Description
In 1949, EMD introduced the successful GP7, a versatile "General Purpose" locomotive with improved visibility and easier maintenance over the F and BL series. Building on this, the six axle “Special Duty” SD7 and later SD9 were later introduced, offering better traction and versatility. The SD9 featured a higher horsepower rating and minor physical changes over production phases. Many were rebuilt in the 1970s to extend their service life, with some operating into the early 2000s before retirement by the Class Is, though some continue to operate on shortlines and at grain elevators.
In versions and paint schemes spanning the transition era to now, the EMD SD7 and SD9 locomotives can be at home on almost any railroad. Our Rivet Counter™ series model renders numerous variations of cabs, dynamic brakes, hoods, fuel and water tanks, etc. We’ve also incorporated LED lighting effects including front, rear, and side walkway lights; ground lights; printed and lighted number boards; Mars or Pyle signal light packages; and ditch lights.
Learn more by clicking the “Product Details” tab below.
Road Number Specific ScaleTrains
- All-new model
- New roadname
- New paint scheme
- New road numbers
- Era: 1953 to Early 1960s
- Series 565 to 572, built Jan-Feb 1953
- Fully-assembled
- Multiple road numbers
- LED-illuminated ground lights on both sides of locomotive*
- LED-illuminated walkway lights on hood ends *
- LED-illuminated, tri-color front and rear, door-mounted class light housings (SD7)**
- Printed and LED-illuminated number boards*
- High short hood and long hood end number boards
- “Straddle” (butterfly) type re-rail frogs
- 4-hose multiple unit (MU) hose clusters with silver gladhands
- Semi-scale “cast” style coupler buffer equipped with durable metal semi-scale Type E knuckle couplers
- Front and rear straight uncoupling levers without loop handles
- As-delivered pilot faces without uncoupling lever loop notches
- Pilot-face mounted MU receptacle, left side
- Standard SD7 stepwells (inset top and middle step) with poling pockets
- “Pipe” style handrail stanchions with end gangways with chain
- Front and rear standard drop steps
- Scale sectioned treadplate detail with EMD “dot” style pattern
- Standard high short hood
- Standard sub-base
- Standard sidesills with louvered access doors on right side
- Early-style EMD LED-illuminated headlight housing with lenses, front and rear
- Cab with “retractable” type armrests
- Detailed cab interior with separate floor, rear wall, seats, and early control stand, long-hood forward operation
- Sliding cab side windows
- No mirrors
- Cab drip rails
- Lost-wax brass cast Leslie S-3-L horn mounted to cab roof
- No radio antennas
- Standard bolted electrical cabinet roof hatch
- Separately-applied, tapered exhaust stacks
- Non-dynamic brake housing
- Separately-applied photoetched radiator intake screens with intake shutters underneath
- See-through 36” fan housings with separate fans, radiator core detail, and hood roof plumbing
- Winterization hatch over #1 radiator fan
- Separately-applied sand fill hatches
- Detailed EMD Flex-i-Coil “C1” trucks with separately applied brake plumbing, brake cylinders, and flexible neoprene rubber sanding lines
- Dimensionally accurate truck centers
- Standard EMD bell mounted to bracket on non-dynamic housing.
- Underbody air filter details
- Single 1,200-gallon fuel tank mounted to the rear with single sight glass per side, and single 1,200-gallon fuel tank to the front
- Factory-applied wire grab irons, end ladders, photoetched lift rings, windshield wipers, trainline hoses with silver gladhands, signal hoses with silver gladhands, air tanks with plumbing, and more
- Motor with 5-pole skew wound armature
- Dual flywheels
- All-wheel drive
- All-wheel electrical pick-up
- Directional LED-illuminated headlights
- Printing and lettering legible even under magnification
- Operates on Code 70, 83, and 100 rail
- Packaging safely stores model
- Minimum radius: 18”
- Recommended radius: 22”
DCC & sound equipped locomotives also feature:
- ESU LokSound 5 DCC & Sound decoder with “Full Throttle” feature
- Two (2) cube-type speakers
- Prime mover sound
- 16-cylinder 567B prime mover sound
- ESU designed “PowerPack” with two super capacitors***
- Operates on both DC and DCC layouts
DC/DCC & sound-ready locomotives also feature:
- Operable on DC layouts
- DCC-ready with 21-pin connector
* Lighting features operate when using an ESU decoder with appropriate programming while operating using DCC
** Class lights illuminate in white color only in DC operation. Access and changing colors requires an ESU decoder with appropriate programming while operating using DCC
***“PowerPack” feature only compatible with appropriately programmed ESU decoders operating on a DCC layout
In the peacetime immediately following World War II, EMD was poised to take the lead in diesel-electric locomotive technology, with America’s railroads eager to replace steam and enjoy the performance and efficiency gains from doing so. Their groundbreaking FT, and subsequent F and E series locomotives, were immensely popular, and by the early 1950s, they could be seen hauling freight and passenger trains from coast to coast.
As popular as they were, however, the basic design of these cab units had a fundamental operational flaw: poor rearward visibility. While their streamlined design was fine for moving passenger or freight trains long distances, when it came time for switching, the design was less than ideal, making it difficult for engineers to see crew members on the ground, not to mention poor visibility when making reverse movements, which happened often when doing yard work or running local freights on branch lines. EMDs solution was the BL1 (“BL” standing for “Branch Line”) locomotive of 1948, and subsequent BL2. Essentially a re-packaged F-unit, they retained the truss body framing of the F-unit series, with the sheet metal around it re-designed in an attempt to provide improved visibility in either direction, and provide corner steps and grabs for switchmen.
