Big, Burly, Memorable: The SD80MAC

Written by: Gary Dolzall

The big, burly, and powerful Electro-Motive SD80MAC will soon be bringing its 5,000 horsepower per unit to TS2014. In CSX livery, the SD80MAC will be a perfect fit on the Norfolk Southern Coal District route, which sees heavy use by both NS and CSX.

Amid a diesel locomotive horsepower race in the 1990s, the burly and powerful Electro-Motive SD80MAC emerged, if only briefly, as Gary Dolzall reports.

“The horsepower race.” Within the context of North American diesel locomotive history, mention of that phase typically evokes recall of the period from the late-1950s to the mid-1960s, when the long-time “1,500 horsepower per unit” standard for road freight locomotives was discarded in a rush. That race among the locomotive builders resulted, by 1966, in single-power-plant locomotives such as Electro-Motive’s GP40 and SD40 and General Electric’s U30B and U30C achieving 3,000 horsepower – and the 20-cylinder EMD SD45 delivering 3,600 horses per unit.

Wearing their original attractive blue and white “Conrail Quality” livery, a pair of CR SD80MACs deliver 10,000 horsepower in forwarding Conrail Train ALPI through Newport, Pennsylvania on May 29, 1999. Photograph by George W. Hamlin.

The horsepower race of the 50s and 60s was driven largely by advances in turbocharger technology and use. And then, nearly a quarter-century later, in the first half of the 1990s, another horsepower race began, this time empowered by the application of A.C. traction (e.g., the use of alternating current traction motors fed via inverters). With A.C. traction came the promise of being able to effectively deliver more power to the railhead, and with it, an appetite for more diesel horsepower.

Following the acquisition of Conrail by Norfolk Southern and CSX, the SD80MAC fleet was divided among the new owners. At Cresson, Pennsylvania (above) in 2004, two NS SD80MACs, one fully repainted and one in a “patch” scheme, await duty with an SD40. Through the years, many NS SD80MACs have regularly worked from Cresson. At Fredericksburg, Virginia, on CSX’s busy ex-RF&P main line (below) CSX SD80MAC 4950 leads a northbound freight in 2009. Both photographs by George W. Hamlin.

In 1991, EMD debuted its 3,800 horsepower A.C. traction SD60MAC testbeds and in short order announced the 4,000 horsepower SD70MAC, of which, between 1993 and 2004, more than 1,000 examples would be built. GE countered with the AC4000CW in 1993, and the big GE racked up mammoth sales (nearly 2,600 units) through 2004. Ah, but surely (at least the builders believed) there was both the capability and market interest in even more horsepower.

Crossing the Monongahela River (above) into West Brownsville, Pa., on the TS2014 NS Coal District route, CSX SD80MAC 4602 leads a long string of empty CSX coal gons (below) that are bound for Bailey Mine to be loaded. All TS2014 screenshots by Gary Dolzall.

What followed was a fascinating if brief period when expectation and promise exceeded reality. Both EMD and GE set their sets on producing and delivering single-power-plant locomotives delivering 6,000 horsepower. For both GE and EMD, that would require new power plants. GE, in concert with Deutz MWM of Germany, developed the 6,000 horsepower, 16-cylinder 7HDL16A engine. EMD, whose primary power plant since 1985 had been its 710-series engine, looked to develop its first 4-stroke diesel power plant, the 6,000 horsepower, 16-cylinder 265H-series engine. The competitive race for 6,000 horsepower diesels was perceived as so urgent that both EMD and GE offered models (the SD90MAC and AC6000CW, respectively) that would be delivered with existing 4,300+ horsepower engines (EMD’s 710-series and GE FDL-series power plants) and that could later be converted to 6,000 horses with new engines. The race to 6,000 horses also proved a flop. GE sold a total of AC6000CW variants to CSX and Union Pacific), while the SD90MAC realized its only significant success in its “convertible” 4,300 horsepower, 710-series-powered variant (we’ll save the sad but captivating full story of the SD90MAC for another day).

As an SD80MAC engineer, you’ll work from a modern isolated comfort cab and have 5,000 horsepower per unit at your control. The CSX SD80MAC also features DTG’s advanced and realistic air brake features, as well as locomotive dynamic braking.

