The Entire History of EMD
For nearly a century, one company defined how freight moved across North America.
Backed by General Motors, Electro-Motive Diesel didn’t just build locomotives; it revolutionized the entire railroad industry.
From humble beginnings building gasoline railcars to creating the diesel engines that conquered American railroads, EMD’s story is one of innovation, dominance, and the relentless pursuit of mechanical perfection.
The story begins in 1922, not with locomotives, but with a vision of cleaner, more efficient rail transportation.
The Electro-Motive Engineering Corporation, later renamed Electro-Motive Company, was founded in Cleveland, Ohio, by Harold L. Hamilton and Paul Turner.
Hamilton was a mechanical visionary, more comfortable with engines and shop floors than boardrooms, while Turner brought the business discipline that kept the company afloat.
Together, they saw an opening in a market the major locomotive builders ignored: small passenger and light-freight service in rural and branch-line territories.
Their early products weren’t the massive freight locomotives that would later make EMD famous.
Instead, they built gasoline-electric railcars—lightweight, self-propelled coaches with a small engine driving a generator, which in turn powered electric traction motors.
These railcars gave struggling railroads a way to provide passenger service on rural lines without the expense of steam engines, large crews, or constant servicing.
The ability to operate cars singly or in multiple units was a revelation in the 1920s when steam trains were rigid, expensive, and often oversized for the demand.
Despite these advantages, Electro-Motive remained a small player.
The rail industry was deeply conservative, and few managers wanted to gamble on gasoline cars built by a start-up.
Hamilton and Turner understood that to survive, they would need partners with deeper pockets and broader vision.
That moment came in 1930, when General Motors acquired Electro-Motive Corporation.
GM’s move was strategic.
The company’s president, Alfred P. Sloan, envisioned GM not just as a car manufacturer but as a diversified transportation empire.
Alongside trucks, buses, and airplanes, he saw potential in railroads.
In 1930, General Motors strategically acquired both the Winton Engine Company (a marine and stationary diesel builder) and the Electro-Motive Company, coordinating their development to create locomotive powerplants tailored for railroads.
The newly formed Electro-Motive, now backed by GM’s engineering and financial resources, began developing medium-speed diesel engines specifically for railroads.
This was a crucial distinction.
While competitors tried to adapt marine diesels, GM poured money into designing engines, generators, and controls as an integrated package.
The company also invested heavily in research facilities, testing labs, and most importantly, mass-production capacity—tools no independent builder could match.
The breakthrough came in 1939 with the FT freight locomotive.
This wasn’t just another diesel experiment; it was a deliberate strike at steam’s dominance.
Each FT unit carried a 1,350-horsepower engine driving traction motors, and a typical four-unit set delivered 5,400 horsepower under the control of a single crew.
In total, 1,096 FT units (555 cab-equipped A units and 541 cabless boosters) were produced during the war.
GM staged a dramatic nationwide demonstration, sending a gleaming yellow-and-green FT set across the country.
At every stop, railroad executives, engineers, and shopmen were stunned.
Here was a locomotive that could do the work of some of the heaviest steam power while consuming less fuel, requiring fewer crew members, and running days without major servicing.
The timing proved decisive.
As the United States prepared for World War II, railroads faced crushing demand for freight and troop movements.
Steam locomotives devoured coal and water, strained shop forces, and demanded constant downtime.
By contrast, the FT promised reliability, fuel efficiency, and flexibility.
Railroads that had once scoffed at diesels began placing orders.
More than 1,000 FT units would be built during the war, and their performance under wartime conditions erased any doubts.
Wartime production not only established EMD’s manufacturing capabilities but also embedded its locomotives into the fabric of the war effort.
FT units hauled endless strings of coal, steel, grain, and military equipment, often running on tight schedules that steam engines struggled to maintain.
Troop trains, too, increasingly relied on diesels, which could run long distances without water stops and required fewer crew members at a time when manpower was precious.
By the end of the war, EMD locomotives weren’t just reliable; they had become essential tools in keeping the arsenal of democracy moving.
The war years also saw the development of the 567 engine, which would become synonymous with EMD reliability for decades to come.
This 567-cubic-inch-per-cylinder engine was designed specifically for railroad service, with emphasis on durability, maintainability, and consistent performance under varying loads and operating conditions.
The end of World War II marked the beginning of EMD’s golden age.
American railroads, convinced by the FT’s wartime performance, began the largest motive power transformation in railroad history.
Steam locomotives that had dominated American railroads for over a century were rapidly replaced by EMD diesels that offered superior economics and operational flexibility.
