Alco "RSC2" Locomotives: Data Sheet, Roster, Specs
Last revised: December 27, 2024
By: Adam Burns
The RSC2 was the Alco's six-axle version of its RS2. It's purpose, as with all of the builder's RSC models, was to decrease the locomotive's axle loading for light branch line work.
In other words, the weight was spread over a wider area (six axles instead of four). A number of railroads were pleased with the concept as the locomotives could handle duties on secondary corridors where track was typically under 100 pounds.
Overview
Interestingly, American Locomotive may have never developed a six-axle road switcher had it not been for the US Army, which requested such as a variant of RS1 model known as an RSD-1.
When Alco cataloged the RSC2 many railroads saw little use for a six-axle locomotive and as such, few sold.
The RSC3 of the early 1950s was the final A1A-A1A design the builder offered to domestic railroads (its Montreal Locomotive Works branch did catalog an RSC13 and RSC24 for Canadian lines through the late 1950s).
Today, at least one RSC2 is preserved, Milwaukee Road #988 at the Mid-Continent Railroad Museum in North Freedom, Wisconsin.
Photos
Union Pacific RSC2 #1282 is seen here in St. Joseph, Missouri on August 30, 1970. This unit was originally #1182 and renumbered in 1955. American-Rails.com collection.The RSC2 began production alongside its sister model, the RS2, in 1946 using the same model 244 prime mover. Railroads still had yet to embrace such a design and even market leader Electro-Motive had difficulty selling its six-motored SD7 and SD9.
Nevertheless, following the Army's interest in the RSD-1, Alco pursued the concept for domestic production. At 1,500 horsepower, the RSC2's primary advantage was weight distribution.
Model Confusion
From a historical perspective, Alco initially never cataloged an RSC-2 model during production. This point is explicitly stated in John Kirkland's book, "The Diesel Builders Volume Two." If you are able, locate a copy of this out-of-print resource.
It not only offers an in-depth look on Alco's diesel production but also how railfans of the era came up with model designations the builder never actually used.
In the RSC-2's case, the model was initially part of Alco's RS2 class (specification E1661) with little distinction made between the two aside from their specific model numbers. As Kirkland points out, the "RSC-2" designation was added two years after the model had ended production.
The advantage of the A1A-A1A design meant that the already lightweight model (at just 117.5 tons) could more easily negotiate secondary and branch lines that were laid with lighter rail.
One railroad that found the model quite useful was the Milwaukee Road. The Milwaukee was the first railroad to begin receiving its batch of RSC2s in November, 1946 wishing to test its usefulness and effectiveness on secondary lines; in this case its Valley Division in north-central Wisconsin (and headquartered in Wausau).
Milwaukee Road RSC-2 #490 with a single boxcar and caboose at a rural grade crossing near Welch, Minnesota on the CGW (trackage rights) in December, 1965. Rick Burn photo.Advantages
Interested in the maintenance savings, as well as retire its fleet of steam locomotives, the Milwaukee employed its first eighteen RSC2s on the route where they proved quite effective.
The railroad would go on to roster twenty-two RSC2s and in future years returned to Alco for many of its six-axle Road Switcher models.
In later years the locomotives were replaced by Electro-Motive's SDL39, a special variant built only for the Milwaukee that was used in a similar fashion. The Seaboard Air Line turned out to be the largest buyer of the RSC2.
However, unlike the Milwaukee, the SAL assigned theirs to various tasks. The first thirty-one delivered between 1947 and 1949 (#1500-1530) were used in light branch work. The rest, however, including #1531-1536 were all equipped with steam generators and used in passenger service.