And so where does the subject of our story – the EMD SD80MAC – fit into this tale? The aforementioned SD45 of 1966 had stretched EMD’s 645-series power plant to 20-cylinders and had met with considerable success until concerns, largely around fuel efficiency, caught up with it. Similarly, EMD had designed a 20-cylinder version of its 710-series engine, and in 1995 found opportunity to put it to work amid the horsepower race, offering the 5,000-horspower SD80MAC. A pair of Electro-Motive SD80MAC demonstrators, dressed in a deep red livery, rolled out of EMD’s London, Ontario, Canada, factory in 1995, and Conrail signed on as the first buyer with an order for 28 new units (CR would also purchase the two EMD demonstrators, which had been built to CR specifications, to bring its fleet to 30 units total). Big, burly, and powerful, the SD80MACs sported an isolated full-width comfort cab, massive rear flared radiators, a dynamic braking compartment tucked behind the radiators, and six-axle HTCR-II radial trucks. Conrail’s units, which underwent final construction and painting at CR’s Altoona, Pennsylvania shops, wore a blue “Conrail Quality” livery with white windshield trim and a V-shaped white band on the nose – quite stunning indeed!

On a wintry day, a pair of CSX SD80MACs arrive at Bailey Mine with a unit train for loading. To-date, the SD80MAC is the only North American diesel type to employ the 20-cylinder, 5000-horsepower version of Electro-Motive’s 710-series power plant.

Given that the SD90MAC was expected right on the heels of the SD80MAC, it was perhaps never likely that the SD80MAC would generate big sales numbers. But its eventual order book was even smaller than anticipated. A Canadian Pacific order for SD80MACs was converted to 90-series units. Chicago & North Western also ordered SD80MACs (15 units), but with the C&NW-UP merger on the horizon and UP intent upon acquiring the SD90, that order was cancelled. And so it was that SD80MAC production lasted less than one year and that Conrail was its only original buyer.

Day and night, unit trains of both the Norfolk Southern and CSX arrive at Bailey Mine (above) for loading. The Dovetail Games SD80MAC DLC also features a modern CSX coal gon that can be loaded at Bailey (below) or Emerald mines on the TS2014 route.

Not surprisingly, Conrail put its SD80MACs (CR 4100-4127) to work largely in heavy-haul coal train service, but the units could often be found lugging merchandise freight and even intermodal trains on occasion. Also not surprisingly, the SD80MACs tended to be used in mountain territory, working regularly both in the Alleghenies of Pennsylvania and on CR’s “Boston & Albany” route through the Berkshires of Massachusetts.

The combination of the TS2014 Norfolk Southern Coal District route and its featured NS GE ES44AC and the CSX SD80MAC DLC brings to full and bustling life this heavy-haul Pennsylvania coal route where NS and CSX operate side-by-side.

What might have been a story of the SD80MACs serving Conrail for a couple decades all changed when Norfolk Southern and CSX jointly acquired CR in 1999. Just like the railroad itself, CR’s SD80MACs were divided between the new owners, with 17 units going to NS (as NS 7200-7216) and 13 units going to CSX (as CSX 4590-4602). During their decade-and-a-half tenures on NS and CSX, the SD80MACs have shown a propensity to show up across the systems and in a variety of heavy-haul services, whether lugging coal amid the Alleghenies or stacks across New York State. And they have also proven to be survivors. Happily, and to some degree remarkably, given their status as minority units using the 20-cylinder, 710-series engine, the SD80MACs, now nearly 20 years into their careers, soldier on, with the majority remaining in service.

The Dovetail Games SD80MAC joins a rapidly growing fleet of CSX diesel available for service on TS2014 routes. Left to right: Dovetail Games’ EMD SD80MAC; Marketplace GE ES44AC and EMD SD70MAC, and EMD SD40-2 (the latter is included with the New York to New Haven route).

The big, burly EMD SD80MAC is soon coming to TS2014. To be available in CSX livery, the Dovetail Games SD80MACs will be a perfect fit for service on the recently released Norfolk Southern Coal District route, where NS and CSX coal trains mingle on a daily basis, hauling massive amounts of tonnage. And in fact, the SD80MAC DLC will also feature CSX black-livery contemporary coal gons, and include scenario for the NS Coal District route. With those 5,000 horses per unit ready for work, the potent SD80MAC will most surely be up to the task! – Gary Dolzall

Gary Dolzall

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