The F-unit series, introduced in 1945 as the successor to the wartime FT, became the backbone of American freight railroading.
The F3, F7, and F9 models, all powered by the reliable 567 engine, could be found on virtually every major railroad in North America.
The streamlined carbody design provided excellent aerodynamics for high-speed freight service, while the modular construction allowed railroads to customize power consists for specific applications.
But it was the introduction of the GP7 in 1949 that truly revolutionized railroad operations.
This “road switcher” design combined the power of mainline freight locomotives with the visibility and flexibility needed for switching operations.
The hood unit configuration provided excellent visibility in both directions, while the 1,500-horsepower 567 engine delivered the power needed for both freight and passenger service and switching duties with equal effectiveness.
This operational flexibility allowed railroads to simplify their fleets and reduce the variety of locomotives.
The uprated 567 engine producing 1,750 horsepower, the GP9 became one of the most successful locomotive designs in railroad history, with over 4,000 units built for North American railroads.
The combination of reliability, versatility, and standardized maintenance made the GP9 the preferred choice for railroads large and small.
During this period, EMD’s competitors struggled to keep pace.
The American Locomotive Company, which had built some of the most powerful steam locomotives of the 1930s, failed to make the transition smoothly.
Its 244 diesel engine suffered cracked cylinder heads and electrical faults that left shop crews frustrated and trains sidelined.
Baldwin, another legendary steam builder, was even slower to adapt, relying on complex designs that proved too costly and unreliable in daily service.
These failures damaged customer confidence and drove railroads to EMD’s proven 567-powered locomotives.
A two-stroke diesel designed from the ground up for railroad duty, it was engineered with durability and ease of maintenance at its core.
Its most radical feature was modular construction: each cylinder assembly could be removed and replaced as a complete unit, allowing major overhauls to be performed without lifting the engine from the locomotive frame.
For railroad shops, this meant a locomotive could be back in service in days instead of weeks.
Maintenance crews quickly came to respect the 567’s reputation.
It wasn’t unusual for these engines to run thousands of hours between major services, and when repairs were needed, they could be handled with ordinary shop tools rather than specialized equipment.
In many cases, railroads rebuilt engines entirely in their own facilities, something unheard of with most competitors.
Stories spread of shop forces swapping power assemblies trackside or over a weekend, feats that kept trains moving and cemented the engine’s status as the workhorse of American railroading.
Backing up this rugged design was EMD’s growing support system.
GM invested heavily in a dealer and service network, ensuring that parts and technical expertise were available in every region of the country.
Standardized designs meant the same procedures applied whether a railroad operated switchers, passenger units, or mainline freight power.
Combined with rapid parts distribution, this gave railroads confidence that their fleets could be maintained with minimal disruption, reducing costs and reinforcing loyalty to EMD.
The 1960s marked the beginning of the “horsepower race” as railroads demanded more powerful locomotives to handle increasingly heavy freight trains.
EMD responded with the SD40, introduced in 1966 as a six-axle locomotive powered by a turbocharged 16-645E3 producing 3,000 horsepower.
The SD40’s success established the six-axle configuration as the standard for heavy freight service.
But it was the SD40-2, introduced in 1972, that became EMD’s most successful locomotive design.
Powered by the new 645 engine—an evolution of the 567 with larger displacement and improved performance—the SD40-2 produced 3,000 horsepower while incorporating advanced electrical systems and improved reliability.
Over 3,900 SD40-2 units were built, and the transition from the 567 to the 645 engine represented a significant technological advancement while maintaining the reliability and serviceability that had made EMD famous.
The 645 engine retained the two-stroke design and modular construction of its predecessor while offering improved fuel efficiency and reduced emissions.
During this period, EMD essentially owned the North American locomotive market.
By the early 1970s, Class I railroads were buying SD40s and SD40-2s in such volume that many divisions operated with little else.
Standardization brought huge advantages: shop crews could focus on one family of locomotives, spare parts inventories shrank, and training was simplified across entire systems.
For railroads trying to cut costs while moving ever-heavier trains, the efficiency of running mostly EMD power was impossible to ignore.
The 1970s brought new challenges that would test EMD’s dominance.
General Electric, which had been a minor player in the locomotive market, began developing competitive locomotives that challenged EMD’s technological leadership.
GE’s U25B, first built in late 1959 but widely entering service around 1961, had initially been rough around the edges, but the company’s persistence in developing four-stroke diesel technology began to pay dividends.
