Alco "C630" Locomotives: Specs, Roster, Data Sheet

Last revised: December 23, 2024

Alco’s C630, introduced in 1965, was the 3,000-horsepower flagship of the company’s Century series of diesel-electric freight locomotives.

A six-axle C-C design powered by the 16-cylinder 251C prime mover, it targeted heavy-haul mainline service and competed directly with EMD’s SD40 and GE’s U30C. The C630 emphasized high tractive effort and adhesion for coal, ore, and manifest trains, and appeared with standard Trimount trucks; later variants used high-adhesion designs.

Built in 1965–1967 at Schenectady, the model sold in modest numbers to several U.S. railroads; a closely related version, the M630, was produced by Montreal Locomotive Works for Canadian carriers into the early 1970s.

Despite strong performance, Alco's eroding market share, parts support concerns, and tough competition limited further orders. The builder exited locomotive production in 1969, but many C630s and M630s worked into the 1980s, in rugged territory. The model remains a potent symbol of Alco's engineering ambitions and the Century line.

Photos

An American Locomotive builder's photo featuring new Louisville & Nashville C630 #1425 at the plant in Schenectady, New York in June, 1966. Warren Calloway collection.

Overview

The C630 began production in 1965 which was a more powerful version of the earlier C628 that had been in the company's catalog since 1963. The new model could produce a respectable 3,000 horsepower using Alco's 251E prime mover.

By this point, most of Alco's orders came from loyal customers as it became almost impossible for the manufacturer to either gain or earn back new customers with its troubled early prime movers.

Buyers of the C630 included:

Union Pacific
Southern Pacific
Pennsylvania
Reading
Norfolk & Western
Atlantic Coast Line
Louisville & Nashville
Chesapeake & Ohio.

Additionally, Canadian Pacific, Canadian National, and the Pacific Great Eastern purchased examples of the M630 and C630M. By the time production had ended in 1969 133 C630s, C630Ms, and M630s had been built.

Norfolk & Western C630 #1135 preserved at the Virginia Museum of Transportation in Roanoke; April, 1992. Rick Burn photo.

The C630, and the Century line in general, offered the most tractive effort of any locomotive in its class, even eclipsing the Electro-Motive Division and General Electric.

As such, railroads showed real interest in the designs as many began to understand the value of six-axle setups and the traction they provided.

For instance, the C630 could produce 85,850 pounds of starting effort and 79,500 continuous making them ideal for heavy drag service hauling freight such as coal and ore.

Through the end Alco continued to rely on General Electric to supply it with internal components for its locomotives despite the fact that GE was now a competitor.

A former Pennsylvania C630, #6329, is seen here in Syracuse, New York during the early Penn Central era in September, 1969. Fred Byerly photo. American-Rails.com collection.

At first railroads liked the six-axle Centuries very much considering Alco no longer had significant reliability problems that plagued its early designs. However, the longer railroads operated them the more they noticed the significant wear the units produced on the track structure.

Data Sheet and Specifications

Entered Production	7/28/1965 (Atlantic Coast Line #2011)
Years Produced	7/28/1965-10/27/1967
Model Specification	DL630
Engine	251E, V-16
Horsepower	3,000
RPM	1,100
Carbody Styling	Alco
Length (Between Coupler Pulling Faces)	69' 6"
Weight	394,000 Lbs. (Optional ballasting available up to 420,000 Lbs.)
Dynamic Brakes	Optional
Trucks	C-C
Truck Type	Hi-Ad (High Adhesion)
Truck Wheelbase	12' 6"
Wheel Size	40"
Traction Motors	GE 752 (6)
Traction Generator (AC)	GTA9
Gear Ratio	74:18
Tractive Effort Rating	79,500 Lbs. at 12 MPH
Top Speed	70 MPH

Production Rosters

C630

Total Built = 77

Owner	Road Number(s)	Construction Number(s)	Completion Date
Atlantic Coast Line	2011-2013	S-3480-1 thru S-3480-3	7/1965-12/1965
Chesapeake & Ohio	2100-2103	S-3486-01 thru S-3486-04	10/1967
Louisville & Nashville	1425-1432	S-3486-01 thru S-3486-08	6/1966-7/1966
Norfolk & Western	1130-1134	S-3456-01 thru S-3456-05	5/1966
Norfolk & Western	1135-1139	S-3480-01 thru S-3480-05	9/1967
Pennsylvania	6315-6329	S-3466-01 thru S-3466-15	10/1966-12/1966
Reading	5300-5306	S-3442-01 thru S-3442-07	6/1966
Reading	5307-5311	S-3487-01 thru S-3487-05	9/1967-10/1967
Southern Pacific	7800-7814	S-3439-01 thru S-3439-15	3/1966-4/1966
Union Pacific	2900-2909	S-3440-01 thru S-3440-10	5/1966-10/1966

C630M

Total Built = 56

Owner	Road Number(s)	Construction Number(s)	Completion Date
Canadian National	2000-2001	M-3479-01 thru M-3479-02	8/1967
Canadian National	2002-2043	M-3491-01 thru M-3491-42	12/1967-6/1968
Canadian Pacific	4500-4507	M-6002-01 thru M-6002-08	7/1968-9/1968
Pacific Great Eastern	701-704	M-6029-01 thru M-6029-04	7/1969

The C630M was built at the Montreal Locomotive Works (MLW) with the "M" designated "Canadianization" for locomotive requirements in that country. When Schenectady ended operations on December 31, 1968, production of this model continued at MLW but were re-designated as the M630.

M630

Total Built = 29

Owner	Road Number(s)	Construction Number(s)	Completion Date
Canadian Pacific	4550-4553	6030-01 thru 6030-04	9/1969-10/1969
Canadian Pacific	4570-4575	6030-05 thru 6030-10	10/1969-11/1969
Canadian Pacific	4508	6030-11	11/1969
Canadian Pacific	4509-4516	6030-12 thru 6030-19	12/1969-1/1970
Canadian Pacific	4554-4555	6030-20 thru 6030-21	2/1970
Canadian Pacific	4556-4557	6036-01 thru 6036-02	2/1970
Canadian Pacific	4576-4581	6036-03 thru 6036-08	2/1970-3/1970

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.

Chesapeake & Ohio C630 #2101 at Wyoming Yard in Grand Rapids, Michigan during July of 1974. The C&O purchased a small batch of four of these big beasts, #2100-2103 in 1967. Plagued with reliability issues they were never liked by the railroad.

In any event, while most companies that purchased the C630 operated main lines that could handle the weight they still found the wear on their infrastructure far too excessive.

As such, nearly all of the C630s were retired by the 1980s. Interestingly, the M630s and M630Ws purchased by both Canadian National, Canadian Pacific, and Pacific Great Eastern (later British Columbia Railway) were well liked and most remained in regular freight service through the early 1990s.