EMD SD75M/SD75I

The EMD SD75M and EMD SD75I represent a series of diesel-electric locomotives produced by General Motors Electro-Motive Division during the period from 1994 to 1996. This series was developed in response to General Electric's Dash 9-44CW locomotives, aiming to provide increased power and advanced features. One of the key enhancements was elevating the output of the 16-710-G3 engine from 4,000 to 4,300 horsepower (3,000 to 3,200 kW), giving rise to the SD75 locomotives.
The "M" designation in the model name signifies the style of the locomotive's cab, specifically the North American style cab.
Conversely, the "I" model, referred to as the SD75I, features an "Isolated Cab," often termed a "WhisperCab" in EMD nomenclature. This design effectively reduces noise and vibration within the cab, providing a more comfortable working environment for the crew. A distinctive feature of this cab is a seam that separates the nose and cab components. This seam is made of rubber, which acts as a vibration dampener, consequently reducing noise. Unlike other units, the cab of an SD75I is not directly attached to the locomotive's frame.
It's noteworthy that the SD75I was the last model to utilize the "I" designation in the model name, as all subsequent units incorporated the isolated cab design but continued to be labeled with the "M" designation.
Various railroad companies acquired these locomotives to bolster their fleets. Notable buyers included Canadian National, procuring 175 units (currently 173), Burlington Northern Santa Fe with 26 (now 24), and Ontario Northland Railway with 6 (now 5).
Both the SD75M and SD75I models feature the HTCR radial truck and are mounted on a 72-foot-4-inch (22.05 m) frame. The SD75M model had 76 units sold and was not as widely popular as the SD70. The Atchison, Topeka and Santa Fe Railway, now part of Burlington Northern Santa Fe, was the largest purchaser of this model with 51 units. An additional 25 units were delivered in early 1996 during the merger process. These SD75Ms were the last new locomotives for the Santa Fe Railway.
The SD75Ms were built primarily to meet special requests from Santa Fe/BNSF and boasted slightly more power than the SD70Ms, with horsepower ratings ranging from 4,300 hp (3,200 kW) to 4,500 hp. They share a close resemblance to the SD70M models, but can be distinguished by an added bulge below the inertial air-intake on the right side of the locomotive.
In September 2014, Norfolk Southern acquired 7 SD75Ms through the National Railway Equipment Company.
Below are some of the major operators of the SD75M and SD75I locomotives:
=== SD75M Operators ===
* Atchison, Topeka and Santa Fe Railway: 51 units (Road Numbers 200–250, later BNSF 8200–8250, and then back to 200–250). Units 202, 209, 218, 222, 225, 229, and 230 were transferred to Norfolk Southern as 2800–2806. The rest were sold to PRLX.
=== SD75I Operators ===
* BNSF Railway: 26 units (Road Numbers 8276–8301). Units 8276–8299 were renumbered to 276–299, and 8300–8301 were renumbered to 249–250. These were delivered in 1997.
* Canadian National Railway: 173 units (Road Numbers 5626–5800). Some units are scheduled to be rebuilt as SD75ACCs by 2023. CN 5658 & 5753 were withdrawn.
* Ontario Northland Railway: 5 units (Road Numbers 2100–2105). Unit 2100 was involved in an accident and retired in 2012.
These locomotives remain a significant part of the rail industry's history, serving various railroads and contributing to the efficient transportation of goods.
== Gallery ==
File:SD75M.jpg
File:CN SD75I.jpg
Category:EMD locomotives
Category:Diesel-electric locomotives
Category:Locomotives
Category:BNSF locomotives
Category:Norfolk Southern locomotives
Category:Canadian National locomotives