Diesel Locomotives, Extinguishing The Fire Of Steam

Diesel locomotives, technically known as diesel-electrics, came into widespread use following development of Electro-Motive Corporation’s (later, General Motors' Electro-Motive Division) EA/EB design, first tested on the Baltimore & Ohio Railroad (B&O) in 1937.  The motive power's genesis, however, dates back even further to the World War I period when an early switcher model entered service.  The industry remained skeptical of the diesel for many years, relegating it primarily to secondary status while steam remained the preferred choice for main line assignments.  In time, railroads came around, particularly after General Motors successfully demonstrated the diesel's viability during testing of its FT freight design.  The demonstrator set toured the country, convincing skeptic after skeptic that diesels were not only efficient and reliable in main line applications but could also outperform the iron horse.  Today's newest models offer an even greater level of efficiency and are heavily computerized to monitor almost every aspect of a locomotive while in service.  As a result, much of the "old school" way in which an engineer operated his or her locomotive(s) has been taken away technological advancements in models like the SD70ACe-T4 and ES44AC.

The mechanics of diesels are rather straightforward, although it is commonly mistaken that the diesel engine itself propels the locomotive.   This is note the case.  While the engine is the prime mover the energy it creates drives an electric generator, which in turn drives the traction motors found within the locomotive’s trucks that actually turns the wheels and propels the unit forward. The engine, itself, has no connection to the actual motion of the wheels and, in essence, the locomotive is an electric locomotive.  The only difference between them?  A true electric was provided its power via overhead catenary or third-rail pickup while a diesel-electric carried its power source on board (the engine).   Diesel-electrics have been around in one shape or form since 1917 when General Electric began tests on an experimental diesel-electric model utilizing a GM-50 prime mover (a V-8 diesel engine designed by GE).   A year later it launched production of these 225 horsepower machines; the line was largely considered a failure although one did sell to the Jay Street Connecting Railroad, given #4.  In addition, another was acquired by the city of Baltimore and the U.S. Army also picked up an example.

American Locomotive Company (Alco)

A History Of The American Locomotive Company, Alco 

Alco's Canadian Arm, The Montreal Locomotive Works 

Alco's First Cab Design, The Experimental Black Maria 

Competing With EMD's F Model, The FA Series 

The Beautiful PA Series

The Century Series, Alco's Final Road-Switcher Catalog

The Early DL Design, The Company's Initial Cab Series

The RS-1, The Road-Switcher Is Born

The RSD-1, For The Army

The Joint EMD/Alco MRS-1 Road-Switcher For Military Service 

The RS-2, Following Its Predecessor

The RSC-2 Variant

The RS-3, Alco's Best-Selling Road-Switcher

The RSD-4, Continuing The Six-Axle Design

The RSD-5, Higher Sales Than Its Predecessor

The RSD-7, Alco Struggles In The Road-Switcher Market

The RS-11, Unable To Keep Pace With EMD

The RSD-12, Another Poor Seller

The RSD-15 "Alligator"