While an interesting concept, they were not well-received by the railroads, with only a single BL1, and a total of 58 BL2s, built. In 1949, EMD would try again with a clean-sheet utilitarian design that was to prove wildly successful: the GP7. With the “GP” designation standing for “General Purpose”, in a nod to its jack-of-all-trades versatility, it was essentially an F7 internally, with a 16-567B prime mover generating 1,500hp, and riding on a pair of the proven “Blomberg” 2-axle trucks. Its key design feature was an all-new fabricated frame, replacing the truss structure of the F/E units. This allowed for a narrow hood to house the internal machinery, side walkways and end platforms, and much deeper steps at the corners for switchmen. All of this made for a locomotive with much greater visibility in either operating direction, and easier access to the internal components for maintenance.
Building on the success of the GP7, in 1951, EMD would take the General Purpose concept a step further with the introduction of the SD7, with “SD” indicating “Special Duty”. While internally it was basically an F7 or GP7, externally it featured a lengthened frame with a pair of 3-axle “Flex-i-Coil” trucks, with a traction motor per axle. While the 4-axle GP7 was fine in most applications, its 4-axles and traction motors could be a bit “slippery” in others, such as hilly/mountainous territory, and on high-tonnage coal or ore trains. The additional pair of axles and traction motors of the SD7 provided greater tractive effort to help start heavy trains and keep them moving on all kinds of territory, as well as helping to distribute the weight of the locomotive, allowing them to operate on lines with lighter rail and/or less than ideal trackwork.
Purchased by numerous railroads, the SD7 was a success, with a total of 188 built. Versatile, when equipped with optional steam generator equipment housed in the high short hood, it could be used for passenger service, and was utilized as such on roads like Burlington Route and Southern Pacific. Another distinctive feature of the SD7 was its fuel and/or water tanks. It could be optioned with a single 1,200-gallon fuel tank, leaving a large gap between it and the front truck, a dual tank setup for passenger service, which had an additional 1,200-gallon tank for steam generator water installed ahead of the fuel tank, or a pair of 1,200-gallon tanks for fuel. In later years, some railroads with the split fuel and water tank arrangement would convert the water tank for fuel only when their passenger hauling days were done, and roads with light trackwork could option for just a single fuel tank, to help keep overall locomotive weight down.
Coinciding with EMDs changeover to the E/F9 series and GP9, the SD7 would morph into an improved model, the SD9, in 1954. Internally, horsepower got a boost to 1,750, while externally, not much changed from the SD7, at least on initial production. The class light placement was the one readily noticeable difference between the two; while the SD7 featured class lights built onto hinged doors placed close to the centerline on each end, on the SD9, they were located at the upper corners of the hood ends, in a fixed mounting. While the SD7 had a pair of inset steps at the corners, the SD9 would have a revised corner step arrangement, with full-depth steps at all locations. With a total of 471 units built for domestic owners, over an extended period of time, the SD9 would undergo cosmetic changes over that timeframe, resulting in what railfans and modelers call production “phases”. Aside from the class lights, early SD9s weren’t much different from SD7s, but this would change with what were dubbed “Phase II '' units, introduced in early 1955. EMD would change the multi-piece “pipe” handrail stanchions from SD7s and early SD9 production, to “channel” style stamped handrail stanchions to help reduce production costs, a design that was to become standard on nearly all subsequent EMD production.
Another phase change, “Phase III”, would be introduced in early 1958. This time, EMD would revise the cooling system, changing from four 36” radiator fans at the rear of the long hood roof, to a pair of 48” fans. Finally, “Phase IV” units, introduced in early 1959, would round out SD9 production with a slew of physical changes. Up front, the cab sub-base would increase in height, and the battery boxes, previously located on the walkways behind the cab, would be relocated to the walkways immediately ahead of the cab. The taller battery boxes and cab sub-base resulted in the cab and high short hood sitting taller than previous production, resulting in a bit of a “hammerhead” appearance. The long hood immediately behind the cab also featured a change in its profile, losing its rounded corners, and changing to a more squared-off corner profile.
The SD7 and successor SD9 locomotives would prove to be popular and long-lived machines. Most major railroads of the era would purchase examples of SD7s and/or SD9s, using them in a multitude of assignments. With such a variety of owners, many differences in optional equipment could be seen, ranging from just standard headlights to extensive lighting packages, to steam generator equipment, to fuel/water tank combinations, and on and on, resulting in many unique-looking SD7s and SD9s. The models would eventually acquire the nickname “Cadillac” among their operators. Much like the GM automobile line of the same name, they were powerful and offered a smooth ride, which was much appreciated by engineers and conductors that endured bone-jarring rides in locomotives from competitors.
By the 1970s, many of these rugged SDs were due for rebuilding, and many railroads would do just that, in order to improve their reliability, maintainability, and lengthen their service lives. While some rebuilds were mostly focused on renewing or updating internal components, some railroads would implement more extensive changes, such as lowering the high short hoods all were initially built with, to a low short hood arrangement with cab face center windshields, in order to improve forward visibility. While most would be retired by the 90s, and sold to secondary operators, a few fleets would linger on for their original (or successor) owners, such as BNSF, Southern Pacific, and Norfolk Southern. By the early 2000s, the last of these long-lived units would be purged from Class One rosters, but many “Cadillacs” are still out there. While they may be in less demanding roles at grain elevators or shortline railroads, they’re still moving freight after upwards of over seven decades of service.
