Well over 1,300 RS-3 road-switcher locomotives were built by ALCO between 1950 and 1956.  It can be considered one of the most successful four-axle diesel road-switchers ever produced by the builder.  ALCO’s Canadian subsidiary, MLW, produced an additional 146 RS-3s in Canada.  These 1,600hp locomotives were powered by an ALCO 244 V-12 engine which was complemented by rugged GE electrical components.  The RS-3 was truly a versatile locomotive.  It could be found in virtually every type of service from passenger and commuter runs to heavy-haul and local freight assignments.  Original owners of the RS-3 tended to be in the eastern and central regions of the US (with heavier concentrations in the northeast and southeast).

During this same time-period, ALCO offered a six-axle road-switcher which was more commonly found in the west.  The RSD-4/5 was externally very similar to the RS-3, having six-axle trucks as an obvious spotting feature.  They produced the same 1,600hp as an RS-3, but offered increased tractive effort due to the use of a larger generator.  Many RSD-4/5s were assigned to operate in mountainous territory (with varying degrees of success) on the Southern Pacific, Santa Fe and the Utah Railway.

Features:

    DCC/Sound version available with LokSound decoder
    Analog version includes an 8-pin socket for DCC
    New! Improved tooling on turbo exhaust stack. Also includes option of water cooled or air cooled turbo exahust stack (Note: this run will only have a water-cooled exhaust stack.)
    Separately-applied handrails and stanchions, including separate drop step detail
    Factory installed AccuMate® couplers
    Dual flywheel-equipped five-pole skewed armature motor for optimum performance at all speeds
    Metal grab irons
    Accurate painting and printing

New Sound Features for Gold Series:

DCC Operation

    Supports all DCC-programming modes
    Flexible mapping of function keys F0 to F28.
    A total of six DCC function outputs are available
    Follows all NMRA DCC standards and recommended practices.

Analog (DC) Operation

    The LokSound Select Dual-Mode decoder allows your Atlas Gold Series locomotive to be used on DC as well as on DCC layouts.
    Please note that the Atlas Quantum Engineer will NOT operate an Atlas Gold Series locomotive equipped with a LokSound Select decoder on an analog (DC) layout. However, the sound and lighting functions of the LokSound Select decoder in the Atlas Gold Series RS-3 locomotive can be controlled by an easy-to-use basic DCC system
    Also note that on a DC-powered layout, a DCC and sound equipped locomotive (such as the Atlas Gold Series RS-3) CANNOT be consisted with another locomotive that does not also have both DCC and sound. (This statement does NOT apply to DCC-equipped locomotives operating on a DCC layout.)

Sound Functionality

    Over 20 sound effects are available, including engine start-up and shutdown, prime mover sounds through all eight notches, bell, air horn, air compressor, dynamic brakes and more.
    There are 16 user-selectable horns, 2 user-selectable bells, and 2 user-selectable synchronized brake squeals.
    Manual and Automatic Notching modes with the ability to change modes ”on the fly” are provided for true realism.