The Electro Motive Division SD70 Series is a line of high-powered, single engined 4000hp to 4,300hp diesel locomotives. The first SD70 units were built in 1992 and production of the SD70ACe continues.
The first variant in the SD70 line was the SD70M, EMD released 20 Demo unit in 1992. The standard cab version came next, the SD70 this was ordered by NS, IC and Conrail. But the revolutionary AC-traction powered SD70MAC was eventually introduced in 1993 as the very first successful major type of AC-traction diesel locomotive produced in North America. Other deviations include the SD70I, the SD75I, and SD75M.
The SD70,SD70I, SD70M, and SD70MAC production could not continue into 2005 due to EPA tier 2 regulations, however, in 2007 the Alaska Railroad received 4 SD70MACs due to Alaska being exempt. These 4 units were built to Tier 1 compliance, and include a HEP generator. These units are known as SD70MAC-T1.
- SD70M: Modified, wide cab version; designed to be safer
- SD70: Original; first ordered by NS, CR, and IC
- SD70MAC : AC-traction version of the SD70M
- SD70I: "Isolated" cab variation of the SD70M; designation no longer used for original CN units as a result of conversion/upgrades
- SD70ACe : Current version; safer, more reliable, and more energy efficient
- SD70ACe-P4: B1-1B trucked variant of the SD70ACe
- SD70M-2: DC version of the SD70ACe
- SD75M: 4300-hp version of the SD70M; bought only by ATSF and inherited into the BNSF
- SD75I: 4300-hp version of the SD70I; bought only by CN and BNSF
SD70s have a smaller cab than any other SD70 locomotive. SD70s are very similar to SD60 locomotives which are built by Electro-Motive Diesel. These are used by Norfolk Southern Railway, Conrail, Illinois Central Railroad, and Southern Peru Copper in Mexico.
- The EMD SD70 Series was also the last series or types of diesel locomotives to be built in EMD's LaGrange, Illinois plant, as well as the last to be built in their London, Ontario shops, and the first to be built in their Muncie, Indiana facility (basically, being one of the only to be built in all three main facilities since production).
- The EMD SD70MAC was one of the first North American diesel locomotives to be AC-traction powered as well as being mass-produced.
- The ATSF (Atchison, Topeka, and Santa Fe; or simply Santa Fe) was the only railroad to purchase the 4300hp SD75M. Though similar, the isolated cab SD75I was purchased by CN & BNSF.
- There are many different versions of the SD70ACe. Such as the DC version, known as the SD70M-2, and numerous foreign versions. Such as the SD70ACs and SD70ACe/lc (aside from the Canadian versions as listed above).
- They are considered to be the very first official high-powered, energy-efficient, single-engined, standard prime-mover diesel locomotives produced by EMD.
- The SD70MAC and SD70ACe are often nicknamed, "Mac" and "Ace".
- Norfolk Southern and Union Pacific have several SD70ACe units painted in special heritage schemes to commemorate railroads purchased by themselves, and railroad trackage that was owned by long-gone railroads that they now operate on.
- The SD70ACs has special air intakes on the rear hood of the actual locomotive used for circulating fresh air into the engine compartment and keeping out sand, dust, dirt, and other particles in the desert climate nation of Saudi Arabia.