Data Sheet and Specifications
| Alco Class | 606-DL-250 |
| Entered Production | 10/2/1946 (Milwaukee Road #975) |
| Years Produced | 10/2/1946-4/11/1950 |
| Model Specification | E1661/A/B/C |
| Engine | 244, V-12 |
| Horsepower | 1,500 (Increased to 1,600 HP in variant E1661C.) |
| Carbody Styling | Alco |
| Length (Between Coupler Pulling Faces) | 55' 11.75" |
| Weight | 250,000 Lbs. |
| Dynamic Brakes | Optional |
| Trucks | A1A-A1A |
| Truck Type | C-Type |
| Truck Wheelbase | 10' 6" |
| Wheel Size | 40" |
| Traction Motors | GE 726 (4): (Later upgraded to GE 752 [4].) |
| Traction Generator | GT564 (Upgraded to GT564C in variant E1661A.) |
| Steam Generator | Optional |
| Gear Ratio | 74:18 |
| Tractive Effort Rating | 34,000 lbs. at 13.5 MPH (Later increased to 42,500 lbs. at 11 MPH.) |
| Top Speed | 65 MPH |
Production Roster
Alco
| Owner | Road Number(s) | Serial Number(s) | Date Built |
|---|---|---|---|
| Alco (Demonstrator) | 1190 (became Union Pacific #1190) | 75136 | 11/1947 |
| Milwaukee Road | 975, 976 | 73643, 73644 | 11/1946 |
| Milwaukee Road | 977, 978 | 73647, 73648 | 11/1946 |
| Milwaukee Road | 979, 980 | 74989, 74990 | 11/1946 - 12/1946 |
| Milwaukee Road | 981-983 | 74994-74996 | 11/1946 - 12/1946 |
| Milwaukee Road | 984 | 74999 | 1/1947 |
| Milwaukee Road | 985, 986 | 75129, 75130 | 12/1946 - 4/1947 |
| Milwaukee Road | 987-989 | 75133-75135 | 12/1946 - 4/1947 |
| Milwaukee Road | 990-992 | 75138-75140 | 12/1946 - 4/1947 |
| Milwaukee Road | 993-996 | 76639-76642 | 2/1949 |
| Minneapolis, St. Paul & Soo Ste. Marie (Soo Line) | 368, 369 | 76977, 76978 | 11/1949 |
| Minneapolis, St. Paul & Soo Ste. Marie (Soo Line) | 370, 371 | 77558, 77559 | 11/1949 |
| Seaboard Air Line | 1500-1503 | 75397-75400 | 10/1947 - 11/1947 |
| Seaboard Air Line | 1504-1516 | 76806-76818 | 4/1949 - 5/1949 |
| Seaboard Air Line | 1517-1525 | 77176-77184 | 8/1949 |
| Seaboard Air Line | 1526-1531 | 77408-77413 | 9/1949 |
| Seaboard Air Line | 1532-1535 | 77967-77970 | 4/1950 |
| Seaboard Air Line | 1536 | 77966 | 4/1950 |
| Union Pacific | 1180 | 75693 | 3/1948 |
| Union Pacific | 1181-1186 | 75936-75941 | 4/1948 |
| Union Pacific | 1187-1189 | 75947-75949 | 4/1948 - 6/1948 |
* #1532 - #1536 were of the E1661C variant boasting 1,600 horsepower. These were the only RSC2's manufactured with the additional 100 horsepower rating.
Export
| Owner | Road Number(s) | Serial Number(s) | Date Built |
|---|---|---|---|
| Comboios de Portugal (Portugal) | 1501-1506 | 75872-75877 | 11/1948 |
| Comboios de Portugal (Portugal) | 1507-1512 | 75878-75883 | 11/1948 |
Sources
- Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.
- Kirkland, John F. Diesel Builders, The: Volume Two, American Locomotive Company And Montreal Locomotive Works. Glendale: Interurban Press, 1989.
- Pinkepank, Jerry A. Diesel Spotter's Guide. Milwaukee: Kalmbach Publishing Company, 1967.
- Solomon, Brian. Alco Locomotives. Minneapolis: Voyageur Press, 2009.
Milwaukee Road RSC2 #582 sits with a pair of Fairbanks Morse H12-44 switchers at the road's small shop complex in Savanna, Illinois on the evening of July 30, 1964. Marty Bernard photo.Interestingly, after less than a decade of service the Seaboard re-trucked several to four axles after they began experiencing wheel slip issues. Only eleven remained in service after 1965 and all were retired by the Seaboard Coast Line after 1974.
Mechanically, the RSC2 was all but identical to its four-axle cousin save for just a slight increase in length at 55 feet, 11 inches. The RSC2 was produced until 1950 but sold less than 100 units (whereas the RS2 sold over 400).
