Alco "C-424" Locomotives: Data Sheet, Roster, History

Last revised: December 26, 2024

When the American Locomotive Company rolled out its Century Series in the early 1960s, the goal was straightforward: modernize Alco’s diesel catalog, correct the shortcomings of earlier models, and compete head-to-head with EMD and the rapidly rising General Electric. Among the first and most important of these new locomotives was the C424—a B-B (four-axle), 2,400-horsepower road-switcher intended to provide railroads with a versatile, modern freight locomotive at a time when power demands and expectations were climbing quickly.

Today, the ruggedness and reliability of these locomotives continues to show through as numerous examples of the C424 not only remained preserved but also are still used in freight service. Some locations where they can still be found hauling freight include the Western New York & Pennsylvania, Morristown & Erie, Buffalo Southern, and the Bath & Hammondsport Railroad.

Photos

Reading C424 #5201 and GP30 #3607 in freight service; May 6, 1972. Location not recorded. American-Rails.com collection.

Overview

The C424 (listed by the builder as its DL640A) emerged as part of Alco’s effort to replace and improve upon earlier road-switcher concepts—particularly the RS-27, a model that sold in limited numbers and never gained broad traction. The Century line was meant to be more standardized, more maintainable, and more competitive in performance and price. In practice, the C424 was positioned as a lower-priced alternative to Alco’s own C425, while still offering strong horsepower for a four-axle unit in the mid-1960s market.

From a historian’s perspective, the C424 is especially interesting because it represents Alco’s “second wind” in road-switcher design—arriving at a moment when railroads were increasingly standardizing on EMD’s GP series and GE’s Universal line. In that competitive environment, even a technically capable locomotive faced an uphill battle if it couldn’t match the support networks, parts availability, and fleet commonality offered by the market leaders.

On the Belt Railway of Chicago the locomotives became a railfan favorite. The terminal road used its small fleet of six (#600-605) from the time they were purchased new from Alco in 1965-1966 until the early 2000's.

Fortunately the C424 sold better than its predecessor as a number of Class I railroads around the country picked up the model.

Additionally, smaller lines also purchased the design including Alco loyalists Green Bay & Western and Erie Mining while the Toledo, Peoria & Western also picked up a few units.

Unfortunately, while Alco sold nearly 200 C424s, 99 were built by the Montreal Locomotive Works for the Canadian Pacific, Canadian National, and Mexican line National de Mexico purchased another 45.

In general, most of the roads that bought the Alco C424 were returning customers, as the company could simply no longer attract new buyers and interest (which was mostly due to the fact that Alco still had a reputation for reliability issues despite having mostly corrected this problem years before).

Production ended on the model in early 1967 and despite the slow sales numbers (in comparison to models being produced by EMD who was selling thousands of GP35s and GP38s) the lines that purchased the C424 were generally quite happy with the models.

Core Specifications and Design

Alco did away with the notched corners on the C424s carbody, instead giving the nose a simple rounded look and the trailing long hood a raised edge for the number boards. At the heart of this model was Alco’s proven 251B diesel engine, delivering a rating of 2,400 horsepower. The locomotive rode on two-axle trucks (B-B), carried four GE 752 traction motors (despite GE being a major competitor by this time), and was offered with features railroads increasingly expected in mainline-capable road-switchers—such as multiple-unit capability and dynamic braking (where specified).

Perception and Longevity

The C424 sold better than its predecessor as a number of Class Is picked up the model. Additionally, smaller lines also purchased the design including Alco loyalists Green Bay & Western and Erie Mining while the Toledo, Peoria & Western also picked up a few units. In general, most of the roads that bought the model were returning customers, as the company could simply no longer attract new buyers and interest by this time.

Despite their modest sales, several customers used theirs for many years. The Green Bay & Western and Belt Railway of Chicago both employed theirs for more than 20 years; the former's surviving until it was acquired by Wisconsin Central in 1993 and the latter's until later that decade (these examlples continue to find use on short line's today). Additionally, the Canadian Pacific was still employing their M424s in service through the early 1990s.

Data Sheet and Specifications

The C424 was built from April 1963 through May 1967, with a total production of 190 units. Importantly, it wasn’t solely a Schenectady product: C424s were constructed by Alco in the United States and by its Canadian affiliate, Montreal Locomotive Works (MLW).

