Discontinued | This Item is No Longer Available
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HO RTR SD40M-2 with DCC & Sound, SP #8645

Item No.
Athearn - ATH72147
Discontinued | This Item is No Longer Available
Brand Logo
5 out of 5 Customer Rating

HO RTR SD40M-2 with DCC & Sound, SP #8645

Item No.
Athearn - ATH72147
Selected Store

Product Details


  • Blanked out/removed gyralights
  • Relocated horn
  • Tall forward ditch lights
  • Modified L window cab
  • Truck mounted spare knuckles
  • Large EMD plow
  • Extra dynamic brake vents
  • Nose ratchet brake
  • GRIP rebuilt battery box doors
  • SP style low mounted brake cylinder trucks


  • Red number boards
  • Nathan P-3 Horn
  • Stratolight Beacon
  • Nathan P-3 horn


  • Relocated horn
  • Vapor style A/C
  • Antenna with stand
  • Large EMD plow
  • Rear mounted brake wheel
  • Morrison Knudsen rebuilds from SD40 cores
  • Alternating front ditch lights with horn effect
  • MK style rebuilt truck sideframes with Timken bearings


  • MK rebuilds
  • cab mounted headlight
  • small ditch lights.
  • MK rebuilds
  • cab mounted headlight
  • small ditch lights.

During the 1980’s, SP’s aging fleet of SD40’s were in dire need of rebuilding. They went through SP’s “GRIP” program which upgraded the whole locomotive, becoming SD40R’s. By the late 1980’s, the original SP equipped gyralights became expensive to maintain and were removed to save costs. By 1994, some got repainted into SP’s then-new “speed lettered” scheme. Around this same time, SP contracted MK to rebuild numerous SD40 locomotive cores to basically a “new” version, a SD40M-2. MK added new features to these such as alternating front ditch lights, Timken roller bearings, and computerized wheel slip control. They were all used system wide and found in many types of service.


  • LED lighting
  • Photo-etched stainless steel windshield wipers
  • Fully assembled and ready-to-run
  • Separately applied wire grab irons
  • Separately applied air tanks
  • Coupler cut levers
  • Rubber MU hoses
  • Fine scale handrails molded in engineering plastic
  • Non-sound version features 21-pin NEM DCC plug
  • See-through dynamic brake and radiator fans
  • Curved radiator fan grab iron
  • Exhaust stack
  • Frame mounted bell (unless noted)
  • Detailed 4000 gallon fuel tank (unless different capacity is noted)
  • Flexicoil-C trucks with high or low brake cylinders (per prototype)
  • McHenry scale knuckle spring couplers
  • Highly-detailed, injection molded body featuring new tooling
  • Painted and printed for realistic decoration
  • See through cab windows
  • Bi-directional LED lighting
  • All-wheel drive with precision gears for smooth and quiet operation
  • All-wheel electrical pickup
  • 5-pole motor with flywheels and multi-link drivetrain for trouble-free operation
  • Wheels with RP25 contours operate on all popular brands of track
  • Window packaging for easy viewing
  • Interior plastic blister safely holds the model for convenient storage
  • Minimum radius: 18”
  • Recommended radius: 22”


  • Onnboard Econami sound decoder by Soundtraxx
  • Sound units operate in both DC and DCC
  • Engine startup sound sequence
  • All functions NMRA compatible in DCC mode
  • Dynamic brake sound or Non-Dynamic Straight to idle on F4
  • Some functions are limited in DC
  • Extra prime mover and horn sounds exclusive to Athearn version
  • Slow speed control
  • Multiple bell sound files user configurable via Configuration Value (CV)
  • CV chart included in the box
  • Sound units operate in both DC and DCC
  • Full DCC functions available when operated in DCC mode
  • Engine, horn, and bell sounds work in DC
  • All functions NMRA compatible in DCC mode
  • Excellent Slow speed control
  • CV chart included in the box
  • Current Keeper ready with on board expansion plug
  • Operating lighting functions with F5 and/or F6
  • Program a multiple unit (MU) lashup with lead unit only horn, bell, and lights
  • Many functions can be altered via CV changes


In 1966, EMD updated its locomotive catalog with entirely new models, all powered by the new 645 diesel engine. The SD40 had 3,000 hp from a turbocharged V16. 856 examples of this locomotive model were built for American railroads, 330 were built for Canadian railroads, and 72 were built for Mexican railroads.

This page is based on the copyrighted Wikipedia article “EMD SD40”; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA.

Product Specifications

Lighting LED
Sound Tsunami
DCC Equipped
Scale N
Axles 6
Reporting Mark SP
Era 1941-1970, 1971-1990
Prototype Manufacturer Electro Motive Division