The mechanics of diesels are rather straightforward, although it is commonly mistaken that the diesel engine itself propels the locomotive, which is not the case. While the diesel engine is the prime mover the energy it creates drives an electrical generator, which in turn drives the traction motors found within the locomotive’s trucks that actually turns the wheels (or the mounts which sit over the axles) and propels unit forward. The diesel engine itself has no connection to the actual motion of the wheels and in essence the locomotive is an electric locomotive which carries its own power source on board.
Diesel-electric locomotives have been around in one shape or form since
1918 when the American Locomotive Company (Alco) joined with General
Electric and Ingersoll-Rand to produce a motor car design
for the Jay Street Connecting Railroad, #4. Designated as model GM-50
it was essentially a diesel powered motor car, somewhat similar to an
interurban car, and built in conjunction with Alco and Ingersoll-Rand.
Later, in 1924 the three companies built a 300 hp, 60-ton boxcab design
that would be purchased by the Central Railroad of New Jersey, followed
by the Baltimore & Ohio Railroad.
|Erie Lackawanna RS-3 #1026 rests between assignments at the engine terminal in Akron, Ohio on June 24, 1975.|
The B&O also has the distinction of being the first railroad in the country to purchase a diesel-electric passenger locomotive in 1935 from EMC (B&O #50). While these early designs were somewhat successful and new diesel switch engines
were becoming quite popular from makers such as Alco, it would not be
until the development of EMD’s legendary E and F models (which followed
the EA/EB design they were nicknamed "covered-wagons") to pull heavy passenger and freight consists did the diesel-electric locomotive really come of age and overtake the steam locomotive as the dominant means of moving freight across America’s rails.
It would take the diesel-electric locomotive nearly fifty years to equal the horsepower output of the steam locomotive during its technological height. However, diesels
offered an advantage that far surpassed steamers and it was the
deciding factor in them becoming the prime choice of motive power,
efficiency. Diesels required far less maintenance in terms of overhauls
(scheduled time in the shops for routine maintenance) and refueling (no
longer were there frequent stops requiring water and coal/oil), which allowed them to be spending much more time moving freight and paying the bills.
|Several Pittsburgh & Lake Erie U28Bs including #2811, #2804, #2813, and #2808 are far from home as they as they roll light through the Delaware & Hudson's SK Yard in Buffalo, New York (thanks to recently acquired trackage rights into the city) on November 19, 1983.|
Below you can find each manufacturer and a number of their most popular first and second-generation diesel locomotive models. Simply click on their link to learn more about them.
American Locomotive Company (Alco)
A History Of Alco
Montreal Locomotive Works
GE/Alco Gas Turbine
|Two Sierra Railroad Baldwin S12s, led by #40, heads eastbound with a freight through Jamestown, California during a cold and overcast December day in 1964.|
Baldwin-Lima Locomotive Works (BLW)
A History Of Baldwin
A History Of Lima
A History Of The Whitcomb Locomotive Works
Baldwin "Baby Face"
|SP H24-66 Train Master #3028 heads up local commuter train #128 as it pulls away from the 3rd & Townsend station in San Francisco during August of 1973. Today, the depot and tracks are no more.|
Locomotives of Fairbanks-Morse
Canadian Locomotive Company
H16-66 "Baby Train Master"
H24-66 "Train Master"
The Consolidated Line, "C-Liners"
|CSX Train #134 rolls along the Mountain Subdivision at Pinto, Maryland led by AC4400CW #5111 on October 5, 2009.|
General Electric (GE)
A History of General Electric
GE/Alco Gas Turbine
"Super 7" Series
|Westbound CSX Train #N626-27 departs Clifton Forge, Virginia with an empty string of coal hoppers led by SD70ACe #4844 on March 25, 2007.|
General Motors’ Electro-Motive Division (EMD)/Electro-Motive Diesel
A History of Electro-Motive Diesel, EMD
General Motors Diesel
Early EMC Switchers: SW, SC, NW, NC
EA, E1, And E2
GP38 and GP38-2
GP40 and GP40-2
SD40 and SD40-2
C&NW's Crandall Cabs
Great Northern's GP5
Rock Island's AB6
Notable Prime Movers
Alco's Model 244
Alco's Model 251
EMD's Model 567
EMD's Model 645
EMD's Model 710
AAR Type A/B
Davenport Locomotive Works
Rail Diesel Car, RDCs
Norfolk Southern's Heritage Program
Streamliners At Spencer
Union Pacific's Commemorative Series
Diesels have come a long way from the early designs by EMC and Alco-GE-IR, with comfort cabs and electronic equipment the norm on new units now being built by Electro-Motive Diesel (now an independent company having been spun-off by EMD in 2005) and GE. However, when the diesel was first coming of age there were still several builders, many of whom were legendary steam locomotive manufacturers (such as Baldwin, Lima, and Alco) that began switching to diesel-electric
development when the writing on the wall became apparent that steam's
days were numbered.
|B&O GP9 #6533 is awaiting its next assignment as it sits at LeRoy, New York on March 15, 1981.|