Entered Production	5/1963 (Erie Lackawanna #2401)
Years Produced	4/1963-5/1967
Model Specification	DL640A
Engine	251B, V-16
Horsepower	2,400
RPM	1,025
Carbody Styling	Alco
Length (Between Coupler Pulling Faces)	59' 4" (Originally 58' 10")
Weight	260,000 Lbs.
Dynamic Brakes	Optional
Trucks	B-B
Truck Type	Swing Bolster, Drop-Side Equalizer (AAR Type-B)
Truck Wheelbase	9' 4"
Wheel Size	40"
Traction Motors	GE 752 (4)
Traction Generator	GT581
Steam Generator	-
Gear Ratio	65:18
Tractive Effort Rating	64,200 Lbs.
Top Speed	75 MPH

Production Roster

Alco

Total Built = 98

Owner	Road Number(s)	Serial Number(s)	Date Built
Belt Railway of Chicago	600 - 602	3382-05 to 07	4/1965
Belt Railway of Chicago	603 - 605	3450-01 to -03	4/1966
Erie Lackawanna	2401 - 2403	84543-84545	5/1963
Erie Lackawanna	2404 - 2415	84546-84557	6/1963
Erie Mining Company	500	3382-03	10/1964
Green Bay & Western	311	84559	9/1963
Green Bay & Western	312	3375-01	6/1964
Green Bay & Western	313, 314	3382-04, -08	1/1965, 9/1965
Pennsylvania	2415	84558	9/1963
Reading	5201 - 5203	84560-84562	10/1963
Reading	5204 - 5210	84733-84739	10/1963 - 11/1963
Spokane, Portland & Seattle	300 - 306		6/1964
Toledo, Peoria & Western	800 - 801		9/1964
Wabash Railroad	B900 - B902*	3372-01 to -03	3/1964
Wabash Railroad	B903 - B906*	3372-04 to -07	3/1964

* The Wabash Railroad's seven C424's, #B900-B906, were originally ordered for the Ferrocarril Nacional de México (NdeM) and expected to become #8000-8006 (construction numbers 3372-1 thru 3372-7).

However, through a lease-purchase contract they were sent to the Wabash and eventually became Norfolk & Western #3900-3906. Afterwards, NdeM acquired seven additional C424's, construction numbers S-3380-1 thru S-3380-7 (#8100-8106).

By this time Alco's construction numbering system had changed from a five-digit number (in sequential order of completion) to a Sales Number along with however many locomotives a customer ordered.

Montreal Locomotive Works

Total Built = 92

Owner	Road Number(s)	Construction Number(s)	Completion Date
Canadian Pacific	8300	84413	4/1963
Canadian National	3200-3201	84837-84838	12/1964
Canadian Pacific	4200-4232	84839-84870	3/1965-8/1965
Canadian Pacific	4233-4250	3436-01 thru 3436-18	12/1965-3/1966
Canadian National	3202-3205	3443-01 thru 3443-04	3/1966-5/1966
Canadian National	3206-3221	3444-01 thru 3443-16	5/1966-8/1966
Canadian National	3222-3228	3477-01 thru 3477-07	1/1967-2/1967
Canadian National	3229-3240	3478-01 thru 3478-12	2/1967-5/1967

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.

Green Bay & Western C424's #312 and #314 layover in Wisconsin Rapids, Wisconsin on April 24, 1974. American-Rails.com collection.

The C424 vs. the C425

From a research standpoint, one of the most important interpretive points is the relationship between the C424 and the C425. The C425 (2,500 hp) is often described as an upgraded evolution of the C424 concept, reflecting Alco’s attempts to refine the product for specific railroad preferences. In practice, railroads that were comparing orders during the mid-1960s were not just choosing horsepower—they were choosing long-term standardization, support, and perceived reliability. That broader purchasing logic is one reason Alco struggled, even when its locomotives could perform.

Legacy

Like many Alcos, the C424’s later years were shaped by the economic realities of parts supply, shop familiarity, and corporate change. As Class I rosters consolidated and standardized, Alco products were often traded, retired, or sold off earlier than equivalent EMD power—not always because they were “bad locomotives,” but because fleet commonality and corporate procurement dynamics strongly favored EMD and GE.

Yet the C424 has enjoyed a meaningful afterlife on short lines, regionals, and industrial operators, where purchase price and rugged tractive performance could outweigh concerns about standardization. Some examples remained active long after their original owners retired them, and a small number are preserved.

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