"SD28": A Rare, Non-Turbocharged Model

Last revised: December 17, 2024

The SD28 is a diesel-electric locomotive built by General Motors' Electro-Motive Division between for a three-month period in 1965.

It is powered by a non-turbocharged 16-cylinder 567D1 power plant, which can produce 1,800 horsepower. The model was essentially a de-rated SD35 and one the last cataloged with the 567 engine prior to EMD unveiling its upgraded 645 prime mover.

The SD28 is known for its six-axle (C-C) wheel arrangement and was used exclusively for freight service. Ultimately, only six units were produced for Reserve Mining and Columbus & Greenville, making it a very rare model in EMD's catalog.

Photos

Reserve Mining SD28 #1236 was photographed here by Warren Calloway at Babbitt, Minnesota in October, 1991.

Background

The SD28 is revered as a rare jewel in EMD's long line of locomotive creations. The engine holds an important position in the history of designs at La Grange. With a grand total of just six units produced, this locomotive is an attractive prospect to the railfan and locomotive enthusiast for its rarity.

Introduced in the mid-1960s, the SD28 was a de-rated, 1,800 horsepower variant of the SD35. This locomotive is a six-axle road switcher type, created during the transition period between EMD's 567 and 645 series power plants.

The model continued the use of EMD’s reliable and time-tested C-C Flexicoil truck. The three-axle design had already been successfully employed on the SD7, SD9, SD18, and SD24.

The truck was the builder's own design. It was a lightweight, high adhesion platform which offered a surprisingly comfortable ride and easy to maintain. From a maintenance perspective its key trait was the ability to easily access the center-axle, which often had been difficult to reach in other early six-axle trucks.

Spotting Features

As part of the new "35 Line," which introduced a common carbody for all road-switchers, the SD28's prominent features included the Spartan Cab (or Standard Cab), wrap-around walkways, light beveling of the hood, and a generally "clean" appearance.

The low-nose cab provided the defining look for the SD28, and all EMD products in the "35 Line." The SD28 can be difficult to differieniate from a SD35 but its one notable feature is a smaller air intake on the left side of the carbody, just behind the cab.

In addition, it includes no cylindrical roof mounted exhaust fans over the dynamic brake blister while its two rear roof radiator exhaust fans over much closer together than on an SD35.

Reception

By the mid-1960s, railroads were favoring more power over on a single platform. All of EMD's cataloged models at this time sold poorly in comparison to the higher horsepower SD40 (3,000) and SD45 (3,600).

On the Reserve Mining their small fleet of SD28s were utlized in standard heavy drag service while the Columbus & Greenville operated its two examples in general freight service.

Data Sheet and Specifications

Entered Production	7/1965 (Reserve Mining #1233)
Years Produced	7/1965 - 9/1965
Engine	567D1
Engine Builder	GM
Horsepower	1800
RPM	800
Cylinders	16
Length	60' 8"
Height (Top Of Rail To Top Of Cab)	15' 8 ½"
Width	10' 3"
Weight	390,000 Lbs
Fuel Capacity	1200 Gallons
Air Compressor	Gardner-Denver
Air Compressor Model	WBO
Air Brake Manufacturer	Westinghouse
Air Brake Schedule	24L
Trucks	C-C
Truck Type	Flexicoil
Truck Wheelbase	13' 7"
Wheel Size	40"
Traction Motors	D57 (6), GM
Primary Generator	D32, GM
Auxiliary Generator	Delco (A8102)
Steam Generator (SDP28)	Vapor-Clarkson (model AR4125)
Alternator	D14
MU (Multiple-Unit)	Yes
Dynamic Brakes	Yes
Gear Ratio	59:15
Tractive Effort (Starting)	97,000 Lbs at 25%
Tractive Effort (Continuous)	77,300 Lbs at 9.3 mph
Top Speed	95 mph

Production Roster

Total Produced = 6

Owner	Road Number(s)	Serial Number(s)	Order Number	Completion Date
Reserve Mining	1233	30305	5681	7/1965
Reserve Mining	1234-1236	30428-30430	5681	7/1965
Columbus & Greenville	701-702	30704-30705	5693	9/1965

Export

Total Produced = 6

SDP28

Owner	Road Numbers	Serial Numbers	Order Numbers	Completion Date
Korean National Railways	6301-6306	31408-31413	710481-710486	5/1966

Interestingly, in 1966 one variant of this model was produced for export, the SDP28 acquired by the Korean National Railways. The model was a standard SD28 with the addition of a steam generator at the rear for passenger service.

In conclusion, the SD28 is a distinct piece in the rich tapestry of American railroading history. Despite its short run and low production numbers, it carries an interesting story of engineering prowess, adaptation, and evolving railroad requirements of the changing times.

It undeniably stands as a testament to EMD's commitment to innovation and efficiency in the ever-evolving world of locomotive design. Today, the SD28 is a fascinating chapter in locomotive history for enthusiasts to delve into and appreciate.

Sources

Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

Hayden, Bob. Diesel Locomotives: Cyclopedia, Volume 2 (Model Railroader). Milwaukee: Kalmbach Publishing Company, 1980.

Marre, Louis A. Diesel Locomotives: The First 50 Years, A Guide To Diesels Built Before 1972. Milwaukee: Kalmbach Publishing Company, 1995.

Pinkepank, Jerry A. Diesel Spotter's Guide. Milwaukee: Kalmbach Publishing Company, 1967.

Schafer, Mike. Vintage Diesel Locomotives. Osceola: MBI Publishing, 1998.

Solomon, Brian. EMD Locomotives. Minneapolis: MBI Publishing Company, 2006.