The Athearn ATH72149 HO Scale SD40u locomotive is a great addition to any model train collection. It features DCC and sound capabilities, bringing an extra level of realism. The SD40u, with Santa Fe #5007 livery, has unique features like nose headlights, a relocated horn, and cab - mounted Prime A/C. There are also Santa Fe style roof - mounted antennas and stands. Road - specific features include a removed front plow, nose headlight, roof - mounted A/C and antenna stands, and a long - hood mounted horn. The locomotive itself has numerous top - notch features. It comes with LED lighting, photo - etched stainless - steel windshield wipers, and is fully assembled and ready to run. There are separately applied wire grab irons, air tanks, coupler cut levers, and rubber MU hoses. The fine - scale handrails are molded in engineering plastic. The non - sound version has a 21 - pin NEM DCC plug. You can see through the dynamic brake and radiator fans, and there's a curved radiator fan grab iron. The exhaust stack, frame - mounted bell, and detailed 4000 - gallon fuel tank add to its authenticity. The Flexicoil - C trucks have high or low brake cylinders as per the prototype, and it uses McHenry scale knuckle spring couplers. The highly - detailed, injection - molded body with new tooling is painted and printed realistically. The see - through cab windows and bi - directional LED lighting enhance the visual appeal. It has all - wheel drive with precision gears for smooth and quiet operation, all - wheel electrical pickup, a 5 - pole motor with flywheels and a multi - link drivetrain for trouble - free operation. The wheels with RP25 contours work on all popular brands of track. It comes in window packaging for easy viewing, and an interior plastic blister for safe storage. The minimum radius is 18 inches, and the recommended radius is 22 inches. Sound - equipped models have an onboard Econami sound decoder by Soundtraxx. The sound units work in both DC and DCC, with an engine startup sound sequence. All functions are NMRA compatible in DCC mode, and there are dynamic brake sounds or Non - Dynamic Straight to idle on F4. Some functions are limited in DC, but it has extra prime mover and horn sounds exclusive to the Athearn version. It offers slow - speed control, multiple bell sound files configurable via CV, and a CV chart is included in the box. The current keeper is ready with an onboard expansion plug, and you can operate lighting functions with F5 and/or F6. You can even program a multiple - unit (MU) lashup with lead - unit - only horn, bell, and lights. Many functions can be altered via CV changes. The prototype SD40 was introduced in 1966 by EMD, with 3000 hp from a turbocharged V16, and was built in large numbers for American, Canadian, and Mexican railroads.

Using your Athearn ATH72149 HO Scale SD40u locomotive is a breeze. First, make sure your track is clean and properly connected. If you're using the DCC system, connect your locomotive to the DCC controller and set the appropriate address. For sound - equipped models, you can start the engine sound sequence and enjoy all the realistic sounds right away. When operating, the all - wheel drive and precision gears ensure smooth movement on the track. Remember, the minimum radius for this locomotive is 18 inches, but for better performance, use a 22 - inch radius track. For maintenance, regularly clean the wheels and electrical pickups to keep the power flowing smoothly. You can use a soft brush to remove any dust or debris from the body, especially around the delicate parts like the windshield wipers and grab irons. If you need to adjust any functions, refer to the CV chart included in the box. Be careful when handling the locomotive, as it has many small, separately applied parts that can be easily damaged. Store it in the provided interior plastic blister when not in use to protect it from scratches and dust.