The energy crisis of the 1970s also changed railroad priorities, with fuel efficiency becoming as important as raw power.
EMD’s two-stroke engines, while reliable and powerful, were less fuel-efficient than GE’s four-stroke alternatives.
This efficiency gap became increasingly important as fuel costs rose and railroads focused on operating economics.
EMD responded to these challenges with the introduction of the 710 engine in 1984, a further evolution of their two-stroke technology that offered improved fuel efficiency and reduced emissions.
The 710 engine powered a new generation of locomotives, including the SD60 and SD70 series, that maintained EMD’s reputation for reliability while addressing changing market demands.
However, GE’s technological persistence was beginning to show results.
The company’s four-stroke engines offered better fuel efficiency and were easier to maintain—systems that provided better performance monitoring and diagnostic capabilities.
The 1990s marked a turning point in the locomotive industry as GE began to surpass EMD in market share.
GE’s Evolution Series locomotives, introduced in the 2000s, offered superior fuel efficiency and emissions performance that EMD’s aging two-stroke technology couldn’t match.
The regulatory environment was also changing, with increasingly strict emissions standards that favored four-stroke engine technology.
EMD’s response was the development of the H-engine, a four-stroke design that represented a complete departure from the company’s two-stroke heritage.
However, the H-engine program was troubled from the start, with reliability issues that damaged EMD’s reputation and drove customers to GE’s proven four-stroke locomotives.
The financial pressures of developing new technology while losing market share led General Motors to divest EMD in 2005.
The locomotive division was sold to Greenbriar Equity Group and Berkshire Partners, becoming Electro-Motive Diesel as an independent company for the first time since 1930.
Independence proved challenging for EMD, as the company lacked the financial resources to compete effectively with GE’s massive research and development investments.
In 2010, Caterpillar Inc. acquired EMD through its Progress Rail subsidiary, bringing the storied locomotive builder under the wing of another industrial giant with the resources and global reach needed to compete in the modern market.
Caterpillar’s ownership immediately gave EMD access to one of the most extensive dealer networks in the world, along with deep experience in heavy equipment manufacturing.
Under this new backing, EMD focused on refining its core designs.
The company continued to produce SD70 variants powered by the proven 710 engine, but now with advanced electronics and emissions controls to meet increasingly strict regulations.
The SD70ACe, for example, became a best-seller in North America during the 2010s, while export versions were delivered to heavy-haul railways in Australia, Brazil, and South Africa.
These locomotives were tailored to extreme environments—from desert heat to tropical humidity—where rugged construction and reliability mattered most.
Global expansion became one of Caterpillar’s key strategies for EMD.
In Australia, SD70ACe units were built for heavy-haul iron ore trains running across the Pilbara region, where triple-digit heat and dust tested every machine to its limits.
In Brazil, broad-gauge versions of the same model entered service on freight lines hauling agricultural exports to coastal ports.
EMD also made inroads in South Africa, where its locomotives supported both coal and general freight operations.
Beyond these major markets, Caterpillar targeted developing regions such as Indonesia and parts of Africa, where railroads valued locomotives that could run for decades with basic servicing rather than cutting-edge electronics.
In each case, EMD’s reputation for ruggedness translated into repeat orders.
At the same time, Caterpillar emphasized remanufacturing as a long-term business.
Instead of simply selling new locomotives, EMD rebuilt older units with upgraded components, extended lifespans, and lower emissions.
For cash-strapped railroads, these rebuilt locomotives offered the performance of new power at a fraction of the cost.
Progress Rail facilities across North America became hubs for overhauling fleets, ensuring that even locomotives built decades earlier could be returned to service with modern capabilities.
Today, EMD’s legacy looms large over the railroad industry, even though their market share is smaller than in their glory days.
The company that revolutionized American railroading with the FT demonstrator and dominated the industry for decades continues to build locomotives that embody the reliability and durability that made EMD famous.
The 567 and 645 engines that powered EMD’s golden age continue to operate in thousands of locomotives across North America, testament to the fundamental soundness of their design.
Many of these engines have accumulated hundreds of thousands of miles over decades of service, proving that EMD’s emphasis on durability and serviceability was well-founded.
EMD’s influence extends beyond the locomotives themselves to the entire concept of diesel-electric railroad operation.
The company’s innovations in diesel engine design, electrical systems, and locomotive construction established the standards that continue to define modern railroading.
The modular construction, standardized maintenance procedures, and emphasis on reliability that characterized EMD locomotives became industry standards that all manufacturers still follow today.
