SD70M/I Diesel Locomotive

Prototype Information

The SD70M has a wide nose and a large comfort cab (officially known as the “North American Safety Cab”), allowing crew members to ride more comfortably inside of the locomotive than the older standard cab designs. There are two versions of this cab on SD70Ms: the Phase 1 cab, which was first introduced on the SD60M, and the Phase 2 cab, which is a boxier design similar to the original three-piece windscreen on the SD60M, which is shared with the Phase 2 SD90MAC, SD89MAC, and SD80ACe. The Phase 2 cab has a two-piece windscreen like the Phase 1 windscreen but the design of the nose is more boxy, with a taller square midsection for more headroom.

The SD70M is equipped with D90TR DC traction motors and the 710G3B prime mover. They are capable of generating 109,000 lbf (480 kN) of continuous tractive effort. From late 2001, the SD70M was produced with SD45-style flared radiators allowing for the larger radiator cores needed for split-cooling. Split-cooling is a feature that separates the coolant circuit for the prime mover and the circuit for the air pumps and turbocharger. There are two versions of this radiator: the older version has two large radiator panels on each side, and the newer version has four square panels on each side. This modification was made in response to the enactment of the United States Environmental Protection Agency’s (EPA) Tier 1 environmental regulations. Also the truck was replaced with HTCR-4, instead of HTCR-I on former model.

Production of the SD70M ceased in late 2004 as production of the SD70M-2 model began (the EPA’s Tier 2 regulations went into effect on 1 January 2005). 1,609 examples of the SD70M model were produced. Purchasers included New York, Susquehanna & Western (NYSW; part of EMDX order no. 946531), Norfolk Southern and Southern Pacific (SP; now part of the Union Pacific Railroad), but the vast majority were purchased by Union Pacific.

Reference: https://en.wikipedia.org/wiki/EMD_SD70_series