The Alco RS-3 was a critical part of the Pennsylvania Railroad’s early dieselization strategy, serving as a versatile road switcher capable of yard work, transfer runs, branch line freights, and secondary mainline service. With 1,600 horsepower from Alco’s 244 prime mover and a sure-footed B-B wheel arrangement, the RS-3 fit seamlessly into the PRR’s massive and varied operating environment.
True to Pennsy practice, the railroad applied its own unique engineering philosophy to the RS-3 fleet. Some units were delivered or rebuilt with high short hoods, earning the nickname “Hammerheads,” while others retained standard low short hoods equipped with Trainphone antennas, allowing communication with train crews across the system. These distinctive variations make the PRR RS-3s some of the most interesting and visually diverse road switchers of the era.
Now, Sunset Models 3rd Rail brings these iconic Pennsy RS-3s to O Scale 2-Rail and 3-Rail for the first time outside of brass, combining a precision ABS plastic shell, die-cast metal chassis, and fine brass detail parts for museum-quality accuracy and performance.
Versions & Road Numbers Offered
High-Short-Hood “Hammerhead” RS-3s
Featuring the distinctive tall short hood unique to select PRR RS-3s, these locomotives are instantly recognizable and highly sought after by Pennsy modelers.
PRR 5569
PRR 8445
Standard-Hood RS-3s with Trainphone Antennas
Equipped with the signature PRR Trainphone antenna system, these units represent the railroad’s emphasis on communication and operational efficiency.
PRR 8591
PRR 8598
PRR 8600
Each version is tooled and detailed specifically to reflect its hood configuration, antenna arrangement, and era-appropriate appliances.
Model Features
• Precision ABS Plastic Shell with Die-Cast Metal Chassis
• Fine Brass Detail Parts — handrails, grab irons, grilles, pilot hardware, lift rings, MU connections, and rooftop fittings
• Distinct Hammerhead & Standard-Hood Tooling — capturing the PRR’s unique RS-3 variations
• Authentic PRR Paint & Lettering — Brunswick Green with correct gold striping, keystone heralds, and number fonts
• Road-Specific PRR Details — Trainphone antennas, lighting packages, horn placement, number boards, and pilot variations matched to each roadnumber
• Powerful Can Motor Drive for smooth, quiet, reliable operation
• All-Wheel Drive and All-Wheel Electrical Pickup
• Advanced electronics: 3R ERR Cruise/TMCC/Railsounds compatible with TMCC/Legacy/DCS, 3R Conventional for your choice of sound, and 2R ESU Loksound 5.0.
• OEM Blunami Upgrade Option Available in both 2-Rail and 3-Rail
• LED Lighting Suite — headlights and number boards
• ERR Cruise is compatible with Legacy, DCS, TMCC, and Conventional control systems
Smoke is not availabe in 3R units due to space constraints
Pennsy Engineering, Perfected "A Cut Above" in O Scale
From the unmistakable Hammerheads to the antenna-equipped standard-hood units, the Pennsylvania Railroad RS-3sshowcase the railroad’s hands-on approach to diesel design and operation. These locomotives worked everywhere the Pennsy ran trains, embodying the practical, no-nonsense character of America’s largest railroad.
With this release, Sunset Models 3rd Rail delivers the first non-brass O Scale production of PRR RS-3s, with accuracy, presence, and performance worthy of the keystone.
Reserve your Pennsylvania Railroad RS-3 today and add a true Pennsy classic to your O Scale roster.
Minimum of 20 of the standard hood are needed to be reserved to build. 50 are needed for the hammerheads.
Photo courtesy of brasstrains.com