Still, four Class I railroads purchased the RSC2 with the Seaboard Air Line owning the most, 37 (the Soo Line owned four units and the Union Pacific purchased another 10 with the rest purchased by foreign lines).
Recent Articles
-
The "Flexi-Van": NYC's Revolutionary TOFC Service
Aug 11, 26 10:10 PM
The so-called "Flexi-Van" was New York Central's trademark service. While far ahead of its time the railroad failed to lure the industry as a whole. It had died out by the Penn Central era. -
New York Central Railroad: Map, History, & The Water Level Route
Aug 11, 26 08:35 PM
The New York Central, known as the "Water Level Route," was pieced together by Cornelius Vanderbilt and battled rival Pennsylvania for generations. -
Alco C430 (Century 430): Specs, Production Roster & History
Aug 11, 26 05:55 PM
The C430 sold very poorly for the builder. Read about who purchased them and those that remain preserved today. -
American Orient Express: History, Tours, Cost & Equipment
Aug 11, 26 03:43 PM
The American Orient Express was an ultra-luxurious private passenger train that operated from 1994 until 2008 in conjunction with Amtrak. It featured different routes for maximum scenic views; unfortu… -
Baldwin DS-4-4-1000 Switchers: Specs, Production Roster & History
Aug 11, 26 03:10 PM
The DS-4-4-1000 was one of the Baldwin's most successful diesel models it every produced, replacing the earlier VO-1000 in 1946. -
B&O Color Position Light (CPL) Signals: History, How They Work, Legacy
Aug 11, 26 02:48 PM
The CPL was Baltimore & Ohio's custom designed trackside signals used throughout its network. Today, few of remain under CSX. -
Gandy Dancer: The Track Maintenance Worker
Aug 11, 26 02:33 PM
The gandy dancer was a slang term used to describe section gangs, railroad men who performed the physical task of the tracks maintained. -
North Carolina -- Dinner Train -- Rides At Spencer
Aug 11, 26 01:39 PM
Tucked into the Piedmont town of Spencer, the North Carolina Transportation Museum is the kind of place that feels less like a typical museum and more like a living rail yard that never quite stopped… -
New York -- Dinner Train -- Rides In The Adirondacks
Aug 11, 26 01:30 PM
Operating over a restored segment of the former New York Central’s Adirondack Division, the Adirondack Railroad has steadily rebuilt both track and public interest in passenger rail across the region. -
Wellington Avalanche (1910): Great Northern Disaster at Stevens Pass
Aug 11, 26 01:15 PM
The Wellington Avalanche was the deadliest such disasters in the U.S. and one of the worst railroad accidents of all time resulting in 96 deaths in 1910. -
Wisconsin Dinner Train Rides In North Freedom
Aug 11, 26 01:12 PM
Featured here is a practical guide to Mid-Continent’s dining train concept—what the experience is like, the kinds of menus the museum has offered, and what to expect when you book. -
New Hampshire Dinner Train Rides At North Conway
Aug 11, 26 01:07 PM
Tucked into the heart of New Hampshire’s Mount Washington Valley, the Conway Scenic Railroad is one of New England’s most beloved heritage railways. -
Ashtabula Bridge Disaster (1876): The Pacific Express & Truss Collapse
Aug 11, 26 01:05 PM
On the night of Friday, December 29, 1876, in a howling Lake Erie blizzard, the Lake Shore and Michigan Southern Railway’s westbound Pacific Express approached the iron bridge over the Ashtabula River… -
Pole Lines In Railroading: Emergence, Purpose, Decline
Aug 11, 26 12:17 PM
Pole lines were once a common sight along railroad rights-of-way serving a multitude of functions, from carrying telephone lines to signaling code. -
The Angola Horror: The 1867 Train Wreck That Shocked the Nation
Aug 11, 26 11:58 AM
The "Angola Horror" was a horrific train accident along the Lake Shore & Michigan Southern that occurred in 1867 when a passenger car derailed at a bridge in Angola, New York and killed 49 passengers. -
Kentucky -- Wine Tasting -- Train Rides
Aug 11, 26 11:49 AM
