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  • The First Turbo SD: Part 1

    by George Melvin

    Santa Fe SD24 900, built in May 1959, was the first production SD24 after the single demonstrator/test-bed unit 5579 built ten months earlier in July 1958. Seen here at Barstow, CA, on November 5, 1969, with just over a decade of service, it still carries its original number but is repainted in the then-standard solid blue with billboard Santa Fe on the long hood. Note the visor above the headlights, added by Santa Fe. Decals: Microscale 87-548.
    Model Railroading - September 2004 - Page 20

    Lets go back 50 years, to 1954, and take a snapshot of the diesel locomotive stage in the ever-changing drama of the development of new models and competition for diesel sales. The success of the diesel in replacing steam was undisputed, and there were only a few pockets of resistance left on Class I railroads where steam operations were not in a steep decline. Elsewhere, railroads were pushing the steamers out of operation just as fast as they could acquire new diesels. In January that year, General Motors Electro-Motive Division (EMD) started delivery of the nine series of road units, the F9, GP9 and SD9. Sticking with its proven strategy of refining and improving the venerable 567 power plant, now in its 15th year of production, EMD added 250-hp to the seven series of 1,500-hp models that had been in production for five years. The replacement for the 567, the 645 was still a decade away.

    As for EMDs competition, the near completion of the replacement of the steam locomotive and slowing sales were about to take its first casualty: Lima-Hamilton had merged with Baldwin in 1950 to form B-L-H, and the new consortium would build locomotives for five more years before ending production in 1956. Fairbanks-Morse (F-M) was offering a 1,600-hp road switcher, a heavy transfer unit with 2,000-hp and its innovative Train-Master, a 2,400-hp six-axle road switcher. While F-M stayed in the game until 1963, its last domestic units were built in 1957. Alco had split with General Electric in 1953 and was now known as Alco Products. They would run in second place to EMD for the next few years in spite of the 1956 intro- duction of the new 251 power plant. In 1954, they cataloged the 1,600-hp FA-2 and RS-3 and also a bigger unit, the 2,250hp six-axle RSD-7 introduced in early 1954 and soon upgraded to 2,400-hp, using a 16-cylinder version of the 244 engine. This model introduced the notched nose road switcher carbody more often associated with the 251-powered RS-11 and RSD-15 that hit the market two years later.Although not diesel locomotives, a second group of 4,500hp General Electric gas turbines was acquired by the Union Pacific. The turbines required different fuel considerations and would not to suited to operate anywhere on any railroad as a diesel could be expected to, but they were a success on the Union Pacific, prompting another order for yet larger 8,500-hp turbines built for UP in 1958-61. Still looking for more efficiency through larger and more powerful locomotives, the UP was not content with the horsepower offered in a GP9. In September 1955, the UP's Omaha shop began fitting GP9s with turbochargers as an experiment to determine what improvement would be offered by increasing the horsepower of a GP9 by 250-hp with a turbocharger.

    Up to this point, EMD had not equipped any new locomotives with turbochargers. Alco had commonly used the turbocharger since the 1930s on all but the smallest switchers such as the S-1 and S-3. Baldwin began use of a turbocharger in 1945. Later dubbed Omaha GP20s, the UP initially equipped 19 units with turbos from two suppliers, AiResearch and Elliott.

    Over the next few years, the testing of the Union Pacific units would continue and EMD would fill orders for its nine series engines. The cab unit was about to become obsolete, with sales of F9s and FP9s totaling only 250 units, compared with over 4,200 for the F7 and FP7 predecessors. The last F9s were built in April 1957 with construction of FP9s for Canada and Mexico continuing two more years. In the road switcher realm, the GP9 and SD9 both outsold their previous comparable model with production ending for both in 1959.

    After testing in Minnesota, the demo 5579 moved to the Union Pacific, the birthplace of the turbo-equipped EMD road switcher, where it is shown at Ogden, UT, in February 1959, five months before UP took delivery of their first SD24. In addition to the unique top-side arrangement, the engineers side louver pattern differed from the production units. Decals: Microscale 87-131 (DM&IR set).
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    With dieselization winding down, F-M found its list of loyal customers diminishing, and the last Train-Master was built in 1956. They built a total of 127 units for eight US roads and Canadian National and Canadian Pacific. The F-M opposed-piston power plant was expensive to maintain, and the company became another victim of the completion of the changeover to diesel operations. Alco Products remained very much in the game as the new 251 power plant debuted in the four-axle RS-11 and six-axle RSD-15 in February 1956. The new power plant was only installed in cab units for the Canadian National in the form of the FPA4/FPB-4, but otherwise the final Alco cab units were FA-2s built in mid 1956 with the old 244 engine. The notched nose design also gave the new Alco road switchers a new look. These two models would be offered into the early 1960s with a not very successful 2,400-hp four-axle variant, the RS-27 introduced in December 1959. To sum it up, not much happened at EMD in the five years from 1954 to 1959. It was business as usual which meant good sales of the proven products and a first-place position in locomotive orders ahead of Alco.

