ScaleTrains 38492 HO Scale GE AC4400CW Diesel Union Pacific UP 7098

Throughout the history of rail transportation, there have been innovations that revolutionized the industry. From Andrew Beard’s patented designs in the late 1800s that resulted in the automatic couplers that are still used today, to the adoption of diesel technology for locomotive propulsion, these seemingly small developments would lead to massive changes in the industry. The adoption of AC traction in the 1990s could arguably be seen as another giant leap forward.

In the early 1900s, diesel-electric locomotives began to appear, initially in the form of “boxcab” design switchers built by the team of ALCO, GE, and Ingersoll-Rand (“ALGEIR”) in 1925. This new propulsion design proved promising. At its most basic definition, a diesel prime mover spins a generator that produces electricity which powers electric traction motors on the axles. Diesel-electric locomotives did not need the extensive and expensive infrastructure required for electric or steam locomotives. Maintenance was also far less intensive and expensive compared to the steam locomotives that ruled the rails of the day.

By the late 1930s, the writing was on the wall for steam locomotives. By the end of World War II, railroads in the U.S. started to “dieselize” en masse. Constrained by the production needs for defense materiel during the war, many of the longtime steam locomotive builders began to develop diesel-electric designs after peace was declared. The upstart Electro-Motive Division (EMD, by then a division of General Motors) turned heads shortly before the U.S. entered the war with its groundbreaking FT diesel-electric locomotive. Heavy industrial manufacturer General Electric (GE) continued to be involved with railroading, but mostly in a support role, providing electrical components such as traction motors to various builders.

Throughout the 1940s and 1950s, EMD would emerge as the number one builder of diesel locomotives with its successful line of E and F-units, along with GP and SD-series units, which were built by the thousands for railroads all over the country. In 1960, GE was to challenge EMDs dominance with their “Universal” series of locomotives, starting with the U25B. While EMDs continued to outsell these early GE efforts for the next three decades, GE steadily improved their product and increased their market share. In the 1980s, EMD stumbled with quality control issues, most notably with the 50-series. This opened the door for GE going into the 1990s, and they would become the leading locomotive builder in the U.S. thanks to their DASH 8 and DASH 9 series of units. Their next step in locomotive evolution was waiting in the wings.

EMD and GE would soon square off in the development of Alternating-Current, or A.C., traction for locomotives. Prior production models from both builders utilized Direct-Current (D.C.) traction motors for propulsion, as was done since the very first diesel-electric locomotives were produced. A.C. traction motors demonstrated significant advantages over their D.C. counterparts by allowing for much greater continuous tractive effort, as well as reduced maintenance. They were also much more resilient than D.C. motors, and were able to endure much higher short-time ratings (the ability of the traction motors to withstand high amperage at low speeds for a set period of time without incurring damage), giving them extraordinary lugging ability.

A.C. units showed their ability to replace their D.C. predecessors on a 3-to-5 basis, being able to walk away with heavy trains from a dead stop on an upgrade, in scenarios that were nearly impossible with an equivalent number of D.C. units. This wizardry required substantial changes to the locomotive’s electrical system, including a system of electrical inverters to “refine” the current being fed to the traction motors and an extensive microprocessor control system to manage it all. While these changes increased per-unit cost, most railroads found the benefits to be more than worth the expense. With that, EMD would introduce the SD70MAC, and GE the AC4400CW. The AC4400CW was based upon GE’s highly successful Dash 9-44CW design, and would become one of the hottest selling locomotives of the 1990s and beyond.

Initial AC4400CW customers utilized their units in applications best suited for their tremendous lugging ability. Based upon their satisfaction with the DASH 9 fleet and their desire for reliable power to move Powder River Basin coal, the Chicago & North Western (C&NW) was one of the first to purchase the newest A.C. power. Sets of AC4400s, painted in the attractive “Lightning Stripe” variation of their classic green and yellow paint scheme, could be seen all over the Powder River Basin moving seemingly endless strings of coal hoppers or gondolas.

CSX Transportation (CSXT) was another early customer and ordered a sizable fleet of ACs for service in the Appalachian coal fields. Delivered in the attractive yellow, blue, and gray “YN2” scheme, the new units quickly became crew favorites. The new AC4400CWs handily outperformed older locomotive models in their daunting assignment.

Western giant Southern Pacific (SP) stunned the industry with a massive order of 278 units. All were delivered in their longtime gray and scarlet, but with the Rio Grande Industries inspired “Speed Lettering” on their flanks. While SP struggled financially throughout the 1980s, by the 1990s they were seemingly on the rebound, ordering large numbers of high-horsepower, 4-axle units over the previous years, for use on high-speed, high-priority intermodal traffic. However, SP’s 6-axle heavy-haul fleet had languished over the years, and the ACs were a much-needed shot in the arm. A.C. power allowed SP to handle growing amounts of bulk traffic (coal, minerals, crude oil, and grain) across the system.

Enticed by the promises of improved train handling and reduced maintenance costs, more and more railroads took notice and joined the A.C. revolution. Eventually, as operating practices evolved, ACs would find themselves in services beyond the heavy-tonnage applications they were originally envisioned for. As piggyback traffic dwindled and heavier double-stack container trains became more prevalent, AC4400s started finding their way onto those trains, where again their performance characteristics proved their value. As older power was retired or cascaded down into more secondary duties, ACs were finding themselves on just about every service on the railroad.

