ad trucks.
    • 114 units, numbered 603-699 & 5000-5016, were built between October 1998 & April 2000.
    • 600-602 original prime movers replaced with 4400 HP 7FDL16 engines. This is due to these units being pre-production models & mechanical differences between them and the production model.
    • 603-699, 5000-5016's original prime movers replaced with 6000 hp 16 cyl. GEVO prime movers and new computer equipment essentially making them ES60ACs.
    • 5015 and 5016 were both classified as a CW60AH.

By 2014 CSX derated the GEVO powered units to 4600 horsepower and reclassed them CW46AC.

  • Union Pacific:
    • 10 units, numbered 7500-7509, were built between November 1995 & December 1996. These units were originally numbered 7000-7009.
    • 45 units, numbered 7510-7554, were built between July & December 1998.
      • 7511 suffered an electrical fire and was retired from the roster in June 1999. The damage was covered under warranty and the unit was sent to GE for repairs. GE built another 7511 unit for UP to replace the original in January 2001, renaming the original 7511 to GECX 6002.
    • 25 units, numbered 7555-7579, were built in January 2001.
    • All were converted to AC4460CW units and renumbered to 6888-6968.
  • Union Pacific Convertibles:
    • 70 units, numbered 7336-7405, were built between November 1995 & September 1996. These units were renumbered to 7010-7079 to make room for ES44ACs.
    • 42 units, numbered 7300-7337, 7339, 7340, 7342, and 7344 were built between March & May 1998.

See also[edit]


  1. ^ Official archived engine description
  2. ^ 7FDL16 Specifications Page 24
  3. ^ BHP breaks its own 'heaviest train' record Railway Gazette 1 August 2001
  4. ^ AC6000 Railpage
  5. ^ Clark, Peter (2012). An Australian Locomotive Guide. Rosenberg Publishing. p. 288. ISBN 9781921719554. 
  6. ^ "BHPB Iron Ore Update" Motive Power Issue 91 January/February 2014 page 9