Kentucky, often celebrated for its rolling pastures, thoroughbred horses, and bourbon legacy, has been cultivating another gem in its storied landscapes; enjoying wine by rail. -
Texas -- Wine Tasting -- Train Rides
Aug 11, 26 11:16 AM
This article invites you on a metaphorical journey through some of these unique wine tasting train experiences in Texas. -
New Mexico -- Wine Tasting -- Train Rides
Aug 11, 26 11:10 AM
For oenophiles and adventure seekers alike, wine tasting train rides in New Mexico provide a unique opportunity to explore the region's vineyards in comfort and style. -
Ohio -- Murder Mystery -- Dinner Train Rides
Aug 11, 26 10:56 AM
The murder mystery dinner train rides in Ohio provide an immersive experience that combines fine dining, an engaging narrative, and the beauty of Ohio's landscapes. -
Tennessee -- Murder Mystery -- Dinner Train Rides
Aug 11, 26 10:43 AM
Amidst the rolling hills and scenic landscapes of Tennessee, an exhilarating and interactive experience awaits those with a taste for mystery and intrigue. -
Famous Railroad Landmarks in the United States
Aug 11, 26 12:45 AM
If you have ever wondered about some of the most well known railroad landmarks around the country you can read about them here. -
Diesel Locomotives Of The 1930s, 1940s, 1950s, and Today
Aug 11, 26 12:35 AM
Read about the history of diesel locomotives, how they function and operate, and the dozens of different models built by the five major manufacturers. -
Heber Valley Railroad Fall Foliage Train Ride (2026)
Aug 11, 26 12:22 AM
The Heber Valley Railroad in Heber City, Utah markets year-round scenic products with a clear seasonal split: the Lakeside Limited is the fall/winter reservoir-side scenic, while the Deer Creek Expres… -
Black Hills Central 1880 Train Fall Foliage Ride (2026)
Aug 11, 26 12:14 AM
The Black Hills Central Railroad—marketed as the 1880 Train—is the primary fall foliage rail excursion offering in South Dakota. -
New Haven’s Roger Williams Streamliner: History, Specs & Legacy
Aug 10, 26 11:07 PM
The Roger Williams, built by the Budd Company in 1956 and delivered for 1956–57 service, was a complete six-car diesel multiple unit (DMU) derived from Budd’s hugely successful Rail Diesel Car (RDC) p… -
Railroad Tycoons List (USA): Men Of The Gilded Age (1800s)
Aug 10, 26 05:54 PM
Railroad tycoons, moguls, and barons were titans of 19th and early 20th century American commerce who laid the foundation of the modern industry we know today. -
Fallen Flags: The Classic American Railroad
Aug 10, 26 04:42 PM
Featured here are detailed histories of more than 100 classic railroads, or "fallen flags," from the mighty Pennsylvania Railroad to the small Monon. -
Railroad History (USA): Facts, Timeline, Definition
Aug 10, 26 04:18 PM
Interested in learning much more about out nation's rail history as well who invented the iron horse and when? Find it all here. -
Steam Locomotives (USA): Invention, History, Types
Aug 10, 26 04:08 PM
The classic iron horse, steam locomotives are legendary machines that still hold awe over the general public today. -
Streamliners (Trains): History, Timetables, Schedules
Aug 10, 26 03:45 PM
Read about many of the most well known streamliners here and why the period of the 1930s to 1960s is often considered the "Silver Age" of rail travel. -
Michigan -- Wild West -- Train Rides
Aug 10, 26 01:35 PM
While the term 'wild west' often conjures up images of dusty plains and expansive deserts, Michigan offers its own unique take on this thrilling period of history. -
Wisconsin -- Wild West -- Train Rides
Aug 10, 26 01:11 PM
Through a unique blend of interactive entertainment and historical reverence, Wisconsin offers a captivating glimpse into the past with its Wild West train rides. -
Florida -- Wine Tasting -- Train Rides
Aug 10, 26 01:00 PM
Wine by train not only showcases the beauty of Florida's lesser-known regions but also celebrate the growing importance of local wineries and vineyards. -
New York -- Wine Tasting -- Train Rides