By the time domestic AC4400 production ended in 2004, nearly every Class 1 railroad had ordered examples of AC4400s except for Norfolk Southern (NS). Ever the holdout, NS avoided safety cabs and AC-traction as long as possible. Instead, they would purchase standard-cab DASH 9s as well as large numbers of its safety-cab equipped version, the C40-9W. Into the 2000s however, NS would eventually acquire AC-traction locomotives, and were impressed with their performance. So much so, they would embark on a rebuilding and upgrading program for their older DASH 9 locomotives, dubbing them “AC44C6M” (AC traction, 4,400hp, C for six axles, the number 6 to signify the number of traction motors, and M for “Modified”). They would have their cabs replaced with the latest GE safety cab design, plus new electrical systems, and components upgraded to AC4400 standards.

In recent years, railroads such as Canadian Pacific, CSX, and Union Pacific have embarked on rebuilding programs for their AC4400 fleets. These programs replace worn out or obsolete components, plus upgrading various systems to improve performance. While examples of the competing EMD product have not been as fortunate. In fact, some have already been retired and scrapped. Aside from wreck victims, nearly all AC4400s are still in service. With rebuild and upgrade programs, they will likely be in service for many years to come.

FEATURES:

• All-new model
• Era: Early 2000s to Present
• Series 7080 to 7298, built 10/97
• Road number 7098
• Yellow sill stripe applied over original red stripe
• Octagonal antenna dome
• Gray swapped HVAC unit
• Nose door window
• Fully-assembled
• Multiple road numbers
• Operating LED-illuminated ground lights on both sides of locomotive*
• Operating LED-illuminated front, rear, and side walkway lights*
• Operating LED-illuminated front pilot face mounted ditch lights**
• Printed low-mount cab number boards with separately controlled backlit LED-illumination*
• Tall snowplow with open doors and two (2) grab irons
• Semi-scale coupler buffer equipped with durable metal semi-scale Type E lower-shelf knuckle couplers
• 5-step stepwells with see-through steps
• Walkway with front anticlimber
• GE “nub” pattern walkway tread
• Narrow profile end handrails
• Single dummy and single live pilot face MU connections
• Front nose headlight
• Two-piece nose top grab irons
• Battery cabinet access door without latch
• GE safety cab with three (3) side windows
• Right side cab under floor access doors: four screened louver sections per door
• Left side cab under floor access doors: dual latch door with grille forward of the HVAC unit
• Cab interior with detailed back wall and front dash, high-back seats, conductor’s workstation, and engineer’s desktop controls
• Tinted cab side windows
• Tall mirror mounted in front of sliding cab side windows on both sides; additional small mirror on right side
• Early inverter cabinet: six (6) tall vertical rectangular bolted panels and three (3) horizontal short panels
• Continuous reinforcement rib under dynamic brake intake grilles
• Standard dynamic brake exhaust (2-port)
• Forward right-side air intake grille
• Left side auxiliary cab: three (3) medium doors with latches on the #2 door
• Capacitor box on left side walkway
• Right side auxiliary cab: four (4) doors with latches on #1 and #4 doors
• Late angled engine cab profile with tri-fold power assembly access doors
• Lost-wax brass cast Nathan AirChime K3LAR2 horn mounted on engine cab
• Late non-flanged exhaust stack housing
• “Bathtub” exhaust silencer
• 26 individually-applied etched metal see-through radiator intake and exhaust grilles on sides and top of radiator compartment
• Late radiator door grilles in alternating heights
• Standard brake wheel
• Left rear hood door grille arrangement: tall, short, tall grilles
• Low-mounted rear sand fill
• Early “box” lifting lugs on ends of radiator wings
• Accurately profiled frame with separately-applied plumbing and traction motor cabling
• Late Hi-Ad trucks with cantilever struts on right front and left rear sideframes
• Rotating axle bearing caps
• No speed recorder
• Dual Graham-White (Salem) 824-100 centrifugal air filters
• No air dryer
• 5,000-gallon fuel tank with vertical weld seams
• Single fuel fills per side
• Round and vertical analog fuel gauges; digital fuel gauges
• Fuel tank mounted steel bell
• Separate air tanks with lower mounting brackets, connector pipe, and connector pipe cover
• Early square handbrake chain bracket
• Spare coupler knuckle holders on rear pilot face
• Factory-applied detail parts: wire grab irons, spare knuckles, trainline hoses with silver gladhands, 3-hose MU clusters with silver gladhands, uncoupling levers, windshield wipers, mirrors, sunshades, and more
• Motor with 5-pole, skew-wound armature
• Dual flywheels
• All-wheel drive
• All-wheel electrical pick-up
• Directional LED headlights
• Printing and lettering legible under magnification
• Operates on Code 70, 83, and 100 rail
• Packaging safely stores model
• Minimum Radius: 18”
• Recommended Radius: 22”
• DCC & sound ready locomotives also feature:
• Operate on DC layouts
• DCC ready with 21-pin connector

* Lighting features operate when using an ESU decoder with appropriate programming while operating using DCC
** In DC operation, both front ditch lights illuminate; rear ditch lights (if equipped) do not illuminate
*** Compatible with appropriately programmed ESU decoders while operating using DCC