The RS-27, Striving For Success

The RS-32, Another Failure

The RS-36, Last In The Road-Switcher Series

The C-415, A Most Unique Design

The C-420, Introducing The "Century" Series 

The C-424,  A More Powerful But Unsuccessful Model 

The C-425, Still Lagging Behind 

The C-430, The Final Four-Axle Century 

The C-628, The First Six-Axle Century 

The Big C-630 Line

The C-636, Powerful Yet Unpopular 

The C-643DH Diesel-Hydraulic, An Experimental For SP 

The C-855, A Beast Built For Union Pacific

The S-1, Alco Finds Success With The Switcher

The S-2, Continuing Strong Sales

The S-3, Another Moderate Success

The S-4, Yet Another Home Run

The S-6, The Final Standard-Model Switcher

The Intriguing T-6, "Transfer" Design

The Joint General Electric/Alco Gas Turbine Design

Despite the lackluster performance of this experimental diesel GE did not give up.  In 1923, it began tests on new locomotive.  This latest trial carried GE electrical components, a prime mover from Ingersoll-Rand (capable of 300 horsepower), and a carbody provided through American Locomotive (Alco).  As the late historian Jim Boyd notes in his book, "The American Freight Train," the 60-ton boxcab was finished in 1924 and proved a success, eventually selling to the Central Railroad of New Jersey (given #1000) to carry out switching assignments around New York City.  Ironically, despite the company's pioneering ways with the diesel it never launched its own line of locomotives until the late 1950's.  Prior to that time the company had partnered with Alco, which for a time provided the strongest competition against Electro-Motive.  Eventually, as Alco fell further behind the GM subsidiary, General Electric went off on its own releasing the initial "Universal" line.  While a commercial success the series not particularly reliable and GE spent many years fine-tuning its design until it had dominated the market by the 1980's.

While the early boxcab designs are often credited as the first carrying a diesel engine the very first rail car to utilize a internal combustion engine was the McKeen Car.  In Brian Solomon's book, "The American Diesel Locomotive," the idea for this concept came from William McKeen, Union Pacific's motive power chief.  Even by the early 20th century railroads were attempting to cut costs on lightly patronized branch lines and UP's chief, the legendary Edward Harriman, approached McKeen in 1904 about developing a self-powered rail car for use on these secondary corridors.  After a long series of tests at the Electric Railway Test Commission in St. Louis they came up with an aerodynamic design powered by a 100 horsepower, gasoline engine manufactured by early pioneer Riotte.  The first unit, listed as #M-1 and given the name "Windsplitter," was out-shopped at UP's shops in Omaha during March of 1905.  Following a refinement which featured a longer frame and marine engine (which could produce twice the horsepower), Harriman was impressed.  He allowed McKeen to setup production of the McKeen Railcar Company in 1908.

Baldwin-Lima Locomotive Works (BLW)

A History Of The Baldwin Locomotive Works 

The Lima Locomotive Works, A Future Baldwin Partner 

The Whitcomb Locomotive Works, A Division Of Baldwin 

The VO-660, Entering The Switcher Market 

The VO-1000, Baldwin's Top Sales Performer

The DS-4-4-660, Replacing The "VO" Series 

The DS-4-4-750, Offering 750 Horsepower

The DS-4-4-1000, The Final "DS" Series Model

The S-8, A New Model Of Switcher

The S-12, Baldwin's Final "Standard" Line Switcher 

The DT-6-6-2000, A Unique Design For Transfer Service

The RT624, The Final Transfer Variant 

The DRS-4-4-1500, The First Road-Switcher 

The DRS-6-4-1500, Struggling To Find Sales

The DRS-6-6-1500, The Most Successful In The "DRS" Series

The AS16, Unveiling The "Standard" Line

The AS416, Fighting To Maintain Market Presence

The Six-Axle AS616, The Most Successful "Standard" Line Model

The RS12, The Light Road-Switcher

The "Baby Face" DR-4-4-1500, Baldwin's First Cab Model 

The DR-6-4-1500, A Failed Design 

The DR-6-4-2000, Another Flop 

The RF16 "Shark," Offering Improved Sales 

The DR-12-8-3000 "Centipede," A Singularly Baldwin Design 

A History Of Baldwin's "Sharknose" Carbody 

The Company's First Carbody Design, The Unpopular "Baby Face" 

Early on McKeen was successful but soon ran into reliability issues and sales had flattened by 1912.  The "Windsplitter" may have had its issues but other company's (including GE and Electro-Motive) did produce a reliable railcar which became popular in branch line service, the so-called "Doodlebug."  The success companies had in this field eventually led to the diesel-powered boxcab switchers mentioned above.  The Baltimore & Ohio also has the distinction of being the first to purchase a diesel-electric (#50) for main line applications, Electro-Motive's boxcab of 1935. While these early examples were somewhat successful and switchers grew in popularity for secondary applications (Alco, in particular, was a leader in this area) it was not until EMC developed its phenomenally successful E and F models did the diesel-electric locomotive truly come of age.  During successful tests of Electro-Motive's original FT, which began in November of 1939, the railroad industry was thoroughly impressed with its ability in main line service.  While not as a powerful on a unit-per-unit basis the savings and efficiency the diesel offered sealed the fate of the iron horse. 