    Before we launch into 1959 and our subject locomotive, a few credits are in order. As with our previous series on the Alco S-1, diesel expert Dr. Louis A. Marre has provided many great photographs and other advice. Another fine source of background material and photos has been the staff of Diesel Era magazine. Publisher Paul Withers has loaned several photos that will appear in this series. For more information, Withers Publishing has a book entitled The GP20 and SD24: EMDs Turbocharged Duo, published in 1998 and available for $29.95 directly from Withers Publishing, 528 Dunkel Hill Road, Halifax, PA 17032. This is the definitive source for information on the two models and background on the introduction of turbocharged locomotives by EMD. Back issues of Extra 2200 South magazine are always one of my standard reference sources.

    After three years, EMD was ready to apply a turbocharger to a new locomotive and do intensive field testing. A single prototype high-nose SD24 numbered 5579 was completed in July 1958. The fact that EMD may have lacked confidence in this new product is demonstrated by its testing history. It was painted in maroon and yellow to match the Duluth, Missabe & Iron Range (DM&IR) SD9 fleet and sent to that roads northern Minnesota operations. It bore no markings beyond the numbers in the numberboards. Working with the DM&IR SD9s gave the EMD field engineers a good opportunity to make adjustments. Being tucked away in the bush in Minnesota would save the company the embarrassment of having it fail on a mountain pass on a busy Class I road. From the frame down and cab forward, the new unit was all SD9, but the long hood bore a lot more louvers and a trademark bulge in the fireman's side that covered the traction motor and generator blowers. Topside, the rear of the roof contained three 48" cooling fans with the forward one under a winterization hatch, then a dynamic-brake blister patterned after that on the SD9, but in front of that was evidence of the new turbocharger lying within...a newly designed air intake and a single exhaust stack.

    By 1959, General Motors was ready with a line-up of five new models. Two were upgrades of the nine series, the 1,800-hp GP18 and SD18 - no surprises here! An odd (and unsuccessful) light road switcher patterned after the NW-5 produced a decade earlier, it offered 1,325-hp and was called an RS-1325. Only two were ever built. More interesting was the pair of turbocharged units being offered: the 2,000-hp four-axleGP20 and the 2,400-hp six-axle SD24. This was one of the few times that EMD’s model designation actually matched the horse-power of the locomotive! The opportunity to reduce the number of units on a train was emphasized by EMD in the marketing of theSD24 with a likely lash-up of three SD24sreplacing a quartet of GP9s or new GP18s.

    ATSF RSD-15 9840 was one of 50 low-nosed alligators bought concurrently with the roads SD24s. The road owned over half of the 87 RSD-15s built and initially used them in mainline cross-country service. Bellville, TX; January 1, 1971. Decals: Microscale 87-548.
    Model Railroading - September 2004 - Page 23

    In ten months, four railroads bought a total of 219 SD24s. This was an impressive but brief showing for the model as no other orders were appearing after the four roads (ATSF, CB&Q, SOU and UP) bought these initial locomotives. Hoping to sway the Southern Pacific, which had bought earlier SD7s and SD9s along with the F-M Trainmaster, EMD built a trio of low-nose SD24 demonstrators in August 1960, equipped them with SP optional equipment and sent them west. The Southern Pacific was unimpressed, and the trio was sold to the UP a year later along with the original high-nose demonstrator number 5579. No other road expressed an interest in the SD24, and a final single unit was built in early 1963 for Kennecott Copper.

    A number of roads chose to avoid the turbocharger option and ordered the SD18; a total of 54 were built for four railroads and one private ore hauler. Despite the demo appearance of the 5579 on the DM&IR, this and another US Steel road, the Bessemer & Lake Erie opted for SD18s, the latter with the low hood. The spotlight seemed to be on the GP20, and while it was sold to eight roads, the total number of 260 units was not that much more than the SD24. The industry was demanding more speed rather than more power, and the GP20 was replaced by the GP30 (the 30 representing 30 improvements) in mid 1961. A total of 948 of this model was sold, but no SD30 was offered. The SD24 remained in the catalog until the 35 series became available, and the first SD35 was built in June 1964.

    In May 1959, the Santa Fe and the Burlington received the first units in their SD24 order. We will take an in-depth look at the Santa Fe fleet next month.

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