Available Items


O Scale RailKing SD-45 Diesel Engine w/Proto-Sound 3.0
  • Erie Lackawanna


O Scale RailKing SD-45 Diesel Engine w/Proto-Sound 3.0
  • Conrail


O Scale RailKing SD-45 Diesel Engine w/Proto-Sound 3.0
  • Montana Rail Link


O Scale RailKing SD-45 Diesel Engine w/Proto-Sound 3.0
  • Seaboard Coast Line


O Scale RailKing SD-45 Diesel Engine w/Proto-Sound 3.0
  • Santa Fe

2023 RailKing O Scale SD-45 Diesel Locomotives Announced

October 4, 2022 - M.T.H. Electric Trains will be releasing a series of 2023 RailKing O Scale SD-45 Diesel Locomotives in five exciting paint schemes beginning early next Spring. Each of these unique schemes will be available in limited production quantities and are expected to begin shipping to M.T.H. Authorized Retailers in April 2023.


In addition to the M.T.H. releases, you can find all the 2022 Custom Run models of the RailKing SD-45 Diesel Engine w/Proto-Sound 3.0 that M.T.H. is producing for M.T.H. Authorized Retailers by going HERE.


Like the Pontiac GTO, the SD45 was a mid-60s General Motors muscle car. Stuffed under its brick-like hood was the largest diesel motor made up to that time, a turbo-charged, 20-cylinder, 3600 hp, Electro-Motive Division model 645E. The Great Northern took delivery of the first SD45 in May of 1966 and promptly painted the nickname “Hustle Muscle” on its flanks. The name said it all: the SD45 was heavy freight power, intended for long trains and high speeds. And it had the muscular looks to match, with flared radiators capping a long body that filled every inch of its frame — as opposed to its baby brother, the SD40, which had an open “porch” at each end of the engine.

Unfortunately, the 20-cylinder motor turned out to have a major flaw: a tendency to break its own crankshaft. Even so, a large number of Class 1 railroads rostered the engine, with 1,260 units sold between 1966 and 1971. The Santa Fe, Burlington Northern, Pennsy, and Southern Pacific each owned more than 100 of the heavy freighters. Looking at the order quantities, one can see that the SD45 marked the beginning of a large-scale shift toward six-axle freight engines on American railroads. Before the late ‘60s, adding a third axle to a truck was mainly an expedient to spread out an engine’s weight for service on lighter rail, particularly branch lines. But with the SD45 and its contemporaries, railroads began favoring the six-axle engine as a way to get more power on the rails for heavier mainline trains. Despite the initial crankshaft problems, many SD45s served their original owners for decades, as well as successor railroads like Conrail and the BNSF, and later went on to new lives at smaller, secondary roads.

The RailKing Scale model comes fully equipped with Proto-Sound 3.0, remotely activated Proto-Couplers, speed control in scale miles-per-hour, operating smoke, LED lighting and much more.

Check out each of the M.T.H. offerings in the list on the left.

Product Features



  • Intricately Detailed Durable ABS Body
  • Die-Cast Truck Sides, Pilots and Fuel Tank
  • Metal Chassis
  • Metal Handrails and Horn
  • (2) Handpainted Engineer Cab Figures
  • Authentic Paint Scheme
  • Metal Wheels, Axles and Gears
  • (2) Remote Controlled Proto-Couplers
  • Prototypical Rule 17 Lighting
  • Directionally Controlled Constant voltage LED Headlights
  • Lighted LED Cab Interior Light
  • Illuminated LED Number Boards
  • Operating LED Ditch Lights
  • (2) Precision Flywheel-Equipped Motors
  • Operating ProtoSmoke Diesel Exhaust
  • Onboard DCC/DCS Decoder
  • Locomotive Speed Control In Scale MPH Increments
  • 1:48 Scale Proportions
  • Proto-Sound 3.0 With The Digital Command System Featuring Freight Yard Proto-Effects
  • Unit Measures: 17 1/4” x 3 3/4” x 2 3/4”
  • Operates On O-31 Curves