Aug 10, 26 12:16 PM
This article will delve into the history, offerings, and appeal of wine tasting trains in New York, guiding you through a unique experience that combines the romance of the rails with the sophisticati… -
Florida Scenic Train Rides (2026): A Complete Guide
Aug 10, 26 12:02 PM
A Florida train rides guide, including all known railroad museums to visit within the state. Learn more about them here. -
Michigan Scenic Train Rides (2026): A Complete Guide
Aug 10, 26 11:53 AM
There is no better way to experience the Great Lakes State's countryside than on the railroad. Michigan train rides offer visitors much to experience. -
Ohio Scenic Train Rides (2026): A Complete Guide
Aug 10, 26 11:05 AM
Most of the Ohio train rides available to the public are small in nature. However, the state is home to the very popular Cuyahoga Valley Scenic Railroad, Byesville Scenic, and Hocking Valley Scenic. -
New York Scenic Train Rides (2026): A Complete Guide
Aug 10, 26 11:03 AM
New York scenic train rides offer about everything you can imagine from steam locomotives to long dinner train rides. -
California -- Murder Mystery -- Dinner Train Rides
Aug 10, 26 10:40 AM
When it comes to experiencing the allure of crime-solving sprinkled with delicious dining, California's murder mystery dinner train rides have carved a niche for themselves among both locals and touri… -
Vermont -- Murder Mystery -- Dinner Train Rides
Aug 10, 26 09:57 AM
There are currently murder mystery dinner trains offered in Vermont but until recently the Champlain Valley Dinner Train offered such a trip! -
Short Line Railroads (Class 3): List, Revenue, Definition
Aug 10, 26 09:02 AM
A close-up look at several Class III railroads, or "short lines." These systems are in vastly greater numbers today as Class Is continue to shed trackage. -
Class 2 "Regional" Railroads: Definition, List, Statistics
Aug 10, 26 12:21 AM
Class II railroads, also referred to as "regionals," are the second-largest such companies within the industry. The information here covers most of these lines. -
Canadian Pacific Kansas City (CPKC): History, Network, Overview
Aug 10, 26 12:00 AM
The Canadian Pacific-Kansas City Railway is a new Class I carrier in 2021 resulting from the Canadian Pacific/Kansas City Southern merger. Learn more here. -
Class 1 Railroads (USA): Revenue, Statistics, Overview
Aug 09, 26 10:57 PM
In railroad jargon, Class 1 refers to the largest companies in the industry and all six in North America are highlighted here. -
Royal Gorge Route Railroad Fall Foliage Train Rides (2026)
Aug 09, 26 03:02 PM
The Royal Gorge Route Railroad in Cañon City, Colorado is a year-round scenic dining railroad whose fall value is the canyon itself: roughly a two-hour out-and-back through the Royal Gorge with granit… -
Huckleberry Railroad Fall Foliage Train Rides (2026)
Aug 09, 26 02:35 PM
The Huckleberry Railroad at Crossroads Village (Genesee County Parks, near Flint, Michigan) is a family autumn destination: three-foot-gauge steam (when scheduled) looping wooded Genesee County countr… -
French Lick Scenic Railway Fall Foliage Train Rides (2026)
Aug 09, 26 02:17 PM
The French Lick Scenic Railway in French Lick, Indiana is the southern Indiana foliage train to watch: scenic excursions of about 90 minutes through hills and forests, departing the historic 1907 lime… -
California -- Beer Tasting -- Train Rides
Aug 09, 26 10:56 AM
While the Niles Canyon Railway is known for family-friendly weekend excursions and seasonal classics, one of its most popular grown-up offerings is Beer on the Rails. -
New Jersey -- Beer Tasting -- Train Rides
Aug 09, 26 10:53 AM
On select dates, the Woodstown Central Railroad pairs its scenery with one of South Jersey’s most enjoyable grown-up itineraries: the Brew to Brew Train. -
Georgia -- Wild West -- Train Rides
Aug 09, 26 10:52 AM
Nestled within its lush hills and historic towns, the Peach State offers unforgettable train rides that channel the spirit of the Wild West.
