EMD "SD75M" and "SD75I" Locomotives: Data Sheet, Specs, Roster

Last revised: December 16, 2024

The SD75M and SD75I were essentially a variant design of the builder's SD70 series except slightly more powerful (and also featured its popular steerable truck), all in an attempt to compete with General Electric's new C44-9W model of the time (which was then the leading model of the industry, eventually selling nearly 2,500 examples).

Unfortunately, both designs had little success competing with the C44-9W with only a few hundred examples of each ultimately manufactured.

The SD75M was essentially a special request by the Atchison, Topeka & Santa Fe Railway and the SD75I was purchased by Santa Fe successor Burlington Northern and Santa Fe, Canadian National, and the Ontario Northland.

Having been built only in the mid-1990s, you can still find the entire fleet of SD75M's and SD75I's in regular service today on the two Class I railroads which purchased the model, Canadian National and BNSF Railway.

Photos

Burlington Northern Santa Fe SD75I #8286 leads CSX train K180-16 over Chartiers Creek at Pittsburgh, Pennsylvania on February 19, 2004. This unit was later involved in a head-on collision on BNSF's Madill Subdivision. Wade Massie photo.

Development

The SD75M and SD75I were constructed at the same time, entering EMD's catalog in 1994. They utilized General Motors' 16-cylinder model 710G3B prime mover, which could produce 4,300 horsepower, a slight increase over the SD70 series which was rated at only 4,000 horsepower.

This bump in horsepower was to compete with GE's C44-9W released around the same time. The SD75 series was virtually identical to the SD70 designs of the time, save for the horsepower increase.

The models featured the same HTCR-II radial trucks and were rated at a powerful 137,000 pounds of continuous tractive effort (175,000 pounds starting, which was also the same as the SD70) using GM's model D90TR traction motors.

The HTCR-II was perhaps the most innovative new feature EMD has debuted in recent times. It allowed the truck to steer itself into curves reducing wear and maintenance costs for railroads.

The truck has become such a big selling point for EMD that some railroads have stated that is the primary reason why they still buy from the builder.

The primary differences in the two SD75 designs was with the cab itself. The EMD SD75M featured the wide, safety cab design (thus the "M" designation) while the SD75I featured the isolated cab (also known as the "Whisper Cab" by EMD).

The latter's cab was not directly attached to the the frame and had added insulation and rubber built around it to decrease vibration and engine noise (it can be distinguished from the SD75M by the seam which can be seen near the front of the nose).

Reception

Ultimately, only the Santa Fe and Canadian National purchased the SD75M and SD75I (the Ontario Northland Railway did purchase a few SD75Is) with a total of 207 of each model produced.

One reason why the SD75 variants were not successful from a sales standpoint is that they were basically a special order, as mentioned above. Not only were GE products more preferred by railroads but they also found the SD70 models suited their particular needs.

The Santa Fe received its order of SD70Ms between March and August, 1995, a total of 51 units numbered 200-250. Additionally, successor Burlington Northern and Santa Fe purchased another batch of 25 between December, 1995 and March, 1996 numbered 8251-8275.

Data Sheet and Specifications

Entered Production	3/1995 (Santa Fe #200)
Years Produced (SD75M)	3/1995 - 8/1995
Years Produced (SD75I)	5/1996 - 12/1999
Engine (SD75M)	710G3
Engine (SD75I)	710G3C
Engine Builder	GM
Horsepower	4300
RPM	950
Cylinders	16
Length	72' 4"
Height (Top Of Rail To Top Of Cab)	15' 7 ½"
Width	10' 3"
Weight	394,000 Lbs
Fuel Capacity	3500 Gallons
Air Compressor	Gardner-Denver
Air Compressor Model	WBO
Air Brake Manufacturer	Westinghouse
Air Brake Schedule	26L
Trucks	C-C
Truck Type	HTCR-II
Truck Wheelbase	13' 7"
Wheel Size	40"
Wheel Slip Control System	EM2000es (EMD)
Traction Motors	D90TR (6), GM
Primary Generator	AR20, GM
Auxiliary Generator	GM (A8589)
Alternator	CA7A
MU (Multiple-Unit)	Yes
Dynamic Brakes	Yes
Gear Ratio	70:17
Tractive Effort (Starting)	175,000 Lbs at 33%
Tractive Effort (Continuous)	137,000 Lbs at 12 mph
Top Speed	70 mph

The SD75I featured Canada's Safety Cab and Isolated Cab.

Production Rosters

SD75M

Total Built = 76

(Built at GMDD)

Owner	Road Number(s)	Serial Number(s)	Completion Date
Santa Fe	200-250	946503-1 thru 946503-51	3/1995-8/1995
Burlington Northern & Santa Fe	8251-8275	956608-1 thru 956608-25	12/1995-3/1996

SD75I

Total Built = 207

Owner	Road Number(s)	Serial Number(s)	Builder	Completion Date
Canadian National	5626-5730	956616-1 thru 956616-105	GMDD	5/1996-12/1996
Canadian National	5731-5765	966726-1 thru 966726-35	GMDD	8/1997-12/1997
Burlington Northern & Santa Fe	8276-8301	966740-1 thru 966740-26	GMDD	10/1997-12/1997
Ontario Northland	2100-2105	976808-1 thru 976808-6	Assembled by Alstom Canada	5/1999-7/1999
Canadian National	5766-5800	976812-1 thru 976812-82	Assembled by Alstom Canada	1/1999-12/1999

As for the SD75I, Canadian National first began receiving its order between May and December, 1995, a total of five units numbered 5626-5730.

It received another 35 units, numbered 5626-5765, between August and December, 1997. Its final order came in 1999 when it received another 35 units numbered 5766-5800. BNSF picked up its only order of SD75Is between October and December, 1997 numbered 8276-8301.

Finally, the Ontario Northern received its only order of 6, numbered 2000-2006, between May and July, 1999. Today, you can still find SD75Is and SD75Ms in regular operation on CN and Santa Fe successor BNSF.

Sources

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

McDonnell, Greg. Locomotives: The Modern Diesel & Electric Reference, 2nd Edition. Buffalo: Boston Mills Press/Firefly Books, 2015.

Solomon, Brian. American Diesel Locomotive, The. Osceola: MBI Publishing, 2000.

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

Solomon, Brian. GE and EMD Locomotives: The Illustrated History. Minneapolis: Voyageur Press, 2014.