In 1965, EMD introduced the six axle SD45. It featured a new 3600 HP EMD 645E3 20 cylinder prime mover. The new engine fit on the same frame as earlier EMD units such as the SD40, but provided an additional 600 horsepower. At the time, this was the most powerful single motor locomotive produced. While moving, the locomotive used less fuel per mile than the SD40's, but did use more when idling owing to the additional four cylinders.

Early on, SD45's were not as reliable as hoped, as the 645E3 did occasionally break crankshafts. EMD addressed this issue by strengthening the block and redesigning the crankshaft, but sales were modest. Production ran from 1965 to the end of 1971 with a total of 1260 units built for North American railroads. It was replaced with the SD45-2 in 1972, along with the rest of the -2 series locomotives. The SD45-2 fared even worse, with few orders, it was discontinued in 1974. The SD45 and SD45-2 were far outpaced by the EMD GP38-2 and SD40-2 locomotives.

Original operators included Great Northern, Northern Pacific, Santa Fe, Southern Pacific and Union Pacific. Some SD45's remain in service today with secondary owners and leasing companies. Most of the remaining units have been rebuilt with sixteen-cylinder 645's, essentially making them SD40's and SD40M-2s depending on the level of upgrades done. Though these locomotives saw limited success in sales, they have gone on to have long service lives and rebuilt examples will certainly be around for years to come.

Features:

• Fully assembled and ready to run
• 14:1 helical gears for ultra-quiet and smooth running
  
• Easy multiple unit operation
  
• Superb paint and lettering
  
• Metal grab irons and lift rings
  
• LED constant and directional headlights
• Operating ditch lights, as per prototype
  
• Powerful five-pole, skew-wound, high-torque, high-efficiency can motor
  
• Low speed under 3 scale MPH
  
• Proto MAX metal knuckle couplers
• Factory installed SoundTraxx Tsunami sound for DC or DCC layouts

Based on ex-PRR #6105-6138 series units transferred to Conrail in 1976 to retirement in mid-1980s with:

• Cab-mounted headlights
  
• Long blower-duct sill
  
• Leslie S-3L air horn
  
• Standard-style coupler cut levers
  
• Large Sinclair antenna
  
• Small two-strap signal equipment box
  
• Oval cab vent
  
• Rear wheel-type hand brake
  
• No footboards on pilots
  
• Late Flexicoil trucks with two high outside mounted brake cylinders