It would take the diesel-electric nearly fifty years to equal the horsepower output of a single steam locomotive during its technological height. However, diesels made up for this setback in many ways.  They required far less maintenance (scheduled time in the shops for routine maintenance) and could operate much further between refueling.  This meant diesels could be out on the road doing what they were designed to do for longer periods of time, moving freight and passengers.   As Brian Solomon points out in his book, "E Units And F Units," while American Locomotive, General Electric, and Ingersoll-Rand pioneered the use of diesel engines within a singular platform it was General Motors which recognized a way to mass-produce them for main line service.  GM had already entered the auto industry and recognized that rugged, durable internal mechanics along with a respectable prime mover, all packaged within an attractive carbody, could be big business.  This led to development of the cab designs previously mentioned and the rest, as they say, is history.

General Electric (GE)

A History Of General Electric's Many Locomotive Models 

A Look At GE's First Road-Switcher Series, The Classic "U-Boat" 

The U18B "Baby Boat," The Light Road-Switcher 

The U25B, GE's Enters the Locomotive Market 

The U28B, Following Its Predecessor 

The Modestly Successful U30B 

The U33B, The Fourth U-Boat 

The U36B, Purchased Only By The SCL And Auto-Train 

The U23C, A Light-Powered Late-Era Design 

The U25C, The First Six-Axle 

The U28C, Adding Power 

The U30C, Providing EMD Competition 

The U33C, Driving Alco Out Of The Market 

The U36C, The Final Cataloged U-Boat 

The U50, An Experimental, 5,000 Horsepower Monster 

Another Experimental, Union Pacific's Enormous U50C 

The Joint General Electric/Alco Gas Turbine Design

The B23-7, Replacing The U-Boat 

The B30-7, Picking Up Sales 

The B36-7, Four Axles And 3,600 Horsepower 

The Popular Six-Axle C30-7, Looking To Supplant EMD 

The Powerful C36-7 

The "Super 7" Series Rebuild Program 

The B32-8 Series, Offering 3,200 Horsepower 

The B39-8 Variant, A Rare, Unsuccessful Design 

The B40-8/W, The Last Four Axle 

The Six-Axle, 3,900 Horsepower C39-8

The C40-8/W Series, Surpassing EMD 

The C40-9/W Variant

The C44-9W, Cementing Its Dominance 

The Popular AC4400CW, Designed For Drag Service 

The AC6000CW, Providing 6,000 Horsepower 

Continuing Its Reign, The Evolution Series 

General Motors’ Electro-Motive Division (EMD)/Electro-Motive Diesel

A History of General Motors' Electro-Motive Division (EMD), Today's Electro-Motive Diesel

EMD's Canadian Division, General Motors Diesel 

Early EMC Switchers: SW, SC, NW, NC 

The Interesting "Cow-Calf" Switcher Designs

The NW2, Offering Early Success

The SW1, Featuring The New 567 Prime Mover 

The SW7, Another Favorite

The SW8, Providing Slightly More Power

The SW9, Maintaining Strong Sales

The 900 Horsepower SW900

The SW1000, Showcasing EMD's Second-Generation, 645 Prime Mover

The SW1001 Variant, Fixing A Problem

The SW1200, Continuing EMD's Dominance

The SW1500, Another Bestseller

The MP15DC/AC/T Series, EMD's Last Switchers

A General History Of The Passenger E Series 

The Early EA/E1/E2 Models

The E3, Replacing The Winton With The 567

The Seaboard Air Line's E4

The Burlington's Sleek, Stainless-Steel E5

The E6, The First Production Passenger Model

Rock Island's Unique AB6, Designed For The "Rocky Mountain Rocket"

The Successful E7, Debuting EMD's Iconic "Bulldog Nose" Carbody

The E8, EMD's Continues Its Reign

The E9, Last In The Series

A Look At EMD's Popular Freight Line, The F Series 

The FT, Replacing The Steam Locomotive

The Rare F2

The F3, Cementing Diesel's Dominance

The F7, The Blockbuster Covered Wagon

The Passenger Model FP7

The F9, Closing Out The "Bulldog" Design

New Haven's Unique, Dual-Service FL9

The F40PH Series

The "Cowl" F45 Series

The Notorious SDP40F Passenger Variant

The BL2, The GP Series Predecessor

Great Northern's GP5

The GP7, Debuting An Icon

The GP9, Another Phenomenal Road-Switcher

The Versatile GP15 Series

The Modestly Successful GP18

The Rare RS1325

The GP20, Entering The Turbocharged Age

The GP30, Offering A Timeless Look

The GP35, Finding Continued, Second-Generation Success

The GP38 Series, EMD Hits The Mark Again

The Successful GP40 Series

The Unsuccessful GP50

The GP60, Last Of The Geeps

The Joint EMD/Alco MRS-1 Road-Switcher For Military Service 

The SD7, EMD's First Six-Axle Road-Switcher

The More Successful SD9, "Cadillac"

The SD18, A Late-Era First-Generation Model

The SD24, EMD's First Turbocharged Road-Switcher

The SD35, Growing Six-Axle Popularity

The SD38 Series, Featuring The New 645

The Blockbuster SD40/SD40-2 Series, The Gold Standard

The Powerful, 20-Cylinder SD45 Series

The SD50, Electro-Motive's Downfall

The SD60 Series, Attempting To Rebound

The Successful SD70 Series

The SD75M/I Variant

Conrail's SD80MAC

The 6,000 Horsepower, But Problematic SD90MAC

Electro-Motive's Latest Model, The SD70ACe

Odd/Unique Designs

B Units 

C&NW's Crandall Cabs 


DDA40X, "Centennial" 

Draper Taper 

Krauss-Maffei ML-4000 


Rock Island's AB6 


Tunnel Motors 

Notable Prime Movers

Alco's Model 244 

Alco's Model 251 

EMD's Model 567 

EMD's Model 645 

EMD's Model 710 

Truck Types

AAR Type A/B 

Blomberg Type A/M 



Related Companies/Designs

Davenport Locomotive Works 

Truck Types


Gensets/Green Goats 

Rail Diesel Car, RDCs 


Notable Events/Programs

Norfolk Southern's Heritage Program 

Streamliners At Spencer 

Union Pacific's Commemorative Series 

Common Designs

The Switcher, Performing Yard Work And Other Light Duties 

The Cab Unit, The Era Of Streamlining

The Standard Road-Switchers, Tasked With Handling Heavy Freights 

The Unique Transfer Switcher Variant 

Diesels have come a long way from the EMC and Alco-GE-IR boxcabs of the 1920's.  Today's model are equipped with comfort cabs, air conditioning, and electronic equipment. However, when the diesel was first introduced there were many builders vying for the top spot.  Many, including Lima, Alco, and Baldwin had earned their reputations manufacturing high quality steam locomotives.   Unfortunately, while Alco did find a bit of success, all three were never able to produce a similar diesel design and exited the market before 1970.  While these companies no longer manufacture locomotives, their legacies will forever live on and many of both their steam and diesel locomotive models still survive, some even continuing to haul freight.  Electro-Motive reigned for decades, producing some of the best remembered models like the F7, GP9, and SD40-2.  In a testament to these locomotives is that some continue to handle freight more than a half-century since they were built!  Today, the two primary manufacturers remaining, General Electric and Progressive Rail, which markets its models using the historic Electro-Motive name.

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